Human Muscular System: Origin, Insertion, and Action Review

Comprehensive vocabulary flashcards detailing the origin, insertion, and action of human axial and appendicular muscles for Exam 2 preparation.

Origin (O)

Usually the more stationary attachment of a muscle.

Insertion (I)

Usually the attachment that moves when the muscle contracts.

Action (A)

The movement produced by the contraction of a muscle.

Occipitalis

Origin: Occipital bone and mastoid region; Insertion: Epicranial aponeurosis; Action: Pulls scalp backward.

Frontalis

Origin: Epicranial aponeurosis; Insertion: Skin of eyebrows and forehead; Action: Raises eyebrows.

Corrugator supercilii

Origin: Medial end of superciliary arch; Insertion: Skin of eyebrow; Action: Draws eyebrows together and downward.

Orbicularis oculi

Origin: Medial orbital margin; Insertion: Skin around eyelids; Action: Closes eyes.

Orbicularis oris

Origin: Maxilla, mandible, and surrounding facial muscles; Insertion: Skin and muscle around lips; Action: Closes and puckers lips.

Buccinator

Origin: Maxilla, mandible, and pterygomandibular raphe; Insertion: Orbicularis oris; Action: Compresses cheeks.

Zygomaticus

Origin: Zygomatic bone; Insertion: Corner of mouth; Action: Raises corners of mouth (smiling).

Platysma

Origin: Fascia over upper chest and shoulder; Insertion: Mandible and skin of lower face; Action: Tenses neck; depresses lower lip and jaw.

Risorius

Origin: Fascia over masseter and parotid gland; Insertion: Corner of mouth; Action: Pulls mouth laterally.

Levator labii superioris

Origin: Maxilla, below orbit; Insertion: Upper lip; Action: Raises upper lip.

Depressor labii inferioris

Origin: Mandible; Insertion: Lower lip; Action: Pulls lower lip downward.

Masseter

Origin: Zygomatic arch; Insertion: Angle and ramus of mandible; Action: Elevates mandible; closes jaw.

Temporalis

Origin: Temporal fossa; Insertion: Coronoid process of mandible; Action: Elevates and retracts mandible.

Medial pterygoid

Origin: Medial surface of lateral pterygoid plate and maxilla; Insertion: Medial surface of mandibular angle; Action: Elevates and protrudes mandible.

Lateral pterygoid

Origin: Greater wing of sphenoid and lateral pterygoid plate; Insertion: Neck of mandible and TMJ articular disc; Action: Protracts and helps depress mandible; side-to-side movement.

Genioglossus

Origin: Superior mental spine of mandible; Insertion: Tongue and hyoid bone; Action: Protrudes and depresses tongue.

Hyoglossus

Origin: Body and greater horn of hyoid; Insertion: Side of tongue; Action: Depresses and retracts tongue.

Styloglossus

Origin: Styloid process of temporal bone; Insertion: Side of tongue; Action: Retracts and elevates tongue.

Sternocleidomastoid

Origin: Manubrium of sternum and medial clavicle; Insertion: Mastoid process and superior nuchal line; Action: Flexes neck; rotates head to opposite side.

Scalenes (anterior, middle, posterior)

Origin: Transverse processes of cervical vertebrae; Insertion: First and second ribs; Action: Laterally flex neck; elevate ribs during inspiration.

Splenius capitis

Origin: Nuchal ligament and spinous processes C7–T3/T4; Insertion: Mastoid process and superior nuchal line; Action: Extends head; rotates and laterally flexes head to same side.

Splenius cervicis

Origin: Spinous processes T3–T6; Insertion: Transverse processes C1–C3/C4; Action: Extends and rotates neck to same side.

Iliocostalis

Origin: Common erector spinae tendon from sacrum and iliac crest; Insertion: Angles of ribs and cervical transverse processes; Action: Extends and laterally flexes vertebral column.

Longissimus

Origin: Common erector spinae tendon and lumbar transverse processes; Insertion: Ribs, thoracic/cervical transverse processes, and mastoid process; Action: Extends and laterally flexes vertebral column.

Spinalis

Origin: Spinous processes of lower thoracic and upper lumbar vertebrae; Insertion: Spinous processes of upper thoracic and cervical vertebrae; Action: Extends vertebral column.

Quadratus lumborum

Origin: Iliac crest and iliolumbar ligament; Insertion: 12th rib and transverse processes L1–L4; Action: Laterally flexes lumbar spine; stabilizes 12th rib.

External intercostals

Origin: Inferior border of rib above; Insertion: Superior border of rib below; Action: Elevates ribs during inspiration.

Internal intercostals

Origin: Inferior border of rib above; Insertion: Superior border of rib below; Action: Primarily depresses ribs during forced expiration.

Thoracic diaphragm

Origin: Xiphoid process, lower six ribs/costal cartilages, and lumbar vertebrae through crura; Insertion: Central tendon; Action: Contracts to increase thoracic cavity volume; inspiration.

