BodyWiki · Category한국어
Anatomy
Bones, joints, muscles and nerves: the structures that make up the body and the names of its regions.
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Abdominal wallThe abdominal wall is made up of layers of skin, fat, fascia, and muscle surrounding the abdomen.Abductor pollicis longusThe abductor pollicis longus runs from the back and outer side of the forearm to the base of the metacarpal on the thumb side and moves the thumb outward, Accessory muscles of respirationAccessory muscles of respiration are reserve muscles around the neck, chest, and shoulders that help the diaphragm when you need to breathe more.Accessory nerveThe accessory nerve is the eleventh cranial nerve, which drives head turning and shoulder shrugging.Accessory sacroiliac jointThe accessory sacroiliac joint is a small supplementary articular surface at the back of the pelvis, just behind the main sacroiliac joint where the sacrumAcetabulumThe acetabulum is a deep, rounded hollow on the side of the pelvis.Achilles tendonThe Achilles tendon connects the calf muscles to the heel bone and is the thickest and strongest tendon in the human body.Acromioclavicular jointThe acromioclavicular joint is a small joint where the outer end of the clavicle meets the acromion of the scapula.Acromioclavicular ligamentThe acromioclavicular ligament directly connects the acromion to the outer end of the clavicle, forming a thickened reinforcement of the upper part of the AcromionThe acromion is the firm, flat bony edge you can feel at the very top of your shoulder.Adductor brevisThe adductor brevis is an adductor muscle deep in the inner thigh that forms a short connection between the pubis and the femur.Adductor longusThe adductor longus is a fan-shaped muscle that extends from the groin to the inner thigh.Adductor magnusThe adductor magnus is the largest and thickest muscle on the inner thigh, with a combination of functions: bringing the leg inward and extending the hip.Adrenal glandThe adrenal glands are small endocrine glands, one sitting above each kidney, that produce the stress hormones cortisol and adrenaline.Agonist and antagonist musclesWhen you move, no muscle works alone: agonists, antagonists, synergists, and stabilizers share the work.Agonist muscleAn agonist muscle produces the greatest force in the intended direction during a movement.Alar ligamentsThe alar ligaments are short, strong ligaments that anchor the dens of the second cervical vertebra to the underside of the skull on both sides.Alpha and gamma motor neuronsAlpha motor neurons are the nerves that actually make muscles contract, while gamma motor neurons regulate the sensitivity of muscle spindles, the sensory Anatomical and movement terminology for muscles and jointsThe names of bones, joints, muscles, and tendons are a shared language for communicating precisely about body positions and movements.Anatomical positionAnatomical position is the agreed standard posture used as a reference when describing the body's locations and directions.Anatomical variationAnatomical variation refers to muscles, nerves, blood vessels, or bones whose shape or course differs slightly from textbook illustrations.Anatomy TrainsAnatomy Trains is a way of viewing muscles not as separate units, but as long chains connected by fascia, like railway routes.AnkleThe ankle is the joint where the two bones of the lower leg meet the talus in the foot.Ankle pump mechanismThe ankle pump refers to the body's mechanism of using ankle flexion and extension to alternately contract the calf muscles, pushing pooled venous blood anAnnular ligament of the radiusThe annular ligament wraps around the head of the radius like a ring at the elbow, holding it in place.Annulus fibrosusThe annulus fibrosus is a tough, fibrous ring surrounding the outside of the intervertebral disc between the vertebrae.Antagonist musclesAn antagonist muscle acts in opposition to the muscle primarily responsible for a movement (the agonist).Anterior cruciate ligamentThe anterior cruciate ligament is a ligament in the center of the knee joint that keeps the shinbone from sliding forward and provides support when the kneAnterior horn of the spinal cordThe anterior horn of the spinal cord is the front portion of the gray matter inside the spinal cord, where the motor neurons that make muscles move are groAnterior inferior tibiofibular ligamentThe anterior inferior tibiofibular ligament connects the lower front portions of the tibia and fibula, holding the two bones together so they do not spreadAnterior interosseous nerveThe anterior interosseous nerve is a motor nerve that branches from the Median nerve, travels deep into the forearm, and activates the muscles that bend thAnterior longitudinal ligamentThe anterior longitudinal ligament is a broad, strong band of ligament that runs vertically along the front surfaces of the vertebral bodies and interverteAnterior sacroiliac ligamentThe anterior sacroiliac ligament covers and connects the front of the sacroiliac joint, where the sacrum meets the ilium.Anterior superior iliac spineThe anterior superior iliac spine is a bony projection at the front of the pelvis that you can feel with your fingertips just below the side of your waistbAnterior talofibular ligamentThe anterior talofibular ligament connects the front of the outer ankle bone to the talus.Anterior tibiotalar ligamentThe anterior tibiotalar ligament is a bundle of fibers forming the front portion of the deep layer of the deltoid ligament, which connects the medial malleAponeurosisAn aponeurosis is a tendon that spreads out like a broad sheet rather than forming a cord.Arachnoid materThe arachnoid mater is the middle of the three membranes surrounding the brain and spinal cord.Arteries, veins and capillariesArteries carry blood from the heart to the rest of the body, while veins bring that blood back to the heart.Articular cartilageArticular cartilage is the smooth layer of cartilage covering the ends of the bones that form a joint, commonly called “soft bone” in Korean.Articular discThe articular disc is fibrocartilaginous tissue that sits between the rounded end of the lower jawbone and the concave surface of the skull within the tempArticular fossaAn articular fossa is a concave joint surface into which the head of a joint fits.Atlanto-occipital jointThe atlanto-occipital joint lies between the occipital bone at the base of the skull and the atlas, the first cervical vertebra.Atlantoaxial jointThe atlantoaxial joint lies between the first cervical vertebra (atlas) and the second cervical vertebra (axis), allowing you to turn your head from side tAtlasThe atlas is the first cervical vertebra, sitting at the very top of the neck just below the skull and supporting the head.Autonomic nervous systemThe autonomic nervous system coordinates internal functions that regulate themselves without our having to consciously attend to each one, such as heartbeaAxillaThe axilla is the hollow space between the arm and chest.Axillary arteryThe axillary artery is a major artery of the arm that passes through the armpit, supplying blood to the shoulder, chest wall, and upper arm.Axillary nerveThe axillary nerve is a key nerve of the shoulder that activates the deltoid muscle, which you use to move your arm out to the side and lift it.AxisThe axis is the second vertebra in the neck. Its upward-projecting dens serves as a pivot that allows the atlas and head to turn from side to side.AxonAn axon is a slender projection that extends from a nerve cell and carries signals to other cells.Ball of the footThe ball of the foot is the rounded, fleshy part of the sole just behind the toes.Basement membraneThe basement membrane is a very thin but strong sheet of collagen that supports the cells covering the skin or lining the intestines (the epithelium).Biceps brachiiThe biceps brachii is the muscle that forms the familiar bulge at the front of your upper arm.Biceps femorisThe biceps femoris is a muscle on the outer back of the thigh that helps bend the knee and extend the hip backward.Bipartite patellaBipartite patella is an inborn variation in shape in which the kneecap (patella) does not fully fuse into one bone during childhood and remains in two piecBone marrowBone marrow is the soft tissue that fills the hollow spaces inside bones and is a key organ that produces most of the body's blood cells.Bone remodelingBone remodeling is a lifelong process in which old bone tissue is removed and replaced with new bone.Brachial plexusThe brachial plexus is a network of nerves from the neck that divide and merge between the lower neck and the armpit, forming the major nerves that travel BrachialisThe brachialis is an elbow-bending muscle hidden just beneath the biceps brachii at the front of the upper arm.BrachioradialisThe brachioradialis is a long muscle along the outer side of the forearm that bends the elbow.Brachioradialis muscleThe brachioradialis is a long muscle