Muscles Flashcards
What is the motor innervation of trapezius?
spinal accessory nerve
What is the sensory innervation of trapezius?
C3 and C4 spinal roots
What is the lateral attachment of the trapezius?
lateral third of the clavicle, acromion and spine of the scapula
What is the medial attachment of the trapezius?
medial third of the superior nuchal line, external occipital protuberance, nuchal ligament, spinous processes of C7 - T12 vertebrae
What is the main action of the upper fibres of trapezius?
elevate the scapula and rotate it during abduction of the arm
What is the main action of the middle fibres of the trapezius?
retract the scapula
What is the main action of the lower fibres of the trapezius?
pull the scapular inferiorly
What are the main actions of latissimus dorsi?
extends, abducts and medially rotates humerus; raises body toward arms during climbing
What is the innervation of latissimus dorsi?
thoracodorsal nerve
What muscles form the rotator cuff?
supraspinatous, infraspinatous, teres minor and subscapularis
What is the innervation of the deltoid?
axillary nerve
What is the innervation of serratus anterior?
long thoracic nerve
What is the innervation of supraspinatus?
suprascapular nerve
What is the innervation of infraspinatus?
suprascapular nerve
What is the proximal attachment of supraspinatus?
supraspinous fossa of scapula
What is the proximal attachment of infraspinatus?
infraspinous fossa of scapula
What is the innervation of teres minor?
axillary nerve
What is the proximal attachment of the deltoid?
lateral third of the clavicle, acromion, spine of scapula
What is the distal attachment of the deltoid?
deltoid tuberosity of humerus
What is the proximal attachment of subscapularis?
subscapular fossa
What is the innervation of subscapularis?
upper and lower subscapular nerves
What are the actions of subscapularis?
responsible for the first 15 degrees of abduction, assists deltoid for the rest, acts with other rotator cuff muscles
What is the distal attachment of infraspinatus?
middle facet of greater tubercle of humerus
What is the distal attachment of supraspinatus?
superior facet of greater tubercle of humerus
Name the 6 scapulohumeral muscles
deltoid, teres major, supraspinatus, infraspinatus, subscapularis, teres minor
What are the three flexors in the arm?
biceps brachii, brachialis, coracobrachialis
What is the extensor in the arm?
triceps brachii
What nerve supplies the the flexor arm muscles?
musculocutaneous
What nerve supplies the extensor arm muscle?
radial nerve
What is the main action of biceps brachii?
supinates forearm and, when it is supinated, flexes forearm; flexes arm
What is the proximal attachment of the short head of biceps brachii?
tip of coracoid process
What is the proximal attachment of the long head of biceps brachii?
supraglenoid tubercle of scapula
What is the distal attachment of the biceps brachii?
tuberosity of the radius
Where are the flexors and protonators of the forearm located?
anterior compartment
Where are the extensors and supinators of the forearm located?
posterior compartment
What are the muscles of the superficial layer of the anterior compartment of the forearm?
pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris
What muscle is the exception to the rule that all flexors lie in the anterior compartment and that the radial nerve supplies only extensor muscles?
brachioradialis
How can palmaris longus be identified?
long, thin tendon (absent in about 15% of the population)
What is the muscle of the intermediate layer of the anterior compartment of the forearm?
flexor digitorum superficialis
What is the innervation of pronator teres?
median nerve
What is the innervation of flexor carpi ulnaris?
ulnar nerve
What is the innervation of flexor carpi radialis?
median nerve
What is the innervation of flexor digitorum superficialis?
median nerve
What muscles are located in the deep layer of the anterior compartment of the forearm?
flexor digitorum profundus, flexor pollicus longus, pronator quadratus
What is the innervation of flexor digitorum profundus?
medial aspect supplied by the ulnar nerve (4th to 5th digit)
lateral aspect supplied by median nerve (2nd and 3rd digit)
What is the main action of pronator teres?
What is the main action of flexor carpi radialis?
flexes and abducts hand at wrist
What is the main action of flexor carpi ulnaris?
flexes and abducts hand at wrist
What is the main action of palmaris longus?
flexes hand at wrist
What is the main action of flexor pollicis longus?
flexes thumb
What nerve are the extensor muscles of the forearm innervated by?
radial nerve
How many muscles are in the superficial layer of the posterior forearm?
6
Why is brachioradialis different from the other extensor muscles?
it is a flexor at the elbow, but has the same origin and innervation as the other extensor muscles in the posterior compartment
What is the proximal attachment of brachioradialis?
lateral supraepicondylar ridge of humerus
What is the distal attachment of brachioradialis?
lateral surface of distal end of radius proximal to styloid process
What are the actions of extensor carpi radialis longus and brevis?
extend and abduct hand at the wrist joint
What is the main action of extensor digitorum?
extends medial four fingers
What is the main action of extensor digiti minimi?
extends fifth finger
What is the main action of extensor carpi ulnaris?
extends and adducts hand at the wrist joint
What is the main action of the supinator muscle?
supinates forearm, rotates radius to turn palm anteriorly or superiorly
Name the muscles that extend and abduct or adduct the hand at the wrist joint
extensor carpi radialis longus, extensor carpi radialis brevis, extensor carpi ulnaris
(carpi = wrist)
Name the muscles that extend the medial four digits
extensor digitorum, extensor indicis, extensor digiti minimi
Name the muscles that extend or abduct the thumb
abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus
