ANA 201 Upper limb 3 Arm, Elbow and Cubital Fossa Flashcards
What muscles are in the anterior compartment of the arm?
the coracobrachialis, brachialis,
and biceps brachii muscles-
What muscles are in the posterior compartment of the arm?
the triceps brachii muscle.
Origin of coracobrachialis
Tip of the coracoid process of the scapula bone
Insertion of the coracobrachialis
Linear roughening on mid-shaft of humerus on medial side
Innervation of the coracobrachialis
Musculocutaneous nerve [C5,C6,C7]
Action of the coracobrachialis
Flexor of the arm at the glenohumeral joint
Origin of the biceps brachii
Long head-supraglenoid tubercle of scapula;
short head-apex of coracoid process
Insertion of the biceps brachii
Radial tuberosity
Innervation of the biceps brachii
Musculocutaneous nerve [C5,C6,C7]
Action of the biceps brachii
Powerful flexor of the forearm at the elbow joint and supinator of the forearm; accessory flexor of the arm at the glenohumeral joint
Origin of the brachialis muscle
Anterior aspect of humerus (medial and lateral surfaces) and adjacent intermuscular septae
Insertion of the brachialis
Tuberosity of the ulna
Innervation of the brachialis
Musculocutaneous nerve [C5,C6, C7];
A small portion of its lateral part may be innervated by the radial nerve
Action of the brachialis
Powerful flexor of the forearm at the elbow joint
Origin of the triceps brachii
Long head-infraglenoid tubercle of scapula;
medial head-posterior suface of humerus; lateral head-posterior surface of humerus
Insertion of the triceps brachii
Superior surface of the Olecranon of the ulna bone
Innervation of the triceps brachii
Radial nerve [C6,C7,C8]
Action of the triceps brachii
Extension of the forearm at the elbow joint. Long head can also extend and adduct the arm at the shoulder joint
What is the major artery of the arm?
The brachial artery
Position of the brachial artery
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.
Branches of the brachial artery
Profunda brachii
Nutrient artery of the humerus
Superior ulnar collateral artery
Inferior ulnar collateral artery
Radial artery
Ulnar artery
Venous supply of the arm
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.
Nerves of the arm
Musculocutaneous nerve
Median nerve
Ulnar nerve
Radial nerve
Musculocutaneous nerve C5-7
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.
Medial, Ulnar and Radial nerve
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.
Definition of elbow joint
The elbow joint is a complex type of hinge type of synovial joint involving three separate articulations, which share a common synovial cavity
Articulation of elbow joint
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)
Capsule of the elbow joint
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
Ligaments of the elbow joint
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.
Innervation of the elbow joint
nerve supply is by the ulnar, radial and musculocutaneous nerves.
May also have innervation from median nerve as it passes through.
Movements of the elbow
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
MUSCLES INVOLVED IN FLEXION of the elbow
FLEXION;
Biceps brachii
Brachialis
Brachoradialis
Pronator teres
Bursae of elbow joint
- Intratendinous olecranon bursa; which is sometimes present in the tendon of triceps brachii.
- Subtendinous olecranon bursa; which is located between the olecranon and the triceps tendon, just proximal to its attachement to the olecranon.
- Subcutaneous olecranon bursa; which is located in the subcutaneous connective tissue over the olecranon
BLOOD SUPPLY of the elbow joint
the arteries supplying the elbow joint are derived from the anastomosis around the elbow
Describe the Bursitis of the elbow
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”)
Descibe Subtendinous olecranon bursitis
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.
Describe the dislocation of the elbow joint
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.
Describe elbow anastomosis
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.
What joins the cephalic and basilic vein?
Medial cubital vein
How does the musculocutaneous nerve enter the arm
By the Coracobrachialis
What does the musculocutaneous nerve of the arm continue as in the e forearm
Lateral cutaneous nerve of the forearm
Which is considered the stabilizing bone of the forearm
Ulna
The medial and lateral epicondyles of the humerus are encapsulated T/F
False they are extracapsular
Muscles involved in extension of the arm
EXTENSION;
Triceps brachii
aconeus
Muscles involved in pronation of the arm
PRONATION;
Pronator teres
Pronator quadratus
Flexor carpi radialis
Muscles involved in supination of the arm
SUPINATOR;
Biceps brachii
Supinator
Extensor pollicis longus
Extensor policis bravis
Abductor policis longus
Purpose of the capsule
Keeps the synovial fluid around the articulating surfaces
Subcutaneous bursa is also known as
Olecranon bursa
Bursitis occurs when
The subcutaneous bursa is inflamed
Describe elbow anastomoses in front of the medial epicondyle;
• Anterior ulnar recurrent branch of ulnar artery anastomoses with inferior ulnar collateral branch of brachial artery.
Describe elbow anastomoses behind the medial epicondyle;
• Posterior ulnar recurrent branch of ulnar artery anastomoses with superior ulnar collateral branch of brachial artery.
Describe elbow anastomoses In front of lateral epicondyle;
• Radial recurrent branch of radial artery anastomoses with the anterior descending branch of profunda brachii artery.
Describe elbow anastomoses 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.
What is the cubital fossa
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
What muscles form the cubital fossa
The brachioradialis muscle originating from the lateral supraepicondylar ridge of the humerus;
The pronator teres muscle originating from the medial epicondyle of the humerus
Boundaries of the cubital fossa
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.
Boundaries of the cubital fossa
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.
Contents of the cubital fossa
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.
How does the brachial artery become the radial and ulnar artery?
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.
When taking a blood pressure reading from a patient, the clinician places the stethoscope where?
over the brachial artery in the cubital fossa.
Describe the relation of the medial nerve to the brachial artery
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.
Describe the position of the radial nerve in relation to the cubital fossa
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.
Describe the roof of the cubital fossa
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.
The ulnar nerve passes through the cubital fossa T/F
FALSE
The ulnar nerve does not pass through the cubital fossa.
Instead, it passes posterior to the medial epicondyle.
Which structure joins the basilic and cephalic vein?
median cubital vein
What structure separates the median cubital vein from the brachial artery and median nerve.
The bicipital aponeurosis