that runs from the outer elbow down the thumb side of the forearm and helps bend the elbow.BrainstemThe brainstem is a stalk-shaped region connecting the brain and spinal cord.Calcaneofibular ligamentThe calcaneofibular ligament is a thick, cord-like ligament that runs diagonally downward from the outer ankle bone to the outer surface of the heel bone.CalcaneusThe calcaneus is the largest bone in the foot, located within the heel.CalfThe calf is the area at the back of the lower leg, extending from just below the back of the knee to just above the ankle.Calf muscle pumpThe calf muscle pump is the action of the gastrocnemius and soleus contracting as you walk or move your ankles, compressing the veins in your legs and pushCapillary exchangeCapillary exchange is the process by which blood and tissues exchange water, oxygen, nutrients, and waste products across the thin walls of capillaries.Carpal bonesThe carpal bones are the 8 small bones that make up the wrist, arranged in two rows: 4 toward the forearm and 4 toward the hand.Cauda equinaThe cauda equina is a bundle of nerve strands that extends downward from where the spinal cord ends in the upper part of the lower back.CecumThe cecum is a pouch-shaped part where the large intestine begins at the end of the small intestine, in the lower right abdomen.Central nervous systemThe central nervous system is the nervous system’s headquarters, consisting of the brain and spinal cord.CerebellumThe cerebellum is a small part of the brain located beneath the back of the head. It fine-tunes movement and helps maintain balance.Cerebral cortexThe cerebral cortex is the thin, folded, grayish-white layer covering the outermost surface of the brain.Cerebrospinal fluidCerebrospinal fluid is a clear liquid that surrounds the brain and spinal cord and fills their internal cavities.Cervical fasciaCervical fascia is a thin connective tissue membrane that wraps around and separates the muscles, blood vessels, nerves, and organs such as the airway and Cervical lordosisCervical lordosis is the normal spinal curvature in which the cervical vertebrae (C1~C7) form a gentle C-shaped curve that is convex toward the front when Cervical plexusThe cervical plexus is a network formed by the upper four cervical nerves (C1–C4) interconnecting deep in the neck.Cervical ribA cervical rib is an extra rib extending from the seventh cervical vertebra, an anatomical variation present from birth.Cervical vertebraeThe cervical vertebrae are the seven spinal bones (C1–C7) that make up the neck.Cervicomandibular relationshipThe cervicomandibular relationship is the concept that the lower jaw and neck are connected through nerves and muscles, influencing each other's movement aCervicothoracic junctionThe cervicothoracic junction is where the highly mobile cervical spine meets the relatively rigid thoracic spine, near the most prominent bone at the back ChondrocyteChondrocytes are the only cells found within cartilage. They are the workers that build cartilage and maintain it throughout life.Circle of WillisThe circle of Willis is a ring of interconnected arteries at the base of the brain that acts as a bypass network, distributing blood evenly to the brain.ClavicleThe clavicle is an S-shaped bone that extends horizontally across each side of the upper chest, just below the neck.Clavipectoral fasciaThe clavipectoral fascia is a thin membrane extending from below the clavicle to the axilla, enclosing both the subclavius and pectoralis minor.CoccyxThe coccyx, or tailbone, is a small bone connected to the tip of the sacrum at the very bottom of the spine.CollagenCollagen is a major structural protein that makes up the skin, tendons, ligaments, fascia, bones and cartilage.Common fibular nerveThe common fibular nerve is a branch formed when the sciatic nerve divides in two behind the knee.Connective tissueConnective tissue is a collective term for tissues such as skin, fascia, tendons, ligaments, cartilage, and bone that connect and support the body's structCoracoacromial ligamentThe coracoacromial ligament connects the projection at the front of the shoulder blade (the coracoid process) to the bony prominence at the top of the shouCoracoclavicular ligamentThe coracoclavicular ligament is a strong ligament connecting the coracoid process of the scapula to the outer end of the clavicle.Coracoid processThe coracoid process is a small, hook-shaped bony projection at the front of the shoulder blade (scapula), where muscles and ligaments connecting the chestCortical boneCortical bone is the hard, dense layer that forms the outside of a bone.Costal cartilageCostal cartilage is the soft, elastic cartilage that extends from the front ends of the ribs to the sternum.Costoclavicular jointThe costoclavicular joint is the site where a ligament firmly connects the medial end of the clavicle to the first rib.Costotransverse jointsThe costotransverse joints are small joints where the ribs meet the branches extending sideways from the thoracic vertebrae (the transverse processes).Costovertebral jointsThe costovertebral joints are small joints where the back ends (heads) of the ribs meet the bodies of the thoracic vertebrae.Cranial nervesThe cranial nerves are twelve pairs of nerves that emerge directly from the brain without passing through the spinal cord.Cranial suturesCranial sutures are the seams where the bones of the skull meet and interlock like teeth.Craniovertebral junctionThe craniovertebral junction is where the base of the skull meets the upper two neck vertebrae, forming the most intricate connection between the head and Crural fasciaThe crural fascia is a tough, thin membrane that surrounds all the calf muscles below the knee and forms partitions between them.Cuboid boneThe cuboid is a small, cube-shaped bone in the middle of the outer side of the foot.Cuneiform bonesThe cuneiform bones are three wedge-shaped bones arranged side by side in the middle of the top of the foot.CytoskeletonThe cytoskeleton is a network of protein fibers that spans the inside of a cell.Deep fasciaDeep fascia is a tough membrane of connective tissue that surrounds muscles and muscle groups and divides them into compartments.Deep fibular nerveThe deep fibular nerve supplies the muscles at the front of the lower leg that lift the ankle, and provides sensation to a small area of skin between the fDeep front lineIn the Anatomy Trains framework of myofascial meridians, the deep front line passes through the body's innermost, or “core,” layer.Deep hip external rotatorsThe deep hip external rotators are a group of six small muscles that support the hip joint deep within the buttock.Deep neck flexorsThe deep neck flexors are small muscles deep in front of the cervical vertebrae that support the head and neck.Deltoid ligamentThe deltoid ligament is a strong group of ligaments on the inside of the ankle that fans out from the medial malleolus to the talus, calcaneus, and naviculDeltoid muscleThe deltoid is a triangular muscle that caps the shoulder and contributes to nearly every shoulder movement, including lifting the arm forward, raising it DermatomeA dermatome is an area of skin whose sensation is supplied by a single nerve root emerging from the spinal cord.DermisThe dermis is the thick, tough layer directly beneath the epidermis, the skin’s outer covering.DiaphragmThe diaphragm is a broad, dome-shaped muscle separating the chest and abdomen and is the primary muscle of breathing.Digital annular pulleysDigital annular pulleys are ring-like structures that hold the finger flexor tendons close to the bones, preventing them from lifting away.Discoid meniscusA discoid meniscus is an inborn variation in shape in which a meniscus inside the knee is thick, broad, and disc-shaped rather than crescent-shaped.Dorsal root ganglionA dorsal root ganglion is a small cluster of nerve cells that the body's sensory signals pass through just before entering the spinal cord.Dorsum of the footThe dorsum of the foot is its upper surface, opposite the sole.Dura materThe dura mater is the tough, thick outermost layer of the three membranes surrounding the brain and spinal cord.Dural sleeveThe dural sleeve is the region where the dura mater extends like a shirtsleeve around a nerve root as it leaves the spinal cord and passes through an openiDural venous sinusesThe dural venous sinuses are channels between the two layers of the dura mater, the tough membrane surrounding the brain inside the skull.Elastic fibersElastic fibers are connective tissue fibers responsible for stretching and returning to their original shape.ElbowThe elbow is a complex joint where the upper arm bone (humerus) meets the two bones of the forearm (radius and ulna).Endocrine systemThe endocrine system is a network of glands that releases chemical messengers called hormones into the bloodstream to regulate functions throughout the bodEnthesisAn enthesis is the site where a tendon or ligament attaches to bone.EosinophilsEosinophils