Muscle origin insertion



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Muscles of The Shoulder


MUSCLE

ORIGIN

INSERTION

NERVE

ACTION

Deltoid

Lateral third of clavicle, acromion, and spine of scapula


Deltoid tuberosity of humerus

Axillary

Abducts, adducts, flexes, extends and rotates arm medially


Supraspinatus

Supraspinatus fossa of scapula

Superior facet of greater tubercle of humerus


Suprascapular

Abducts arm

Infraspinatus

Infraspinous fossa

Middle facet of greater tubercle of humerus


Suprascapular

Rotates arm laterally

Subscapularis

Subscapular fossa

Lesser tubercle of humerus


Upper and lower subscapular

Rotates arm medially

Teres major

Dorsal surface of inferior angle of scapula

Medial lip of intertubercular groove of humerus


Lower subscapular

Adducts and rotates arm medially

Teres minor

Upper portion of lateral border of scapular


Lower facet of greater tubercle of humerus

Axillary

Rotates arm laterally

Muscles of the Arm



MUSCLE

PROXIMAL

DISTAL

NERVE

ACTION

Coracobrachialis

Coracoid process

Middle third of medial surface of humerus


Musculocutaneous

Flexes and adducts arm

Biceps brachii

Long head, supraglenoid tubercle; short head, coracoid process


Radial tuberosity of radius

Musculocutaneous

Flexes arm and forearm, supinates forearm

Brachialis

Lower anterior surface of humerus

Coronoid process of ulna and ulnar tuberosity


Musculocutaneous


Flexes forearm

Triceps

Long head, infraglenoid tubercle, lateral head, superior to radial groove of humerus; medial head, inferior to radial groove


Posterior surface of olecranon process of ulna

Radial

Extends forearm

Aconeus

Lateral epicondyle of humerus

Olecranon and upper posterior surface of ulna

Radial

Extends forearm

(Elbow joint stabilizer)



Muscles of the Anterior Forearm




MUSCLE

PROXIMAL

DISTAL

NERVE

ACTION

Pronator teres

Medial epicondyle and coronoid process of ulna


Lateral radius

Median

Pronates forearm

Flexor carpi radialis

Medial epicondyle of humerus

Bases of SECOND and sometimes third metacarpals

Median

Flexes forearm, flexes and abducts hand (ie flexes and abducts at the wrist)


Palmaris longus

Medial epicondyle of humerus

Palmar aponeurosis (flexor retinaculum)


Median

Flexes hand and forearm

Flexor carpi ulnaris

Medial epicondyle, upper posterior border of ulna


Pisiform, hook of hamate, and base of fifth metacarpal

Ulnar

Flexes and adducts hand, flexes forearm

Flexor digitorum superficialis

Medial epicondyle, humeroulnar head arises from the common flexor tendon and the medial border of coronoid process; radial head arises from the proximal anterior border of radius


Base of middle phalanges, digits 2-5

Median

w/ ulnar artery both pass bet 2 heads of origin



Flexes proximal interphalangeal joints, flexes hand and forearm

DEEP MUSCLES (all innervated by ANTERIOR INTEROSSEUS NERVE – a branch of the median nerve)

Flexor digitorum profundus

Anteromedial surface of ulna, interosseous membrane


Bases of distal phalanges of digits 2-5

Ulnar (medial portion of FDP) and anterior interosseous nerve

Flexes distal interphalangeal joints and hand

Flexor pollicis longus

Anterior surface of radius, interosseous membrane


Bases of distal phalanx of thumb

Anterior interosseous nerve

Flexes thumb

Pronator quadratus

Anterior surface of distal ¼ of ulnar

Anterior surface of distal ¼ of radius

Anterior interosseous nerve

Pronates forearm

Muscle of Posterior Forearm

(origin – humerus and COMMON EXTENSOR TENDON)

MUSCLE

PROXIMAL

DISTAL

NERVE

ACTION

Brachioradialis

Lateral supracondylar ridge of humerus


Lateral lower end of radius (base of radial styloid process)

Radial

Flexes forearm

Extensor carpi radialis longus

Lateral supracondylar ride of humerus


Dorsum of base of second metacarpal

Radial

Extends and abducts hand

Extensor carpi radialis brevis

Lateral epicondyle of humerus


Posterior base of third metacarpal

Radial (deep)

Extends fingers and abducts hands

Extensor digitorum

Lateral epicondyle of humerus

Extensor expansion of digits 2-5

Posterior interosseous nerve


Extends fingers and hand (2-5); extends digits and all three phalanxes

Extensor digiti minimi

Common extensor tendon and interosseous membrane


Extensor expansion of digit 5

Post interosseous n.

