Muscle Anatomy Flashcards

Flashcards for muscle anatomy review.

Pectoralis Major

Origin: Medial half of clavicle, manubrium & body of sternum, cartilages of first 6–7 ribs
Insertion: Crest of greater tubercle of humerus
Action: Flexion, medial rotation, horizontal adduction of shoulder; scapular protraction and depression
Innervation: Lateral pectoral nerve

Pectoralis Minor

Origin: Ribs 2–5
Insertion: Medial border of the coracoid process
Action: Downward rotation of scapula, scapular protraction and depression
Innervation: Medial pectoral nerve

Serratus Anterior

Origin: Ribs 1–8
Insertion: Medial border, costal surface of scapula
Action: Upward rotation of scapula, scapular protraction and depression
Innervation: Long thoracic nerve

Trapezius

Origin: Superior nuchal line and external occipital protuberance, ligamentum nuchae, spinous processes and supraspinous ligaments of C7 and all thoracic vertebrae
Insertion: Upper part: Lateral one third of the clavicle

Middle part: Acromion and upper lip of the spine of the scapula

Lower part: Spine of the scapula
Action: Upper fibers- Scapula elevation,

Middle fibers- Scapula Retraction

Lower fibers- Scapula Depression Upper and lower fibers-Upward rotation of scapula

Innervation: Cranial nerve XI (Spinal accessory nerve)

Rhomboid Major and Minor

Origin: Ligamentum nuchae and spinous processes of C7 to T5
Insertion: Medial border of scapula
Action: Adduction, elevation, and downward rotation of scapula
Innervation: Dorsal scapular nerve

Levator Scapulae

Origin: Transverse processes of C1–C4
Insertion: Medial border of scapula between superior angle and root of spine
Action: Scapular elevation and downward rotation
Innervation: Ventral rami of spinal nerves (C3–C4) and dorsal scapular nerve

Sternocleidomastoid

Origin: Manubrium and medial portion of clavicle
Insertion: Mastoid process of temporal bone
Action: Unilateral: same side flexion & opposite side rotation of neck
Innervation: Spinal accessory nerve (CN XI)

Latissimus Dorsi

Origin: Spinous processes of T7–T12, thoracolumbar fascia from lumbar and sacral vertebrae, last 3–4 ribs, and slip from inferior angle of scapula
Insertion: Intertubercular groove of humerus
Action: Medial rotation, adduction, and extension of shoulder joint
Innervation: Thoracodorsal nerve

Deltoid

Origin: Anterior: lateral clavicle; Middle: acromion; Posterior: spine of scapula
Insertion: Deltoid tuberosity of humerus
Action: Abduction at shoulder; anterior fibers: flex shoulder; posterior fibers: extend shoulder
Innervation: Axillary nerve

Teres Major

Origin: Inferior angle of scapula
Insertion: Crest of lesser tubercle of humerus
Action: Shoulder medial rotation, extension, adduction
Innervation: Lower subscapular nerve

Coracobrachialis

Origin: Coracoid process of scapula
Insertion: Medial aspect of middle shaft of humerus
Action: Flexion of arm
Innervation: Musculocutaneous nerve

Subscapularis

Origin: Subscapular fossa of scapula
Insertion: Lesser tubercle of humerus
Action: Medially rotate and adduct shoulder
Innervation: Upper and lower subscapular nerves

Supraspinatus

Origin: Supraspinatus fossa of scapula
Insertion: Upper facet of greater tubercle of humerus
Action: Shoulder abduction up to 15 degrees
Innervation: Suprascapular nerve

Infraspinatus

Origin: Infraspinatus fossa of scapula
Insertion: Middle facet of greater tubercle of humerus
Action: Lateral rotation at shoulder
Innervation: Suprascapular nerve

Teres Minor

Origin: Lateral border of scapula
Insertion: Lower facet of greater tubercle of humerus
Action: Lateral rotation at shoulder
Innervation: Axillary nerve

Long head of Biceps

Origin: Supraglenoid tubercle of scapula
Insertion: Bicipital tuberosity of the radius
Action: Flexion of elbow, supination of forearm, flexion of shoulder
Innervation: Musculocutaneous nerve

Short head of biceps

Origin: Coracoid process of scapula
Insertion: Bicipital tuberosity of the radius
Action: Flexion of elbow, supination of forearm, flexion of shoulder
Innervation: Musculocutaneous nerve

Brachialis

Origin: Distal anterior surface of humerus
Insertion: Coronoid process and tuberosity of proximal ulna
Action: Flex elbow
Innervation: Musculocutaneous nerve