are white blood cells that defend against parasites and take part in allergic reactions.Epicranial aponeurosisThe epicranial aponeurosis is a tough, broad sheet of tendon that covers the top of the head and connects the muscles at the forehead to those at the back Epimysium, perimysium and endomysiumThe epimysium, perimysium and endomysium are three thin layers of connective tissue that wrap around muscle, from the outside inward.Epineurium, perineurium and endoneuriumThe epineurium, perineurium and endoneurium are three layers of connective tissue that surround peripheral nerves, from the outside inward.EpiphysisThe epiphyses are the two ends of a long bone, such as the femur or tibia.EpitheliumEpithelium is the tissue that covers body surfaces and lines internal spaces, such as the outer surface of the skin and the inner walls of the intestines, Erector spinaeThe erector spinae are long muscles running vertically along either side of the spine in the back and lower back.EsophagusThe esophagus is a muscular tube about 25 centimeters long that connects the throat (pharynx) to the stomach.Extensor carpi radialis brevisThe extensor carpi radialis brevis (ECRB) is a short muscle that starts near the top of the outer forearm and bends the wrist backward.Extensor carpi radialis longusThe extensor carpi radialis longus (ECRL, long radial wrist extensor) is an elongated muscle on the outer side of the forearm that bends the wrist backwardExtensor carpi ulnarisThe extensor carpi ulnaris is a muscle at the back of the forearm that extends the wrist toward the back of the hand and tilts it toward the little finger.Extensor digitorum longusThe extensor digitorum longus is a muscle at the front of the lower leg that extends the second through fifth toes upward.Extensor pollicis brevisThe extensor pollicis brevis is a small muscle that starts at the back of the forearm and straightens the first joint of the thumb backward.Extensor pollicis longusThe extensor pollicis longus runs from the back of the forearm to the tip segment of the thumb and straightens the thumb’s end joint.External oblique muscleThe external oblique is a large abdominal muscle that forms the outermost layer along the sides of the abdomen.Extracellular matrixThe extracellular matrix is the collection of fibers and gel-like substances that fill the space outside cells and give tissues their shape and elasticity.Extrinsic foot musclesThe extrinsic foot muscles originate in the lower leg, with only their long tendons crossing the ankle to attach to the bones of the foot.Facet jointFacet joints are small joints at the back of the vertebrae where the bones above and below meet. They are also called zygapophyseal joints.FasciaFascia is a thin, tough connective tissue that surrounds and connects muscles, bones, nerves, blood vessels, and organs.Fascia lataThe fascia lata is a thick, tough sheet of connective tissue that wraps around the entire thigh like a stocking.Femoral arteryThe femoral artery is a large artery that begins where the external iliac artery, descending from the abdomen, passes through the groin and enters the thigFemoral headThe femoral head is the rounded, ball-shaped part at the upper end of the thigh bone (femur).Femoral nerveThe femoral nerve is a large nerve that emerges from the lower back (L2–L4) and travels down the front of the thigh.FemurThe femur is the thighbone connecting the pelvis and knee, and it is the longest and strongest bone in the body.FibroblastFibroblasts are cells within connective tissues such as fascia, tendons, ligaments, and skin that produce collagen, elastic fibers, and the gel-like groundFibrocartilageFibrocartilage is firm cartilage densely packed with tough collagen fibers. It is found in places that need to withstand both compression and tension.FibulaThe fibula is a long, slender bone that runs alongside the tibia on the outer side of the lower leg.Fibularis longus and brevisFibularis longus and brevis are two muscles that lie alongside each other on the outer side of the lower leg.Filum terminaleThe filum terminale is a slender fibrous cord that extends from the very bottom of the spinal cord to the Coccyx.FingersThe fingers are intricate structures made up of segments of bone and joints connected to the metacarpal bones, tendons that move them, and ligaments that sFirst carpometacarpal jointThe first carpometacarpal joint sits at the base of the thumb, near the wrist.First ray of the footThe first ray is the name for the big toe, the first metatarsal behind it, and the medial cuneiform, considered together as a single column.Fixator muscleA fixator muscle holds the bone or joint to which an agonist attaches firmly in place so that the agonist can generate force effectively.Flexor carpi radialisThe flexor carpi radialis is a muscle that starts on the inner side of the forearm and runs down toward the thumb side of the wrist.Flexor carpi ulnarisThe flexor carpi ulnaris runs down the inner forearm, bending the wrist toward the palm and tilting it toward the little finger.Flexor digitorum longusThe flexor digitorum longus begins deep in the back of the lower leg, curves behind the inner ankle bone, and passes through the sole to attach to the tipsFlexor digitorum profundusThe flexor digitorum profundus begins deep in the forearm and extends to the distal phalanges of the second through fifth fingers.Flexor digitorum superficialisThe flexor digitorum superficialis is a muscle that runs from the front of the forearm to the middle phalanges of the second through fifth fingers.Flexor pollicis longusThe flexor pollicis longus runs from deep in the front of the forearm to the tip segment of the thumb and bends the thumb’s end joint.Foot archThe foot arch is the concave curve formed by the slightly raised inner part of the sole.Foramen magnumThe foramen magnum is the largest opening at the base of the skull and forms the passage connecting the brain and spinal cord.ForearmThe forearm is the region between the elbow and wrist, known anatomically as the antebrachium.Forearm musclesForearm muscles is the collective name for the many muscles in the lower arm, between the elbow and wrist.Free nerve endingsFree nerve endings are the ends of sensory nerves that extend without an enclosing capsule and are distributed throughout the skin, fascia, muscles, and joFundamentals of blood, lymph and edemaThe body has separate pathways for blood flow (blood vessels) and for collecting excess fluid between tissues (the lymphatic system).Galea aponeuroticaThe galea aponeurotica is a tough, broad sheet of fibrous tissue connecting the frontalis muscle in the forehead to the occipitalis muscle at the back of tGastrocnemiusThe gastrocnemius is a two-headed muscle that forms the palpable bulge just beneath the skin at the back of the calf.Glenohumeral jointThe glenohumeral joint is where the head of the upper arm bone meets the socket of the scapula, and it is among the joints with the greatest range of motioGlossopharyngeal nerveThe glossopharyngeal nerve is the ninth cranial nerve.Gluteal musclesThe gluteal muscles are the three muscles of the buttocks: the gluteus maximus, gluteus medius, and gluteus minimus.Gluteus maximusThe gluteus maximus is the largest, most superficial muscle shaping the buttocks, and the most powerful muscle for extending the hip backward.Gluteus mediusThe gluteus medius is a fan-shaped muscle on the side of the hip. It moves the leg out to the side and keeps the pelvis from tilting as you walk.Gluteus minimusThe gluteus minimus is the smallest and deepest of the three gluteal muscles. It fans out just beneath the Gluteus medius, helping keep the pelvis stable.GlycosaminoglycanGlycosaminoglycans (GAGs) are long sugar-chain molecules that hold water firmly within connective tissues such as cartilage, fascia, tendons, and skin.Golgi tendon organThe Golgi tendon organ is a small sensor at the junction between muscle and tendon that measures tension in the tendon—in other words, how hard the muscle Gracilis muscleThe gracilis is a thin, flat muscle that runs down the inner thigh.Granulation tissueGranulation tissue is the red, moist tissue that starts growing a few days after an injury to fill the wound.GranulocyteGranulocytes are white blood cells filled with small particles called granules.Greater occipital nerveThe greater occipital nerve travels up from the upper neck and carries sensation from the scalp at the back and crown of the head.Greater omentumThe greater omentum is a thin, fat-rich membrane that hangs down like an apron from the lower part of the stomach and covers the organs in the abdomen.Greater trochanterThe greater trochanter is a bony prominence on the upper, outer part of the thigh bone (femur).Ground substanceGround substance is a water-rich, gel-like material that fills the spaces between collagen fibers and cells.Growth plateThe growth plate is a plate of cartilage between the epiphysis and metaphysis at either end