Extends little finger

Extensor carpi ulnaris

Lateral epicondyle and posterior surface of ulna


Base of fifth metacarpal

Posterior Interosseous nerve

Extends and adducts hand

DEEP MUSCLES (mostly innvervated by POSTERIOR INTEROSSEOUS NERVE)

Supinator


Lateral epicondyle,

Lateral border of radius

Radial

(deep)


Supinates forearm

Abductor pollicis longus

Interosseous membrane, posterior surfaces of radius and ulna

Lateral surface of base of first metacarpal

Posterior Interosseous n.

Abducts thumb (and hand)

Extensor pollicis longus

Interosseous membrane and posterior surface of ulna

Base of distal phalanx of thumb

Posterior interosseous n.

Extends distal phalanx of thumb and abducts hand

Extensor pollicis brevis

Interosseous membrane and posterior surface of radius

Base of proximal phalanx of thumb

Posterior interosseous n.

Extends proximal phalanx of thumb and abducts hand

Extensor indicis

Posterior surface of ulna and interosseous membrane

Extensor expansion of index finger (2nd digit)

Posterior interosseous n.

Extends index finger

Aconeus

Lateral epicondyle of humerus

Olecranon and upper posterior surface of ulna

Radial

Extends forearm (assists triceps)

Muscles of Hand



MUSCLE

PROXIMAL

DISTAL

NERVE

ACTION

THENAR COMPARTMENT (RECURRENT MEDIAN NERVE)

Abductor pollicis brevis

Flexor retinaculum, scaphoid, trapezium


Sesamoid bone, proximal phalanx and extensor expansion

Recurrent median nerve

Abduction and flexion of proximal phalanx


Flexor pollicis brevis


Flexor retinaculum, scaphoid, trapezium

Sesamoid, proximal phalanx and extension expansion

Superficial head by recurrent median nerve

Flexion of proximal phalanx

Opponens pollicis

Flexor retinaculum and trapezium

First metacarpal

(lateral side)



Recurrent median nerve

Rotation of metacarpal during opposition (opposes thumb to other digits)

HYPOTHENAR COMPARTMENT

Palmaris brevis

Medial side of flexor retinaculum, palmar aponeurosis


Skin of medial side of palm

Superfical branch of ulnar n.

Draws the skin at the ulnar side of palm towards the middle of the palm. Deepens the hollow of the palm. (wrinkles skin on medial side of palm)

Abductor digiti mini

Pisiform


proximal phalanx of 5th digit (little finger)

Ulnar (deep branch)

Abduction of digit 5

Flexor digiti minimi brevis

hamate

proximal phalanx of 5th digit

Ulnar (deep)

Flexion of proximal phalanx, digit 5

Opponens digiti minimi

hamate

5th metacarpal


Ulnar (deep)

Draws 5th metacarpal anteriorly thus bringing digit 5 into contact with thumb during opposition. Only thumb can oppose other fingers. (Opposes little finger)

MID-PALMAR COMPARTMENT

Adductor pollicis (2 heads)

2nd metacarpal and capitate. Transverse head origin. 3rd metacarpal.

Medial sesamoid bone and base of proximal phalanx, and extensor expansion of thumb

Ulnar (deep branch)

Adduction of thumb, aids in opposition

Lumbricals (4)


Lateral side of tendons of flexor digitorum profundus

Lateral side of extensor expansion of 2nd to 5th digits.

Recurrent Median (two lateral lumbricals) and ulnar (deep) (two medial 3rd & 4th)

Flex metacarpophalangeal joints and extend interphalangeal joints


DEEP MUSCLES OF HAND

Dorsal interossei (4)

1st – 1st and 2nd metacarpals

(adjacent sides of metacarpal bones)



1st – lateral side of prox phalanx of index finger; 2nd & 3rd – middle finger, 2nd lat side & 3rd medial side. 4th – medial side of ring finger (Lateral sides of bases of proximal phalanges; extensor expansion)

Ulnar (deep branch)

Abduction of digits 2,3,4; Abduct fingers; flex metacarpophalangeal joints, extend interphalangeal joints; adducts fingers toward the middle fingers

Palmar interossei (3)

1st origin - Medial side of 2nd metacarpal; 2nd - lateral sides of 4th metacarpal; 3rd – lateral side of 5th metacarpals. (medial side of second metacarpal; lateral sides of fourth and fifth metacarpals)

1st – medial side proximal phalanx digit 2, and extensor expansion; 2nd – lat side prox phalanx digit 4 and extensor expansion; 3rd – lat side prox. Phalanx digit 5. and extensor expansion; (proximal phalanges in same sides as their origins; extensor expansion)

Ulnar (deep)

Adduct fingers toward the middle finger (flex metacarpolangeal joints; extend interphalangeal joints)

