In this sub-unit of human physiology we will explore contents of:

• Arteries convey blood at high pressure from the ventricles to the tissues of the body


• Arteries have muscle cells and elastic fibres in their walls


• The muscle and elastic fibres assist in maintaining blood pressure between pump cycles


• Blood flows through tissues in capillaries


• Capillaries have permeable walls that allow exchange of material between cells in the tissue and the blood in the capillary


• Veins collect blood at low pressure from the tissues of the body and return it to the atria of the heart


• Valves in veins and the heart ensure circulation of blood by preventing backflow