Anatomy- Shoulder Joint, Posterior Arm and Posterior Forearm

Question 1

what nerve supplies the deltoid muscle

Answer 1

axillary nerve (along with teres minor)

Question 2

what are the proximal and distal attachments of the deltoid

Answer 2

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

Question 3

what is the role of the rotator cuff muscles tendons

Answer 3

strengthen the fibrous capsule of the shoulder joint superiorly (supraspinatus) and posteriorly (infraspinatus and teres minor)

Question 4

where is the subacromial bursa

Answer 4

between the supraspinatus tendon and acromion process of scapula

Question 5

what movement in particular causes pain in subacromial bursitis

Answer 5

abduction

Question 6

what is the sensory innervation of the medial posterior arm

Answer 6

anterior rami of spinal nerves (C8, T1 & T2)

Question 7

what nerve is a common site of cardiac referred pain in the medial posterior upper arm

Answer 7

intercostobrachial nerve and medial and posterior cutaneous nerves of arm and medial cutaneous nerve of forearm

Question 8

what is the nerve supply to the lateral posterior upper arm

Answer 8

anterior rami of spinal nerves (C5 and C6) via the axillary nerve

Question 9

what is the only muscle in the posterior compartment of the arm

Answer 9

triceps brachii

Question 10

what is the innervation of the triceps brachii

Answer 10

the nerve of the posterior compartment of the arm- the radial nerve

Question 11

what are the proximal attachments of the triceps brachii

Answer 11

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

Question 12

what are the distal attachments of the triceps brachii

Answer 12

all three heads combine to form the triceps tendon, which attaches to the olecranon process of the ulna

Question 13

what is the action of the ticeps brachii

Answer 13

weak extension of the arm at the shoulder joint

extension of the forearm at the elbow joint

Question 14

where is the axillary nerve found

Answer 14

quadrangular space between teres minor superiorly, teres major inferiorly, the long head of triceps medially and the humerus laterally

Question 15

what dies the axillary nerve supply

Answer 15

the deltoid and the teres minor

Question 16

what is the badge patch

Answer 16

area of skin innervated by the axillary nerve (lateral aspect of the arm)

Question 17

what is the relevance of the badge patch

Answer 17

people who have sustained an inferior shoulder dislocation should undergo assessment of sensation in badge patch to test function of the axillary nerve

Question 18

how can the axillary nerve be tested using movement

Answer 18

asking the patient to abduct the upper limb beyond 15 degrees

Question 19

what is the spinal roots of the radial nerve

Answer 19

C5-T1

Question 20

what is the path of the radial nerve in the upper arm

Answer 20

passes from the axilla into the posterior compartment of the arm where it is found in the radial groove of the humerus

Question 21

what happens to the radial nerve after it supplies the triceps brachii

Answer 21

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

Question 22

what does the position of the radial nerve in the radial groove of the humerus make (and its accompanying vessels) it vulnerable to

Answer 22

damage in a (spiral) mid-shaft fracture of the humerus

Question 23

where do the muscles of the superficial layer of the posterior forearm attach proximally

Answer 23

common extensor tendon on the lateral epicondyle of the humerus

Question 24

what muscles in the superior posterior forearm extend, abduct and adduct the wrist

Answer 24

group A- Carpus muscles:

• extensor carpi radialis longus and brevis (attach to metacarpals 2 and 3)
• extensor carpi ulnaris (5th metacarpal)

Question 25

what muscles in the superior posterior forearm extend the fingers

Answer 25

group B- Digitorum muscles:

• extensor digitorum (extensor hood of each finger (x4))
• extensor digiti minimi (extensor hood of little finger)

Question 26

what nerve supplies the muscles of the posterior forearm

Answer 26

radial nerve- apart from group D

Question 27

what is the shared proximal attachment of the deep posterior forearm muscles

Answer 27

shafts of the radius and ulna and interossseous membrane

Question 28

what is the anconeus

Answer 28

muscle in superificial posterior forearm, blends with fibres of triceps- extends elbow joint, abducts the ulna during pronation of the forearm

Question 29

what are the proximal and distal attachments of the brachioradialis

Answer 29

proximal aspect of the lateral supracondylar ridge of the humerus

radius just before the radial styloid process

Question 30

what is the function and innervation of the brachioradialis

Answer 30

flexes at the elbow of a semi pronated arm (drinking from a cup)

radial nerve

Question 31

what muscles of the deep proximal forearm extend and abduct the thumb

Answer 31

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)

Question 32

what muscles of the deep proximal forearm supinate the forearm at the proximal and distal radioulnar joints

Answer 32

group D:

supinator (insert into posterior surface of the radius)

Question 33

what does the extensor indicis proprius

Answer 33

extends the index finger

Question 34

what holds the muscle tendons of the posterior forearm in place as they cross the wrist

Answer 34

extensor retinaculum

Question 35

into what and where does the radial neve divide

Answer 35

divides into a superficial and deep branch anterior to the lateral epicondyle

Question 36

what is the path of the deep branch of the radial nerve

Answer 36

passes into the posterior compartment of the forearm by winding around the neck of the radius and passing through the supinator muscle

Question 37

what is the innervation of the supinator muscle

Answer 37

the deep branch of the radial nerve

Question 38

what is the posterior interosseous nerve

Answer 38

what the deep branch of the radial nerve is renamed after it passes through the supinator

Question 39

what does the posterior interosseous nerve supply

Answer 39

the muscles of the posterior compartment of the forearm