2026 IGCSE - Transport in Animals

The circulatory system is...

a system of blood vessels with a pump and valves to insure one-way blood flow

The heart functions by...

contracting the muscles of the ventricles and atria and the actions of the valves

What is the effect of physical activity on heart rate?

Physical activity increases heart rate and cardiac output to supply working muscles with oxygen and glucose to increase respiration

Coronary heart disease is caused by...

blockage of the coronary artery

Risk factors of coronary heart disease are...

diet, lack of exercise, stress, smoking, genetic disposition, age and sex

Structures of the veins, arteries and capillaries are...

relative thickness of the wall, diameter of lumen and presence of valves.

Components of blood are...

red blood cells, white blood cells, platelets and plasma

The structures of the mammalian heart are...

the muscular wall, septum, left and right ventricles, left and right atria, one-way valves and coronary arteries

Blood is pumped...

AWAY from the heart in arteries and RETURNS through the veins

The activity of the heart can be monitored by...

electrocardiogram, pulse rate and listening to the sound of valves closing

The function of the red blood cell is...

carrying oxygen

The function of white blood cells are...

phagocytosis and antibody production

The function of platelets is...

clotting the blood

The function of plasma is...

transport of blood cells, ions, nutrients, urea, hormones and carbon dioxide

The function of blood clotting is...

prevention of blood loss and entry of pathogens