The Arm Anatomy PDF

The arm Dr. Asaad AL-SHOUK M.D.PH.D. The arm  Fascia  Anterior compartment  Biceps brachii  Brachialis  Coracobrachialis  Posterior compartment  Triceps  Brachial artery Blood pressure Fascia  The arm is enclosed in a sheath of deep...

The arm Dr. Asaad AL-SHOUK M.D.PH.D. The arm  Fascia  Anterior compartment  Biceps brachii  Brachialis  Coracobrachialis  Posterior compartment  Triceps  Brachial artery Blood pressure Fascia  The arm is enclosed in a sheath of deep fascia from which two fascial intermuscular septa extend to the medial and lateral supracondylar ridges of the Compartments  The medial and lateral intermuscular septa divide the arm into anterior and posterior fascial compartments. Anterior compartment contains three muscles  Biceps brachii Anterior compartment contains three muscles  Biceps brachii  Coracobrachialis Anterior compartment contains three muscles  Biceps brachii  Coracobrachialis  Brachialis biceps brachialis Anterior compartment  The nerve of the compartment is the musculocutaneous nerve  the artery is the brachial artery Biceps brachii  This muscle has 2 short head heads of origin (as its name implies), Long head long head (which is lateral, L. for L.) and short head which is medial Long head of biceps brachii  arises from the supraglenoid tubercle of the scapula within the capsule of the shoulder joint Long head of biceps brachii  emerges at the top of the intertubercular sulcus  surrounded by a tube-like extension of synovial membrane Long head of biceps brachii  lies in the sulcus short head then joins the short head Long head Medial head of biceps brachii Coracoid process  arises from the tip of the coracoid process of the coracobrachialis scapula in common with coracobrachialis short head muscle Biceps brachii  The muscle lies in front of brachialis with the musculocutaneous nerve sandwiched between them biceps biceps brachialis brachialis Insertion of biceps brachii  The tendon is inserted into the radial tuberosity Insertion of biceps brachii  A bursa is present between the tendon and radial tuberosity Bicipital aponeurosis  An extension from the tendon of biceps brachii  A thin sheet of connective tissue that passes medially to blend with the deep fascia of the forearm Action of biceps brachii  The muscle is a powerful flexor and supinator of the forearm Alimentary muscle Action of biceps brachii  its long head helps in flexion at the shoulder Action of biceps brachii  The supinator action of biceps is due to its insertion onto the posterior aspect of the radial tuberosity Action of biceps brachii  when the biceps contracts, not only is the forearm flexed but the radius unwinds as its tuberosity is rotated anteriorly i.e. the forearm supinates Brachialis origin  Arises from the front of the distal part of the humerus and brachialis brachialis the intermuscular septa Medial & lateral intermuscular septa Brachialis insertion  Is inserted into the coronoid process and tuberosity of the ulna. brachialis Brachialis action  Passing in front of the elbow joint the muscle is a powerful flexor of the elbow Coracobrachialis origin  Is a small muscle  arises from the tip of the coracoid process in common with the short head of biceps brachii Coracobrachialis insertion  into the middle third of the short medial surface of head of the humerus. biceps Coracobrachialis action  It is a weak flexor and adductor of the shoulder Coracobrachialis  The musculocutaneous nerve passes through the muscle giving its branch of supply before doing so Posterior compartment of the arm  Contains one muscle with three heads (triceps) Posterior compartment of the arm  the nerve of the compartment is the radial nerve Posterior compartment of the arm  The artery of the compartment is the profunda brachii and ulnar Ul;nar Profunda collateral arteries collaterals brachii branches of the brachial artery Triceps As its name indicates this muscle has three heads of origin  Long medial  Lateral  Medial lateral long Long head of triceps  arises from the infraglenoid tubercle of the scapula Lateral head of triceps  arises from the posterior surface of the humerus superior to the radial groove Medial head of triceps  Arises from the posterior surface of the humerus inferior to the radial groove Radial nerve in the radial groove Triceps heads  It might help to understand the relations of the heads to consider long lateral a superficial part of the muscle formed biceps of the long and lateral heads lie side by side and are comparable to lateral long biceps Triceps heads  the medial head is actually in a deeper plane and is comparable to brachialis brachialis in that it medial is deep and takes origin from the lower part of the shaft and the intermuscular septum Triceps insertion  The tendon of the muscle is inserted into the olecranon of the ulna Triceps action  The muscle is an extensor of the elbow Triceps action  its long head arising from the infraglenoid tubercle aids in extending the shoulder joint and is an important factor in the stability of the abducted shoulder Bursae related to triceps tendon  Subcutaneous bursa  located in the subcutaneous tissue  Subtendinous olecranon bursa  located between the tendon and olecranon Student’s elbow The subcutaneous bursa is liable to be inflamed by repeated friction this is called "student's elbow " Brachial artery  is the continuation of the axillary artery Brachial artery  At the cubital fossa in front of the elbow joint, it ends opposite the neck of the radius by dividing into radial and ulnar arteries Median nerve  The median nerve is formed by the union of the medial and lateral roots lateral to the axillary artery Median n. Median nerve  The median nerve crosses anterior to the brachial artery in the middle of the arm Median nerve  at the elbow, the median nerve lies Brachial a. medial to the Median n. brachial artery