Lateral Head of Triceps

Origin: Posterior humerus, superior and lateral to the radial groove
Insertion: Olecranon process of ulna
Action: Extend elbow and shoulder
Innervation: Radial nerve

Long Head of Triceps

Origin: Infraglenoid tubercle of scapula
Insertion: Olecranon process of ulna
Action: Extend elbow and shoulder
Innervation: Radial nerve

Medial Head of Triceps

Origin: Posterior humerus, inferior and medial to the radial groove
Insertion: Olecranon process of ulna
Action: Extend elbow and shoulder
Innervation: Radial nerve

Brachioradialis

Origin: Lateral supracondylar ridge of humerus
Insertion: Near styloid process of distal radius
Action: Elbow flexion (especially in mid-prone position)
Innervation: Radial nerve

Anconeus

Origin: Posterior lateral epicondyle of humerus
Insertion: Olecranon process and posterior ulna
Action: Weak elbow extensor
Innervation: Radial nerve

Extensor Carpi Radialis Longus and Brevis

Origin: Lateral epicondyle of humerus (common extensor origin)
Insertion:

• ECRL: Base of 2nd metacarpal

• ECRB: Base of 3rd metacarpal
  Action: Wrist extension and radial deviation
  Innervation: Radial nerve

Extensor Digitorum

Origin: Lateral epicondyle of humerus
Insertion: Extensor mechanism and dorsal base of proximal phalanges of fingers
Action: Extends MCP and IP joints of digits 2–5
Innervation: Radial nerve

Extensor Digiti Minimi

Origin: Ulnar side of the belly of the extensor digitorum
Insertion: Joins tendon of extensor digitorum to little finger
Action: Extends MCP and IP joints of little finger
Innervation: Radial nerve

Extensor Carpi Ulnaris

Origin: Lateral epicondyle of humerus
Insertion: Base of 5th metacarpal
Action: Wrist extension and ulnar deviation
Innervation: Radial nerve

Abductor Pollicis Longus

Origin: Posterior surface of middle radius, ulna, and interosseous membrane
Insertion: Base of 1st metacarpal
Action: Abduction and extension of thumb at CMC joint
Innervation: Radial nerve

Extensor Pollicis Brevis

Origin: Posterior radius and interosseous membrane
Insertion: Proximal phalanx of thumb
Action: Extension of thumb at MCP and IP joints
Innervation: Radial nerve

Extensor Pollicis Longus

Origin: Posterior ulna and interosseous membrane
Insertion: Distal phalanx of thumb
Action: Extension of thumb at MCP and IP joints
Innervation: Radial nerve

Extensor Indicis

Origin: Posterior ulna and interosseous membrane
Insertion: Joins index tendon of extensor digitorum
Action: Extension of 2nd digit and wrist
Innervation: Radial nerve

Supinator

Origin: Lateral epicondyle of humerus and supinator crest of ulna
Insertion: Lateral surface of proximal radius
Action: Supination of forearm
Innervation: Radial nerve

Pronator Teres

Origin:

• Humeral head: medial epicondyle

• Ulnar head: medial to the tuberosity of ulna
  Insertion: Lateral surface of middle radius
  Action: Pronation of forearm and elbow flexion
  Innervation: Median nerve

Flexor Carpi Radialis

Origin: Medial epicondyle of humerus
Insertion: Bases of 2nd and 3rd metacarpals
Action: Wrist flexion and radial deviation
Innervation: Median nerve

Palmaris Longus

Origin: Medial epicondyle of humerus
Insertion: Carpal ligament and palmar aponeurosis
Action: Flexion of wrist
Innervation: Median nerve

Flexor Carpi Ulnaris

Origin:

• Humeral head: medial epicondyle

• Ulnar head: posterior border of ulna
  Insertion: Pisiform, pisohamate and pisometacarpal ligaments, base of 5th metacarpal
  Action: Wrist flexion and ulnar deviation
  Innervation: Ulnar nerve

Flexor Digitorum Superficialis

Origin:

• Humeroulnar head: medial epicondyle and coronoid process

• Radial head: oblique line of radius
  Insertion: Sides of middle phalanges of fingers
  Action: Flexion at PIP joints of fingers
  Innervation: Median nerve

Flexor Pollicis Longus

Origin: Anterior radius and interosseous membrane
Insertion: Distal phalanx of thumb
Action: Flexion of distal phalanx of thumb
Innervation: Median nerve

Flexor Digitorum Profundus

Origin: Proximal 3/4 of ulna and interosseous membrane
Insertion: Distal phalanges of digits 2–5
Action: Flex wrist and all finger joints to DIP
Innervation:

