Comprehensive Muscle Anatomy: Upper Limb, Lower Limb, Head, Neck, and Thorax

Vocabulary practice flashcards detailing origins, insertions, and actions for upper limb, lower limb, head, neck, thoracic, and abdominal muscles.

Deltoid

An upper limb muscle originating at the acromion and spine of scapula, and clavicle; inserting into the deltoid tuberosity of the humerus. Actions: flex and medially rotate arm, abduct arm, extends and laterally rotates humerus, anterior position flexes the shoulder, and posterior portion extends the shoulder.

Biceps brachii

An upper limb muscle originating at the glenoid cavity or coracoid process of scapula, and intertubercular sulcus of humerus; inserting into the radial tuberosity. Actions: flexes arm, flexes and supinates forearm, slight shoulder flexion, stabilizes shoulder by holding humeral head in glenoid cavity.

Brachioradialis

An upper limb muscle originating at the lateral ridge and distal end of the humerus; inserting into the base of the styloid process of radius. Actions: flexes forearm and flexes elbow.

Teres major

An upper limb muscle originating at the inferior angle of the scapula; inserting into the intertubercular sulcus and lesser tubercle of the humerus. Actions: extends and medially rotates humerus, rotates and adducts arm, and produces extension, adduction, and medial rotation at shoulder.

Triceps brachii

An upper limb muscle originating at the glenoid cavity of scapula and posterior or lateral surface of the humerus; inserting into the olecranon of ulna, fascia of forearm, and tuberosity of ulna. Actions: extends elbow, adducts humerus, extends and adducts arm, extends forearm, and adduction at shoulder.

Supraspinatus

A rotator cuff muscle originating at the supraspinous fossa of scapula; inserting into the greater tubercle of humerus. Actions: aids in abduction of arm, resists downward slippage of humeral head when arm is relaxed, helps stabilize shoulder joint, and performs abduction at shoulder.

Infraspinatus

A rotator cuff muscle originating at the infraspinous fossa of scapula; inserting into the greater tubercle of humerus. Actions: laterally rotates arm/humerus, prevents humeral head from sliding upward, and helps stabilize shoulder joint.

Teres minor

A rotator cuff muscle originating at the lateral border of the scapula; inserting into the greater tubercle of humerus and posterior surface of shoulder joint capsule. Actions: laterally rotates arm/humerus, prevents humeral head from sliding upward, and helps stabilize shoulder joint.

Subscapularis

A rotator cuff muscle originating at the subscapular fossa of scapula; inserting into the lesser tubercle of humerus and anterior surface of shoulder joint capsule. Actions: medially rotates arm/humerus, prevents humeral head from sliding upward, and helps stabilize shoulder joint.

Biceps femoris

A lower limb muscle originating at the ischial tuberosity and linea aspera of femur; inserting into the head of fibula. Actions: flexes knee, extends hip/thigh, laterally rotates tibia on femur when knee is flexed, laterally rotates femur when hip is extended, and counteracts forward bending at hips.

Semitendinosus

A lower limb muscle originating at the ischial tuberosity; inserting into the proximal, medial tibia. Actions: flexes knee, extends thigh, medially rotates tibia on femur when knee is flexed, medially rotates femur when hip is extended, and counteracts forward bending at hips.

Semimembranosus

A lower limb muscle originating at the ischial tuberosity; inserting into the medial condyle of tibia. Actions: flexes knee, extends thigh, medially rotates tibia on femur when knee is flexed, medially rotates femur when hip is extended, and counteracts forward bending at hips.

Iliopsoas

A muscle combination composed of Iliacus (origin: iliac crest and fossa, superolateral sacrum, anterior sacroiliac and iliolumbar ligaments) and Psoas major (origin: transverse processes, bodies, and intervertebral discs of thoracic 12 to lumbar 5 vertebrae); inserting into the lesser trochanter and shaft of femur. Actions: flexes thigh at hip when trunk is fixed, flexes trunk at hip when thigh is fixed, lateral flexion of vertebral column (psoas), and flexes thigh and lumbar vertebrae.

Rectus femoris

A quadriceps femoris muscle originating at the spine of ilium, acetabulum of coxal bone, and anterior inferior iliac spine; inserting into the patella, tibial tuberosity, and lateral and medial condyles of tibia. Actions: flexes thigh, extends leg, extends knee, and flexes trunk on hip if thigh is fixed.

Vastus intermedius

A quadriceps femoris muscle originating at the greater trochanter, linea aspera, anterior and lateral surface, and proximal shaft of femur; inserting into the patella, tibial tuberosity, and lateral and medial condyles of tibia. Actions: extends knee and extends leg.

Vastus lateralis

A quadriceps femoris muscle originating at the greater trochanter, linea aspera, and gluteal tuberosity of femur; inserting into the patella, tibial tuberosity, and lateral and medial condyles of tibia. Actions: extends leg, extends knee, and retains patella in groove on femur during movement.

Vastus medialis

A quadriceps femoris muscle originating at the greater trochanter and linea aspera of femur; inserting into the patella, tibial tuberosity, and lateral and medial condyles of tibia. Actions: extends leg and extends knee.

Gluteus maximus

A lower limb muscle originating at the outer iliac surface, iliac crest, superior spine of ilium, sacrum, and coccyx; inserting into the gluteal tuberosity of femur and lateral condyle of tibia via iliotibial tract. Actions: extends and abducts thigh, extends thigh at hip, elevates trunk after stooping, prevents trunk from pitching forward when running, and stabilizes femur on tibia.

Gastrocnemius

A lower limb muscle originating at the medial and lateral condyles of femur, popliteal surface of femur, and capsule of knee joint; inserting into the calcaneus via calcaneal tendon. Actions: plantar flexion, flexes leg, and flexes knee.

