The human muscular system: an interactive 3D muscle model with every muscle labelled

The body has three types of muscle tissue. Skeletal muscle moves the skeleton and depends completely on signals from the nervous system to contract. Cardiac muscle forms the heart, whose fibres are connected so that the whole heart contracts as one unit. Smooth muscle lines the walls of arteries, visceral organs and internal passageways. Skeletal and cardiac muscle are striated; smooth muscle is not. (OpenStax Anatomy and Physiology 2e, 10.1: Overview of Muscle Tissues.)

All muscle tissue shares four properties. Excitability lets the membrane change its electrical state and send an action potential. Contractility lets the muscle pull on its attachment points and shorten with force. Elasticity lets it return to its resting length, and extensibility lets it stretch. (OpenStax Anatomy and Physiology 2e, 10.1: Overview of Muscle Tissues.)

When people talk about the muscular system, or look at a muscle labelled diagram, they usually mean the skeletal muscles. The rest of this page is about them.

To move a bone, a muscle must pull on it while its other end is anchored to a fixed part of the skeleton. The movable end, attached to the bone being pulled, is the insertion. The end attached to the fixed, stabilised bone is the origin. (OpenStax Anatomy and Physiology 2e, 11.1: Interactions of Skeletal Muscles, Their Fascicle Arrangement, and Their Lever Systems.)

Several muscles usually take part in one movement. The principal muscle is the prime mover, or agonist: when you lift a cup, the biceps brachii is the prime mover for flexing the elbow. A synergist assists it, as the brachialis does here, and a synergist that stabilises the bone of the prime mover's origin is called a fixator. A muscle with the opposite action is an antagonist, as the triceps brachii is to the biceps brachii and the hamstrings are to the quadriceps femoris at the knee. (OpenStax Anatomy and Physiology 2e, 11.1: Interactions of Skeletal Muscles, Their Fascicle Arrangement, and Their Lever Systems.)

Muscle fibres are bundled into fascicles, and the arrangement of the fascicles shapes the muscle. Most muscles are parallel, with fascicles running along the long axis; a spindle-shaped parallel muscle with a central belly is fusiform. Convergent muscles, such as pectoralis major, spread over a wide area and meet at one attachment. Pennate muscles attach their fascicles to a central tendon: unipennate like extensor digitorum, bipennate, or multipennate like the deltoid. Circular muscles (sphincters), such as orbicularis oris around the mouth, open and close an opening. (OpenStax Anatomy and Physiology 2e, 11.1: Interactions of Skeletal Muscles, Their Fascicle Arrangement, and Their Lever Systems.)

Muscle names look daunting, but each describes the muscle. Names can give its shape (orbicularis), its relative size (gluteus maximus, medius and minimus), its location (frontalis lies over the frontal bone), the number of origins (biceps brachii has two; quadriceps names a group of four), its attachments, with the origin first (sternocleidomastoid runs from the sternum and clavicle to the mastoid process), the direction of its fibres (rectus means straight, as in rectus abdominis, versus the obliques), or its action (flexor, extensor, abductor, adductor). (OpenStax Anatomy and Physiology 2e, 11.2: Naming Skeletal Muscles.)

Once you know the code, a name such as flexor carpi radialis tells you a lot: it flexes, it acts on the carpus (wrist) and it lies on the radial side of the forearm. Reading names this way is the quickest route to learning the labels of the muscular system. (OpenStax Anatomy and Physiology 2e, 11.2: Naming Skeletal Muscles.)

The muscles of facial expression insert into the skin rather than bone, so they move the skin when they contract. The masseter is the main muscle of chewing, helped by the temporalis and the pterygoid muscles. The extrinsic eye muscles, inside the orbit, move the eyeball. In the neck, the sternocleidomastoid laterally flexes and rotates the head, and when both sides contract together they flex it. (OpenStax Anatomy and Physiology 2e, 11.3: Axial Muscles of the Head, Neck, and Back.)

The erector spinae group makes up most of the muscle mass of the back and is the main extensor of the vertebral column, arranged in three columns: iliocostalis laterally, longissimus in the middle and spinalis medially. The splenius muscles extend, tilt and rotate the head, and the deep transversospinales run from transverse to spinous processes, linking neighbouring vertebrae. (OpenStax Anatomy and Physiology 2e, 11.3: Axial Muscles of the Head, Neck, and Back.)

