Week 2

Question 1

Elbow Joint

Answer 1

Classification: synovial hinge

Articulating surfaces: 1. Trochlea of humerus with the trochlear notch of ulna
2. Capitulum of humerus with head of radius

Ligaments: Radial collateral and ulnar collateral

Movements: flexion and extension of forearm

Blood supply: anastomotic network; collateral and recurrent branches of brachial, profunda brachii, radial ulnar

Innervation: mainly radial and musculocutenous, also ulnar and median nerve

Question 2

Ligaments

Answer 2

1. Lateral radial collateral: lateral epicondyle - annular ligament
2. Medial ulnar collateral: anterior, posterior, oblique bands

Question 4

Proximal radioulnar joint

Answer 4

Classification: synovial pivot

Articulating surfaces: head of radius with a sleeve formed by radial notch of the ulna and the annular ligament

Ligaments: Annular ligament

Movements: Pronation and supination of forearm (together with distal radioulnar joint)

Question 5

Muscles of the arm anterior compartment

Answer 5

1. Biceps brachii
2. Brachialis
3. Coracobrachialis

Question 6

Biceps brachii

Answer 6

origin: long head- supraglenoid tubercle
Short head - coracoid process

insertion: radial tuberosity, bicipital aponeurosis- fascia of the anterior compartment of the forearm

innervation: musculocutaneous nerve

action: flex arm, flex and supinate forearm

Question 7

brachialis

Answer 7

origin: anterior surface of humerus

insertion: ulnar tuberosity

innervation: musculocutaneous nerve

action: flex forearm

Question 8

coracobrachialis

Answer 8

origin: coracoid process

insertion: medial surface of humerus

innervation: musculocutaneous nerve

action: flex arm at glenohumeral joint

Question 9

popeye sign

Answer 9

rupture of biceps tendon

Question 10

posterior compartment

Answer 10

1. Triceps brachii
2. Anconeus

Question 11

Triceps brachii

Answer 11

origin: long head; infraglenoid tubercle
medial head: posterior surface of humerus inferior to the radial groove
lateral head: posterior surface of humerus superior to the radial groove

insertion: olecranon

innervation: radial nerve

action: extend forearm and also extend and adduct the arm at the glenohumeral joint

Question 12

anconeus

Answer 12

origin: posterior surface of the lateral epicondyle (humerus)

insertion: posterior surface of the ulna

innervation: radial nerve

action: assists in extension of the elbow