Brachium and Cubital Fossa

Question 1

Brachium Fascia

Answer 1

• continuous with fascia of shoulder muscles above
• attached to humeral epicondyles and olecranon process
• continuous with antebrachial fascia below
• encases entire arm in cylindrical sheath
• fascial extensions to lateral and medial supracondylar ridges from lateral and medial intramuscular septa; partition arm into anterior and posterior muscle compartments

Question 2

Brachial medial intramuscular septum

Answer 2

• 2 laminae that enclose neuromuscular compartment
• superiorly contains:
  brachial artery
  brachial vein
  musculocutaneous nerve
  medial brachial cutaneous nerve
  medial antebrachial cutaneous nerves
  ulnar nerve
  median nerve

Question 3

anterior surface of brachium muscles

Answer 3

• biceps brachii
• brachialis
• brachioradialis (?)
• coracobrachialis

Question 4

posterior surface of brachium muscles

Answer 4

• triceps brachii

- anconeus

Question 5

biceps brachii

Answer 5

O- long head- supraglenoid tubercle of scapula
short head- coracoid process of scapula
I- common tendon to radial tuberosity; bicipital apneurosis to antebrachial fascia covering flexor forearm musculature
A- Flexes forearm and supinates hand (most powerful supinator above 90o of flexion; long head also assisting in flexion
N- musculocuntaneous nerve

Question 6

Brachialis

Answer 6

O-Distal half of the anterior surface of the humerus
I- Coronoid process and tuberosity of the ulna
A- Flexion of forearm (most powerful of 3 primary forearm flexors)
N- Musculocutaneous nerve

Question 7

Brachioradialis

Answer 7

O- Lateral supracondylar ridge of humerus
I- Lateral radius at base of styloid process
A- Flexion of forearm (handshake)
N- Radial nerve

Question 8

Coracobrachialis

Answer 8

O- Coracoid process of scapula
I- Middle 3rd medial surface of humerus
A- Flexion and adduction of humerus
N- Musculocutaneous nerve

Question 9

Triceps Brachii

Answer 9

O- long head- infraglenoid tubercle of scapula
lateral head- posterior surface of humerus proximal to radial groove
medial head- posterior surface of humerus distal to radial groove
I- Posterior surface olecranon process of ulna
A- Extend forearm; long head- acts at shoulder joint to extend and adduct the arm
N- Radial nerve

Question 10

Anconeus

Answer 10

O- Posterior surface lateral epicondyle of humerus
I- Lateral surface of olecranon and proximal posterior surface of ulna
A- Assists triceps in extension of forearm
N- Radial nerve

Question 11

Brachial Artery

Answer 11

• continuation of axillary artery
• courses within neuromuscular compartment through medial brachium
  -ends within cubital fossa where it divides into ulnar and radial arteries
  3 branches:
  1. profunda (deep) brachial branch
  2. superior ulnar collateral
  3. inferior ulnar collateral

Question 12

Profunda (deep) brachial branch of brachial artery

Answer 12

• largest branch
• arises posteromedial aspect of brachial artery
  -accompanies radial nerve around humerus
  ends by dividing into middle and radial collateral arteries
• collateral arteries anastomose with interosseous and radial recurrent arteries

Question 13

Superior ulnar collateral branch of brachial artery

Answer 13

• arises from medial aspect of mid-portion of brachial artery
• courses inferiorly with ulnar nerve to pass posterior to medial epicondyle
• anastomose with posterior ulnar recurrent artery

Question 14

Inferior ulnar collateral

Answer 14

• arises from medial aspect of distal portion of brachial artery
• courses anterior to medial epicondyle
• anastomose primarily with anterior ulnar recurrent artery

Question 15

Superficial veins of brachium

Answer 15

• cephalic veins

- basillic vein

Question 16

Cephalic Vein

Answer 16

• arises from junction of small tributaries on lateral dorsum of hand
• courses superiorly through forearm along lateral surface and through arm along anteroloateral surface of biceps
• courses between deltoid and pectoralis major muscles in shoulder and pectoral regions
• disappears within deltopectoral triangle by piercing costocoracoid membrane to join axillary vein

Question 17

Basilic Vein

Answer 17

• arises from medial dorsum of hand from dorsal venous arch
• ascends the posteromedial aspect of forearm
• medial surface of the arm and pierces brachial fascia at its midpoint

Question 18

medial cubital vein

Answer 18

• joins basilica and cephalic vein superficial to cubital fossa
• many variation

Question 19

Brachial vein

Answer 19

• only deep vein
• formed by union of radial and ulnar veins
• course parallel to brachial artery
• superficial basilic vein runs parallel to brachial vein after piercing brachial fascia
• joins brachial vein to form axillary artery at level of inferior border of trees major muscle

Question 20

Median Nerve

Answer 20

C6-T1

• exits axilla anterior to brachial artery
• becomes medial to brachial artery distally
• course through cubits fossa deep to bicipital aponeurosis
• passes into forearm between 2 heads of pronator trees muscle
• NO branches to brachium

Question 21

Ulnar Nerve

Answer 21

C8-T1

• exits axilla medial to brachial artery within brachial neurovascular compartment
• exits compartment with superior ulnar collateral artery midway between brachium- piercing posterior lamina of medial intramuscular septum
• course along posterior surface of septum- exits arm between the medial epicondyle of humerus and olecranon process of ulna

Question 22

Musculocutaneous nerve

Answer 22

C5-C7

• leaves axilla lateral to axillary artery
• pierces coracobrachialis muscle
• continue inferior between biceps and brachialis
• exits from under the lateral inferior edge of biceps to become lateral ante brachial cutaneous nerve
• in arm innervates muscles of anterior compartment (coracobrachialis, brachialis, biceps)

Question 23

Radial nerve

Answer 23

C5-T1

• exits axilla posterior to brachial artery and anterior t long head of triceps
• passes laterally
• courses between lateral and medial heads of triceps within radial groove with deep brachial artery
• circumvents humerus
• peirces lateral intermuscular septum and goes between brachial is and brachioradialis
• at lateral epicondyle divides into superficial and deep branches
• branches pass via separate routes to forearm
• innervates triceps, portion of skin on posterior surface of arm

Question 24

articular branches to elbow joint

Answer 24

ulnar, musculocutaneous, radial, and median nerve innervate elbow joint before leaving brachium

Question 25

Cubital Fossa Boundaries

Answer 25

``` Lateral- brachioradialis medial- pronator teres superior- line drawn through both humeral epicondyles roof- deep fascia floor- brachial is and supinator muscles ```

Question 26

Cubital fossa contents

Answer 26

1. Tendon of biceps 2. Brachial artery dividing int radial and ulnar arteries 3. median nerve ("TAN")

Question 27

Superficial associated structures of cubital fossa

Answer 27

1. median cubital vein | 2. lateral antebrachial cutaneous nerve (from musculocuntaneous nerve)

Question 28

Deep associated structures of cubital fossa

Answer 28

1. bifurcation of radial nerve into superficial and deep branches