Biology Grade 9 - Unit B1 Blood Circulatory System

Flashcards for Biology Grade 9 - Unit B1 Blood Circulatory System

Blood Circulatory System

The main transport system in the human body for substance transport and protection against diseases.

Human Blood Circulatory System

Consists of blood, blood vessels, and the heart.

Heart

A muscular organ, approximately the size of a clenched fist, that pumps blood into blood vessels to all parts of the body.

Blood

A red fluid composed of plasma, red blood cells, white blood cells, and platelets.

Blood Plasma

Pale yellowish liquid, about 55% of blood, consisting mainly of water and dissolved substances like glucose, salts, gases, proteins, and waste substances.

Blood cells and platelets

Blood cells and platelets that make up about 45% of the blood; includes red blood cells, white blood cells and cell fragments.

Red Blood Cells (RBCs)

Blood cells which contain the red pigment haemoglobin, which carries oxygen around the body.

White Blood Cells (WBCs)

Protect the body against diseases by killing pathogenic germs or producing antibodies.

Platelets

Small cell fragments found in blood that help in blood clotting.

Blood Vessels

Tube-like structures that transport blood to all parts of the body.

Arteries

Blood vessels that carry blood away from the heart; typically carry oxygen-rich blood under high pressure.

Veins

Blood vessels that carry blood towards the heart; typically carry blood rich in carbon dioxide under low pressure.

Capillaries

Tiny blood vessels that allow exchange of substances between blood and cells in adjacent tissues.

Pulse

Stretching and recoiling of an artery every time the heart pumps blood into it.

Cardiovascular Diseases

Diseases that affect the proper functioning of the heart and blood vessels.

Heart attack

Occurs when the artery supplying blood to heart muscles is blocked, decreasing oxygen and nutrient supply.

Stroke

Occurs when an artery supplying nutrients and oxygen to the brain is blocked.

Hypertension

When blood pressure increases above the normal range and can damage the lining of blood vessels.