Four pairs of muscles form the anterolateral abdominal wall: the external oblique (outermost), the internal oblique, the transversus abdominis (deepest) and the rectus abdominis, which lies in its sheath on either side of the linea alba. The diaphragm is the main muscle of breathing, helped by the external intercostals in inhalation and the internal intercostals in exhalation. In the posterior abdominal wall, quadratus lumborum bends the trunk to the side. (OpenStax Anatomy and Physiology 2e, 11.4: Axial Muscles of the Abdominal Wall and Thorax.)

The pectoral girdle is positioned by muscles of the anterior thorax (subclavius, pectoralis minor and serratus anterior) and the posterior thorax (trapezius, rhomboid major and rhomboid minor). The humerus is moved by two axial muscles, pectoralis major and latissimus dorsi, and by the scapular muscles: deltoid, subscapularis, supraspinatus, infraspinatus, teres major, teres minor and coracobrachialis. The tendons of subscapularis, supraspinatus, infraspinatus and teres minor form the rotator cuff around the shoulder joint. (OpenStax Anatomy and Physiology 2e, 11.5: Muscles of the Pectoral Girdle and Upper Limbs.)

In the arm, biceps brachii, brachialis and brachioradialis flex the elbow, and triceps brachii and anconeus extend it. The forearm muscles are split into an anterior (flexor) compartment, including flexor carpi radialis and flexor digitorum profundus, and a posterior (extensor) compartment, including extensor digitorum and extensor pollicis longus; each compartment has superficial and deep layers. (OpenStax Anatomy and Physiology 2e, 11.5: Muscles of the Pectoral Girdle and Upper Limbs.)

The intrinsic muscles of the hand both start and end within the hand. They form three groups: the thenar muscles, which make the rounded thenar eminence at the base of the thumb; the hypothenar muscles on the medial side of the palm, which act on the little finger; and the intermediate muscles in the mid-palm, the lumbricals and the palmar and dorsal interossei, which act on all the fingers. (OpenStax Anatomy and Physiology 2e, 11.5: Muscles of the Pectoral Girdle and Upper Limbs.)

The gluteal muscles, from superficial to deep gluteus maximus, gluteus medius and gluteus minimus, are some of the largest and most powerful muscles in the body. Psoas major and iliacus together form the iliopsoas, the main hip flexor group. (OpenStax Anatomy and Physiology 2e, 11.6: Appendicular Muscles of the Pelvic Girdle and Lower Limbs.)

Deep fascia divides the thigh into three compartments. The anterior compartment holds the quadriceps femoris (rectus femoris, vastus lateralis, vastus medialis and vastus intermedius), which extends the knee, and the sartorius. The medial compartment holds the adductors (longus, brevis and magnus), gracilis and pectineus. The posterior compartment holds the hamstrings (biceps femoris, semitendinosus and semimembranosus), which flex the knee. (OpenStax Anatomy and Physiology 2e, 11.6: Appendicular Muscles of the Pelvic Girdle and Lower Limbs.)

The leg also has three compartments. The anterior compartment (tibialis anterior, extensor hallucis longus, extensor digitorum longus and, in some people only, fibularis tertius) lifts the front of the foot. The lateral compartment holds fibularis (peroneus) longus and fibularis brevis. The posterior compartment has a superficial group, gastrocnemius, soleus and plantaris, inserting through the calcaneal (Achilles) tendon, and a deep group: popliteus, flexor digitorum longus, flexor hallucis longus and tibialis posterior. (OpenStax Anatomy and Physiology 2e, 11.6: Appendicular Muscles of the Pelvic Girdle and Lower Limbs.)

The 3D model on this page is male, but almost every muscle on it has the same name, the same attachments and the same action in women. The musculoskeletal anatomy of women and men is described as grossly similar; the sex differences are mainly in skeletal geometry and in tissue characteristics rather than in which muscles exist or where they attach. (Petrie KA et al. Considerations of Sex Differences in Musculoskeletal Anatomy Between Males and Females. In: The Active Female. Springer, 2023.)

The clear exception is the perineum, where some muscles are arranged around different reproductive structures. Bulbospongiosus, for example, is a sexually dimorphic muscle: in males it wraps around the bulb of the penis and the corpus spongiosum, while in females it encircles the vaginal orifice. (Kenhub: Bulbospongiosus muscle.)

