Human Circulatory System

Pulmonary circulation specifically refers to the blood flow pathway from the heart to the lungs for oxygenation and back to the heart. Systemic circulation is the circuit to the rest of the body. The question specifically mentions 'lungs' as the destination.

This is correct.

Blood is not known as the fluid of brain.

This is the correct option. Arteries lie deep in the tissue, except at certain places they lie closer to the skin.

This is the correct option. Arteries are blood vessels in which blood is carried away from the heart to different body parts. Capillaries are a network of fine connecting blood vessels. Veins are blood vessels which carry blood towards the heart. 

Capillaries are the smallest vessels; in fact they are microscopic vessels which are in close contact of the body tissue.

Blood flows from the heart, through the aorta (largest artery), into smaller arteries, and finally through capillaries where exchange occurs. This sequence matches Option B. Other options reverse this logical flow.

Blood is the correct answer. The circulatory system's primary function is transporting blood throughout the body, which carries oxygen, nutrients, hormones, and waste products. Water, oil, and minerals are not the main transport medium - they are substances dissolved or carried IN the blood.

Blood vessels are the correct answer. The circulatory system comprises three main components: the heart (pump), blood (transport medium), and blood vessels (the network of tubes). Lungs, bones, and ribcage are parts of other body systems (respiratory, skeletal).

Arteries is correct. Arteries carry oxygenated blood away from the heart to body tissues (except pulmonary arteries which carry deoxygenated blood to lungs). Veins bring blood back to the heart. Capillaries are tiny vessels for exchange. Ventricles are heart chambers.

Veins carry blood toward the heart. After body cells use oxygen, blood becomes deoxygenated (impure) and returns through veins to the right side of the heart, which then pumps it to the lungs via pulmonary arteries. The key distinction is that veins carry blood back to the heart regardless of oxygenation level.

The three types of blood vessels in the circulatory system are arteries (carry blood away from heart), veins (carry blood toward heart), and capillaries (tiny vessels where gas/nutrient exchange occurs between blood and tissues). Arteries and veins are transport vessels; capillaries are exchange vessels.

Heart valves are one-way gates that prevent backflow of blood. The atrioventricular valves (tricuspid on right, mitral on left) prevent backflow from ventricles to atria. Semilunar valves (pulmonary and aortic) prevent backflow from arteries back into ventricles. This ensures blood flows only in the forward direction.

The right side of the heart receives deoxygenated blood from the body through the superior and inferior vena cava. This blood has delivered its oxygen to body tissues and picks up carbon dioxide as waste. The right ventricle then pumps this deoxygenated blood to the lungs via pulmonary arteries for reoxygenation.