Arm, Cubital Fossa P.T 2024 PDF

L7 Arm and Cubital Fossa Anatomy Department Axillary nerve (circumflex nerve): Origin: from posterior cord of brachial plexus. Root value: C5, 6 nerves. Course & relations: Runs with posterior circumflex humeral vessels through quadrangular space; turns behind the surgical neck of humerus. Branch...

L7 Arm and Cubital Fossa Anatomy Department Axillary nerve (circumflex nerve): Origin: from posterior cord of brachial plexus. Root value: C5, 6 nerves. Course & relations: Runs with posterior circumflex humeral vessels through quadrangular space; turns behind the surgical neck of humerus. Branches: 1. Articular: shoulder joint (from trunk of the nerve). 2. Muscular: to deltoid muscle & teres minor 3. Cutaneous: upper lateral cutaneous nerve of arm to skin on upper part of lateral side of arm (lower ½ of deltoid). Injury of axillary nerve: Causes: fracture surgical neck of humerus or dislocation of the shoulder. Effect: 1. Paralysis of: 1. Deltoid: leading to loss of abduction from 15 to 90, and flattening of shoulder. 2. Teres minor; weakening of lateral rotation of the shoulder. 2. Loss of sensation of upper part of lateral side of arm (over the lower 1/2 of deltoid)  Compartments of The Arm - Two compartments; anterior and posterior, by two Anterior intermuscular septa ( medial and lateral ). A) The anterior compartment of the arm: Three muscles; coracobrachialis, biceps and brachialis, that flex the elbow joint; these muscles are supplied by musculocutaneous nerve. B) The posterior compartment: - Contains the triceps muscle that extends the elbow joint; it is supplied by the radial nerve. - Nerves: of arm includes; Musculocutaneous nerve , radial nerve , part of course of median and ulnar nerves. Posterior - The artery: is the brachial artery and its branches.  Muscles of the arm Coracobrachialis: Origin: From tip of the coracoid process of the scapula together with the short head of biceps. Insertion: It is inserted into the middle of the medial border of the humerus. Nerve Supply: It is innervated by the musculocutaneous nerve. Action: It helps in the flexion & adduction of shoulder joint. Musculocutaneous nerve Biceps brachii: Origin : 1-Short head: from tip of the coracoid process together with the coracobrachialis. 2-Long head: by a tendon from the supraglenoid tubercle. Insertion: - By a single tendon that inserted into radial tuberosity; from the medial border of this tendon, the bicipital aponeurosis passes medially and downwards to be attached into the deep fascia of the forearm. - The aponeurosis protects the underlying brachial artery and median nerve. Nerve supply: Musculocutaneous nerve. Action: The muscle crosses three joints ; shoulder, elbow and superior radioulnar, so it can, therefore act on all of them. 1. The short head is a flexor of the shoulder joint; the long head helps to keep the head of the humerus in normal position during movements at this joint. 2. It is a powerful flexor of the forearm at the elbow joint. 3. It is also the most powerful supinator of the forearm when the elbow joint is flexed as tightening the screw with screw driver. Brachialis: Origin: The muscle arises from the lower half of the anterior surface of the humerus. Insertion: It is inserted into the ulnar tuberosity. Nerve supply: Mainly by the musculocutaneous nerve; the radial nerve supplies the lateral part of the muscle (double nerve supply). Action: It is the principal flexor (pure flexion) of the elbow joint. Triceps brachii: Origin (3 heads): 1.Long head: arises from the infraglenoid tubercle of the scapula. 2.Medial head: arises from the lower half of the posterior surface of the shaft of the humerus below the spiral (radial) groove. 3.Lateral head: arises from oblique line above the radial groove (spiral) of the humerus. Insertion: The three heads form a large tendon which inserts into the upper surface of the olecranon process of the ulna. Nerve supply: By the radial nerve. Action: Extension of the forearm at the elbow joint. Nerves of the arm: Musculocutaneous: nerve of the anterior compartment of the arm. Radial: for the posterior compartment of the arm. Ulnar: crossing the arm giving no branches. Median: crossing the arm giving no branches.  Nerves of the arm Musculocutaneous nerve : Origin: From the lateral cord of the brachial plexus (C5, 6, 7). Course and relations: - The nerve enters the arm by passing through the coracobrachialis muscle; it then descends between the biceps brachii and the brachialis muscles; supplying them, emerging lateral to the tendon of the biceps brachii muscle at the elbow, continues as the lateralcutaneous nerve of the forearm. Branches: 1. Muscular: to coracobrachialis , biceps brachii and brachialis. 