The real differences are in size and fibre make-up. A 2025 systematic review notes that the skeletal muscles of males are larger, stronger and more powerful than those of females across the lifespan, with lower-limb muscles in males about 40% more powerful and even larger sex differences in the upper limb. Its pooled data showed that females had a greater share of type I (slow-twitch) fibres, about 51% vs 48%, while males had larger type I fibres in cross-section. (James JJ et al. Sex differences in human skeletal muscle fiber types: a systematic review and meta-analysis. Physiol Rep. 2025.)

A review in Physiology reports a prevalence of slower type I and type IIA fibres in females and states that, in general, male muscles are more fatigable than female muscles, with higher endurance and quicker recovery in women. Testosterone is associated with an increase in muscle mass, and oestrogen (estrogen) influences fibre size, muscle weight, regeneration and contractility. (Haizlip KM, Harrison BC, Leinwand LA. Sex-based differences in skeletal muscle kinetics and fiber-type composition. Physiology. 2015.)

Much of the visible difference in muscular female anatomy comes from fat, not muscle. Compared with men, women have a higher percentage of body fat and store relatively more of it in the hips and thighs (the gluteofemoral region), whereas men carry more visceral fat inside the abdomen. The same muscles therefore look different through the skin. (Karastergiou K et al. Sex differences in human adipose tissues: the biology of pear shape. Biol Sex Differ. 2012.)

The breast is not part of the muscular system. It is made of mammary glands surrounded by fibrous and fatty connective tissue, and it lies superficial to pectoralis major and serratus anterior, separated from the pectoral fascia by a layer of loose connective tissue called the retromammary space. (TeachMeAnatomy: The Breast.)

The model is built from BodyParts3D, a set of anatomical meshes of an adult male body, and shows more than 200 named muscles and muscle parts over a ghosted skeleton. Large muscles that have distinct parts, such as the deltoid, trapezius and pectoralis major, are split into those parts, and the heads of biceps brachii, triceps brachii, gastrocnemius and biceps femoris are separate. Click any muscle to identify it, then follow the link to its own page for origin, insertion, innervation and action.

Some muscles are missing from the dataset, so look for them in the diagrams on the regional pages instead. Of the four pairs of anterolateral abdominal muscles, only the external oblique is in the model; rectus abdominis, internal oblique and transversus abdominis are not, and neither are quadratus lumborum or latissimus dorsi. The muscles of facial expression (other than platysma) and the chewing muscles, masseter, temporalis and the pterygoids, are also absent. (OpenStax Anatomy and Physiology 2e, 11.4: Axial Muscles of the Abdominal Wall and Thorax.)

The model does include many deep and small muscles that are hard to see in a flat labelled diagram: the rotator cuff, the deep back muscles such as the rotatores and interspinales, the extrinsic eye muscles, the muscles of the larynx, pharynx and tongue, the pelvic floor, and the intrinsic muscles of the hand and foot.

Abdominal part of pectoralis major

The lowest fibres of pectoralis major, arising from the abdominal wall.

Abductor digiti minimi of foot

A muscle along the lateral border of the sole of the foot.

Abductor digiti minimi of hand

The muscle forming the ulnar (little-finger) side of the hypothenar eminence.

Abductor hallucis

A muscle along the medial border of the sole of the foot.

Abductor pollicis brevis

A thenar muscle on the lateral side of the thenar eminence.

Abductor pollicis longus

A deep forearm extensor that forms the lateral border of the anatomical snuffbox.

Acromial part of deltoid

The middle fibres of the deltoid, forming the rounded contour of the shoulder.

Adductor brevis

A short adductor in the medial thigh, lying behind pectineus and adductor longus.

Adductor longus

The most anterior adductor muscle; its medial edge forms the medial border of the femoral triangle.

Adductor magnus

The largest adductor, with an adductor part and a hamstring part.

Adductor minimus

The upper, anterior fibres of adductor magnus, sometimes described as a separate part.

Anconeus

A small triangular muscle on the posterior elbow.

Ascending part of trapezius

The lower fibres of trapezius, running upward and laterally to the scapular spine.

Brachialis

The main flexor of the elbow, lying deep to biceps brachii.

Brachioradialis

An elbow flexor that forms the lateral border of the cubital fossa; unusually for a flexor, it is supplied by the radial nerve.

Calcaneal tendon

The thick tendon joining gastrocnemius and soleus to the heel bone.

Cervical rotator

Small deep muscles of the neck's transversospinalis group (rotatores cervicis).