Rectus abdominis

Origin: Pubic crest and pubic symphysis; Insertion: Xiphoid process and costal cartilages 5–7; Action: Flexes trunk; compresses abdomen.

External oblique

Origin: Ribs 5–12; Insertion: Linea alba, pubic tubercle, and iliac crest; Action: Rotates trunk to opposite side; compresses abdomen.

Internal oblique

Origin: Thoracolumbar fascia, iliac crest, and inguinal ligament; Insertion: Ribs 10–12, linea alba, and pubis; Action: Rotates trunk to same side; compresses abdomen.

Transversus abdominis

Origin: Lower costal cartilages, thoracolumbar fascia, iliac crest, and inguinal ligament; Insertion: Linea alba and pubis; Action: Compresses abdominal contents.

Trapezius

Origin: Occipital bone, nuchal ligament, and spinous processes C7–T12; Insertion: Clavicle, acromion, and spine of scapula; Action: Elevates, retracts, depresses, and upwardly rotates scapula.

Levator scapulae

Origin: Transverse processes C1–C4; Insertion: Superior medial border of scapula; Action: Elevates scapula.

Rhomboid major

Origin: Spinous processes T2–T5; Insertion: Medial border of scapula; Action: Retracts and downwardly rotates scapula.

Rhomboid minor

Origin: Nuchal ligament and spinous processes C7–T1; Insertion: Medial border of scapula near scapular spine; Action: Retracts and downwardly rotates scapula.

Serratus anterior

Origin: Ribs 1–8/9; Insertion: Anterior surface of medial scapular border; Action: Protracts and upwardly rotates scapula.

Pectoralis minor

Origin: Ribs 3–5; Insertion: Coracoid process of scapula; Action: Protracts and depresses scapula.

Pectoralis major

Origin: Clavicle, sternum, and costal cartilages 1–6; Insertion: Lateral lip of intertubercular sulcus of humerus; Action: Flexes, adducts, and medially rotates arm.

Deltoid

Origin: Lateral clavicle, acromion, and spine of scapula; Insertion: Deltoid tuberosity of humerus; Action: Abducts arm; anterior fibers flex, posterior fibers extend.

Supraspinatus

Origin: Supraspinous fossa of scapula; Insertion: Greater tubercle of humerus; Action: Initiates arm abduction.

Latissimus dorsi

Origin: Lower thoracic vertebrae, thoracolumbar fascia, iliac crest, and lower ribs; Insertion: Floor of intertubercular sulcus of humerus; Action: Extends, adducts, and medially rotates arm.

Teres major

Origin: Posterior inferior angle of scapula; Insertion: Medial lip of intertubercular sulcus of humerus; Action: Extends, adducts, and medially rotates arm.

Biceps brachii

Origin: Supraglenoid tubercle (long head); coracoid process (short head); Insertion: Radial tuberosity and bicipital aponeurosis; Action: Flexes elbow and supinates forearm.

Brachialis

Origin: Anterior distal half of humerus; Insertion: Coronoid process and ulnar tuberosity; Action: Flexes elbow.

Triceps brachii

Origin: Infraglenoid tubercle (long head); posterior humerus (lateral and medial heads); Insertion: Olecranon process of ulna; Action: Extends elbow.

Flexor carpi radialis

Origin: Medial epicondyle of humerus; Insertion: Bases of metacarpals 2–3; Action: Flexes and abducts wrist.

Palmaris longus

Origin: Medial epicondyle of humerus; Insertion: Palmar aponeurosis and flexor retinaculum; Action: Flexes wrist; tenses palmar aponeurosis.

Flexor carpi ulnaris

Origin: Medial epicondyle, olecranon, and posterior ulna; Insertion: Pisiform, hook of hamate, and base of fifth metacarpal; Action: Flexes and adducts wrist.

Flexor digitorum superficialis

Origin: Medial epicondyle, coronoid process, and radius; Insertion: Middle phalanges of fingers 2–5; Action: Flexes fingers at proximal interphalangeal joints.

Flexor digitorum profundus

Origin: Anterior/medial ulna and interosseous membrane; Insertion: Distal phalanges of fingers 2–5; Action: Flexes fingers at distal interphalangeal joints.

Flexor pollicis longus

Origin: Anterior radius and interosseous membrane; Insertion: Distal phalanx of thumb; Action: Flexes thumb.

Extensor carpi radialis

Origin: Lateral supracondylar ridge (longus); lateral epicondyle (brevis); Insertion: Bases of metacarpals 2 and 3; Action: Extends and abducts wrist.

Extensor carpi ulnaris

Origin: Lateral epicondyle and posterior ulna; Insertion: Base of fifth metacarpal; Action: Extends and adducts wrist.

Extensor digitorum

Origin: Lateral epicondyle of humerus; Insertion: Extensor expansions of fingers 2–5; Action: Extends fingers 2–5.

Extensor digiti minimi

Origin: Lateral epicondyle of humerus; Insertion: Extensor expansion of fifth finger; Action: Extends little finger.

