Arm region

basic anatomy of ara

1. Arm Region Abhishek Jha

2. Boundaries of arm Superiorly = conditional line connecting the lower borders of the pectoralis major muscle and latissimus dorsi. Inferiorly = conditional line passing above epicondyles on two transverse finger. It is divide into anterior and posterior by t w o vertical line drowing up from epicondyles.

3. Laterally and medially sulcuses are located on skin. Deep fascia form sheath for muscles and neurovascular bundles. It form two fascial septa, and with humerus form two fasical compartments. Sulcuses are located btw muscles of anterior and posterior facial compartments.

4. Anterior region Skin is thin and mobile. Lateral surface is supplied by lower lateral cutaneous nerve of arm (radial nerve branch) below the deltoid. Medially by medial cutaneous nerve and intercostobrachial nerves. Subcutaneous tissue contain cutaneous nerve.

5. Btw superficial and deep fascia superficial veins lies. Lateral side of biceps = Cephalic vein ascends, reaching infraclavicular fossa, pierces clavipectoral fascia to drains into axillary vein. Medially side = Basilica vein ascends, pierces the deep fascia and contribute to formation of axillary vein.

6. Superficial lymph vessels draining superficial tissue of upper arm pass upward to axilla. Cephalic vein follow to interclavicular group of nodes on lateral side. Basilica vein follow to lateral group of axillary nodes. Deep lymphatic vessels draining the muscles and deep structure of arm drain into lateral group of axillary nodes.

7. Brachial fascia surround the arm, where anterior side is thin and posterior is thick. It gives lateral intermuscular septum that extends from the lateral lip of intertubercularis sulcus to the lateral epicondyle. Medial intermuscular septum extends from medial lip of intertubercularis sulcus to medial epicondyle. These septum gives anterior and posterior flexor/fascial compartment.

8. Anterior fascial compartment formed anterior by deep fascia, posteriorly by humerus , medially and laterally by intermuscular septa. It contains biceps brachii, coracobrachialis and brachialis muscles. Musculocutaneous, median and ulnar nerve brachial artery and basilica vein. Radial nerve present on lower part of compartment.

9. Posterior region Skin is thick and mobile. Supplied by upper lateral cutaneous nerve of arm (branch of axillary nerve) and posterior cutaneous nerve of arm( branch of radial nerve). Superficial fascia is thin. Deep and brachial fascia is thick on posterior facial compartment than on anterior region.

10. Posterior fascial compartment formed by anteriorly by humerus, posteriorly by deep fascia, medially and laterally by intermuscular septa. Profunda brachii artery and its branch, vein and radial nerve pass through posterior fascial compartment. Ulnar nerve present in lower part of compartment.