Clavicular part of deltoid

The anterior fibres of the deltoid.

Clavicular part of pectoralis major

The upper fibres of pectoralis major.

Coccygeus

A small muscle of the posterior pelvic floor.

Common tendinous ring

A fibrous ring at the back of the orbit giving origin to the recti muscles of the eye.

Coracobrachialis

A slender muscle on the medial side of the upper arm.

Descending part of trapezius

The upper fibres of trapezius, running down from the skull and neck.

Diaphragm

The dome-shaped muscle separating the thoracic and abdominal cavities and the main muscle of inspiration.

Digastric

A two-bellied muscle above the hyoid bone linking the mandible and the mastoid region.

Extensor carpi radialis brevis

A wrist extensor in the posterior forearm.

Extensor carpi radialis longus

A wrist extensor lying just distal to brachioradialis.

Extensor carpi ulnaris

A wrist extensor on the ulnar side of the posterior forearm.

Extensor digiti minimi

An extensor of the little finger.

Extensor digitorum

The main extensor of the fingers.

Extensor digitorum longus

A long extensor in the anterior leg compartment.

Extensor hallucis brevis

A small muscle on the dorsum of the foot.

Extensor hallucis longus

A long extensor of the great toe, lying between tibialis anterior and extensor digitorum longus.

Extensor indicis

A deep forearm muscle giving the index finger independent extension.

Extensor pollicis brevis

A deep thumb extensor forming the lateral border of the anatomical snuffbox.

Extensor pollicis longus

A thumb extensor whose tendon turns around the dorsal tubercle of the radius.

External anal sphincter

A ring of voluntary skeletal muscle surrounding the anal canal.

External intercostal muscle

The outermost layer of muscles between the ribs.

External oblique

The largest and most superficial lateral abdominal wall muscle.

Fibularis brevis

A lateral leg muscle lying beneath fibularis longus.

Fibularis longus

A long lateral leg muscle whose tendon crosses the sole of the foot.

Fibularis tertius

A small muscle of the anterior leg, sometimes absent.

First lumbrical of foot

A small muscle in the sole arising from the flexor digitorum longus tendon to the 2nd toe.

First plantar interosseous of foot

A small muscle between the metatarsals on the sole of the foot.

Flexor accessorius

A muscle of the sole that assists the long toe flexor.

Flexor carpi radialis

A superficial anterior forearm flexor lateral to palmaris longus.

Flexor digiti minimi brevis of foot

A small muscle of the lateral sole.

Flexor digiti minimi brevis of hand

A small hypothenar muscle.

Flexor digitorum brevis

A central muscle of the sole.

Flexor digitorum longus

A deep posterior leg muscle whose tendon passes behind the medial malleolus.

Flexor digitorum profundus

A deep forearm flexor that bends the distal phalanges.

Flexor digitorum superficialis

An intermediate-layer forearm flexor of the fingers.

Flexor hallucis longus

A deep posterior leg muscle that bends the great toe, running beneath the sustentaculum tali.

Flexor pollicis brevis

A thenar muscle medial to abductor pollicis brevis.

Flexor pollicis longus

A deep forearm flexor of the thumb.

Flexor retinaculum of wrist

A strong fibrous band across the front of the wrist forming the roof of the carpal tunnel.

Fourth lumbrical of foot

A small muscle in the sole acting on the 5th toe.

Gemellus inferior

A small lateral rotator of the hip, below obturator internus.

Gemellus superior

A small lateral rotator of the hip, above obturator internus.

Genioglossus

The largest extrinsic tongue muscle, forming most of the tongue bulk.

Geniohyoid

A narrow muscle above the mylohyoid in the floor of the mouth.

Gluteus maximus

The largest and most superficial buttock muscle.

Gluteus medius

A fan-shaped muscle under gluteus maximus on the outer ilium.

Gluteus minimus

The smallest and deepest gluteal muscle.

Gracilis

A long, thin muscle on the medial side of the thigh.

Humeral head of flexor carpi ulnaris

The humeral origin of flexor carpi ulnaris, the ulnar-side wrist flexor.

Humeral head of pronator teres

The larger, superficial head of pronator teres.

Hyoglossus

A flat extrinsic tongue muscle rising from the hyoid bone.

Iliacus

A fan-shaped muscle filling the iliac fossa.

Iliococcygeus

The posterior part of levator ani in the pelvic floor.