• Medial half: Ulnar nerve

• Lateral half: Median nerve

Pronator Quadratus

Origin: Anterior surface of distal ulna
Insertion: Anterior surface of distal radius
Action: Pronation of forearm
Innervation: Median nerve

Abductor Pollicis Brevis

Origin: Palmar tubercles of trapezium and scaphoid
Insertion: Base of proximal phalanx of thumb
Action: Abduction of thumb at MCP and CMC joints
Innervation: Median nerve

Flexor Pollicis Brevis

Origin: Transverse carpal ligament and palmar tubercle of trapezium
Insertion: Radial side of proximal phalanx of thumb
Action: Flexion of thumb
Innervation: Median nerve

Opponens Pollicis

Origin: Transverse carpal ligament and palmar tubercle of trapezium
Insertion: Shaft of the thumb metacarpal
Action: Opposition of thumb
Innervation: Median nerve

Adductor Pollicis

Origin:

• Oblique head: Capitate and base of 2nd & 3rd metacarpals

• Transverse head: Palmar surface of 3rd metacarpal
  Insertion: Ulnar side of base of proximal phalanx of thumb
  Action: Adduction of thumb
  Innervation: Ulnar nerve

Abductor Digiti Minimi

Origin: Pisiform bone and tendon of flexor carpi ulnaris
Insertion: Base of proximal phalanx of little finger
Action: Abduction of little finger at MCP joint
Innervation: Ulnar nerve

Flexor Digiti Minimi

Origin: Hook of the hamate
Insertion: Base of proximal phalanx of little finger
Action: Flexion of little finger
Innervation: Ulnar nerve

Opponens Digiti Minimi

Origin: Transverse carpal ligament & hook of hamate
Insertion: Shaft of 5th metacarpal
Action: Flexion and lateral rotation of 5th metacarpal (opposition)
Innervation: Ulnar nerve

Lumbricals of the hand

Origin:

• 1st & 2nd: Radial surface of FDP tendons of index and middle fingers

• 3rd & 4th: Adjacent sides of FDP tendons of middle, ring, and little fingers
  Insertion: Radial border of extensor expansion on dorsum of digits
  Action: MCP flexion, IP extension
  Innervation:

• Lateral two: Median nerve

• Medial two: Ulnar nerve

Dorsal Interossei

Origin: Adjacent sides of metacarpals 1–5
Insertion:

• 1st: Radial side of index finger

• 2nd: Radial side of middle finger

• 3rd: Ulnar side of middle finger

• 4th: Ulnar side of ring finger
  Action: Abduction of digits 2–4, MCP flexion
  Innervation: Ulnar nerve

Palmar Interossei

Origin:

• 1st: Ulnar side of thumb metacarpal

• 2nd: Ulnar side of 2nd metacarpal

• 3rd: Radial side of 4th metacarpal

• 4th: Radial side of 5th metacarpal
  Insertion:

• 1st: Ulnar side of thumb

• 2nd: Ulnar side of index finger

• 3rd: Radial side of ring finger

• 4th: Radial side of little finger
  Action: Adduction of digits 2, 4, and 5; MCP flexion, IP extension
  Innervation: Ulnar nerve

External Intercostals

Origin: Lower border of rib
Insertion: Upper border of rib below
Action: Elevate ribs during inspiration
Innervation: Intercostal nerves

Internal Intercostals

Origin: Inner surface of a rib and costal cartilage
Insertion: Upper border of adjacent rib below
Action: Depress ribs during forced expiration
Innervation: Intercostal nerves

Transversus Thoracis

Origin: Inner surface of lower sternum and xiphoid process
Insertion: Internal surface of ribs 2–6 near sternocostal joints
Action: Depresses ribs
Innervation: Intercostal nerves

Quadratus Lumborum

Origin: Iliolumbar ligament and crest of ilium
Insertion: 12th rib and transverse processes of L1–L4
Action: Lumbar spine extension and side flexion, expiration
Innervation: Ventral rami of T12–L3

Psoas Major

Origin: Transverse processes and bodies of T12–L5 vertebrae
Insertion: Lesser trochanter of femur
Action: Lumbar spine flexion and lateral flexion, hip flexion
Innervation: Branches of ventral rami L1–L3

Iliacus

Origin: Upper two-thirds of iliac fossa and iliac crest
Insertion: Lesser trochanter of femur
Action: Hip flexion
Innervation: Femoral nerve

