Learning some Advanced Anatomy: Upper Limb Veins, Nerves, and Lymphatics

Lymphatic Drainage of Upper Limb

The superficial lymphatic vessels exist in the skin, fingers, palm of the hands, and flow up the arm in close proximity with the basillic and cephalic veins. Some of these vessels enter into the cubital lymph nodes while some continue and terminate at the humeral axillary lymph nodes. Other nodal locations for superficial vessels are the deltopectoral lymph nodes and the apical axillary lymph nodes. For deeper lymphatic vessels, they flow in cross proximity with the basilic and cephalic veins and terminate at the humeral axillary lymph nodes. These nodes drain the lymph from the following locations: joint capsules, periosteum, tendons, nerves and muscles.

Lymphatic drainage is important for the filtration of harmful toxins to our body. One important clinical notation about the lymph nodes is their relationship to cancer. For my cadaver dissection, the lymph nodes of my cadaver were severely swollen, which lead to our discovery that he died due to prostate cancer. These nodes are usually very small, about the size of a pea but flat, however, his were severely enlarged in the apical axillary lymph nodes for example.

Venous Drainage of Upper Limbs

The two major superficial veins of the upper limbs are the basilic and cephalic. The median cubital vein provides a connection between these two superficial veins. The cephalic vein is located on the lateral side of the upper limb and runs up the arm along the deltopectoral groove into the clavipectoral triangle. It continues on its path toward the costocoracoid membrane and finally terminates at the axillary vein. The basilica vein, in contrast, follows along the medial side of the forearm and ascends up the arm. The basilic runs parallel with the brachial artery and medial cutaneous nerve until it terminates at the axillary vein. A smaller network of veins known as the perforating veins, serve as a connection between the superficial veins and the deep veins of the upper limbs. Common deep veins of the upper limbs are the radial, ulnar and deep brachial to name a few.

The axillary vein dumps into the subclavian vein and at the end of the axillary vein is the point of entry for subclavian vein puncture. This occurs during catheterization, but it is referred to subclavian due to the needle being pushed medially to the start point of the subclavian vein. This central line is necessary to administer parenteral (venous nutrients) fluids and medications.

Nerves of the Upper Limbs

Most nerves of the upper limbs all have a correlating origin at the brachial plexus. The brachial plexus consists of nerves from the anterior rami of C5-T1. The nerves are grouped into lateral, medial, and posterior in the brachial plexus. Surprisingly, the shoulder actually obtains its nerve source from the cervical plexus. This particular network of nerves originates from the first four cranial nerves. Important nerves to notate in the arm are the radial, median, and ulnar nerves.

Several different injuries can occur to the brachial plexus and cause temporary or permanent paralysis of the arm depending on the severity of the injury. When avulses (tears) occur to the brachial plexus it causes this paralysis. If there is no movement it is referred to complete paralysis while some movement is referred to incomplete paralysis. In infants, delivery by pulling excessively on the arms or making sharp angles with the head can cause avulses in the brachial plexus.