Anatomy & Physiology Flashcards

Which artery is the main supplier of blood to the brain?

Answer: Internal carotid artery

The internal carotid artery is a major artery in the neck that branches off the common carotid artery and is the primary supplier of oxygenated blood to the brain. It ascends to the base of the skull, where it enters the cranial cavity and gives off several branches that supply the cerebrum. Without its crucial blood supply, brain function would be severely compromised.

Which vessel carries deoxygenated blood from the lower body to the heart?

Answer: Inferior vena cava

The inferior vena cava (IVC) is the largest vein in the human body, responsible for carrying deoxygenated blood from the lower body, including the legs, abdomen, and pelvis, back to the right atrium of the heart. It ascends through the abdominal and thoracic cavities, collecting blood from various smaller veins along its path. This vital vessel ensures proper circulation by returning blood for reoxygenation.

What function do valves serve in peripheral veins?

Answer: Prevent backflow

Valves in peripheral veins play a critical role in preventing the backflow of blood, particularly against gravity, as blood returns to the heart. These one-way valves ensure unidirectional flow, especially in the limbs, by closing to stop blood from pooling. This mechanism is essential for efficient venous return and preventing conditions like venous insufficiency.

Which vessel branches off the abdominal aorta to supply the kidneys?

Answer: Renal artery

The renal arteries are direct branches off the abdominal aorta, specifically designed to supply oxygenated blood to the kidneys. Each kidney receives its blood supply from a single renal artery, which then divides into smaller vessels within the kidney. This dedicated arterial supply is vital for the kidneys' function in filtering blood and producing urine.

Which layer of the artery contains smooth muscle for vasoconstriction?

Answer: Tunica media

The tunica media is the middle layer of the arterial wall, primarily composed of smooth muscle cells and elastic fibers. This layer is responsible for vasoconstriction and vasodilation, allowing arteries to regulate blood flow and maintain blood pressure. Its muscular nature enables arteries to adapt to varying physiological demands by changing their diameter.

What causes venous return to increase during inhalation?

Answer: Negative thoracic pressure

During inhalation, the diaphragm contracts and moves downward, increasing the volume of the thoracic cavity and creating negative thoracic pressure. This negative pressure acts like a vacuum, drawing blood from the abdominal veins into the thoracic veins and subsequently into the heart. This mechanism, known as the respiratory pump, significantly enhances venous return.