Rectus Abdominis

Origin: Pubic crest and anterior pubic ligament
Insertion: Cartilages of ribs 5–7 and xiphoid process
Action: Trunk flexion, posterior pelvic tilt, expiration
Innervation: Lower 6–7 thoracic nerves

External Oblique

Origin: Lateral sides of ribs 4–12
Insertion: Iliac crest, linea alba, and contralateral rectus sheath
Action:

• Bilateral: Trunk flexion and posterior tilt

• Unilateral: Lateral flexion, contralateral rotation
  Innervation: Lower 6 thoracic nerves

Internal Oblique

Origin: Iliac crest, inguinal ligament, thoracolumbar fascia
Insertion: Ribs 9–12, linea alba, contralateral rectus sheath
Action:

• Bilateral: Trunk flexion and posterior tilt

• Unilateral: Lateral flexion and ipsilateral rotation
  Innervation: Lower 6 thoracic nerves and first lumbar nerve

Transversus Abdominis

Origin: Iliac crest, thoracolumbar fascia, ribs 6–12 cartilage, inguinal ligament
Insertion: Linea alba
Action: Compresses abdominal cavity, stabilizes core
Innervation: Lower 6 thoracic nerves and first lumbar nerve

Rectus Femoris

Origin: Anterior inferior iliac spine (AIIS)
Insertion: Base of patella and via patellar tendon to tibial tuberosity
Action: Extends knee and flexes hip
Innervation: Femoral nerve

Vastus Lateralis

Origin: Intertrochanteric line, greater trochanter, gluteal tuberosity, lateral lip of linea aspera
Insertion: Lateral patella, via patellar tendon to tibial tuberosity
Action: Extends knee
Innervation: Femoral nerve

Vastus Medialis

Origin: Intertrochanteric line, medial lip of linea aspera, proximal medial supracondylar line
Insertion: Medial patella, via patellar tendon to tibial tuberosity
Action: Extends knee
Innervation: Femoral nerve

Vastus Intermedius

Origin: Anterior and lateral upper two-thirds of femoral shaft
Insertion: Base of patella, via patellar tendon to tibial tuberosity
Action: Extends knee
Innervation: Femoral nerve

Sartorius

Origin: Anterior superior iliac spine (ASIS)
Insertion: Medial surface of tibia (pes anserinus)
Action: Hip flexion, abduction, lateral rotation; knee flexion
Innervation: Femoral nerve

Pectineus

Origin: Pectineal line on superior pubic ramus
Insertion: Pectineal (spiral) line on posterior femur
Action: Hip flexion, adduction, medial rotation
Innervation: Femoral nerve

Adductor Longus

Origin: Body of pubis
Insertion: Middle third of linea aspera
Action: Hip adduction, flexion, medial rotation
Innervation: Obturator nerve

Adductor Brevis

Origin: Inferior pubic ramus
Insertion: Proximal third of linea aspera
Action: Hip adduction, flexion, medial rotation
Innervation: Obturator nerve

Adductor Magnus

Origin: Ischial ramus and ischial tuberosity
Insertion: Linea aspera and adductor tubercle of femur
Action: Hip adduction, extension, medial rotation
Innervation: Obturator nerve and tibial portion of sciatic nerve

Gracilis

Origin: Inferior pubic ramus and body of pubis
Insertion: Medial surface of tibia (pes anserinus)
Action: Hip flexion, adduction, medial rotation; knee flexion
Innervation: Obturator nerve

Gluteus Maximus

Origin: Outer ilium, posterior gluteal line, thoracolumbar fascia, sacrum, coccyx
Insertion: Gluteal tuberosity and iliotibial band
Action: Hip extension and external rotation; secondary action: hip adduction
Innervation: Inferior gluteal nerve

Gluteus Medius And Gluteus Minimus

Origin: Outer surface of ilium
Insertion: Greater trochanter of femur
Action: Abduction of hip; assists in medial and lateral rotation
Innervation: Superior gluteal nerve

Tensor Fasciae Latae

Origin: Iliac crest and ASIS
Insertion: Proximal one-third of iliotibial band
Action: Flexes, abducts, medially rotates hip
Innervation: Superior gluteal nerve

Piriformis

Origin: Anterior surface of sacrum
Insertion: Apex of greater trochanter
Action: Lateral rotation of hip
Innervation: Nerve to piriformis

Biceps Femoris

Origin:

• Long head: ischial tuberosity

• Short head: lateral lip of linea aspera
  Insertion: Fibular head
  Action: Knee flexion, hip extension
  Innervation: Sciatic nerve

