ANA 201 Upper limb 3 Arm, Elbow and Cubital Fossa

Question 1

What muscles are in the anterior compartment of the arm?

Answer 1

the coracobrachialis, brachialis,
and biceps brachii muscles-

Question 2

What muscles are in the posterior compartment of the arm?

Answer 2

the triceps brachii muscle.

Question 3

Origin of coracobrachialis

Answer 3

Tip of the coracoid process of the scapula bone

Question 4

Insertion of the coracobrachialis

Answer 4

Linear roughening on mid-shaft of humerus on medial side

Question 5

Innervation of the coracobrachialis

Answer 5

Musculocutaneous nerve [C5,C6,C7]

Question 6

Action of the coracobrachialis

Answer 6

Flexor of the arm at the glenohumeral joint

Question 7

Origin of the biceps brachii

Answer 7

Long head-supraglenoid tubercle of scapula;
short head-apex of coracoid process

Question 8

Insertion of the biceps brachii

Answer 8

Radial tuberosity

Question 9

Innervation of the biceps brachii

Answer 9

Musculocutaneous nerve [C5,C6,C7]

Question 10

Action of the biceps brachii

Answer 10

Powerful flexor of the forearm at the elbow joint and supinator of the forearm; accessory flexor of the arm at the glenohumeral joint

Question 11

Origin of the brachialis muscle

Answer 11

Anterior aspect of humerus (medial and lateral surfaces) and adjacent intermuscular septae

Question 12

Insertion of the brachialis

Answer 12

Tuberosity of the ulna

Question 13

Innervation of the brachialis

Answer 13

Musculocutaneous nerve [C5,C6, C7];
A small portion of its lateral part may be innervated by the radial nerve

Question 14

Action of the brachialis

Answer 14

Powerful flexor of the forearm at the elbow joint

Question 15

Origin of the triceps brachii

Answer 15

Long head-infraglenoid tubercle of scapula;
medial head-posterior suface of humerus; lateral head-posterior surface of humerus

Question 16

Insertion of the triceps brachii

Answer 16

Superior surface of the Olecranon of the ulna bone

Question 17

Innervation of the triceps brachii

Answer 17

Radial nerve [C6,C7,C8]

Question 18

Action of the triceps brachii

Answer 18

Extension of the forearm at the elbow joint. Long head can also extend and adduct the arm at the shoulder joint

Question 19

What is the major artery of the arm?

Answer 19

The brachial artery

Question 20

Position of the brachial artery

Answer 20

It begins as a continuation of the axillary artery at the lower border of the teres major muscle, it terminates just distal to the elbow joint where it divides into the radial and ulnar arteries.
In the proximal arm, the brachial artery lies on the medial side.
In the distal arm, it moves laterally to assume a position midway between the lateral epicondyle and the medial epicondyle of the humerus.
It crosses anteriorly to the elbow joint where it lies immediately medial to the tendon of the biceps brachii muscle.

Question 21

Branches of the brachial artery

Answer 21

Profunda brachii
Nutrient artery of the humerus
Superior ulnar collateral artery
Inferior ulnar collateral artery
Radial artery
Ulnar artery

Question 22

Venous supply of the arm

Answer 22

The basilic vein passes vertically in the distal half of the arm, penetrates deep fascia to assume a position medial to the brachial artery, and then becomes the axillary vein at the lower border of the teres major muscle. The brachial veins join the basilic, or axillary, vein.
The cephalic vein passes superiorly on the anterolateral aspect of the arm and through the anterior wall of the axilla to reach the axillary vein.

Question 23

Nerves of the arm

Answer 23

Musculocutaneous nerve
Median nerve
Ulnar nerve
Radial nerve

Question 24

Musculocutaneous nerve C5-7

Answer 24

Is a large terminal branch of the lateral cord.
Enters the arm by passing through the coracobrachialis muscle.
It passes diagonally down the arm in the plane between the biceps brachii and brachialis muscles.
After giving rise to motor branches in the arm, it emerges laterally to the tendon of the biceps brachii muscle at the elbow, penetrates deep fascia, and continues as the lateral cutaneous nerve of forearm.

Question 25

Medial, Ulnar and Radial nerve

Answer 25

As discussed in brachial plexus- both the median and ulnar nerve passes through the arm into the forearm with no branches to the arm.
The radial nerve originate from the posterior cord of the brachial plexus, it enters the arm after crossing the inferior margin of the teres major muscle lying posterior to the brachial artery and accompanied by the profundal brachial artery to the posterior aspect of the arm.

