Human Muscular System: Anatomy, Actions, and Innervations

Comprehensive vocabulary flashcards covering the origin, insertion, action, and innervation of muscles of the head, neck, back, upper limb, hip, thigh, leg, and foot.

Femoral triangle

An anterior hip and thigh region bounded by the inguinal ligament, sartorius, and adductor longus, containing the lateral femoral cutaneous nerve, superficial circumflex iliac artery, iliopsoas muscle, femoral nerve, femoral artery, tensor fasciae latae muscle, rectus femoris muscle, femoral ring, femoral vein, pectineus muscle, and great saphenous vein.

Iliacus

A pelvic muscle originating at the iliac fossa and inserting into the lesser trochanter of the femur (along with the psoas major); it flexes at the hip joint and flexes joints of the vertebral column.

Psoas major

A pelvic muscle originating at the transverse processes of lumbar vertebrae and inserting into the lesser trochanter of the femur (along with the iliacus); it flexes at the hip joint and flexes joints of the vertebral column.

Gluteus maximus

A hip muscle originating from the iliac crest, sacrum, coccyx, and aponeurosis of the lumbar region, inserting into the gluteal tuberosity and iliotibial tract; it extends and rotates the thigh laterally at the hip joint.

Gluteus medius

A hip muscle originating on the lateral surface of the ilium and inserting into the greater trochanter of the femur; it abducts and rotates the thigh medially at the hip joint.

Gluteus minimus

A hip muscle originating on the lateral surface of the lower half of the ilium and inserting into the greater trochanter of the femur; it abducts and rotates the thigh medially at the hip joint.

Tensor fasciae latae

A hip muscle originating on the anterior border of the ilium and iliac crest and inserting into the iliotibial tract; it abducts and rotates the thigh medially at the hip joint.

Tibialis anterior

An anterior leg muscle originating from the lateral condyle and body of the tibia and inserting into the first metatarsal bone and first cuneiform bone; it dorsiflexes the ankle and inverts the foot and ankle.

Extensor digitorum longus

An anterior leg muscle originating on the lateral condyle of the tibia and anterior surface of the fibula, inserting into the extensor expansions of digits II–V; it extends digits II–V and dorsiflexes the foot at the ankle.

Extensor hallucis longus

An anterior leg muscle originating on the anterior surface of the fibula and interosseous ligament, inserting into the distal phalanx of digit I; it extends joints of the big toe and assists dorsiflexion of the foot at the ankle.

Fibularis tertius

An anterior leg muscle originating on the anterior surface of the fibula and interosseous ligament, inserting into the dorsal surface of the fifth metatarsal bone; it dorsiflexes and everts the foot at the ankle.

Fibularis longus

A lateral leg muscle originating on the lateral condyle of the tibia and head and shaft of the fibula, inserting into the first cuneiform and metatarsal bone I; it plantar flexes and everts the foot at the ankle.

Fibularis brevis

A lateral leg muscle originating from the lower aspect of the fibula and inserting into metatarsal bone V; it plantar flexes and everts the foot at the ankle.

Gastrocnemius

A superficial posterior leg muscle originating on the lateral and medial condyles of the femur and inserting into the posterior surface of the calcaneus via the calcaneal tendon; it plantar flexes the foot at the ankle and flexes the knee joint.

Soleus

A posterior leg muscle originating on the posterior aspect of the fibula and tibia and inserting into the calcaneus via the calcaneal tendon; it plantar flexes the foot at the ankle.

Plantaris

A posterior leg muscle originating on the supracondylar ridge of the femur and inserting into the calcaneus; it plantar flexes the foot at the ankle.

Popliteus

A posterior knee/leg muscle originating on the lateral condyle of the femur and inserting into the upper posterior aspect of the tibia; it flexes and medially rotates the leg at the knee joint.

Flexor hallucis longus

A deep posterior leg muscle originating on the posterior surface of the tibia and inserting into the distal phalanx of the big toe; it flexes the joint of the great toe and plantar flexes the foot.

Flexor digitorum longus

A deep posterior leg muscle originating on the posterior surface of the tibia and inserting into the distal phalanges of digits II–V; it flexes the joints of digits II–V and plantar flexes the foot.