Semimembranosus

Origin: Ischial tuberosity
Insertion: Medial condyle of tibia
Action: Knee flexion, hip extension
Innervation: Sciatic nerve

Semitendinosus

Origin: Ischial tuberosity
Insertion: Medial surface of tibia (pes anserinus)
Action: Knee flexion, hip extension
Innervation: Sciatic nerve

Tibialis Anterior

Origin: Lateral condyle and proximal two-thirds of lateral tibia, interosseous membrane
Insertion: Medial cuneiform and base of 1st metatarsal
Action: Dorsiflexion and inversion of foot
Innervation: Deep peroneal (fibular) nerve

Extensor Digitorum Longus

Origin: Lateral condyle of tibia, medial surface of fibula, interosseous membrane
Insertion: Dorsal base of middle and distal phalanges of toes 2–5 via extensor expansion
Action: Toe extension, ankle dorsiflexion, eversion
Innervation: Deep peroneal nerve

Extensor Hallucis Longus

Muscle: Extensor Hallucis Longus
Origin: Medial surface of fibula and interosseous membrane
Insertion: Distal phalanx of great toe
Action: Extension of great toe, dorsiflexion, inversion
Innervation: Deep peroneal nerve

Peroneus Tertius

Origin: Distal third of fibula and interosseous membrane
Insertion: Base of 5th metatarsal
Action: Dorsiflexion and eversion
Innervation: Deep peroneal nerve

Peroneus Longus

Origin: Lateral condyle of tibia; head and proximal two-thirds of fibula
Insertion: Lateral surface of medial cuneiform and base of 1st metatarsal
Action: Plantarflexion and eversion
Innervation: Superficial peroneal nerve

Peroneus Brevis

Origin: Lateral surface of fibula
Insertion: Styloid process of 5th metatarsal
Action: Plantarflexion and eversion
Innervation: Superficial peroneal nerve

Gastrocnemius

Origin: Posterior femoral condyles
Insertion: Calcaneal tuberosity via Achilles tendon
Action: Plantarflexion and knee flexion
Innervation: Tibial nerve

Soleus

Origin: Posterior fibular head and shaft, posterior tibia
Insertion: Calcaneal tuberosity via Achilles tendon
Action: Plantarflexion
Innervation: Tibial nerve

Plantaris

Origin: Lateral supracondylar line of femur
Insertion: Medial aspect of Achilles tendon
Action: Weak knee flexion, plantarflexion
Innervation: Tibial nerve

Popliteus

Origin: Lateral condyle of femur
Insertion: Posterior surface of tibia
Action: Knee flexion and internal rotation
Innervation: Tibial nerve

Flexor Digitorum Longus

Origin: Posterior surface of tibia
Insertion: Distal phalanges of toes 2–5
Action: Flexion of toes 2–5, plantarflexion, inversion
Innervation: Tibial nerve

Flexor Hallucis Longus

Origin: Posterior fibula
Insertion: Distal phalanx of great toe
Action: Flexion of great toe, plantarflexion, inversion
Innervation: Tibial nerve

Tibialis Posterior

Origin: Posterior tibia, fibula, and interosseous membrane
Insertion: Navicular tuberosity and all tarsals except talus
Action: Plantarflexion and inversion
Innervation: Tibial nerve

Abductor Hallucis

Layer: 1st layer
Action: Abducts the big toe
Nerve: Medial plantar nerve

Flexor Digitorum Brevis

Layer: 1st layer
Action: 2-4 toe Flextion
Nerve: Medial plantar nerve

Abductor Digiti Minimi

Layer: 1st layer
Action: 5th Toe abduction and flexion
Nerve: Lateral plantar

Quadratus Plantae

Layer: 2nd layer
Action: Flexion of toes
Nerve: Lateral plantar

Lumbricals

Layer: 2nd layer
Action: MTP flexion, IP extension
Nerve: Toe 2: Medial plantar

Toe 3-5: Lateral plantar

Flexor Hallucis Brevis

Layer: 3rd layer
Action: Flexes big toe
Nerve: Medial plantar nerve

Adductor Hallucis

Layer: 3rd layer
Action: Abducts the big toe
Nerve: Lateral plantar

Flexor Digiti Minimi

Layer: 3rd layer
Action: Flexion of little toe
Nerve: Lateral plantar

Dorsal Interossei

Layer: 4th layer
Action: Adduction of 2-4 toes, Flexion at MTP joints
Nerve: Lateral plantar

Plantar Interossei

Layer: 4th layer
Action: Adduction of 3-5 toes, Flexion at MTP joints
Nerve: Lateral plantar