of a growing bone. It is where bones actually grow longer.HamstringsThe hamstrings are a group of three muscles at the back of the thigh: the biceps femoris, semitendinosus, and semimembranosus.Haversian canalHaversian canals are tiny passages that run lengthwise through hard bone, carrying blood vessels and nerves.HeelThe heel is the area made up of the calcaneus (heel bone), the largest and strongest bone at the back of the foot, and the fat pad beneath it that absorbs Hip adductor musclesThe hip adductors are a group of muscles on the inner thigh that bring the legs back toward the body from a spread position.Hip dipsHip dips are the slight inward curves along the contour between the sides of the pelvis and the outer thighs.Hip jointThe hip joint is where the pelvis meets the femur.Humeral epicondylesThe two bony bumps you can feel with your fingertips on either side of the elbow are the humeral epicondyles.Humeroradial jointThe humeroradial joint is where the upper arm bone meets the head of the radius on the outer side of the elbow.Humeroulnar jointThe humeroulnar joint is where the humerus and ulna meet at the elbow, and it is central to bending and straightening the arm.HumerusThe humerus is the bone of the upper arm, extending from the shoulder to the elbow, and is the longest bone in the arm.Hyaline cartilageHyaline cartilage is translucent, smooth tissue with a glass-like appearance, and it is the most common type of cartilage in our bodies.Hyaluronic acidHyaluronic acid is a gel-like substance that fills spaces within the body's connective tissues, retains water, and provides lubrication.Hyoid boneThe hyoid is a small U-shaped bone suspended at the front of the neck beneath the jaw.Hyoid musclesThe hyoid muscles are the collective name for the muscles that attach to the hyoid bone, a small bone at the front of the neck.HypothalamusThe hypothalamus is an almond-sized area in the lower central part of the brain.Hypothenar eminenceThe hypothenar eminence is the fleshy mound on the little-finger side of the palm, where three small muscles that move the little finger are grouped togethIliac crestThe iliac crest is a thick ridge running along the upper border of the pelvic bone.IliacusThe iliacus is a deep muscle that starts in the hollow on the inside of the pelvis and extends to the inner side of the thighbone.Iliocostalis lumborumThe iliocostalis lumborum is part of the outermost column of the erector spinae, which straighten your back on either side of your lower back.Iliofemoral ligamentThe iliofemoral ligament is a thick, strong ligament that connects the ilium of the pelvis to the thigh bone (femur) and covers the front of the hip joint.Iliolumbar ligamentThe iliolumbar ligament is a strong ligament connecting the fifth lumbar vertebra, the lowest bone in the lumbar spine, to the upper part of the pelvis.IliopsoasThe iliopsoas is a deep muscle that begins at the lumbar vertebrae and the inside of the pelvis and attaches to the inner side of the femur.Iliotibial bandThe iliotibial band is a long, tough band of fibers that runs from the outside of the pelvis down the outer thigh and attaches to the outside of the shinboIliumThe ilium is a broad, wing-shaped bone that forms part of the pelvis. It is the hard bone you feel when you place your hands on your waist.Inferior glenohumeral ligamentThe inferior glenohumeral ligament is a thickened portion of the lower joint capsule surrounding the shoulder joint.Inferior gluteal nerveThe inferior gluteal nerve begins in the nerve plexus near the sacrum and carries motor signals to the gluteus maximus, the largest muscle in the buttocks.Infraspinatus muscleThe infraspinatus is a rotator cuff muscle that starts on the broad surface below the spine on the back of the scapula and attaches to the humerus.Inguinal canalThe inguinal canal is a short passage, around 4cm long, that runs diagonally through the lower abdominal wall, connecting the abdominal cavity to the frontIntegrinIntegrins are proteins embedded in the cell surface that act as "handles," attaching cells to the surrounding support structures and transmitting external Intercostal musclesThe intercostal muscles fill the spaces between the ribs and help expand and narrow the rib cage (thorax) as you breathe.Intercostal nervesThe intercostal nerves run along the spaces between the ribs, wrapping around the chest in individual bands.Intermuscular septumAn intermuscular septum is a thin partition of fascia that separates groups of muscles in the arms and legs.Internal abdominal oblique muscleThe internal oblique is a muscle that wraps around the trunk deep in the flank. It helps bend the trunk sideways, rotate it, and keep the abdomen firm.Interosseous membraneThe interosseous membrane is a thin, tough membrane connecting the radius and ulna in the forearm, and the tibia and fibula in the lower leg.Interosseous muscles of the handThe interosseous muscles are small muscles between the metacarpal bones on the back of the hand.Interphalangeal joints of the handThe interphalangeal joints are small joints connecting the segments of the finger bones, allowing the fingers to bend and straighten.Interstitial fluidInterstitial fluid is the body fluid that fills the spaces between cells outside the blood vessels.Intervertebral discAn intervertebral disc is a cushion-like structure between the vertebrae above and below it, commonly called a disc.Intervertebral foramenAn intervertebral foramen is a small passage on the side of the spine, between two vertically adjacent vertebrae.Intrinsic foot musclesIntrinsic foot muscles are small muscles that originate and end within the foot.Ischial tuberosityThe ischial tuberosity is a hard bony prominence at the bottom of the buttock that supports your body weight when you sit on a chair.Ischiofemoral ligamentThe ischiofemoral ligament is a tough ligament that connects the pelvic bone (ischium) to the femur at the back of the hip joint.IschiumThe ischium is the lower rear bone among the three bones that make up the pelvis.JointJoints are places where bones meet, serving as centers of movement that let us bend, turn, and walk.Joint capsuleThe joint capsule is connective tissue that surrounds a movable joint like a pouch.KidneyThe kidneys are a pair of organs toward the back of the upper waist that filter blood and produce urine to balance the body's fluids and electrolytes.KneeThe knee is the largest joint in the body, where the femur, tibia, and patella meet.LabrumThe labrum is a rim of fibrocartilage that forms a ring around the edge of the socket in ball-and-socket joints such as the shoulder and hip.LarynxThe larynx is a cartilage box at the front of the neck, between the throat (pharynx) and the trachea.Lateral ankle ligamentsThe lateral ankle ligaments are three bands of tissue that extend from the bony bump on the outside of your ankle and help keep it from rolling inward.Lateral collateral ligament of the kneeThe lateral collateral ligament is a thin, rounded, cord-like ligament on the outside of the knee that connects the thigh bone to the head of the fibula.Lateral femoral cutaneous nerveThe lateral femoral cutaneous nerve supplies sensation to the skin on the front and outer side of the thigh.Lateral patellofemoral ligamentThe lateral patellofemoral ligament (LPFL) is a thin band connecting the patella (kneecap) to the femur (thighbone) on the outer side of the knee.Lateral plantar nerveThe lateral plantar nerve supplies sensation to the outer half of the sole and sends signals to several small muscles within the foot that move the toes.Latissimus dorsiThe latissimus dorsi is the broadest muscle in the back.Levator aniThe levator ani is a broad muscle that spans the floor of the pelvis, supporting the bladder, rectum, and, in women, the uterus from below.Levator scapulaeThe levator scapulae is a long, slender muscle that runs diagonally down from the sides of the neck vertebrae to the upper inner corner of the shoulder blaLigamentLigaments are tough, cord-like bands of fibrous tissue that connect bones to other bones and help guide joints to move in the proper direction.Ligament of the head of the femurThe ligament of the head of the femur is a small ligament inside the hip joint that connects the floor of the socket to a depression in the head of the thiLigament of TreitzThe ligament of Treitz is a thin band that suspends the bend where the duodenum ends and the jejunum begins from the upper part of the back wall inside theLigamentum flavumThe ligamentum flavum is a thin, broad ligament that connects adjacent vertebrae along the back of the spine.Linea albaThe linea alba is a white band of connective tissue that runs vertically down the middle of the abdomen, connecting the left and right rectus abdominis musLiverThe liver is the body's largest internal organ, located in the upper right abdomen, inside the rib cage.Long plantar ligamentThe long plantar ligament is the longest ligament in the sole