Cubital Fossa - Boundaries, Content, Functions

The cubital fossa is a triangular anatomical depression located on the anterior aspect of the elbow. It serves as a vital passage for several important neurovascular structures transitioning between the arm and forearm. It is a common site for venipuncture, blood pressure measurement, and arterial access.

Boundaries

Border	Structure
Superior (Base)	Imaginary line between the medial and lateral epicondyles of the humerus
Medial	Pronator teres muscle
Lateral	Brachioradialis muscle
Apex	Where pronator teres and brachioradialis meet inferiorly
Floor	Brachialis and supinator muscles
Roof	Skin, superficial fascia (containing veins), bicipital aponeurosis

Contents (Lateral to Medial)

Structure	Details
Radial nerve	Lies just under brachioradialis; divides into superficial and deep branches
Biceps brachii tendon	Centrally located; inserts into radial tuberosity
Brachial artery	Lies medial to biceps tendon; bifurcates into radial and ulnar arteries
Median nerve	Most medial structure; passes between heads of pronator teres

Superficial Structures

Median cubital vein: Connects cephalic and basilic veins; common for venipuncture
Medial and lateral cutaneous nerves of the forearm

Function / Significance

Provides a protected passageway for neurovascular structures from the arm to the forearm
Key surface landmark for clinical procedures

Clinical Significance

Venipuncture: Median cubital vein is easily accessible and commonly used for blood draws and IV access
Brachial artery access: Used for catheterization or measuring blood pressure
Nerve compression: Median nerve may be compressed by hypertrophy of pronator teres or other structures within the fossa
Trauma: Deep lacerations or fractures can injure multiple vital structures in this compact area

Comparative Anatomy

The cubital fossa is more pronounced in bipedal primates like humans due to the upright limb posture. Its triangular configuration and superficial vein layout make it uniquely useful for clinical procedures and non-invasive vascular access.