Iliocostalis cervicis

The cervical part of the iliocostalis column of erector spinae.

Iliocostalis lumborum

The lumbar part of the iliocostalis column of erector spinae.

Iliocostalis thoracis

The thoracic part of the iliocostalis column of erector spinae.

Iliotibial tract

A thick band of fascia lata on the outer thigh.

Inferior oblique

An extraocular muscle that elevates and turns the eye outward (this name refers to the eye muscle, not the abdominal or suboccipital one).

Inferior oblique part of longus colli

The lower oblique fibres of longus colli on the front of the cervical spine.

Inferior pharyngeal constrictor

The lowest of the three constrictors of the pharynx.

Inferior rectus

An extraocular muscle on the floor of the orbit.

Infraspinatus muscle

A rotator cuff muscle on the back of the scapula.

Innermost intercostal muscle

The deepest layer of intercostal muscles.

Intermediate tendon

A tendon linking two muscle bellies in series (the mesh is a single right-side item, most likely the digastric intermediate tendon).

Internal intercostal muscle

The middle layer of intercostal muscles.

Interspinalis thoracis

A tiny muscle between adjacent thoracic spinous processes, often poorly developed.

Lateral crico-arytenoid

An intrinsic laryngeal muscle that closes the vocal folds.

Lateral head of flexor hallucis brevis

The lateral part of flexor hallucis brevis in the sole.

Lateral head of gastrocnemius

The lateral head of the superficial calf muscle.

Lateral head of triceps brachii

The lateral head of the triceps.

Lateral lumbar intertransversarius

A small muscle between adjacent lumbar transverse processes.

Lateral rectus

An extraocular muscle on the lateral wall of the orbit.

Levator palpebrae superioris

The muscle that lifts the upper eyelid.

Levator scapulae

A muscle of the posterolateral neck that raises the scapula.

Levator veli palatini

A muscle of the soft palate.

Linea alba

A fibrous midline band running down the abdominal wall.

Long head of biceps brachii

The long head of biceps, passing through the shoulder joint.

Long head of biceps femoris

The long, superficial head of biceps femoris, the lateral hamstring.

Long head of triceps brachii

The long head of triceps, crossing the shoulder joint.

Longissimus capitis

The part of longissimus attaching to the skull.

Longissimus cervicis

The cervical part of the longissimus column.

Longissimus thoracis

The largest part of the longissimus column of erector spinae.

Longus capitis

A prevertebral muscle in front of the upper cervical spine.

Lumbar rotator

Small deep muscles of the transversospinalis group in the lumbar spine (rotatores lumborum).

Medial head of flexor hallucis brevis

The medial part of flexor hallucis brevis in the sole.

Medial head of gastrocnemius

The larger medial head of the superficial calf muscle.

Medial head of triceps brachii

The deep head of triceps, lying beneath the long and lateral heads.

Medial lumbar intertransversarius

A small muscle between adjacent lumbar vertebrae (accessory and mammillary processes).

Medial rectus

An extraocular muscle on the medial wall of the orbit.

Median cricothyroid ligament

A fibro-elastic ligament in the midline joining the cricoid and thyroid cartilages.

Middle pharyngeal constrictor

The middle of the three pharyngeal constrictors.

Mylohyoid

A flat muscle forming the muscular floor of the mouth.

Oblique arytenoid

An intrinsic laryngeal muscle behind the arytenoid cartilages.

Oblique head of adductor hallucis

The larger head of adductor hallucis in the sole.

Oblique head of adductor pollicis

The larger head of adductor pollicis in the palm.

Oblique part of cricothyroid

The oblique fibres of cricothyroid, an intrinsic laryngeal muscle.

Obliquus capitis inferior

A suboccipital muscle below the atlas.

Obliquus capitis superior

A small suboccipital muscle forming the superolateral border of the suboccipital triangle.

Obturator externus

A flat, fan-shaped deep muscle of the medial thigh that wraps behind the neck of the femur.

Obturator internus

A lateral rotator of the hip that arises inside the pelvis and leaves through the lesser sciatic foramen.

Omohyoid

A thin infrahyoid strap muscle with two bellies joined by an intermediate tendon.

Opponens digiti minimi of foot

An inconstant small muscle of the little toe, usually regarded as a deep slip of flexor digiti minimi brevis.

Opponens digiti minimi of hand

A hypothenar muscle that deepens the hollow of the palm on the little finger side.