of the foot, extending from the underside of the heel bone, past the cuboid on the outer sideLong thoracic nerveThe long thoracic nerve emerges from the neck and travels down along the side of the chest to activate the Serratus anterior.Longissimus thoracisThe longissimus thoracis is a long muscle running vertically along either side of the spine, forming the middle column of the erector spinae, which keeps tLongus colli and longus capitis musclesThe longus colli and longus capitis are a pair of muscles deep in front of the cervical vertebrae that support the neck and head from the front.Lower backThe lower back is the rear part of the trunk between the ribs and the pelvis.Lumbar plexusThe lumbar plexus is a network of nerves formed deep in the lower back, where nerve roots emerging from between the lumbar vertebrae intertwine.Lumbar vertebraeThe lumbar vertebrae are the five spinal bones (L1–L5) that form the lower back.Lumbosacral junctionThe lumbosacral junction is the joint region where the lowest lumbar vertebra, L5, meets the top of the sacrum, S1.Lunate boneThe lunate is a half-moon-shaped bone in the center of the wrist, among its eight carpal bones.LymphLymph is the clear fluid collected from the spaces between tissues outside blood vessels as it flows through lymphatic vessels.Lymph nodeLymph nodes are small, bean-shaped organs located at intervals along lymphatic vessels.Lymphatic circulationLymphatic circulation is the body's drainage pathway, collecting fluid left between tissues outside the blood vessels and returning it to the veins.LymphocyteLymphocytes are a type of white blood cell involved in immunity.MacrophageMacrophages are immune cells that gather at injured sites and engulf bacteria and dead-cell debris to clear them away.Major arteries of the limbsThe large arteries that carry oxygen-rich blood to the arms and legs branch from the aorta in the trunk and form a continuous pathway, changing names accorMandibleThe mandible is the horseshoe-shaped bone that forms the lower jaw and is the only movable bone in the skull.Mandibular condyleThe mandibular condyle is a rounded projection at the upper rear of the lower jawbone.Masseter muscleThe masseter is a powerful chewing muscle that connects the cheekbone to the lower jaw at the back of the cheek.Mast cellMast cells are immune cells found in large numbers in the connective tissue of the skin and around blood vessels.Mastoid processThe mastoid process is the rounded bony prominence you can feel just behind your ear. It is part of the temporal bone.MechanoreceptorMechanoreceptors are sensory receptors in the body that detect mechanical stimuli such as pressure, vibration, pulling, and rubbing.Medial collateral ligamentThe medial collateral ligament (MCL) is a broad, flat ligament that connects the thighbone to the shinbone along the inner side of the knee, helping keep tMedial patellofemoral ligamentThe medial patellofemoral ligament (MPFL) connects the inner side of the kneecap (patella) to the inner side of the thighbone, keeping the kneecap from sliMedial plantar nerveThe medial plantar nerve travels from the inner ankle into the sole, providing sensation to the inner sole and the toes on the big-toe side, and controllinMedian nerveThe median nerve is a major nerve of the arm that starts in the neck, travels along the inner arm and the front of the forearm, and passes through a narrowMediastinumThe mediastinum is the space in the center of the chest between the two lungs, behind the breastbone and in front of the spine.MegakaryocyteMegakaryocytes are enormous cells that produce platelets in the bone marrow.MeniscusThe menisci are C-shaped cartilage cushions that sit between the femur and tibia inside the knee joint.MesenchymeMesenchyme is undifferentiated connective tissue that forms early in embryonic development and differentiates into various supporting structures in the bodMesenteryThe mesentery is a thin membrane that suspends the intestines from the back wall of the abdomen and provides a route for the blood vessels, lymphatic vesseMetacarpophalangeal jointThe metacarpophalangeal joint is where a metacarpal bone, which forms part of the palm, meets the first bone of a finger.MetaphysisThe metaphysis is the flared, trumpet-shaped region between the shaft and the end of a long bone.Metatarsal bonesThe metatarsal bones are five long bones that form the middle part of the foot, acting as a bridge that transfers body weight toward the toes when you walkMicrocirculationMicrocirculation refers to blood flow and the exchange of substances in arterioles, capillaries, and venules—blood vessels too small to see with the naked MicrogliaMicroglia are small immune cells that live in the brain and spinal cord, monitoring their surroundings, clearing away debris, and responding to danger signMonocytesMonocytes are white blood cells that circulate in the blood, then move into tissues where they are needed and become macrophages.MultifidusThe multifidus consists of small bundles of muscle deep beside the vertebrae that connect individual spinal segments.Muscle architectureMuscle architecture refers to the angles and lengths at which muscle fibers are arranged.Muscle fiberMuscle fibers are the individual long, slender cells that make up muscle.Muscle spindleMuscle spindles are tiny sensory organs inside muscles that tell the spinal cord and brain how much and how quickly a muscle is being stretched.Muscles and tendonsMuscles contract to generate force, and tendons are tough bands that transmit that force to bones.Muscles of masticationMuscles of mastication is the collective name for the muscles that move the lower jaw when you chew food.Musculocutaneous nerveThe musculocutaneous nerve branches off from a bundle of nerves near the armpit and travels down to the muscles at the front of the upper arm, carrying sigMyelinMyelin is a fatty membrane that wraps around nerve fibers like the insulation on an electrical wire, allowing signals to travel quickly.MyofibrilMyofibrils are thin, threadlike contractile structures that fill muscle fibers.MyofibroblastMyofibroblasts are cells that develop when fibroblasts change their form and acquire the ability to contract after an injury.Myotendinous junctionThe myotendinous junction is the boundary region where muscle connects to a tendon, serving as the main pathway for transferring the force generated by musMyotomeA myotome is a group of muscles supplied by a single spinal nerve root. It is the motor counterpart of a dermatome, which relates to sensory nerves.NapeThe nape is the area extending from below the back of the head, down the back of the neck, and into the shoulders.NeckThe neck connects the head and torso and lets you bend your head forward, tilt it back, and turn it.Nerve rootA nerve root is the starting portion of a nerve that branches off to either side of the spinal cord—literally, the root of a nerve.NeutrophilsNeutrophils make up roughly half of the white blood cells in the blood and are the first cells to arrive at the scene of an injury or bacterial invasion.Nuchal ligamentThe nuchal ligament is a broad, thin, band-shaped ligament that runs from the occipital bone down along the back of the cervical spine.Nucleus pulposusThe nucleus pulposus is the jelly-like tissue at the very center of the intervertebral disc between the bones of the spine.Obturator internus and externus musclesThe obturator internus and externus cover the obturator foramen of the pelvis from the inside and outside, respectively.Obturator nerveThe obturator nerve starts from the lumbar nerves, passes through the pelvis, and travels down the inner thigh.Occipital boneThe occipital bone forms the back and lower part of the skull. It is the hard bone you can feel at the back of your head.OccipitofrontalisThe occipitofrontalis is a scalp muscle made up of the frontalis at the forehead and the occipitalis at the back of the head, connected by a broad sheet caOdontoid processThe odontoid process is a tooth-shaped projection extending upward from the body of the second cervical vertebra (axis).Oncotic pressureOncotic pressure is the force generated by proteins in the blood, mainly albumin, that draws water into blood vessels.Ossification centerAn ossification center is a site where the cartilage framework of a bone begins to turn into hard, actual bone.OsteoblastOsteoblasts are cells that make new bone. They line up along bone surfaces, build the framework for hard bone, and help calcium accumulate in it.OsteocyteOsteocytes sit within the hard bone matrix, acting as sensors that detect the forces placed on bone and send signals about which areas to strengthen or redPalmar aponeurosisThe palmar aponeurosis is a tough, thick sheet of fibrous tissue that fans out in a triangular shape just beneath the skin of the palm, extending from the Palmaris longusThe palmaris longus is a long, slender muscle that runs down the middle of the front of the forearm, becoming a thin