transport in humans

What vessels carry blood to the heart from the body?

Pulmonary veins, upper vena cava, lower vena cava.

What are the main blood vessels leaving the heart?

Pulmonary arteries and the aorta.

Which blood vessel carries blood to the lungs?

Pulmonary artery.

What is the function of the renal artery?

It carries blood to the kidneys.

What is the role of the hepatic portal vein?

It carries blood from the small intestine to the liver.

What is the structure of arteries?

Thick elastic walls to withstand high blood pressure.

Why do veins have valves?

To prevent backflow of blood.

What are the distinguishing features of capillary walls?

They are made of a single layer of flattened cells allowing for rapid substance diffusion.

What is the function of tissue fluid?

It transports dissolved substances between tissue cells and blood capillaries.

What is the role of hemoglobin in red blood cells?

To transport oxygen by binding reversibly to form oxyhemoglobin.

What are the two types of white blood cells and their functions?

Phagocytes (engulf and destroy foreign particles) and lymphocytes (produce antibodies).

What do platelets do when blood vessels are damaged?

They release an enzyme that helps form a clot to prevent blood loss.

What are the different ABO blood groups?

A, B, AB, and O.

Why can blood type O be considered a universal donor?

It has no antigens present on red blood cells.

What is the function of the heart's septum?

It prevents mixing of deoxygenated and oxygenated blood.

What happens during ventricular systole?

The ventricular muscles contract, increasing pressure and forcing blood out of the heart.

What is the effect of coronary artery occlusion?

It can deprive heart muscles of blood and oxygen, potentially leading to a heart attack.

Identify a possible cause of coronary heart disease.

Unhealthy diet high in cholesterol and saturated fats.

What preventative measure can help reduce the risk of coronary heart disease?

Maintaining a healthy diet and engaging in regular physical exercise.