Human Circulatory System

The spleen functions as the body's blood bank by storing platelets and red blood cells, filtering damaged blood cells, and releasing stored blood during emergencies. It also plays important roles in immune function and recycling iron from old red blood cells.

Arteriosclerosis is the thickening and hardening of arterial walls due to loss of elasticity. An aneurysm is a weakened bulging area, not thickening, and arthritis is joint inflammation unrelated to arteries.

Pulmonary circulation specifically describes the pathway where deoxygenated blood travels from heart to lungs for oxygenation, then returns oxygenated blood to the heart. Systemic circulation serves the body, while coronary circulation serves heart muscle.

The aorta is the largest artery in human body. It originates from the left ventricle of the heart and extends down to the abdomen.

Coronary arteries supply oxygenated blood to the heart muscle itself. Carotid arteries supply the brain and head, hepatic arteries serve the liver, and pulmonary arteries carry deoxygenated blood from heart to lungs.

This is the correct answer as humans, frogs and lizards have a double circulation system.

This is the correct answer as the heart pumps blood to the gills in fishes (pisces) and not to different parts of the body. Fishes have a two-chambered heart.

This is the correct answer. In the circulatory system, blood flows through three types of vessels. These are veins, arteries and capillaries.

This is the correct answer as all the statements are correct.

Arteries are thick walled blood vessels which carry blood from heart to all parts of the body.

Veins are thin walled blood vessels that carry blood from organs to the heart.

The pulmonary and the umbilical arteries carry deoxygenated blood.

At high altitudes, atmospheric pressure decreases significantly while blood pressure remains relatively constant. This pressure differential causes blood vessels in the nose (which are delicate and close to the surface) to rupture, resulting in nosebleeds. The external pressure drops more than internal blood pressure adjusts, creating outward pressure on capillary walls.

Arteries carry blood away from the heart under high pressure, requiring them to have much thicker, more muscular and elastic walls compared to veins. Veins operate under lower pressure and have thinner walls with valves.

Blood follows the path: heart (right ventricle) to lungs (oxygenation) back to heart (left atrium) then to body tissues. This describes the double circulation pattern with pulmonary and systemic circuits.

The right side of the human heart receives deoxygenated blood that has already circulated through and passed the tissues of the body. This blood is then pumped to the lungs for oxygenation.

The hepatic portal vein carries nutrient-rich blood from the alimentary canal (stomach, intestines) directly to the liver for processing before it enters general circulation. The hepatic artery supplies oxygenated blood to the liver, and the hepatic vein drains processed blood FROM the liver. The portal vein's unique function is first-pass nutrient processing.

Veins carry deoxygenated blood from body tissues back to the heart's right atrium, while arteries carry oxygenated blood away from the heart. The veins have valves to prevent backflow since the blood pressure is lower in the venous system. This distinction is fundamental to understanding circulatory system function.