Circulatory and Respiratory Structure and Function
Circulatory system
Circulation is the one way movement of blood through the body which involves 4 main structures:
- Heart
- Function – a double pump containing 2 circuits
- The pulmonary circuit carries blood to and from the lungs
- The systemic circuit carries blood to and from all other parts of the body
- Function – a double pump containing 2 circuits
- Arteries
- Function – to carry away from the heart under high pressure to the capillaries
- Capillaries
- Function – to allow for exchange between the blood and body cells or between the blood and air in the lung tissues
- Veins
- Function – to drain capillaries in the tissues and return the blood to the heart under much lower pressure
Respiratory system
Respiration is the supply of oxygen to the cells and removal of carbon dioxide which involves 7 main structures:
- Nasal cavities
- Function – to filter warm and moisten air
- Pharynx (throat)
- Function – carries air into respiratory tract and food into the digestive system
- Larynx (voice box)
- Function – contains vocal cords for speech
- Trachea (windpipe)
- Function – to conduct air between the larynx and the lungs
- Bronchi
- Function – branches of the trachea that enter lungs and then subdivide to conduct air
- Lungs
- Function – space for the diffusion of gasses to take place
- Alveoli
- Function – tiny air sacs in the lungs where the diffusion of gasses occurs