Extensor indicis

Origin: Posterior ulna and interosseous membrane; Insertion: Extensor expansion of index finger; Action: Extends index finger.

Abductor pollicis longus

Origin: Posterior radius, ulna, and interosseous membrane; Insertion: Base of first metacarpal; Action: Abducts and assists extension of thumb.

Abductor pollicis brevis

Origin: Flexor retinaculum and carpal bones; Insertion: Base of proximal phalanx of thumb; Action: Abducts thumb.

Extensor pollicis longus

Origin: Posterior ulna and interosseous membrane; Insertion: Distal phalanx of thumb; Action: Extends thumb.

Extensor pollicis brevis

Origin: Posterior radius and interosseous membrane; Insertion: Proximal phalanx of thumb; Action: Extends thumb.

Iliopsoas (iliacus and psoas major)

Origin: Iliac fossa (iliacus); bodies, discs, and transverse processes of T12–L5 (psoas major); Insertion: Lesser trochanter of femur; Action: Flexes thigh at hip; assists trunk flexion.

Gluteus maximus

Origin: Posterior ilium, sacrum, and coccyx; Insertion: Gluteal tuberosity and iliotibial tract; Action: Extends and laterally rotates thigh.

Gluteus medius

Origin: Lateral surface of ilium; Insertion: Greater trochanter of femur; Action: Abducts and medially rotates thigh; stabilizes pelvis.

Gluteus minimus

Origin: Lateral surface of ilium; Insertion: Greater trochanter of femur; Action: Abducts and medially rotates thigh.

Tensor fasciae latae

Origin: ASIS and anterior iliac crest; Insertion: Iliotibial tract, continuing to lateral tibia; Action: Flexes, abducts, and medially rotates thigh.

Pectineus

Origin: Superior ramus of pubis; Insertion: Pectineal line of femur; Action: Adducts and flexes thigh.

Adductor brevis

Origin: Body and inferior ramus of pubis; Insertion: Pectineal line and proximal linea aspera; Action: Adducts and assists flexion of thigh.

Adductor longus

Origin: Body of pubis; Insertion: Middle linea aspera; Action: Adducts and assists flexion of thigh.

Adductor magnus

Origin: Inferior pubic ramus, ischial ramus, and ischial tuberosity; Insertion: Linea aspera and adductor tubercle; Action: Adducts thigh; assists flexion and extension.

Rectus femoris

Origin: AIIS and superior acetabular rim; Insertion: Patella and tibial tuberosity through patellar ligament; Action: Extends knee; flexes hip.

Vastus lateralis

Origin: Greater trochanter and linea aspera; Insertion: Patella and tibial tuberosity through patellar ligament; Action: Extends knee.

Vastus medialis

Origin: Intertrochanteric line and linea aspera; Insertion: Patella and tibial tuberosity through patellar ligament; Action: Extends knee; stabilizes patella.

Vastus intermedius

Origin: Anterior and lateral shaft of femur; Insertion: Patella and tibial tuberosity through patellar ligament; Action: Extends knee.

Biceps femoris

Origin: Ischial tuberosity (long head); linea aspera (short head); Insertion: Head of fibula; Action: Flexes knee; long head extends hip; laterally rotates leg.

Semitendinosus

Origin: Ischial tuberosity; Insertion: Medial proximal tibia; Action: Flexes knee; extends hip; medially rotates leg.

Semimembranosus

Origin: Ischial tuberosity; Insertion: Medial condyle of tibia; Action: Flexes knee; extends hip; medially rotates leg.

Tibialis anterior

Origin: Lateral condyle and upper lateral tibia; interosseous membrane; Insertion: Medial cuneiform and base of first metatarsal; Action: Dorsiflexes and inverts foot.

Extensor digitorum longus

Origin: Lateral tibial condyle, anterior fibula, and interosseous membrane; Insertion: Middle and distal phalanges of toes 2–5; Action: Extends toes; dorsiflexes foot.

Fibularis longus

Origin: Head and upper lateral fibula; Insertion: Base of first metatarsal and medial cuneiform; Action: Everts and plantar flexes foot.

Fibularis brevis

Origin: Lower lateral fibula; Insertion: Base of fifth metatarsal; Action: Everts and plantar flexes foot.

Gastrocnemius

Origin: Medial and lateral femoral condyles; Insertion: Calcaneus through calcaneal (Achilles) tendon; Action: Plantar flexes foot; flexes knee.

Soleus

Origin: Posterior tibia and fibula; Insertion: Calcaneus through calcaneal tendon; Action: Plantar flexes foot.

Plantaris

Origin: Lateral supracondylar line of femur; Insertion: Calcaneus, usually through calcaneal tendon; Action: Weakly plantar flexes foot and flexes knee.

Flexor digitorum longus

Origin: Posterior tibia; Insertion: Distal phalanges of toes 2–5; Action: Flexes toes; plantar flexes foot.