The Arm

Question 1

Describe the ligaments of the glenohumeral joint.

Answer 1

Superior glenohumeral ligament
From superior glenoid labrum to upper humeral neck
Provides anterior and inferior joint stability

Middle glenohumeral ligament
From the superior anterior glenoid labrum to anterior aspect of humerus
Provides anterior joint stability

Inferior glenohumeral ligament
Anterior and posterior ligament bands with axillary pouch
Joint stabilizer when arm is abducted beyond 45 degress

Coracohumeral ligament
From the base of the coracoid process

Question 2

Describe the components of the subacromial space

Answer 2

Region between the coracoarcomial arch and the head of the humerus

Coracoid process, coracoarcromial ligament and acromion foram a vault over the humeral head

Contains the subacromial bursa, rotator cuffs, and tendon of the long head of the bicep brachii

Question 3

Describe the joints of the elbow

Answer 3

Humeroulnar joint (Hinge)
Articulation of the trochlea of the humerus and the trochlear notch of ulna
Supported by the ulnar collateral ligament
Humeroradial joint (Hinge)
Articulation of the capitulum of the humerus and the head of the radius
Supported by the radial collateral ligament
Proximal radial ulnar joint (Pivot)
Articulation between the head of the radius and the radial notch of the ulna
Permits pronation and supination
Supported by the annular ligament and the quadrate ligament
Distal radio ulnar joint (Pivot)
Articulation between head of the ulna and larger ulnar notch of the radius
Permits pronation and supination
Separated by synovial cavity

Question 4

Brachialis

Answer 4

Origin: distal half of the anterior surface of the humerus

Insertion: coronoid process and tuberosity (ulna)

Action: primary forearm flexor

Innervation: musculocutaneous

Question 5

Bicep Brachii

Answer 5

Origin:
Short head: tip of the coracoid process
Long head: supraglenoid tubercle

Insertion: tuberosity of radius and bicipital aponeurosis

Action: supinate forearm flexes elbow when supine and weakly assists in arm flexion
Short head: stabilizes the shoulder

Innervation: musculocutaneous

Question 6

Coracobrachialis

Answer 6

Origin: coracoid process (shares with short head of bicep brachii)

Insertion: middle third surface of the humerus

Action: secondary flexor, adductor of the arm, and stabilizes shoulder

Question 7

Tricep Brachii

Answer 7

Origin:
Long head: infraglenoid tubercle
Lateral head: posterior surface of the humerus (superior to radial groove)
Medial head: posterior surface of the humerus (inferior to radial groove)

Insertion: proximal surface of olecranon (ulna)

Action: Extends the forearm and stabilizes the glenohumeral joint (long head)

Innervation: radial nerve

Question 8

Anconeus

Answer 8

Origin: lateral epicondyle of the humerus

Insertion: Lateral surface olecranon

Action: Assists with elbow extension and stablizes elbow

Innervation: Radial nerve

Question 9

Brachial Artery

Answer 9

Continuation of the axillary artery
Begins at the inferior border of teres major to the cubital fossa

Branches
Deep brachial artery
Superior ulnar collateral artery
Inferior ulnar collateral artery

Question 10

Superficial Veins of the Arm

Answer 10

Basilic Vein
Travels medially
Connects with the axillary vein

Cephalic Vein
Travels laterally
Connects with the axillary vein

Communicate via the median cubital vein