Arm and Brachial plexus dissection

Question 1

How many flexor muscles are found in the anterior compartment of the arm?

Answer 1

3

Question 2

Where are the muscles in the flexor compartment of the arm located?

Answer 2

One of these muscles is a flexor at the shoulder joint, one a flexor at the elbow joint, and the third is a flexor at both the shoulder and elbow joint.

Question 3

Name the largest flexor muscle in the anterior compartment of the arm

Answer 3

Biceps brachii

Question 4

How many heads does the biceps brachii have?

Answer 4

2

Question 5

Give the origin of the long head of the biceps brachii

Answer 5

supraglenoid tubercle of the scapula

Question 6

Give the origin of the short head of the biceps brachii

Answer 6

coracoid process of the scapula

Question 7

Where does the long head of biceps brachii travel?

Answer 7

Inside the capsule of the shoulder joint and continues down the intertubercular sulcus

Question 8

What do the two heads of the biceps brachii insert?

Answer 8

Radial tuberosity

Question 9

Name an expansion of the tendon of biceps

Answer 9

Bicipital aponeurosis

Question 10

Where does the bicipital aponeurosis cross?

Answer 10

crosses medially over the superficial flexors of the forearm

Question 11

Where does the bicipital aponeurosis attach?

Answer 11

posterior border of the ulna via the deep fascia.

Question 12

What action does biceps exert when it crosses the shoulder and elbow joint?

Answer 12

Flexor action on both joints

Question 13

Name a powerful supinator muscle of the forearm

Answer 13

Biceps

Question 14

Give the origin of coracobrachialis

Answer 14

from the coracoid process

Question 15

What forms the conjoint tendon?

Answer 15

The short head of biceps and coracobrachialis

Question 16

Where does coracobrachialis insert?

Answer 16

medial aspect of the humerus half way down the shaft.

Question 17

Where does coracobrachialis lie in relation to biceps?

Answer 17

Medial

Question 18

Give the origin of brachialis

Answer 18

distal half of the anterior of the humerus

Question 19

Give the insertion of brachialis

Answer 19

ulna tuberosity

Question 20

Where does brachialis lie in relation to biceps?

Answer 20

Deep

Question 21

How many muscles are in the posterior compartment of the arm?

Answer 21

1

Question 22

Name the muscle in the posterior compartment of the arm

Answer 22

Triceps brachii

Question 23

How many heads does triceps brachii have?

Answer 23

3

Question 24

Give the origin of the long head of triceps brachii

Answer 24

infraglenoid tubercle of the scapula

Question 25

Give the origin of the lateral head of triceps brachii

Answer 25

posterior aspect of the humerus above the spiral (or radial) groove of the humerus

Question 26

Give the origin of the medial head of triceps brachii

Answer 26

posterior surface of the humerus but below the spiral groove.

Question 27

Give the insertion of triceps brachii

Answer 27

olecranon process of the ulna

Question 28

What are the muscles of the arm, forearm and hand innervated by?

Answer 28

Brachial plexus

Question 29

Describe the roots of the brachial plexus

Answer 29

C5-T1

Question 30

What do the roots of the brachial plexus form?

Answer 30

Trunks - superior, middle and inferior

Question 31

What do the trunks of the brachial plexus form?

Answer 31

Cords - lateral, posterior and medial

Question 32

What are the cords of the brachial plexus related to?

Answer 32

Axillary artery

Question 33

What does the lateral cord of brachial plexus give rise to?

Answer 33

lateral pectoral nerve

Question 34

What does the lateral pectoral nerve supply?

Answer 34

Pectoralis minor/major

Question 35

Name the terminal branches of the lateral cord

Answer 35

lateral head of the median nerve and the musculocutaneous nerve

Question 36

What does the Musculocutaneous nerve pierce?

Answer 36

coracobrachialis approximately 5cm distal to the conjoint tendon.

Question 37

Name the terminal branch of the Musculocutaneous nerve

Answer 37

lateral cutaneous nerve of the forearm

Question 38

What does the lateral cutaneous nerve of the forearm supply?

Answer 38

supplies the skin of the lateral forearm on both the dorsal and ventral aspects

Question 39

What does the medial cord give rise to?

Answer 39

medial pectoral nerve

cutaneous nerves of the arm and forearm

Question 40

What does the medial pectoral nerve supply?

Answer 40

Pectoral muscles

Question 41

Name the terminal branches of the median nerve

Answer 41

medial head of the median nerve and the ulnar nerve.

Question 42

What does the ulnar nerve give rise to?

Answer 42

limited supply to the flexor muscles of the forearm and is the main supply is the small muscles of the hand.

Question 43

Describe the pathway of the ulnar nerve

Answer 43

The nerve lies medial to the brachial artery in the arm and passes behind the medial epicondyle of the humerus at the elbow joint (the cubital tunnel) to gain access to the forearm.

Question 44

What does the median nerve supply?

Answer 44

It supplies almost all of the muscles of the anterior compartment of the forearm.

Question 45

What are the branches of the posterior cord?

Answer 45

upper subscapular, thoracodorsal and lower subscapular nerve

Question 46

What are the terminal branches of the posterior cord

Answer 46

Radial nerve

Axillary

Question 47

What does the radial nerve supply?

Answer 47

muscles and skin over the whole posterior aspect of the upper limb. The radial nerve supplies the triceps muscles and the extensor muscles of the forearm.

Question 48

What does the axillary nerve supply?

Answer 48

The axillary nerve supplies teres minor and the deltoid muscle as well as a small area of skin over the insertion of the deltoid, known as the badge area.

Question 49

What is the origin of the subclavian artery on the right

Answer 49

Brachiocephalic trunk

Question 50

What is the origin of the subclavian artery on the left?

Answer 50

Aorta

Question 51

Describe the course of the blood supply of the arm

Answer 51

As the subclavian artery passes over the first rib it changes its name to the axillary artery. In the axilla, the axillary artery is accompanied by the cords of the brachial plexus. Once the axillary artery crosses the lower border of teres major it changes its name again to become the brachial artery, which is the main artery within the arm. The brachial artery gives off many small muscular branches and also the profunda (or deep) brachii artery, which accompanies the radial nerve in the spiral groove of the humerus to supply triceps and the elbow joint. Locate the subclavian artery and follow it as it becomes the axillary artery and then the brachial artery.