Tag: blood and blood vessels

Arteries have thicker muscular walls to handle high pressure, lack valves (except at the heart exit), and exhibit pulsatile (jerky) flow. Since all these statements accurately describe differences between arteries and veins, D is the correct choice.

Blood capillaries are composed of a single layer of endothelial cells resting on a basement membrane. They lack the smooth muscle and connective tissue layers found in larger blood vessels to facilitate rapid diffusion.

The wall of a blood capillary is extremely thin, consisting only of a single layer of squamous endothelial cells. This structure is essential for the efficient exchange of substances between blood and tissues.

The splenic artery, which supplies the spleen, is one of the three main branches of the coeliac artery (or celiac trunk). The other branches are the left gastric artery and the common hepatic artery.

The hepatic portal vein is unique because it carries blood from the digestive organs to the liver, where it breaks up into a second capillary bed (sinusoids). This allows the liver to process nutrients and toxins absorbed from the gut.

The carotid arteries are major blood vessels in the neck that supply oxygenated blood to the brain, neck, and face. They are essential for maintaining cerebral perfusion.

The hepatic vein carries blood away from the liver. Since the liver is the site of urea production (via the urea cycle), the blood in the hepatic vein has a high concentration of urea compared to blood entering the liver.

Systole refers to the phase of the cardiac cycle where the heart muscle contracts, specifically the atria and ventricles, to pump blood out of the heart chambers.

Arteries, including the pulmonary artery, have thicker walls than veins to withstand the pressure of blood being pumped from the heart. Pulmonary veins, like other veins, have thinner walls and contain valves.

Capillaries are the only blood vessels whose walls are composed of a single layer of endothelial cells, making them single-cell in thickness to facilitate diffusion.