Cubital fossa and Brachium

Question 1

Triangular space

Answer 1

Borders: teres minor, teres major, long head triceps
contents: circumflex scapular artery

Question 2

Quadrangular space

Answer 2

borders: teres minor, teres major, long head of the triceps, humerus

Contents: axillary nerve, posterior humeral circumflex artery

Question 3

Brachial fascia

Answer 3

is continuous with fascia of the shoulder muscles above, attached to the humeral epicondyles and olecranon process and continuous with the antebrachial fascia below.

Encases the entire arm in a cylindrical sheath

Fascial extensions to the lateral and medial supracondylar ridges form lateral and medial intermuscular septa, respectively, which partition the arm into anterior and posterior muscular compartments.

Question 4

Medial intermuscular septum

Answer 4

hast two laminae that enclose a neurovascular compartment which SUPERIORLY contains the brachial a. & vv., median n., medial brachial & antebrachial cutaneous nn., and ulnar n.

Question 5

Biceps Brachii

Answer 5

O: long head- supraelnoid tubercle of scapula. Short head- coracoid process of scapula
I: By common tendon to the radial tuberosity; also via the bicipital aponeurosis to the antebrachial fascia covering the flexor forearm musculature.

A: flexes the forearm and supinates the hand; most powerful supinator of hand above 90 degrees of flexion; long head also assists in flexion of the arm.

N: Musculocutaneous N.

Remember: Bye-bye, Biceps. Waving bye-bye supinates.

Question 6

Brachialis

Answer 6

O: distal half of the anterior surface of hte humerus
I: Coronoid proess and tuberosity of the ulna
A: flexion of the forearm (most powerful of three primary forearm flexors)
N: Musculocutaneous N.

Question 7

Brachioradialis

Answer 7

O: lateral supracondylar ridge of humerus

I: lateral radius at base of styloid process

A: flexion ofthe forearm (best mechanical advantage when hand is midway between supination and pronation, i.e. handshake)

N: Radial n.

Question 8

Coracobrachialis

Answer 8

O: coracoid process of scapula

I: middle third, medial surface of humerus

A: flexion, adduction of humerus

N: Musculocutaneous n.

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 o ulna

A: all heads act to extend the forearm; long head also acts at teh shoulder joint to extend and adduct the arm

N: radial n.

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 the forearm

N: Radial N.

Question 11

Brachial Artery

Answer 11

continuation of axillary artery distal to inferior border of teres major

Courses within neurovascular compartment through medial brachium

Ends within cubital fossa where it divides into radial and ulnar arteries.

Branches: Profunda brachial, superior ulnar collateral, inferior ulnar collateral

Question 12

Profunda brachial artery

Answer 12

largest branch of brachial artery
arises from the posteromedial aspect of the brachial artery, ACCOMPANIES THE RADIAL NERVE as it courses around the humerus and ends by dividing into middle and radial collateral arteries which will anastomose mainly with the interosseous and radial recurrent arteries, respectively.

Question 13

Superior ulnar collateral artery

Answer 13

arises from the medial aspect of the mid-portion of the brachial artery, courses inferiorly WITH THE ULNAR NERVE to pass posterior to teh meial picondyle adn will anstomose primarily with the posterior ulnar recurrent artery

Question 14

Inferior ulnar collateral artery

Answer 14

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

Question 15

Cephalic vein

Answer 15

arises from teh junction of small tributaries on the lateral dorsum of the hand (dorsal venous arch) and courses superiorly through the forearm along its lateral surface and through the arm along the anterolateral surface of the biceps. In the shoulder and pectoral regions it courses between the deltoid and pectoralis major muscles to disappear within the deltopectoral triangle where it will pierce the costocoracoid membrane to join the axillary vein.

Question 16

Basilic vein

Answer 16

arises on teh medial dorsum of the hand from the dorsal venous arch, ascends the posteromedial aspect of the forearm, the medial surface of the arm and pierces the brachial fascia at its approxiate midportion.

Question 17

Median cubital vein

Answer 17

the cephalic and basilic veins are joined superficial to the cubital fossa by the median cubital vein. This anastomosis is variable.

Question 18

Brachial veins

Answer 18

deep veins formed by the union of radial and ulnar veins and course parallel to the brachial artery. The superficial basilic vein, after piercing the brachial fascia, runs parallel to the brachial veins. At approximately the level of the inferior border of teres major the basilic vein joins the brachial veins to form the axillary vein.

Question 19

Nerves that provide articular branches to the elbow joint

Answer 19

Median- courses through the cubital fossa deep to the bicipital aponeurosis
Ulnar nerve pierces teh posterior lamina of the medial intermuscular septum and travels with superior ulnar collateral artery inferiorly along the posterior surface of the septum to exit the arm between the medial epicondyle of the humerus and the olecranon process of the ulna.
Musculocutaneous n. pierces coracbrachialis, then runs inferiorly between the bieps and brachialis. Exits from under the lateral inferior edge of the biceps to become the lateral anebrachial cutaneous nerve.
Radial n. pierces the lateral intermuscular septum and comes to lie between the brachialis and brachioradialis muscles. At the lateral epicondyle it divides into superficial and depep branches which pass via separate routes into the forearm.

Question 20

Cubital fossa boundaries and contents

Answer 20

lateral: brachioradialis muscle
medial: pronator teres muscle
superior: line drawn through both humeral epicondyles
Roof: deep fascia
floor: brachialis and supinator muscles

contents: Tendon of the biceps
Brachial Artery dividing into radial and ulnar arteries
Median Nerve

(lateral to medial)

Question 21

Structures associated with the cubital fossa

Answer 21

superficial: median cubital vein, lateral antebrachial cutaneous n. (from MSC n.)

Deep: bifurcation of the radial n. into its superficial and deep branches.