Edexcel GCSE Biology Unit 8

Small pockets in which gases are exchanged between the air and the blood.

The difference in concentration of a chemical across a membrane.

The net movement of particles from an area of high concentration to an area of low concentration.

Red blood cells. They have a biconcave shape to increase the SA:V for maximum diffusion rate, and no nucleus to maximise space for (answer below).

Protein found in red blood cells which binds with oxygen in the lungs and releases it in the tissues.

Type of white blood cell that surrounds and engulfs foreign cells (due to their flexible cell membranes) to digest them with enzymes.

Type of white blood cell that produces antibodies which bind to foreign cells in order to destroy them.

Cell fragments that have no nuclei. They produce substances needed to clot blood at the site of an injury.

Straw-coloured liquid component of blood which carries dissolved substances such as glucose, carbon dioxide and urea.

Blood vessels that carry blood away from the heart. They have thick walls with elastic and muscle fibres and a narrow lumen as blood flows under high pressure.

Blood vessels that carry blood towards the heart. They have thin walls and a wide lumen as blood flows under low pressure. Also contain valves to prevent backflow of blood.

Blood vessels with one cell thick walls, allowing faster diffusion of substances into and out of the vessels.

Vein that brings deoxygenated blood from the rest of the body.

Artery that carries oxygenated blood to the rest of the body from the left ventricle.

Vein that carries oxygenated blood from the lungs to the left atrium.

Artery that carries deoxygenated blood from the right ventricle to the lungs.

Wall of tissue separating the two sides of the heart.

Stop valves from turning inside out.

Flaps of tissue in the veins and heart to prevent backflow of blood.

Stroke volume x heart rate = ?

A series of exothermic chemical reactions, catalysed by enzymes, that release energy from substances such as glucose or fat which occur continuously in living cells to release energy for metabolic processes.

Glucose + oxygen --> carbon dioxide + water

Glucose -> lactic acid

All the chemical reactions that occur in the body.