Opponens pollicis

A thenar muscle lying deep to abductor pollicis brevis that allows the thumb to oppose.

Palatopharyngeus

A muscle of the soft palate and pharynx that forms the posterior pillar of the fauces.

Palmaris longus

A slender forearm flexor with a short belly and a long tendon that fans into the palm.

Pectineus

A flat quadrangular muscle at the top of the medial thigh forming part of the floor of the femoral triangle.

Pectoralis minor

A thin triangular muscle lying deep to pectoralis major on the upper chest wall.

Perineal muscle

A general name for the muscles of the perineum, such as the transverse perineal muscles, bulbospongiosus and ischiocavernosus.

Piriformis

A pear-shaped lateral rotator of the hip that passes through the greater sciatic foramen.

Plantaris

A small, inconstant calf muscle with a very long thin tendon.

Platysma

A thin superficial sheet of muscle in the subcutaneous tissue of the neck.

Popliteus

A small triangular muscle forming part of the floor of the popliteal fossa.

Posterior crico-arytenoid

An intrinsic laryngeal muscle on the back of the cricoid cartilage.

Pronator quadratus

A square deep muscle on the front of the distal forearm.

Psoas major

A long muscle of the posterior abdominal wall that forms the main part of iliopsoas.

Pterygomandibular raphe

A tendinous band between the pterygoid hamulus and the mandible, not a true muscle.

Pubococcygeus

A part of levator ani forming the main muscular floor of the pelvis.

Puborectalis

The most medial part of levator ani, forming a sling around the anorectal junction.

Quadratus femoris

A flat quadrangular deep gluteal muscle below the inferior gemellus.

Rectus capitis anterior

A small deep prevertebral muscle at the base of the skull.

Rectus capitis lateralis

A small deep muscle lateral to the atlanto-occipital joint.

Rectus capitis posterior major

A suboccipital muscle forming the superomedial border of the suboccipital triangle.

Rectus capitis posterior minor

A small suboccipital muscle lying medial to rectus capitis posterior major.

Rectus femoris

The only part of quadriceps femoris that crosses both the hip and knee.

Rhomboid major

A flat muscle deep to trapezius that connects the spine to the scapula.

Rhomboid minor

A small muscle lying above rhomboid major.

Salpingopharyngeus

A thin muscle of the pharynx running from the pharyngotympanic tube.

Sartorius

The longest muscle in the body, a strap-like muscle crossing the thigh obliquely.

Scalenus anterior

A deep neck muscle and an important landmark in the root of the neck.

Scalenus medius

The largest and longest of the scalene muscles.

Scalenus posterior

The smallest and deepest of the scalene muscles.

Second lumbrical of foot

A small intrinsic muscle of the sole attached to the flexor digitorum longus tendons.

Second plantar interosseous of foot

One of three plantar interossei, small muscles beneath the metatarsals in the fourth layer of the sole.

Semimembranosus

A hamstring muscle on the posteromedial thigh with a long flat tendon of origin.

Semispinalis capitis

A large muscle of the posterior neck forming the bulge beside the midline.

Semispinalis cervicis

A transversospinal muscle of the neck deep to semispinalis capitis.

Semispinalis thoracis

A transversospinal muscle of the upper back.

Semitendinosus

A hamstring muscle with a long cord-like tendon on the posteromedial thigh.

Serratus anterior

A broad muscle on the side of the thorax that holds the scapula against the chest wall.

Serratus posterior inferior

A thin muscle of the lower back deep to latissimus dorsi.

Serratus posterior superior

A thin muscle of the upper back deep to the rhomboids.

Anterior cervical intertransversarii

Small paired muscles between the anterior parts of adjacent cervical transverse processes.

Dorsal interossei of hand

Four bipennate muscles between the metacarpals that spread the fingers.

Interspinales cervicis

Short paired muscles between the spinous processes of adjacent cervical vertebrae.

Interspinales lumborum

Short paired muscles between the spinous processes of adjacent lumbar vertebrae.

Levatores costarum breves

Short triangular muscles on the back of the thorax, part of the twelve pairs of levatores costarum.

Levatores costarum longi

Longer slips of the levatores costarum on the lower thoracic back.

Lumbricals of hand

Four small muscles of the palm that arise from the flexor digitorum profundus tendons.

Palmar interossei of hand

Small unipennate muscles in the palm that bring the fingers together.