Tibialis anterior

A lower limb muscle originating at the lateral condyle of tibia, proximal tibia, and interosseous membrane; inserting into metatarsal I and medial cuneiform. Actions: dorsiflexes and inverts foot, and helps support medial longitudinal arch of foot.

Brachialis

An upper limb muscle whose action is to flex forearm; it serves as the prime mover of elbow flexion.

Extensor digitorum

An upper limb muscle whose actions are to extend wrist, spread digits apart, finger extension, and extend hand.

Palmaris longus

An upper limb muscle whose actions are to anchor skin and fascia of the palmar region and weakly flex hand.

Flexor carpi ulnaris

An upper limb muscle whose actions are to flex and adduct wrist, flex wrist anteriorly, aid in ulnar flexion of wrist, and flex and adduct hand.

Extensor carpi radialis longus

An upper limb muscle whose action is extension and abduction at wrist.

Extensor carpi radialis brevis

An upper limb muscle whose action is extension and abduction at wrist.

Pronator teres

An upper limb muscle whose actions are pronation and flexion of forearm.

Sartorius

A lower limb muscle whose actions are knee and hip flexion, abducting and laterally rotating thigh, flexing thigh, and flexing leg.

Piriformis

A lower limb muscle whose action is lateral rotation and abduction at hip.

Extensor digitorum longus

A lower limb muscle whose actions are to extend toes, dorsiflex foot, and tauten plantar aponeurosis.

Gracilis

A lower limb muscle whose actions are to flex and medially rotate tibia at knee, flex and medially rotate leg, and adduct thigh.

Soleus

A lower limb muscle whose actions are plantar flexion and steadying the leg on the ankle during standing.

Iliotibial tract

A non-muscle lower limb structure whose action is the stabilization of hip and knee in extension and in partial flexion.

Calcaneal tendon

A non-muscle lower limb structure whose action is plantar flexion.

Masseter

A muscle of the head originating at the zygomatic arch; inserting into the angle or ramus of mandible. Action: elevates or closes mandible.

Sternocleidomastoid

A muscle originating at the manubrium of sternum and clavicle; inserting into the mastoid process of temporal bone. Actions: abducts, rotates, or flexes head; each laterally flexes neck to the same side and rotates head to the opposite side; together they pull the head forward and down; can aid in forceful inhalation by elevating sternum and first ribs.

Temporalis

A muscle of the head originating at the temporal fossa; inserting into the coronoid process or ramus of mandible. Action: elevates or closes mandible.

Trapezius

A muscle originating at the posterior occipital bone or nuchal ligament, and spinous processes of cervical 7 to thoracic 12; inserting into the clavicle, acromion, or spine of scapula. Actions: extends head, abducts hand, rotates or adducts scapula, fixes scapula; superior portion elevates scapula; inferior portion depresses scapula.

Latissimus dorsi

A muscle originating at the spinous processes of thoracic 7-12, lumbar 1-5, iliac crest, and ribs 10-12; inserting into the intertubercular sulcus of humerus. Actions: extends, adducts, medially rotates humerus; draws shoulder inferiorly; extends the shoulder joint.

Pectoralis major

A muscle originating at the clavicle, sternum, costal cartilage of ribs 1-7, and aponeurosis of external oblique; inserting into the intertubercular sulcus of humerus. Actions: flexes, adducts, and medially rotates humerus.

Pectoralis minor

A thoracic muscle originating at ribs 3-5; inserting into the coracoid process of scapula. Actions: depresses glenoid cavity of scapula, draws scapula laterally forward, depresses apex of shoulder, and elevates ribs during forceful inhalation.

Rectus abdominis

An abdominal muscle originating at the pubic crest and pubic symphysis; inserting into costal cartilage 5-7 or xiphoid process of sternum. Actions: flexes spine, compresses abdominal wall, flexes waist in bending forward, and stabilizes pelvic region during walking.

Zygomaticus major

A facial muscle originating at the zygomatic bone; inserting into the superolateral angle of mouth or muscles of upper lip. Action: elevates corner of mouth as in smiling and laughing.

Buccinator

A facial muscle whose action is to compress the cheek.

Occipitofrontalis/Epicranius

A scalp muscle consisting of two bellies: the frontal belly raises eyebrows and draws scalp anteriorly; the occipital belly retracts scalp.

Mentalis

A facial muscle whose actions are to protrude the lower lip and elevate and wrinkle skin on chin.

Orbicularis oris

A facial muscle whose actions are to close lips and protrude lips as in kissing.

Orbicularis oculi

A facial muscle whose actions are to close eyelids as in blinking and aid in the flow of tears across eye.

Diaphragm

A thoracic muscle whose actions are inspiration; contracting for sneezing, coughing, crying, laughing, and weightlifting; and compressing abdominal viscera for childbirth and expulsion of urine and feces.

External intercostals

Thoracic muscles whose actions are to elevate ribs, increase volume in thorax, and provide a braking action during expiration so it is not abrupt.

Internal intercostals

Thoracic muscles whose actions are to elevate ribs, depress ribs during forced expiration, and compress the thoracic cavity.

External oblique

An abdominal muscle whose actions are to compress abdominal wall, laterally rotate waist, support abdominal viscera, and flex and rotate vertebral column.

Internal oblique

An abdominal muscle whose actions are to compress abdominal wall, laterally rotate waist, and flex and rotate vertebral column.

Serratus anterior

A muscle whose actions are to abduct and rotate scapula, draw scapula laterally and forward, protract scapula, and flex scapula during abduction of arm.

Transversus abdominis

An abdominal muscle whose actions are to compress abdominal wall, laterally rotate waist, and flex and rotate vertebral column.

Zygomaticus minor

A facial muscle whose action is to elevate the corner of the mouth as in smiling and laughing.