Module 8: The structure and function of the cardiovascular system

The Body in Action

1. Introduction to the cardiovascular system
2. The heart
   1. Structure of the heart
   2. The heart valves
3. Labelling the heart activity
4. Circulatory system
   1. Animation of the circulation systems
5. Blood vessels
   1. Arteries
   2. Capillaries
   3. Veins
6. Characteristics of blood vessels activity
7. Function of the cardiovascular system
8. Function of the blood

Arteries

The arteries always carry blood away from the heart. They have thick muscular walls and contain elastic cartilage and smooth muscle, allowing the vessels to contract and expand to cope with the high pressure of blood within them. The blood within arteries is generally bright red as it is oxygenated; the one exception to this is the pulmonary artery as this is carrying de-oxygenated blood from the heart to the lungs. Most arteries lie deep in the body, however, some such as the carotid artery are nearer the surface and it is in these places that a pulse can be felt.

By branching and re-branching the arteries progressively become smaller and are known as arterioles. These arterioles then join the smallest blood vessels known as capillaries and it is here that tissue diffusion occurs.