The phrenic nerve is credited for innervating the diaphragm and helping us breathe. It originates from the cervical nerves C3, C4, and C5. It enters the thoracic cavity by passing in front of the subclavian arteries and travelling anterior to the root of the lungs. The right and left phrenic nerves innervate the diaphragm, primarily for motor function, but also provide sensory function for the central tendon. If there is an injury to the phrenic nerve, there may be partial or complete paralysis of the diaphragm on the affected side. However, since there is an accessory phrenic nerve, it may be sectioned when there is a case of chronic hiccups. Chronic hiccups result from irritated nerves in the digestive tract or the diaphragm.

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

The inferior gluteal nerve supplies the gluteus maximus. The gluteus medius and gluteus minimus are supplied by the superior gluteal nerve. 

The femoral vein, femoral artery, and femoral nerve all pass through the inguinal canal; the rectus femoris is a muscle and does not pass through this structure. The most medial structure at the entrance of the canal is the femoral vein; the most lateral structure is the femoral nerve.

The thoracoacromial trunk is one of the branches off of the second part of the axillary artery. The four branches make the acronym CAPD. This stands for: Clavicular Acromion Pectoral and Deltoid.

The femoral and popliteal arteries are found in the thigh and leg. The vessel changes from the femoral artery to the popliteal artery after it travels through a foramen, or hole. Of our four answer choices only two of them are holes. The obturator foramen is located in the pelvis. The adductor foramen is located at the adductor magnus muscle in the thigh, making it the only correct answer. 

The brachial plexus is divided into roots, trunks, divisions, cords, and terminal branches. There are three cords which are named the lateral, medial, and posterior because of their locations in the arm. 

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.