Question 26

Definition of elbow joint

Answer 26

The elbow joint is a complex type of hinge type of synovial joint involving three separate articulations, which share a common synovial cavity

Question 27

Articulation of elbow joint

Answer 27

It involves three separate articulations, which share a common synovial cavity viz;
1. The humero-ulnar, between the trochea of the humerus and the trochlear notch of the ulna (a hinge joint)
2. The humero-radial, between the capitulum and the upper concave surface of the radial head (a ball and socket joint)
3. The the superior radio-ulnar, between the head of the radius and the radial notch of the ulna, the head beign held in place by the tough annular ligament (a pivot joint)

Question 28

Capsule of the elbow joint

Answer 28

the capsule is closely applied around this complex articular arrangement.
The non-articular medial and lateral epicondyles are extracapsular
It is thin and loose anteriorly and posteriorly to allow flexion and extension, whereas it is strongly thickened on either side to form the medial andlateral collateral ligaments

Question 29

Ligaments of the elbow joint

Answer 29

The radial collateral ligament (fan-like) is found on the lateral side of the joint, extending from the lateral epicondyle, and blending with the annular ligament of the radius.

The ulnar collateral ligament originates from the medial epicondyle, and attaches to the coronoid process and olecranon of the ulna.

Question 30

Innervation of the elbow joint

Answer 30

nerve supply is by the ulnar, radial and musculocutaneous nerves.
May also have innervation from median nerve as it passes through.

Question 31

Movements of the elbow

Answer 31

two sets of movements take place at the elbow:
Flexion and extension at the humero-ulnar and humero-radial joints;
Pronation and supination at the proximal radio-ulnar

Question 32

MUSCLES INVOLVED IN FLEXION of the elbow

Answer 32

FLEXION;
Biceps brachii
Brachialis
Brachoradialis
Pronator teres

Question 33

Bursae of elbow joint

Answer 33

1. Intratendinous olecranon bursa; which is sometimes present in the tendon of triceps brachii.
2. Subtendinous olecranon bursa; which is located between the olecranon and the triceps tendon, just proximal to its attachement to the olecranon.
3. Subcutaneous olecranon bursa; which is located in the subcutaneous connective tissue over the olecranon

Question 34

BLOOD SUPPLY of the elbow joint

Answer 34

the arteries supplying the elbow joint are derived from the anastomosis around the elbow

Question 35

Describe the Bursitis of the elbow

Answer 35

The subcutaneous olecranon bursa is exposed to injury during falls on the elbow and to infection from abrasions of the skin covering the olecranon.
Repeated excessive pressure and frictions, as occurs in wrestling, for example, may cause this bursa to become inflamed, producing a friction called subcutaneous olecranon bursitis. (“student elbow”)

Question 36

Descibe Subtendinous olecranon bursitis

Answer 36

is much less common.
Results from excessive friction between the triceps tendon and olecranon, e.g; resulting from repeated flexion-extension of the forearm as occurs during some assembly line job.

Question 37

Describe the dislocation of the elbow joint

Answer 37

Posterior dislocation of the elbow joint may occur when children fall on their hands with their elbows flexed.
The distal end of the humerus is driven through the weak anterior part of the fibrous capsule as the radius and ulna dislocate posteriorly.

Question 38

Describe elbow anastomosis

Answer 38

In front of the medial epicondyle;
Anterior ulnar recurrent branch of ulnar artery anastomoses with inferior ulnar collateral branch of brachial artery.

Behind the medial epicondyle;
Posterior ulnar recurrent branch of ulnar artery anastomoses with superior ulnar collateral branch of brachial artery.
In front of lateral epicondyle;

Radial recurrent branch of radial artery anastomoses with the anterior descending branch of profunda brachii artery.

Behind the lateral epicondyle;
Interosseous recurrent artery from posterior interosseous branch of common interosseous of ulnar artery anastomoses with posterior descending branch of profunda brachii artery.

Question 39

What joins the cephalic and basilic vein?

Answer 39

Medial cubital vein

Question 40

How does the musculocutaneous nerve enter the arm

Answer 40

By the Coracobrachialis

Question 41

What does the musculocutaneous nerve of the arm continue as in the e forearm

Answer 41

Lateral cutaneous nerve of the forearm

Question 42

Which is considered the stabilizing bone of the forearm

Answer 42

Ulna

Question 43

The medial and lateral epicondyles of the humerus are encapsulated T/F

Answer 43

False they are extracapsular

Question 44

Muscles involved in extension of the arm

Answer 44

EXTENSION;
Triceps brachii
aconeus

Question 45

Muscles involved in pronation of the arm

Answer 45

PRONATION;
Pronator teres
Pronator quadratus
Flexor carpi radialis

Question 46

Muscles involved in supination of the arm

Answer 46

SUPINATOR;
Biceps brachii
Supinator
Extensor pollicis longus
Extensor policis bravis
Abductor policis longus

Question 47

Purpose of the capsule

Answer 47

Keeps the synovial fluid around the articulating surfaces

Question 48

Subcutaneous bursa is also known as

Answer 48

Olecranon bursa

Question 49

Bursitis occurs when

Answer 49

The subcutaneous bursa is inflamed

Question 50

Describe elbow anastomoses in front of the medial epicondyle;

Answer 50

• Anterior ulnar recurrent branch of ulnar artery anastomoses with inferior ulnar collateral branch of brachial artery.