Tibialis posterior

A deep posterior leg muscle originating from the tibia, fibula, and interosseous ligament, inserting into the navicular, cuneiform, cuboid, and metatarsal bones II–IV; it plantar flexes and inverts the foot at the ankle and supports the arches of the foot.

Pectoralis major

An anterior chest muscle originating from the clavicle, sternum, and costal cartilages of the second to sixth ribs, inserting into the greater tubercle of the humerus; it flexes, adducts, and rotates the shoulder joint medially.

Latissimus dorsi

A wide back muscle originating from the spines of sacral, lumbar, and lower thoracic vertebrae and lower ribs, inserting into the intertubercular groove of the humerus; it extends, adducts, and rotates the shoulder joint medially.

Deltoid

A shoulder muscle originating on the clavicle, acromion, and spine of the scapula, inserting into the deltoid tuberosity of the humerus; it abducts, extends, and flexes the shoulder joint.

Supraspinatus

A rotator cuff muscle originating in the supraspinous fossa of the scapula and inserting into the greater tubercle of the humerus; it abducts the shoulder joint.

Infraspinatus

A rotator cuff muscle originating in the infraspinous fossa of the scapula and inserting into the greater tubercle of the humerus; it rotates the shoulder joint laterally.

Teres major

A shoulder muscle originating on the inferior angle and lateral border of the scapula and inserting into the intertubercular groove of the humerus; it extends and rotates the shoulder joint medially.

Teres minor

A rotator cuff muscle originating on the lateral border of the scapula and inserting into the greater tubercle of the humerus; it rotates the shoulder joint laterally.

Subscapularis

A rotator cuff muscle originating in the subscapular fossa and inserting into the lesser tubercle of the humerus; it rotates the shoulder joint medially.

Coracobrachialis

An anterior arm muscle originating on the coracoid process of the scapula and inserting into the body of the humerus; it flexes and adducts the shoulder joint.

Biceps brachii

An anterior brachial muscle originating from the coracoid process and tuberosity above the glenoid fossa, inserting into the radial tuberosity; it flexes the elbow joint and supinates the forearm and hand at the radioulnar joint.

Brachialis

An anterior brachial muscle originating on the anterior body of the humerus and inserting into the tuberosity of the ulna; it flexes the elbow joint.

Brachioradialis

A forearm muscle originating on the lateral supracondylar ridge of the humerus and inserting proximal to the styloid process of the radius; it flexes the elbow joint.

Triceps brachii

A posterior brachial muscle originating from the tuberosity below the glenoid fossa and the lateral and medial surfaces of the humerus, inserting into the olecranon of the ulna; it extends the elbow joint.

Anconeus

A posterior elbow muscle originating on the lateral epicondyle of the humerus and inserting into the olecranon of the ulna; it extends the elbow joint.

Gracilis

A medial hip and thigh muscle originating on the inferior edge of the symphysis pubis and inserting into the proximomedial surface of the tibia; it adducts the thigh at the hip joint and flexes the leg at the knee joint.

Pectineus

A medial hip muscle originating on the pectineal line of the pubis and inserting distal to the lesser trochanter of the femur; it adducts and flexes the thigh at the hip joint.

Adductor longus

A medial hip muscle originating on the pubis below the pubic crest and inserting into the linea aspera of the femur; it adducts the thigh at the hip joint.

Adductor brevis

A medial hip muscle originating on the inferior ramus of the pubis and inserting into the linea aspera of the femur; it adducts the thigh at the hip joint.

Adductor magnus

A medial hip muscle originating on the inferior ramus of the ischium and inferior ramus of the pubis, inserting into the linea aspera and medial epicondyle of the femur; it adducts the thigh at the hip joint.

Sartorius

An anterior thigh muscle originating on the anterior superior iliac spine and inserting into the medial surface of the tibia; it flexes the leg and thigh, and abducts and rotates the thigh laterally.

Quadriceps femoris

A four-part anterior thigh muscle group (rectus femoris, vastus lateralis, vastus medialis, vastus intermedius) that inserts into the patella by a common tendon continuing as the patellar ligament to the tibial tuberosity; it extends the leg at the knee joint.

Rectus femoris

A quadriceps muscle originating on the anterior inferior iliac spine and inserting via the common tendon into the tibial tuberosity; it extends the leg at the knee joint.

