cv system structure

Arteries structure and function

• thick walls, elastic fibre, layer of smooth muscle

• Resist high pressure blood

• Can stretch when blood flows through

• Allow blood to be diverted where it’s needed in the body (working muscles)

Capillaries structure and function

• one cell thick

• Allow efficient gaseous exchange

Veins structure and function

• One way valves

• Prevent back flow of blood

• Ensure blood return from the heart

Valves structure and function

• elastic tissue

• To allow movement of blood in one direction only and control the flow of blood

Atria structure and function

• thick muscular walls

• Pump blood to the ventricles

Ventricles structure and function

• thick muscular walls

• Pump blood to the lungs and body and tolerate high pressure

Summarise the flow of blood within the heart during a cardiac cycle

• pressure builds up in the atria

• Some blood passes through from right atrium to ventricle

• Atrial systole - blood flows to the right ventricle

• Through tricuspid valve

• Blood flows through pulmonary artery to lungs

• Oxygenated blood flows back to heart through pulmonary vein