heart, lungs and blood vessels

Heart

A hollow and muscular organ that pumps blood throughout the body

Lungs

The main organs of the respiratory system, responsible for gas exchange where oxygen is exchange with carbon dioxide in the blood

Gaseous exchange

The process where oxygen is taken in from the air and exchanged for carbon dioxide

Left ventricle

Pumps oxygenated blood to the body through the aorta

Right ventricle

Pumps deoxygenated blood to the lungs through the pulmonary artery

Atria

Upper chambers of the heart that receive blood, the right atrium receives blood from the vena cava and the left atrium receives blood from the pulmonary vein

Aorta

The largest artery in the body, carries oxygenated blood to the body from the left ventricle

Vena cava

The largest vein in the body, carries deoxygenated blood from the body back to the heart, specifically to the right atrium

Pulmonary artery

Carries deoxygenated blood from the heart to the lungs

Pulmonary vein

Carries oxygenated blood from the lungs to the heart

Coronary arteries

Blood vessels that supply the muscle of the heart

Trachea

Allows air to pass to and from lungs

Bronchi

Two short branches at the lower end of the trachea that carry air into the lungs

Alveoli

Tiny sacs of lung tissue where gaseous exchange takes place with the blood

Capillary network

An interconnecting network of capillaries surrounding the alveoli

Arteries

Blood vessels with thick walls, a narrow lumen and elastic fibres, they carry blood away from the heart

Veins

Blood vessels with valves to prevent the back-flow of blood, thin walls and a large lumen, they carry blood back to the heart

Capillaries

Smallest and thinnest blood vessels where the exchange of molecules takes place, they consist of a single layer of cells

Blood flow rate

The volume of blood passing through a blood vessel per unit of time

Pacemaker

The natural resting heart rate is controlled by a group of cells in the right atrium that act as a pacemaker

Artificial pacemaker

Electrical devices used to correct irregularities in the heart rate

Double circulatory system

The human circulatory system is a double system that has a circuit linking the heart and lungs and a circuit that links the heart to the rest of the body