Identifying Nerves and Blood Vessels - Anatomy

The brachial plexus is divided into roots, trunks, divisions, cords, and terminal branches. There are three trunks which are named the superior, middle, and inferior based on their locations in the body.

On the left side of the body, the gonadal vein drains into the renal vein. Remember this only happens on the left side. This is because the inferior vena cava is located on the right side of the body, making this a location issue.

The azygos vein runs along the esophagus and spine in the thoracic cavity. It get oxygen-poor blood from the intercostal muscles and drains into the superior vena cava.

The vertebral arteries serve to supply blood to the posterior head. They also run into the skull and branch together into the basilar artery. This artery runs along the cerebellum and supplies it and the brain stem with oxygenated blood.

The brachial plexus is a network of nerves that run though the axial region. This means the only correct choice is the ulnar nerve. The femoral and tibial nerves are located in the lower extremities and the phrenic nerve is located in the thoracic cavity.

The celiac trunk supplies blood to the stomach, liver, spleen, pancreas, and duodenum. It is located in the abdominal cavity above the left and right renal arteries. The renal artery branches off directly from the abdominal aorta.

The thoracodorsal nerve as well as the upper and lower subscapular nerves branch off of the posterior cord. This means the correct answer is the long thoracic nerve which branches off of the inferior trunk.

The three branches off of the human aortic arch are the brachiocephalic trunk, the left common carotid artery, and the left subclavian artery. The brachiocephalic trunk bifurcates into the right subclavian artery and the right common carotid artery.

The maxillary artery supplies blood to the mouth and nose. The axillary artery is located near the armpit and does not supply the head with blood. The carotid supplies most of the tissues of the head, but divides into branches, and most of its blood is taken to the brain. The superficial temporal artery supplies the top and sides of the head.

Cranial nerve (CN) II is also known as the optic nerve, which carries visual stimuli to the brain. CN I is the olfactory nerve and it allows for the detection of odors. CN III is the oculomotor nerve, which allows the eyeball to move. CN IV is the trochlear nerve, which helps rotate the eye inferiorly and laterally.

C7 gives rise to the middle trunk of the brachial plexus because it is the middle root. C5 and C6 are superior while C8 and T1 are inferior.

There are 6 division in the brachial plexus: 3 anterior of the superior, middle, and inferior trunks as well as 3 posterior of the superior, middle, and inferior trunks.

The arm has a few major veins that drain it. The brachial vein drains the deep portions of the arm, the basilic vein drains the medial superficial portion of the arm, and the cephalic vein drains the lateral superficial portion of the arm. The brachial and basilic veins join in the armpit (axilla) to form the axillary vein.

There are 31 pairs of spinal nerves: 8 cervical nerves, 12 thoracic nerves, 5 lumbar nerves, 5 sacral nerves and 1 coccygeal nerve.

Each nerve separates from the spinal cord and exits the spine through the intervertebral foramen found between adjacent vertebrae. The nerves innervate regions of the peripheral nervous system and relay information to and from the central nervous system.

A dermatome is an area of skin innervated by the cutaneous branches of a single spinal nerve. When spinal nerves diverge from the spinal cord, they innervate regions of the periphery and serve to relay information between the periphery and central nervous system. T10 innervates tissue around the level of the umbilicus, or navel. The C4 spinal nerve innervates the top of the shoulder, T4 innervates the level of the chest, T7 innervates slightly lower at the level of the xiphoid process, and L1 innervates the inguinal region around the groin.

When at rest, the neuron initially has a negative membrane potential. At the beginning of an action potential, voltage-gated sodium channels open, allowing sodium ions to enter the cell. This causes the cell to become positively charged compared to the outside of the cell. This process is called depolarization.

After depolarization occurs, the sodium channels close, initiating the absolute refractory period. Voltage-gated potassium channels then open and potassium ions exit the cell. This results in hyperpolarization and the relative refractory period. The potassium channels then close and the sodium-potassium pump returns the cell to its resting potential by removing sodium and collecting potassium.

The aorta has three crucial segments. The aortic arch is the beginning of the aorta, where it exits the left ventricle. Three blood vessels branch from the aortic arch: the brachiocephalic artery, the left subclavian artery, and the left common carotid artery. Around the T4 vertebra the aortic arch transitions into the thoracic aorta. The thoracic aorta has four major branches: the intercostal, bronchial, esophageal, and phrenic arteries. After the thoracic aorta, the vessel transitions into the abdominal aorta.

The vertebral arteries come off of the subclavian arteries, which branch off of the aortic arch (left) and brachiocephalic artery (right).

The recurrent branch of the median nerve innervates the lateral two lumbricals and the thenar muscles. Damage along any part of the median nerve will result in the "papal sign" when the patient is asked to make a fist.

The ulnar nerve divides into the deep and superficial branches when it terminates in the hand. The deep branch innervates the third and fourth lumbricals, while the superficial branch innervates the palmaris brevis. The radial nerve innervates several structures, including the biceps brachii and triceps brachii.

The two medial lumbricals are innervated by the deep branch of the ulnar nerve. The lateral two lumbricals are innervated by the digital branches of the median nerve.

The other answer choices show correct muscle-nerve pairings.