tendon at the front of the wrist and cParasympathetic nervous systemThe parasympathetic nervous system is the part of the autonomic nervous system that works mainly when the body rests, digests, and recovers.ParatenonThe paratenon is a thin membrane that loosely surrounds the outside of a tendon.Parietal boneThe parietal bones are a pair of broad bones that cover the top and sides of the head. They form the area commonly called the crown.Parietal lobeThe parietal lobe is an area toward the back of the upper cerebrum.Pars interarticularisThe pars interarticularis is a slender portion of bone at the back of a vertebra that connects the upper and lower articular processes.PatellaThe patella is a rounded, triangular bone you can feel at the front of the knee, commonly called the kneecap.Patellar tendonThe patellar tendon is a thick, flat tendon running from the lower tip of the kneecap to the prominence at the front of the shinbone.PectineusThe pectineus is a flat muscle in the upper front-inner thigh, just below the groin.Pectoralis majorThe pectoralis major is a large, fan-shaped muscle that broadly covers the front of the chest.Pectoralis minorThe pectoralis minor is a small triangular muscle hidden beneath the pectoralis major.Pelvic floorThe pelvic floor is a group of muscles, fascia, and ligaments that supports the very bottom of the pelvis like a net.PelvisThe pelvis is a bowl-shaped bony framework between the lower spine and the two legs.PericardiumThe pericardium is a double-layered membrane that surrounds the heart like a sac.PeriosteumThe periosteum is a thin, tough membrane that covers the outside of bones, except at joint surfaces.Peripheral nervesPeripheral nerves are the body's wiring, extending beyond the brain and spinal cord into the arms, legs, trunk, and internal organs.PeritoneumThe peritoneum is a thin, smooth membrane that covers the inner abdominal wall and the surfaces of abdominal organs such as the stomach, intestines, and liPes anserinusThe pes anserinus is the attachment site where the tendons of three muscles come together side by side on the upper shinbone, below the inner side of the kPhrenic nerveThe phrenic nerve makes the diaphragm, the main muscle of breathing, move.Pia materThe pia mater is the thin, transparent, innermost of the three membranes surrounding the brain and spinal cord.Pineal glandThe pineal gland is a small, pine-cone-shaped endocrine gland deep in the center of the brain.Piriformis muscleThe piriformis is a pear-shaped muscle deep in the buttock that connects the sacrum to the femur. It rotates the leg outward and stabilizes the hip joint.Plantar calcaneonavicular ligamentThe spring ligament connects the calcaneus to the navicular on the sole side of the foot and supports the medial longitudinal arch.Plantar fasciaThe plantar fascia is a thick, tough sheet of tissue that fans out from the heel bone toward the toes, supporting the arch of the foot from below.PlateletsPlatelets are small cell fragments without a nucleus that are the first to rush to plug the opening when a blood vessel is injured.PleuraThe pleura is a thin, double-layered membrane that surrounds the lungs and lines the inner chest wall.Popliteal arteryThe popliteal artery is a large artery that runs deep behind the knee and carries blood to the lower leg and foot.Popliteal fossaThe popliteal fossa is the diamond-shaped hollow at the back of the knee when you bend it.Popliteus muscleThe popliteus is a small muscle deep in the hollow behind the knee, connecting the outer side of the femur to the back of the tibia.Posterior cruciate ligamentThe posterior cruciate ligament is a thick, strong ligament inside the knee joint that keeps the shinbone from sliding backward.Posterior inferior tibiofibular ligamentThe posterior inferior tibiofibular ligament connects the tibia and fibula at the back, preventing them from separating just above the ankle.Posterior interosseous nerveThe posterior interosseous nerve is a peripheral nerve that continues from the deep branch of the radial nerve below the elbow.Posterior longitudinal ligamentThe posterior longitudinal ligament is a long ligament that runs vertically inside the spinal canal along the back surfaces of the vertebral bodies and thePosterior sacroiliac ligamentThe posterior sacroiliac ligament is a collection of ligament fiber bundles that firmly bind the sacrum and ilium together from behind.Posterior superior iliac spineThe posterior superior iliac spine is a bony projection at the rear end of the ilium (hip bone), palpable below the lower back and above the buttocks.Posterior talofibular ligamentThe posterior talofibular ligament runs from the rear portion of the inner surface of the outer ankle bone to the back of the talus.Posterior tibial arteryThe posterior tibial artery continues from the artery behind the knee, travels deep down the back of the calf, and carries blood to the sole of the foot.Pronator teresThe pronator teres is a muscle that runs diagonally across the front of the forearm from the inner elbow and performs 'pronation,' the movement that turns ProteoglycansProteoglycans are substances that fill the spaces within the body's connective tissues, such as cartilage, discs, and tendons.Psoas minorThe psoas minor is a thin, long, slender muscle that lies just in front of the psoas major.Pterygoid musclesThe pterygoid muscles are muscles of mastication deep inside the jaw that move the lower jaw.Pubic symphysisThe pubic symphysis is the joint that connects the left and right pubic bones at the center of the front of the pelvis.PubisThe pubis is a bone at the very front and bottom of the pelvis, and one of the three bones that make up the hip bone.Pubofemoral ligamentThe pubofemoral ligament reinforces the lower front portion of the joint capsule surrounding the hip.Pudendal nerveThe pudendal nerve is a peripheral nerve that arises from nerve roots in the lower sacrum, provides sensation around the anus, perineum, and external genitQuadratus femorisThe quadratus femoris is a flat, rectangular muscle deep in the buttock that connects the ischium to the femur.Quadratus lumborumThe quadratus lumborum is a roughly square muscle deep in the back of the lower back, between the pelvis and the twelfth rib.Quadriceps femorisThe quadriceps femoris is the collective name for four muscles at the front of the thigh that straighten the knee.Radial arteryThe radial artery runs down the thumb side of the forearm to the wrist. It is the blood vessel you feel when checking your pulse at the wrist.Radial collateral ligament of the elbowThe radial collateral ligament connects the upper arm bone to the forearm on the outside of the elbow.Radial nerveThe radial nerve travels down the back of the arm, providing the strength to bend the wrist and fingers backward toward the back of the hand, as well as seRadiocarpal jointThe radiocarpal joint is where the radius in the forearm meets the wrist bones.Radioulnar jointsThe radioulnar joints are where the two bones of the forearm, the radius and ulna, meet. They allow you to turn your palm up and down.RadiusThe radius is the bone on the thumb side of the forearm's two bones.Reciprocal tension membraneThe reciprocal tension membrane is the concept that the membranes surrounding the brain inside the skull (the dura mater) maintain balance by pulling on onRectus abdominisThe rectus abdominis is a pair of long muscles running vertically down the middle of the front of the abdomen.Rectus femorisThe rectus femoris runs straight down the center of the front of the thigh.Red blood cellRed blood cells are cells in the blood that carry oxygen from the lungs to tissues throughout the body.Respiratory pumpThe respiratory pump helps blood in the veins return toward the heart as pressure inside the chest and abdomen changes with each breath.Reticular fibersReticular fibers are thin, branching fibers that support organs and cells throughout the body like a net.Reticuloendothelial systemThe reticuloendothelial system is an older name that grouped together the body's macrophages, which engulf and clear away bacteria, old cells, and foreign Retinacula and orthopedic supportsThe Korean term for “support” has two meanings.Rhomboid musclesThe rhomboids are diamond-shaped muscles connecting the spine to the inner border of the shoulder blade (scapula).RibsThe ribs are twelve pairs of curved bones that surround the chest.Rotator cuffThe rotator cuff is the collective name for four muscles—the supraspinatus, infraspinatus, teres minor, and subscapularis—and their tendons, which originatRotatores musclesThe rotatores are short muscles located right beside the vertebrae, in the deepest layer of the back muscles.Ruffini corpuscleRuffini corpuscles are small sensory receptors in the joint capsules and ligaments surrounding joints.Sacral plexusThe sacral plexus is a network of nerves formed when nerve roots from the lower lumbar spine and sacrum come together inside the pelvis