The Cardiovascular System

What are the main components of blood?

Red blood cells (RBC), white blood cells (WBC), platelets, and plasma.

What pigment binds oxygen for transport in red blood cells?

Haemoglobin.

What is the function of red blood cells (erythrocytes)?

Carries oxygen, nutrients, and waste.

What is the primary role of white blood cells (leucocytes)?

Fights diseases and protects the body from infection.

What do platelets (thrombocytes) do?

Gather at the site of injury and help the clotting process.

What is plasma?

A mixture of water and dissolved substances including protein, electrolytes, and nutrients.

What are arteries characterized by?

Thickest wall, withstand high pressure, and carry blood away from the heart.

What is the role of capillaries?

Site of exchange; form extensive branching networks through tissues.

What are the characteristics of veins?

Less muscular and stretchy, with lower pressure flow and special valves to ensure one-way blood flow.

What do the atria of the heart do?

Receive blood.

What functions do the ventricles serve?

Eject blood from the heart.

What is the purpose of the septum in the heart?

Divides the heart into left and right sides.

What type of blood does the right atrium receive?

Deoxygenated blood.

How does deoxygenated blood flow through the heart?

Vena cava → Right atrium → Tricuspid valve → Right ventricle —> Pulmonary valve → Pulmonary artery → Lungs

What type of blood does the left atrium receive?

oxygenated.

How does oxygenated blood flow through the heart?

Pulmonary vein → Left atrium → Bicuspid/Mitral valve → Left ventricle —> Aortic valve → Aorta → Body

What is the pulmonary circuit responsible for?

Carrying deoxygenated blood from the body to the lungs.

What occurs in the lungs during the pulmonary circuit?

Oxygen replaces carbon dioxide; blood becomes oxygenated.

What characterizes the systemic circuit?

Carries oxygenated blood from the lungs to the body.

What initiates the cardiac cycle?

An impulse from the SA node.

How do the left and right sides of the heart work during the cardiac cycle?

Simultaneously.

What happens to atriums during the cardiac cycle as it receives blood from veins?

Each atrium pumps blood into their respective ventricles.

What is myogenic contraction?

The heart contracts by itself without nerve stimulation.