Vastus lateralis

A quadriceps muscle originating inferior to the greater trochanter and linea aspera of the femur, inserting into the tibial tuberosity via the common tendon; it extends the leg at the knee joint.

Vastus medialis

A quadriceps muscle originating on the medial surface and linea aspera of the femur, inserting into the tibial tuberosity via the common tendon; it extends the leg at the knee joint.

Vastus intermedius

A quadriceps muscle originating on the anterior and lateral surfaces of the femur, inserting into the tibial tuberosity via the common tendon; it extends the leg at the knee joint.

Biceps femoris

A hamstring muscle with a long head originating from the ischial tuberosity and a short head from the linea aspera of the femur, inserting into the head of the fibula and proximolateral part of the tibia; it extends the thigh at the hip joint and flexes the leg at the knee joint.

Semitendinosus

A hamstring muscle originating on the ischial tuberosity and inserting into the proximomedial surface of the tibia; it extends the thigh at the hip joint and flexes the leg at the knee joint.

Semimembranosus

A hamstring muscle originating on the ischial tuberosity and inserting into the proximomedial surface of the tibia; it extends the thigh at the hip joint and flexes the leg at the knee joint.

Supinator

A forearm muscle originating on the lateral epicondyle of the humerus and crest of the ulna, inserting into the lateral surface of the radius; it supinates the forearm and hand.

Pronator teres

An anterior forearm muscle originating on the medial epicondyle of the humerus and inserting into the lateral surface of the radius; it pronates the forearm and hand.

Pronator quadratus

A deep anterior forearm muscle originating on the distal fourth of the ulna and inserting into the distal fourth of the radius; it pronates the forearm and hand.

Flexor carpi radialis

An anterior forearm muscle originating on the medial epicondyle of the humerus and inserting into the base of the second and third metacarpal bones; it flexes and abducts the wrist.

Palmaris longus

An anterior forearm muscle originating on the medial epicondyle of the humerus and inserting into the palmar aponeurosis; it flexes the wrist.

Flexor carpi ulnaris

An anterior forearm muscle originating on the medial epicondyle of the humerus and olecranon of the ulna, inserting into carpal and metacarpal bones; it flexes and adducts the wrist.

Flexor digitorum superficialis

An anterior forearm muscle originating on the medial epicondyle of the humerus and coronoid process of the ulna, inserting into the middle phalanges of digits II–V; it flexes the wrist and digits.

Flexor digitorum profundus

A deep anterior forearm muscle originating on the proximal two-thirds of the ulna and interosseous ligament, inserting into the distal phalanges of digits II–V; it flexes the wrist and digits.

Flexor pollicis longus

An anterior forearm muscle originating on the body of the radius and coronoid process of the ulna, inserting into the distal phalanx of the thumb; it flexes the joints of the thumb.

Extensor carpi radialis longus

A posterior forearm muscle originating on the lateral supracondylar ridge of the humerus and inserting into the second metacarpal bone; it extends and abducts the wrist.

Extensor carpi radialis brevis

A posterior forearm muscle originating on the lateral epicondyle of the humerus and inserting into the third metacarpal bone; it extends and abducts the wrist.

Extensor digitorum

A posterior forearm muscle originating on the lateral epicondyle of the humerus and inserting into the posterior surfaces of digits II–V; it extends the wrist and phalanges.

Extensor digiti minimi

A posterior forearm muscle originating on the lateral epicondyle of the humerus and inserting into the extensor aponeurosis of the fifth digit; it extends the joints of the fifth digit and wrist.

Extensor carpi ulnaris

A posterior forearm muscle originating on the lateral epicondyle of the humerus and olecranon of the ulna, inserting into the base of the fifth metacarpal bone; it extends and adducts the wrist.

Extensor pollicis longus

A posterior forearm muscle originating on the lateral and posterior surface of the ulna and inserting into the base of the distal phalanx of the thumb; it extends joints of the thumb and abducts joints of the hand.

Extensor pollicis brevis

A posterior forearm muscle originating on the distal body of the radius and interosseous ligament, inserting into the base of the proximal phalanx of the thumb; it extends joints of the thumb and abducts joints of the hand.