and then branch outSacrococcygeal jointThe sacrococcygeal joint is a small joint where the tip of the sacrum meets the tailbone at the very bottom of the spine.Sacroiliac jointThe sacroiliac joints are a pair of joints at the back of the pelvis where the sacrum and the ilium meet, one on each side.Sacrospinous ligamentThe sacrospinous ligament is a triangular ligament that runs from the sides of the sacrum and coccyx to the ischial spine.Sacrotuberous ligamentThe sacrotuberous ligament is a thick, flat ligament that runs from the sacrum to the bone you sit on (the ischial tuberosity).SacrumThe sacrum is an inverted triangular bone below the lumbar vertebrae, at the center of the back of the pelvis.Saphenous nerveThe saphenous nerve starts at the front of the thigh and runs a long course down the inner knee, inner calf, and inner side of the foot, carrying sensationSarcomereThe sarcomere is the smallest basic unit of muscle contraction.Sarcoplasmic reticulumThe sarcoplasmic reticulum is a network of sacs spread throughout muscle fibers.SartoriusThe sartorius is the longest muscle in the human body.Scalene musclesThe scalene muscles are a group of three muscles that run from the sides of the cervical vertebrae to the first and second ribs.ScaphoidThe scaphoid is a small, boat-shaped bone on the thumb side of the wrist.ScapulaThe scapula is a flat, triangular bone on each side of the upper back, commonly called the shoulder blade.Scapulothoracic jointThe scapulothoracic joint is where the shoulder blade glides over the ribs of the upper back.Schwann cellSchwann cells surround and protect peripheral nerve fibers in the limbs and body.Sciatic nerveThe sciatic nerve is the thickest and longest peripheral nerve in the body, formed when nerve roots from the lower back and sacral region come together witSclerotomeThe sclerotome is the part of an embryonic body segment (somite) that develops into skeletal tissues such as vertebrae, ribs, and ligaments.Semimembranosus muscleThe semimembranosus is a hamstring muscle deep in the inner back of the thigh.Semispinalis capitisThe semispinalis capitis is a thick, long muscle deep in the back of the neck that tilts the head backward and holds it upright.Semitendinosus muscleThe semitendinosus is a hamstring muscle on the inner side of the back of the thigh, distinguished by its lower half continuing as a long, rounded tendon.Sensory and motor nerve fibersSensory fibers carry information from the skin, muscles, and joints up to the brain and spinal cord, while motor fibers carry commands from the brain and sSensory function of fasciaFascia is a membrane that envelops the body, but it is also a tissue densely populated with sensory endings that detect pressure, pulling, and vibration.Serratus anteriorThe serratus anterior is a broad, saw-toothed muscle that begins along the sides of the ribs and attaches to the inner surface of the scapula.Sesamoid boneSesamoid bones are small bones embedded within tendons.ShinThe shin refers to the shinbone (tibia) at the front of the leg, between the knee and ankle, and the muscles running alongside it.ShoulderThe shoulder is where the arm connects to the trunk, and it has the greatest range of motion of any joint in the body.Shoulder girdleThe shoulder girdle is the collective term for the clavicle and scapula, which connect the arm to the trunk, along with the joints and muscles that move thSigmoid colonThe sigmoid colon is the final part of the large intestine, curving in an S shape in the lower left abdomen before joining the rectum.Skeletal muscleSkeletal muscles attach to bones through tendons, moving the body and supporting posture.Skeletal muscle pumpThe skeletal muscle pump is an auxiliary pump in the body: when the leg muscles contract, they compress the veins within them and push blood upward toward Skeletal systemThe skeletal system is the body's framework, made up of bones, cartilage, joints, and ligaments.SkullThe skull is the collective term for the twenty-two bones that make up the head.Skull baseThe skull base forms the floor of the skull, supporting the brain and serving as the junction where the head meets the neck.Small intestineThe small intestine is a long digestive tube folded into coils between the stomach and the large intestine.Smooth muscleSmooth muscle forms the walls of hollow organs such as the stomach and intestines, blood vessels, bronchi, bladder, and uterus.Soft tissueSoft tissue is a collective term for the body's soft tissues other than bones and internal organs.Sole of the footThe sole is the entire underside of the foot that contacts the ground.SoleusThe soleus is a broad, flat muscle deep in the calf that stabilizes the ankle and lifts the heel when you stand or walk.Spinal canalThe spinal canal is a tube-shaped passage formed by the vertebrae stacked one above another, with the spinal cord and nerves running through it.Spinal cordThe spinal cord is a thick, cylindrical bundle of nerve tissue that extends from the brain and runs down the passage inside the vertebrae.Spinal curvatureSpinal curvature refers to the front-to-back curves of the spine when viewed from the side.Spinalis muscleThe spinalis is a slender muscle that runs lengthwise along the spine, right beside the vertebrae.Spiral lineThe spiral line is a fascial pathway that winds around the body from head to foot.Splenius capitis and splenius cervicisThe splenius capitis and splenius cervicis are bandage-shaped muscles located in a superficial layer at the back of the neck.Stabilizer muscleStabilizer muscles hold joints or the trunk in place during movement to reduce wobbling.Starling forcesStarling forces are the balance of four pressures that determine which way water moves across capillary walls.Sternoclavicular jointThe sternoclavicular joint is where the inner end of the collarbone (clavicle) meets the upper part of the breastbone.SternocleidomastoidThe sternocleidomastoid is the thick muscle that stands out diagonally along the side of your neck when you turn your head.Sternocostal jointThe sternocostal joint is where the breastbone meets the costal cartilage at the front of the chest.SternumThe sternum is a long, flat bone that runs vertically down the center of your chest.Subclavian arteryThe subclavian artery is a large artery that begins in the chest, passes beneath the clavicle, and continues toward the arm.SubclaviusThe subclavius is a small, slender muscle that runs obliquely from the first rib to the underside of the clavicle.Subcutaneous tissueSubcutaneous tissue is a layer of fat and connective tissue just beneath the skin that covers the muscles and fascia.Subdural spaceThe subdural space is a narrow gap between the tough outer membrane surrounding the brain (the dura mater) and the arachnoid mater just beneath it.Suboccipital musclesThe suboccipital muscles are four small, deep muscles connecting the area beneath the occipital bone with the first and second cervical vertebrae.Suboccipital spaceThe suboccipital space is a deep, narrow region between the occipital bone and the first cervical vertebra (atlas), where the head meets the neck.Suboccipital triangleThe suboccipital triangle is a triangular space enclosed by three muscles deep beneath the occipital bone, where the neck meets the head.SubscapularisThe subscapularis begins on the front surface of the shoulder blade and attaches to a small prominence on the front of the upper arm bone.Subtalar jointThe subtalar joint is where the talus and calcaneus meet just below the ankle. It allows the foot to tilt inward and outward to adapt to uneven ground.Superficial fasciaSuperficial fascia is a layer of soft connective tissue mixed with fat just beneath the skin.Superficial fibular nerveThe superficial fibular nerve branches off from the common fibular nerve and travels down the outer side of the lower leg.Superior and inferior gemelliThe superior and inferior gemelli are a pair of small muscles deep in the buttock that flank the obturator internus tendon above and below.Superior glenohumeral ligamentThe superior glenohumeral ligament is a slender ligament in the upper front part of the shoulder joint capsule.Superior gluteal nerveThe superior gluteal nerve activates the gluteus medius and gluteus minimus on the outer side of the buttock, as well as the tensor fasciae latae on the ouSupinatorThe supinator is a muscle that wraps around the radius deep in the back of the forearm, just below the outside of the elbow.Supraspinatus muscleThe supraspinatus is a small muscle that starts at the upper back of the shoulder blade and attaches to the upper part of the humerus.Supraspinous and interspinous ligamentsThe supraspinous and interspinous ligaments connect the projections at the back of the vertebrae (spinous processes) along the middle of your back.Sural nerveThe sural nerve carries skin sensation, running down the back of the calf, behind the lateral malleolus, and along the outer edge of the foot.Sympathetic