The trachea bifurcates into right and left mainstem bronchi at approximatley the level of T5; this is called the carina. The right mainstem bronchus is wider. shorter, and more vertical in orientation than the left. At the hilum the mainstem bronchi enter the lungs and divide into lobar bronchi, and they correspond to the lobes of the lungs; which means there are three on the right and two on the left.  There is further division into tertiary or segmental bronchi, they extend into the bronchopulmonary segments. Typically there are ten segments in each lung. Each lung functions independently and can be removed surgically.

The bony orbits are cone shaped recesses that contain two globes, extraoccular muscles, blood vessels and nerves. They also contain adipose and connective tissues. The junction of the frontal, sphenoid, and ethmoid bones of the cranium and the lacrimal, maxillary, palatine and zygoma bones of the face form the orbit.

The left pulmonary vein drains the inferior lobes of the left lung and passes toward the left atrium anterior to the bronchi

The superior and inferior mesenteric arteries and veins supply and drain the blood from the large intestine. The major function of the large intestine is to reabsorption of water and the storage and elimination of fecal material.

The tibialis anterior muscle is a long spindle shaped muscle located just lateral to the anterior surface of the tibia. It arises from from the upper two thirds of the lateral surface of the tibia and adjoining interosseous membrane:becoming tendinous over the lower one third. The tibialis anterior runsdistally and medially over the tibia to insert on the plantar surface of the medial cuneform and first metatarsal. Its actions include dorsiflexion of the foot at the ankle joint and together with the tibialis posterior muscle it inverts the foot