Rotator cuff (382-397)

Question 1

What muscles do the nerves arising from the medial cord innervate?;

Answer 1

Medial pectoral nerve (C8-T1)- pectoralis minor.
Medial cutaneous nerve of arm (C8-T1)- sensory to medial forearm.
Ulnar nerve (C8-T1)- muscles of hand (apart from LOAF), flexor carpi ulnaris and medial half of flexor digitorum profundus.
Medial root of Median nerve (joins lateral root to form median nerve)

Question 2

Name the branches that arise from the posterior cord of the branchial plexus;

Answer 2

Upper subscapular nerve (C5-6). Lower subscapular nerve(C5-6). Axillary nerve (C5-6). Thoracodorsal nerve (C6-8). Radial nerve (C5-T1)

Question 3

What muscles do the nerves arising from the posterior cord innervate?;

Answer 3

Upper subscapular nerve (C5-6)- subscapularis muscles (upper part) and teres major.
Lower subscapular nerve(C5-6)- subscapularis muscle (lower part).
Axillary nerve (C5-6)- teres minor and deltoid muscles plus sensory regimental badge area.
Thoracodorsal nerve (C6-8)- latimus dorsi.
Radial nerve (C5-T1)- triceps and muscles in posterior compartment.

Question 4

Name the five terminal branches of the brachial plexus;

Answer 4

Musculocutaneous (C5-7). Axillary (C5-6). Median (C6-T1). Radial (C5-T1). Ulnar (C8-T1).

Question 5

What is the origin and insertion of the pectorialis minor muscle?;

Answer 5

3rd/4th/5th rib and inserts to corocoid process of scapula.

Question 6

What is the innervation of the pectorialis minor muscles?;

Answer 6

Medial pectoral nerve.
(Branch from medial cord of brachial plexus)

Question 7

What is the innveration of the pectoralis major muscle?;

Answer 7

Lateral pectoral nerve and medial pectoral nerve (sternocostal head of pectoralis major)

(Lateral pectoral nerve is branch from lateral cord of brachial plexus)
(Medial pectoral nerve is branch from medial cord of brachial plexus)

Question 8

Which nerve supplies the serratus anterior and where does it lie?;

Answer 8

Long throacic nerve - lies in midaxillary line

Question 9

What is the nerve supply to the teres major and teres minor muscles?;

Answer 9

Teres major- lower subscapular nerve.
Teres minor- axillary nerve.

Question 10

What is the nerve supply to subscapularis?;

Answer 10

Upper and lower subscapular nerves [C5-6]
(branches of posterior cord)

Question 11

Name the muscles that attach to the coracoid process;

Answer 11

3 muscles- short head of biceps, coracobrachialis and pectoralis minor.

Question 12

Name the muscles that make up the rotator cuff;

Answer 12

Supraspinatus. Infraspinatus. Teres minor. Subscapularis.

Question 13

Where do the rotator cuff muscles attach?;

Answer 13

All attach to greater tubercle of humerus expect subscapularis which attaches to lesser tubercle of humerus.
ORGINS- Supraspinatus- supraspinous fossa of scapula. Infraspinatus- infraspinous fossa of scapula. Subscapularis- subscapula fossa on costal surface of scapula. Teres minor- posterior surface of scapula, adjacent to lateral border.

Question 14

Which nerves innverate the rotator cuff muscles?;

Answer 14

Supraspinatus- suprascapular nerve (branch from trunk bracial plexus) [C5-6]
Infraspinatus- suprascapular nerve.

Teres minor- axillary nerve (terminal branch of posterior cord). [C5-6]

Subscapularis- upper and lower subscapular nerve (branches of posterior cord) [both C5-6]

Question 15

Which muscles are responsible for abduction of the shoulder?;

Answer 15

0-15 degrees- supraspinatus.
15-90 degrees- deltoid.
Past 90 degrees- scapula need to rotate- trapezius and serratus anterior.

Question 16

Which muscles are responsible for adduction of the shoulder?;

Answer 16

Pectoralis major, teres major, latissimus dorsi.