nervous systemThe sympathetic nervous system is the part of the autonomic nervous system that gets your body “ready to move right now.”Synovial bursaA synovial bursa is a flattened sac located where bones, tendons, muscles, and skin come into contact and are prone to friction.Synovial fluidSynovial fluid is a clear, viscous fluid inside movable joints.Synovial membraneThe synovial membrane is a thin membrane lining the inside of the joint capsule in freely movable joints.T cellT cells are a type of lymphocyte, one of the white blood cells responsible for the body's immune defenses.Talocrural jointThe talocrural joint is what we commonly call the “ankle joint,” where the lower ends of the tibia and fibula meet the talus.TalusThe talus is a small bone nestled between the tibia and the heel bone at the ankle, transmitting body weight to the foot.Tarsal bonesThe tarsal bones are a group of 7 bones extending from below the ankle to the middle of the foot.Tarsal tunnelThe tarsal tunnel is a narrow passage on the inner side of the ankle, behind the medial malleolus.Temporal boneThe temporal bones are a pair of skull bones on either side of the head, around the ears.TemporalisThe temporalis is a fan-shaped muscle that spreads across the temple and attaches to the lower jaw.Temporomandibular jointThe temporomandibular joints are a pair of joints, one on each side just in front of the ears, where the lower jawbone meets the skull (temporal bone).TendonA tendon is a tough band of connective tissue that connects muscle to bone, transmitting the tension generated by muscle contraction to the bone to move a Tendon sheathA tendon sheath is a thin, tube-shaped membrane that surrounds a tendon in places where tendons move frequently, such as the wrist, fingers, and ankle.TenocyteTenocytes are the primary cells that synthesize collagen and maintain the matrix within tendons.Tensor fasciae lataeThe tensor fasciae latae is a small muscle that starts at the front outer part of the pelvis and connects to the Iliotibial band along the outside of the tTentorium cerebelliThe tentorium cerebelli is a tough membrane that spans the space between the cerebrum and cerebellum.Teres majorThe teres major is a muscle that starts at the lower part of the shoulder blade and attaches to the front of the upper arm bone.Teres minorThe teres minor is a small muscle that runs from the back of the shoulder blade to the upper arm bone.Thenar eminenceThe thenar eminence is the fleshy mound on the palm at the base of the thumb, where three small muscles that control fine thumb movements come together.Thoracic cageThe thoracic cage is the framework of the chest, enclosed like a birdcage by the thoracic vertebrae, ribs, sternum, and costal cartilage at the ends of theThoracic ductThe thoracic duct is the body's largest lymphatic vessel.Thoracic inletThe thoracic inlet is an anatomical opening at the very top of the thoracic cage, at the boundary connecting the neck and chest.Thoracic vertebraeThe thoracic vertebrae are the 12 spinal bones (T1–T12) that form the middle of the back and connect to the ribs to form the rib cage.Thoracolumbar fasciaThe thoracolumbar fascia is a tough sheet of tissue that broadly covers the lower back and lumbar region.Thoracolumbar junctionThe thoracolumbar junction is the boundary around T12 and L1 where the rib-bearing thoracic spine meets the lumbar spine, which has no ribs.ThumbThe thumb is the first digit of the hand. Its ability to move to face the other four fingers makes it central to picking up, gripping, and turning objects.Thyroid cartilageThe thyroid cartilage is the largest laryngeal cartilage, forming a shield around the larynx at the front of the neck.Thyroid glandThe thyroid gland is a small, butterfly-shaped endocrine organ at the front of the neck, below the Adam’s apple, wrapping around the trachea.TibiaThe tibia is the thick bone on the inner side of the lower leg. Its native Korean name means “shinbone.”Tibial nerveThe tibial nerve is a large branch formed when the sciatic nerve splits in two in the hollow behind the knee.Tibial plateauThe tibial plateau is the broad, flat supporting surface at the upper end of the shinbone.Tibial tuberosityThe tibial tuberosity is the bony prominence you can feel with your fingertips on the upper front of the shinbone, just below the kneecap.Tibialis anteriorThe tibialis anterior runs along the outer front surface of the shinbone.Tibialis posteriorThe tibialis posterior is a muscle that starts deep in the calf, passes around the inside of the ankle, and attaches to bones on the inner side of the footTibiofemoral jointThe tibiofemoral joint is the main joint of the knee, where the thigh bone and shin bone meet to let the knee bend and straighten.Tibiofibular jointsThe tibiofibular joints connect the tibia and fibula.ToesThe toes are the five digits at the very front of the foot. They help maintain balance while walking and provide the final push off the ground.Tonic and phasic musclesTonic and phasic muscles are two categories in a muscle classification developed by Czech neurologist Vladimir Janda.TracheaThe trachea is a tube that carries air from the front of your neck down toward the lungs in your chest.Transverse processThe transverse processes are short bony projections extending from either side of a vertebra.Transversus abdominisThe transversus abdominis is the deepest muscle of the abdominal wall, wrapping horizontally around the sides of your abdomen like a belt.TrapeziusThe trapezius is a broad, diamond-shaped superficial muscle that extends from the back of the neck to the middle of the back.Triceps brachiiThe triceps brachii is a three-headed muscle that occupies the entire back of the upper arm and straightens the elbow.Trigeminal nerveThe trigeminal nerve is a cranial nerve that carries sensation from the face, inside the mouth, and front of the head, and controls the muscles used for chUlnaThe ulna is the long bone on the little-finger side of the forearm, one of the two bones that make up the forearm.Ulnar collateral ligament of the elbowThe ulnar collateral ligament (UCL) of the elbow connects the humerus and ulna on the inner side of the elbow, keeping the elbow from opening outward.Ulnar nerveThe ulnar nerve passes along the inside of the elbow and extends to the little finger.Upper cervical spineThe upper cervical spine is the uppermost part of the neck, formed by the occipital bone (C0), the first cervical vertebra (atlas, C1), and the second cervVagus nerveThe vagus nerve is the 10th cranial nerve.Vasoconstriction and vasodilationBlood vessels narrow and widen to direct blood to where the body needs it at any given moment.Vastus intermediusThe vastus intermedius is one of the four muscles that make up the quadriceps at the front of the thigh. It lies deep beneath the rectus femoris.Vastus lateralisThe vastus lateralis is the largest of the four parts of the quadriceps femoris, the muscle group at the front of the thigh, and lies along the outer thighVastus medialisThe vastus medialis is one of the four parts of the quadriceps femoris, the muscle group at the front of the thigh.Venous circulationVenous circulation is the route by which blood returns to the heart after traveling throughout the body.Venous poolingVenous pooling is the accumulation of blood in the leg veins when you stand or sit for a long time.Venous valvesVenous valves are thin flaps attached to the inside of veins.Vertebral arteryThe vertebral arteries are a pair of arteries, one on each side, that travel upward through openings along the sides of the neck vertebrae to supply blood Vertebral bodyThe vertebral body is the thick, cylindrical part at the front of a vertebra. It supports most of the load from body weight and movement.Vertebral columnThe vertebral column is the central column of bones extending from the neck to the coccyx.Vertebral endplateThe endplate is a thin plate between a vertebra and the disc next to it.Vestibular apparatusThe vestibular apparatus is the sensory organ for balance in the inner ear, an internal sensor that tells your body when your head turns, tilts, and moves,White blood cellWhite blood cells are the body's defense cells: they circulate in the blood, fight bacteria and viruses, and clear away debris in injured tissue.WristThe wrist is a joint where the two forearm bones (radius and ulna) meet eight small carpal bones in multiple layers.Wrist extensorsThe wrist extensors are a group of muscles on the back of the forearm (the side facing the back of the hand) that bend the wrist backward toward the back oWrist flexorsThe wrist flexors are a group of muscles on the inner (palm-facing) side of the forearm that bend the wrist and fingers.Wrist ligamentsWrist ligaments are tough, cord-like tissues that connect the eight small carpal bones to one another and to the forearm bones.Zygomatic boneThe zygomatic bone is the anatomical name for the cheekbone, which projects from the upper cheek.