2. Lateral cutaneous nerve of forearm: to the skin of lateral surface of forearm. 3. Articular: to elbow and shoulder joints. Median nerve: Origin: The median nerve arises by two roots: 1. Lateral root (C.5, 6, 7): from the lateral cord of the brachial plexus. 2. Medial root (C. 8, T.1): from the medial cord of the brachial plexus; the two roots unite forming the median nerve on the lateral side of 3rd part of axillary artery. Course of median nerve in the arm: - It passes vertically down in the arm lateral to the brachial artery (upper part); about the middle of the arm, it crosses in front of the brachial artery, then descends on its medial side to enter the cubital fossa medial to brachial artery Branches: The median nerve has no major branches in the arm Ulnar nerve: Origin: It is a branch of the medial cord of the brachial plexus (C.7, 8, and T.1). Course of ulnar nerve in the arm : - It descends on the medial side of the third part of the axillary artery and brachial artery. - At the middle of the arm , it pierces the medial intermuscular septum to enter the posterior compartment of the arm; then it descends accompanied with superior ulnar collateral artery, passing behind the medial epicondyle of the humerus (dangerous position). - The ulnar nerve has no branches in the arm Radial nerve: Origin: It arises from the posterior cord of the brachial plexus (C.5, 6,7, 8 and T.1), It is the largest branch of the brachial plexus. Course of radial nerve in the arm : - It descends behind the third part of the axillary artery and then behind the brachial artery , accompanied by the profunda brachii artery. - Then it enters the posterior compartment of the arm; then, the nerve passes obliquely between the lateral and medial heads of the triceps brachii muscle to reach the spiral groove. - At the middle of the arm, the radial nerve pierces the lateral intermuscular septum to enter the anterior compartment of the arm and then descends in a groove between the brachialis and the brachioradialis muscles. 1. In the axilla: a. Nerves to long and medial heads of triceps. b. Posterior cutaneous nerve of the arm. 2. In the spiral groove: a. Nerves to lateral and medial heads of triceps. b. Nerve to anconeus. c. Lower lateral cutaneous nerve of the arm. d. Posterior cutaneous nerve of forearm. 3. In the anterior compartment of the arm: a. Nerves to brachialis, brachioradialis, and extensor carpi radialis longus. b. Articular branches to the elbow joint. c. Deep radial nerve. Terminal branches d. Superficial radial nerve.  Blood vessels of arm Brachial artery: - Beginning: as a continuation of the axillary artery at the lower border of the teres major. - Termination: in the cubital fossa at the level of the neck of the radius by dividing into radial and ulnar arteries. Course: - In the upper part of the arm, the brachial artery is medial to the humerus, then becomes in front of the humerus in the lower part of the arm and separated from it by the brachialis muscle. - The brachial artery is palpable along its whole course since it is only covered by skin and fascia. Branches: 1.Profunda brachii artery (deep brachial artery): - Largest branch of the brachial artery, arising close to the lower border of the teres major muscle. 2. Nutrient artery: to the humerus. 3. Muscular branches: to the muscles of the anterior compartment of the arm.t 4. Superior ulnar collateral artery: passes downwards and medially accompanying the ulnar nerve and both of them pierce the medial intermuscular septum to descend behind the medial epicondyle. 5. Inferior ulnar collateral artery: divides into anterior and posterior branches which descend in front of and behind the medial epicondyle of the humerus. 6. Terminal branches: which are the radial and ulnar arteries. Cubital fossa Def.: It is triangular tissue space in front of elbow, between the arm and forearm. Boundaries: Lateral border: brachioradialis. Medial border: pronator teres. Apex: directed downwards, and formed of meeting of two borders. Base: imaginary line of meeting of two epicondyles. Floor: - Brachialis medially. - Supinator laterally. Roof: - Skin. -Superficial Fascia containing cephalic, basilic and median cubital veins. - Medial and lateral cutaneous nerves of forearm - Bicipital aponeurosis Contents of cubital fossa from medial to lateral: 1- Median nerve: It passes medial to brachial artery and passes between the two heads of pronator teres. 2 - Termination of brachial artery just medial to biceps tendon into radial and ulnar arteries. 3-Tendon of insertion of biceps 4- Radial nerve: It is in front of supinator and overlapped by brachioradialis Identify contents & boundaries of cubital fossa 1 5 2 6 3 7 4 8