Abductor pollicis longus

A posterior forearm muscle originating on the distal radius, ulna, and interosseous ligament, inserting into the base of the first metacarpal bone; it abducts joints of the thumb and joints of the hand.

Frontalis

A muscle of facial expression originating from the galea aponeurotica and inserting into the skin of the eyebrow; it wrinkles the forehead and elevates the eyebrow.

Orbicularis oculi

A muscle of facial expression originating on the bones of the orbit and inserting into the tissue of the eyelid; it closes the eyes.

Nasalis

A muscle of facial expression originating on the maxilla and nasal cartilage and inserting into the aponeurosis of the nose; it compresses the nostrils.

Orbicularis oris

A muscle of facial expression originating on the maxilla and mandible and inserting into the lips; it closes and purses the lips.

Levator labii superioris

A muscle of facial expression originating on the upper maxilla and inserting into the orbicularis oris and skin above the lips; it elevates the upper lip.

Zygomaticus

A muscle of facial expression originating on the zygomatic bone and inserting into the superior corner of the orbicularis oris; it elevates the corner of the mouth.

Depressor labii inferioris

A muscle of facial expression originating on the mandible and inserting into the inferior corner of the orbicularis oris; it depresses the corner of the mouth.

Mentalis

A muscle of facial expression originating on the mandible and inserting into the skin of the lower lip; it elevates and protrudes the lower lip.

Buccinator

A cheek muscle originating on the maxilla and mandible and inserting into the orbicularis oris; it compresses the cheek.

Temporalis

A muscle of mastication originating in the temporal fossa and inserting into the coronoid process of the mandible; it elevates the mandible.

Masseter

A muscle of mastication originating on the zygomatic arch and inserting into the lateral ramus of the mandible; it elevates the mandible.

Medial pterygoid

A muscle of mastication originating on the sphenoid bone and inserting into the medial ramus of the mandible; it elevates and laterally moves the mandible.

Lateral pterygoid

A muscle of mastication originating on the sphenoid bone and inserting into the anterior side of the condylar process of the mandible; it protracts the mandible.

Sternocleidomastoid

A neck muscle originating on the sternum and clavicle, inserting into the mastoid process of the temporal bone; it flexes the neck and rotates the head to the side.

Digastric

A suprahyoid neck muscle originating on the inferior border of the mandible and mastoid process of the temporal bone, inserting into the hyoid bone; it depresses the mandible and elevates the hyoid bone.

Mylohyoid

A suprahyoid neck muscle originating on the inferior border of the mandible and inserting into the hyoid bone and median raphe; it elevates the hyoid bone and floor of the mouth.

Geniohyoid

A neck muscle originating on the medial surface of the mandible at the chin and inserting into the hyoid bone; it elevates the hyoid bone.

Stylohyoid

A neck muscle originating on the styloid process of the temporal bone and inserting into the hyoid bone; it elevates and retracts the tongue.

Sternohyoid

An infrahyoid neck muscle originating on the manubrium and inserting into the hyoid bone; it depresses the hyoid bone.

Sternothyroid

An infrahyoid neck muscle originating on the manubrium and inserting into the thyroid cartilage; it depresses the thyroid cartilage.

Thyrohyoid

A neck muscle originating on the thyroid cartilage and inserting into the hyoid bone; it depresses the hyoid bone and elevates the thyroid cartilage.

Omohyoid

An infrahyoid neck muscle originating on the superior border of the scapula and inserting into the hyoid bone; it depresses the hyoid bone.

Levator scapulae

A posterior back and neck muscle originating on C1–C4 and inserting into the superior border of the scapula; it elevates the scapula.

Trapezius

A large back and neck muscle originating on the cervical and thoracic vertebrae (C & T vertebrae) and inserting into the acromion and spine of the scapula; it elevates and retracts the scapula.

Rhomboid major

A back muscle originating on T2–T5 and inserting into the medial border of the scapula; it retracts the scapula.

Rhomboid minor

A back muscle originating on C7 and T1 and inserting into the medial border of the scapula; it retracts the scapula.

Erector spinae

A deep muscle group of the back originating from the sacrum, ilium, and lumbar vertebrae, inserting onto the occipital bone and cervical and thoracic vertebrae (C & T); it produces extension of the vertebral column.