Posterior cervical intertransversarii

Small paired muscles between the posterior parts of adjacent cervical transverse processes.

Short head of biceps brachii

The medial head of biceps brachii at the front of the arm.

Short head of biceps femoris

The head of biceps femoris that does not cross the hip joint.

Soleus

A broad flat calf muscle lying deep to gastrocnemius.

Spinal part of deltoid

The posterior fibers of deltoid arising from the scapular spine.

Spinalis

The most medial column of the erector spinae group, lying beside the spinous processes.

Spinalis thoracis

The thoracic part of spinalis, the medial column of the erector spinae.

Splenius capitis

A flat bandage-like muscle on the back of the neck.

Splenius cervicis

A strap-like muscle deep to splenius capitis.

Sternocleidomastoid

A thick superficial neck muscle forming the main landmark dividing the anterior and posterior triangles.

Sternocostal part of pectoralis major

The large lower part of pectoralis major arising from the sternum and ribs.

Sternohyoid

A thin infrahyoid strap muscle at the front of the neck.

Sternothyroid

An infrahyoid strap muscle lying deep to sternohyoid.

Straight part of cricothyroid

The anterior straight fibers of the cricothyroid muscle of the larynx.

Stylohyoid

A slender suprahyoid muscle running from the styloid process to the hyoid bone.

Stylopharyngeus

A slender pharyngeal muscle arising from the styloid process.

Subclavius

A small muscle between the clavicle and the first rib.

Subscapularis

The largest rotator cuff muscle, filling the subscapular fossa.

Superficial head of flexor pollicis brevis

The larger, lateral head of flexor pollicis brevis in the thenar eminence.

Superior oblique

An extraocular muscle that passes through a pulley (trochlea) before reaching the eyeball.

Superior oblique part of longus colli

The upper oblique part of longus colli, a prevertebral neck muscle.

Superior pharyngeal constrictor

The uppermost of the three constrictors forming the pharyngeal wall.

Superior rectus

An extraocular muscle on the top of the eyeball.

Supinator

A deep forearm muscle wrapping around the upper radius.

Supraspinatus

A rotator cuff muscle on the back of the scapula above its spine.

Tendinous arch of levator ani

A fibrous thickening of the obturator fascia from which part of levator ani arises.

Tendon of levator palpebrae superioris

The flattened tendon (aponeurosis) of the muscle that raises the upper eyelid.

Tensor fasciae latae

A small hip muscle at the front and side of the thigh.

Tensor veli palatini

A palatal muscle that tenses the soft palate.

Teres major

A thick muscle of the posterior shoulder, sometimes called the lat's little helper.

Teres minor

A rotator cuff muscle on the lateral scapula.

Third lumbrical of foot

A small intrinsic muscle of the sole attached to the flexor digitorum longus tendons.

Third plantar interosseous of foot

One of three plantar interossei, small muscles beneath the metatarsals in the fourth layer of the sole.

Thoracic rotator

Small muscles deep in the groove between the spinous and transverse processes of thoracic vertebrae, called rotatores thoracis.

Thyro-arytenoid

An intrinsic laryngeal muscle forming the body of the vocal fold.

Tibialis anterior

The main dorsiflexor on the front of the leg.

Tibialis posterior

The deepest muscle of the posterior leg compartment.

Transverse arytenoid

An unpaired intrinsic laryngeal muscle crossing between the arytenoid cartilages.

Transverse head of adductor hallucis

The transverse part of adductor hallucis in the sole.

Transverse head of adductor pollicis

The transverse head of adductor pollicis in the palm.

Transverse part of trapezius

The middle fibers of trapezius, running horizontally.

Transversus thoracis

A thin muscle on the inner surface of the anterior thoracic wall.

Ulnar head of flexor carpi ulnaris

The ulnar origin of flexor carpi ulnaris.

Ulnar head of pronator teres

The smaller ulnar head of pronator teres.

Uvular muscle

A small paired muscle forming the core of the uvula.

Vastus intermedius

The deep quadriceps muscle lying beneath rectus femoris.

Vastus lateralis

The largest quadriceps muscle on the lateral thigh.

Vastus medialis

The medial quadriceps muscle with oblique fibers near the patella.

Vertical intermediate part of longus colli

The central vertical part of longus colli, a prevertebral neck muscle.

Vocalis

The medial part of thyro-arytenoid lying along the vocal ligament.