Anatomy- Shoulder Joint, Posterior Arm and Posterior Forearm Flashcards
what nerve supplies the deltoid muscle
axillary nerve (along with teres minor)
what are the proximal and distal attachments of the deltoid
proximal- lateral third of the clavicle (anterior) and the inferior aspects of the scapular spine (posterior) and acromion (lateral)
distally- deltoid tuberosity of the humerus
what is the role of the rotator cuff muscles tendons
strengthen the fibrous capsule of the shoulder joint superiorly (supraspinatus) and posteriorly (infraspinatus and teres minor)
where is the subacromial bursa
between the supraspinatus tendon and acromion process of scapula
what movement in particular causes pain in subacromial bursitis
abduction
what is the sensory innervation of the medial posterior arm
anterior rami of spinal nerves (C8, T1 & T2)
what nerve is a common site of cardiac referred pain in the medial posterior upper arm
intercostobrachial nerve and medial and posterior cutaneous nerves of arm and medial cutaneous nerve of forearm
what is the nerve supply to the lateral posterior upper arm
anterior rami of spinal nerves (C5 and C6) via the axillary nerve
what is the only muscle in the posterior compartment of the arm
triceps brachii
what is the innervation of the triceps brachii
the nerve of the posterior compartment of the arm- the radial nerve
what are the proximal attachments of the triceps brachii
long head- infraglenoid tubercle of the scapula
lateral head- superior to the radial groove of the humerus
medial head- inferior to the radial groove of the humerus
what are the distal attachments of the triceps brachii
all three heads combine to form the triceps tendon, which attaches to the olecranon process of the ulna
what is the action of the ticeps brachii
weak extension of the arm at the shoulder joint
extension of the forearm at the elbow joint
where is the axillary nerve found
quadrangular space between teres minor superiorly, teres major inferiorly, the long head of triceps medially and the humerus laterally
what dies the axillary nerve supply
the deltoid and the teres minor
what is the badge patch
area of skin innervated by the axillary nerve (lateral aspect of the arm)
what is the relevance of the badge patch
people who have sustained an inferior shoulder dislocation should undergo assessment of sensation in badge patch to test function of the axillary nerve
how can the axillary nerve be tested using movement
asking the patient to abduct the upper limb beyond 15 degrees
what is the spinal roots of the radial nerve
C5-T1
what is the path of the radial nerve in the upper arm
passes from the axilla into the posterior compartment of the arm where it is found in the radial groove of the humerus
what happens to the radial nerve after it supplies the triceps brachii
leaves the posterior compartment of the arm to enter the lateral aspect of the cubital fossa
then returns to the posterior aspect of the limb in the posterior compartment of the forearm
what does the position of the radial nerve in the radial groove of the humerus make (and its accompanying vessels) it vulnerable to
damage in a (spiral) mid-shaft fracture of the humerus
where do the muscles of the superficial layer of the posterior forearm attach proximally
common extensor tendon on the lateral epicondyle of the humerus
what muscles in the superior posterior forearm extend, abduct and adduct the wrist
group A- Carpus muscles:
- extensor carpi radialis longus and brevis (attach to metacarpals 2 and 3)
- extensor carpi ulnaris (5th metacarpal)
what muscles in the superior posterior forearm extend the fingers
group B- Digitorum muscles:
- extensor digitorum (extensor hood of each finger (x4))
- extensor digiti minimi (extensor hood of little finger)
what nerve supplies the muscles of the posterior forearm
radial nerve- apart from group D
what is the shared proximal attachment of the deep posterior forearm muscles
shafts of the radius and ulna and interossseous membrane
what is the anconeus
muscle in superificial posterior forearm, blends with fibres of triceps- extends elbow joint, abducts the ulna during pronation of the forearm
what are the proximal and distal attachments of the brachioradialis
proximal aspect of the lateral supracondylar ridge of the humerus
radius just before the radial styloid process
what is the function and innervation of the brachioradialis
flexes at the elbow of a semi pronated arm (drinking from a cup)
radial nerve
what muscles of the deep proximal forearm extend and abduct the thumb
group c- Pollicis muscles:
- abductor pollicis longus (lateral side of base of metacarpal 1)
- extensor pollicis brevis (base of proximal phalanx)
- extensor pollicis longus (extends all joints of thumb)
what muscles of the deep proximal forearm supinate the forearm at the proximal and distal radioulnar joints
group D:
supinator (insert into posterior surface of the radius)
what does the extensor indicis proprius
extends the index finger
what holds the muscle tendons of the posterior forearm in place as they cross the wrist
extensor retinaculum
into what and where does the radial neve divide
divides into a superficial and deep branch anterior to the lateral epicondyle
what is the path of the deep branch of the radial nerve
passes into the posterior compartment of the forearm by winding around the neck of the radius and passing through the supinator muscle
what is the innervation of the supinator muscle
the deep branch of the radial nerve
what is the posterior interosseous nerve
what the deep branch of the radial nerve is renamed after it passes through the supinator
what does the posterior interosseous nerve supply
the muscles of the posterior compartment of the forearm