Question 51

Describe elbow anastomoses behind the medial epicondyle;

Answer 51

• Posterior ulnar recurrent branch of ulnar artery anastomoses with superior ulnar collateral branch of brachial artery.

Question 52

Describe elbow anastomoses In front of lateral epicondyle;

Answer 52

• Radial recurrent branch of radial artery anastomoses with the anterior descending branch of profunda brachii artery.

Question 53

Describe elbow anastomoses behind the lateral epicondyle;

Answer 53

• Interosseous recurrent artery from posterior interosseous branch of common interosseous of ulnar artery anastomoses with posterior descending branch of profunda brachii artery.

Question 54

What is the cubital fossa

Answer 54

The cubital fossa is an important area of transition between the arm and the forearm.
It is located anterior to the elbow joint and is a triangular depression formed between two forearm muscles

Question 55

What muscles form the cubital fossa

Answer 55

The brachioradialis muscle originating from the lateral supraepicondylar ridge of the humerus;
The pronator teres muscle originating from the medial epicondyle of the humerus

Question 56

Boundaries of the cubital fossa

Answer 56

Superiorly–an imaginary line connecting the medial and lateral epicondyles.
* Medially–the pronator teres.
* Laterally–the brachioradialis.
The base of the triangle is an imaginary horizontal line between the medial and lateral epicondyles.
The bed or floor of the fossa is formed mainly by the brachialis muscle.

Question 57

Boundaries of the cubital fossa

Answer 57

Superiorly–an imaginary line connecting the medial and lateral epicondyles.
* Medially–the pronator teres.
* Laterally–the brachioradialis.
The base of the triangle is an imaginary horizontal line between the medial and lateral epicondyles.
The bed or floor of the fossa is formed mainly by the brachialis muscle.

Question 58

Contents of the cubital fossa

Answer 58

The major contents of the cubital fossa, from lateral to medial, are:
1. The tendon of the biceps brachii muscle;
2. The terminal part of brachial artery;
3. The median nerve.

Question 59

How does the brachial artery become the radial and ulnar artery?

Answer 59

The brachial artery normally bifurcates into the radial and ulnar arteries in the apex of the cubital fossa, although this bifurcation may occur much higher in the arm, even in the axilla.

Question 60

When taking a blood pressure reading from a patient, the clinician places the stethoscope where?

Answer 60

over the brachial artery in the cubital fossa.

Question 61

Describe the relation of the medial nerve to the brachial artery

Answer 61

The median nerve lies immediately medial to the brachial artery and leaves the fossa by passing between the ulnar and humeral heads of the pronator teres muscle.

The brachial artery and the median nerve are covered and protected anteriorly in the distal part of the cubital fossa by the bicipital aponeurosis.
This flat connective tissue membrane passes between the medial side of the tendon of the biceps brachii muscle and deep fascia of the forearm.
The sharp medial margin of the bicipital aponeurosis can often be felt.

Question 62

Describe the position of the radial nerve in relation to the cubital fossa

Answer 62

The radial nerve lies just under the lip of the brachioradialis muscle

radial nerve divides into superficial and deep branches: the superficial branch continues into the forearm just deep to the brachioradialis muscle;
the deep branch passes between the two heads of the supinator muscle to access the posterior compartment of the forearm.

Question 63

Describe the roof of the cubital fossa

Answer 63

The roof of the cubital fossa is formed by superficial fascia and skin.
The most important structure within the roof is the median cubital vein, which passes diagonally across the roof and connects the cephalic vein on the lateral side of the upper limb with the basilic vein on the medial side.
The bicipital aponeurosis separates the median cubital vein from the brachial artery and median nerve.
Other structures within the roof are cutaneous nerves-the medial cutaneous and lateral cutaneous nerves of the forearm.

Question 64

The ulnar nerve passes through the cubital fossa T/F

Answer 64

FALSE
The ulnar nerve does not pass through the cubital fossa.
Instead, it passes posterior to the medial epicondyle.

Question 65

Which structure joins the basilic and cephalic vein?

Answer 65

median cubital vein

Question 66

What structure separates the median cubital vein from the brachial artery and median nerve.

Answer 66

The bicipital aponeurosis