Antecubital fossa Flashcards
What are the surface boundaries of the antecubital fossa?
Base (red] = line joining the medial and lateral epicondyles of the humerus
Lateral (green, radial) = medial border of brachioradialis
Medial (blue, ulnar) = lateral border of pronator teres
Apex (yello) = directed inferiorly. Meeting point of lateral and medial borders
What are the roof (and other structures in the same plane) and floor of the antecubital fossa?
Roof = bicipital aponeurosis, deep fascia and skin. The medial cubital vein lies above the deep fascia but below the skin.
In the same plane:
- Medially: medial cutaneous nerve of the forearm and basilic vein
- Laterally: lateral cutaneous nerve of the forearm and cephalic vein
Floor = brachialis (more medial) and supinator (lateral) muscles
What are the contents of the antecubital fossa?
From lateral to medial (Really Need Booze To Be At My Nicest)
* Radial nerve (gives rise to posteiror interosseous branch)
* Biceps tendon (insertes into the tuberosity of the radius)
* Brachial artery (bifurcates into the radial and ulnar arteries at the apex)
* Median nerve
Note the ulnar nerve lies posterior to the medial epicondyle of the humerus and is NOT in the antecubital fossa
With regards to the median nerve, describe the:
- Source
- Relations in the antecubital fossa
- Exit from the fossa
- Supply
C5-T1, formed by union of medial and lateral cords of the brachial plexus
Relations:
- Superficial: bicipital aponeurosis and median cubital vein
- Deep: brachialis muscle
- Medial: pronator teres and medial cutaneous nerve of the forearm
- Lateral: brachial artery. i.e. the median nerve is medial to the brachial artery in the ACF
Exit: passes between two heads of pronator teres
Supplies
- Motor: most of long flexors of the forearm and the thenar muscles
- Sensory (cutaneous): skin of the elbow, wrist, radial aspect of the palm of the hand
Cephalic vein:
- course
- relevance to Picc lines
Starts from the lateral end of the dorsal venous arch
- Ascends the lateral border of the forearm and arm
- (Lies in the roof (lateral) of the ACF )
- Enters the deltopectoral groove
- Pierces the clavipectoral fascia
- Drains into the axillary vein
PICC lines via the cephalic vein frequenly fail to pass into the axillary vein because get stuck at the point where hte cephalic vein takes a sharp turn to pierce the clavipectoral fascia.
Therefore is easier to insert a peripherally inserted central catheter line through a median cubital vein or a basilic vein rather than a cephalic vein
Basilic vein
- course
- Starts medially on the dorsum of the hand
- Ascends on the medial side of the forearm (and through roof of ACF on medial side)
- Progresses up the arm -> pierces the deep fascia medial to biceps brachii
- Combines with the brachial veins at the lower border of teres major: forms axillary vein
Describe the median cubital vein
- Originates from the cephalic vein
- Ascends medially in the antecubital fossa, superficial to the bicipital aponeurosis
- Joins the basilic vein
Note usually forms an ‘H’ shaped pattern with the cephalic and basilic veins, but this can vary
Describe the course and supply of the brachial artery
- Axillary artery continues into the arm as the brachial artery
- Initially lies medially, but soon turns towards lateral aspect of the arm. Fairly superficial
- In ACF: lies beneath the bicipital aponeurosis with the median nerve (lies LATERAL to the median nerve)
- Terminates in the ACF by dividing into radial and ulnar arteries
- Supplies the muscles of the flexor compartment of the arm
Describe the bicipital aponeurosis
A strong fibrous band
- starts from the medial border of the lower end of the biceps muscle, progresses medially and inferiorly to blend with the deep fascia of the forearm
- crosses superior to the the brachial artery and median nerve, but inferior to the medial cubital vein
note i.e. protects the brachial artery
Name 4 clinical applications of the ACF
- Blood pressure measurement
- Venepucture
- PICC lines
- Median nerve block