MUSCLES OF THE BACK



MUSCLE

ORIGIN

INSERTION

NERVE

ACTION

The Extrinsic Muscles

The Superficial Group



Trapezius

Occiptal region of skull; ligamentum nuchae, spinous processes of CV7-T12

Spine of scapula, acromion, and lateral third of clavicle
Blood supply: transverse cervical artery

Subtrapezial plexus = accessory nerve CNXI, ventral rami of C3-C4 spinal nerves

Superior fibers elevate scapula; middle fibers retract scapula; lower fibers depress scapula and lower the shoulder


Levator scapulae

Transverse processes of C1-C4 vertebrae

Superior part of medial border of scapula

Dorsal scapular nerve (C5); spinal nerves C3 & C4;

Elevates scapula and helps to tilt its glenoid cavity inferiorly by rotating the scapula

Rhomboid minor

Ligamentum nuchae and spinous processes of C7 & T1 vertebrae

Medial border of scapula (usually at level of scapula spine)


Dorsal scapular nerve (C5), with small contribut from C4 & Dorsal scapula artery

Retract scapula and rotate it to depress the glenoid cavity

Rhomboid major

Spinous processes of T2-T5

Medial border of scapula (inferior to scapula spine)

Dorsal scapular nerve (C5), with small contribut from C4 & Dorsal scapula artery

Retract scapula and rotate it to depress the glenoid cavity

Latissimus dorsi

Aponeurosis from the spinous processes of inferior 6 vertebrae: T5-T12, thoracolumbar fascia, sacral spines, iliac crest, lower 4 ribs: 9-12

Floor of intertubercular groove of humerus (ant surface)

Thoracodorsal nerve (C6,C7 and some contribution by C8) and artery

Adducts, extends, and rotates arm medially

The Intermediate Group (two muscles responsible for aiding in respiration

Serratus Posterior Superior

Inferior part of ligamentum nuchae and spinous process of C7 and T1-T3 vertebrae

Superior Borders of second to fourth (or fifth ribs)

Intercostal nerves (C8-T3)

As the muscle pulls toward its origin during inspiration, it elevates the first four (or five) ribs increasing the diameter of the thorax

Serratus Posterior Inferior

Spinous processes of last two thoracic T11-L2) and first two lumbar vertebrae

Inferior border of the inferior 3 or 4 ribs (ribs (9) 10-12)

Intercostal nerves (T9-T11)

During inspiration, the muscle depresses the inferior ribs, preventing them from being pulled superiorly by the diaphragm.

Intrinsic Muscles of the Back (the deep group)

Splenius muscle (superficial layer of intrinsic muscles)

Inferior half of the ligamentum nuchae (CV4-CV6) and the spinous processes of CV7, T1-T6

A. Splenius capitis:lateral aspect of mastoid region of the temporal bone to the later 1/3rd of the superior nuchal line of the occipital bone.

B. Splenius cervicis: Posterior tubercles located on the transverse processes of C1-C4)



Dorsal rami of cervical nerves

Acting alone, laterally flex and rotate the head and neck to the same side. Acting together, they extend the neck back

Erector Spinae muscle (superficial layer)

Illiocostalis (lateral column): regions – illiocostalis, lumborum, thoracis and cervices

Longissimus (intermediate column): regions – longissimus throacis, cervicis, and capitis

Spinalis( medial column): regions – spinalis thoroacis, cervicis, and capitis

Major: Extend the vertebral column and bend it posteriorly.

Minor: maintain posture and head movement



The Transversospinalis group (the deep layer of intrinsic muscles)

Semispinalis (forms the largest muscle mass in posterior aspects of the neck

Multifidus


Rotatores

Levator costorum

(longus and brevis)



The semispinalis, multifidus, rotators muscles lat flex vert column (alone) & assist w/ post ext when working together. Levator costorum assist w/ the process of inspiration by elevating the ribs.

Muscles of Pectoral Region




MUSCLE

ORIGIN

INSERTION

NERVE

ACTION

Pectoralis major

Medial half of clavicle, manubrium, body of the sternum, upper six costal cartilages

Lateral tip of the intertubercular groove (the crest of the greater tubercle) of humerus

Medial and lateral pectoral nerves

Adducts and medially rotates arm; clavicular part – rotates arm medially and flex it; sternocostal part depresses arm and shoulder, its lower fibers can help extend arm when it is flexes


Pectoralis minor

External surfaces of second to fifth ribs


Coracoid process

Medial and lateral pectoral nerves

Depresses shoulder


Subclavius

Junction of the first rib and its cartilage

Lower surface of the clavicle

Nerve to subclavius

Depresses lateral portion of clavicle


Serratus anterior

External surfaces of ribs 1-8

Medial border of inferior angle of scapula

Long thoracic nerve

Rotates scapula upward, so that the inferior angle swings laterally and abducts the arm and elevates it above a horizontal position



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