B2 Heart and blood vessels

What is the heart?

The heart is an organ that pumps blood around the body in a double circulatory system.

Which ventricle pumps blood to the lungs?

Right ventricle

- pumps blood to the lungs where gas exchange takes place

Which ventricle pumps blood to the body?

Left ventricle

- pumps blood around the rest of the body.

What circulatory system do humans have?

Double circulatory system

Vena cava (vein)

a large vein carrying deoxygenated blood into the heart

Right atrium

Receives deoxygenated blood from the body

Where are the pacemaker cells located?

right atrium

What do the pacemaker cells do?

Controls the natural resting heart rate

Right ventricle

pumps deoxygenated blood to the lungs for gas exchange

Pulmonary artery

artery carrying deoxygenated blood from the heart to the lungs

Aorta (artery)

takes oxygenated blood to the body from heart

Pulmonary vein

carries oxygenated blood from the lungs to the heart

Left atrium

receives oxygenated blood from the lungs

Left ventricle

pumps oxygenated blood to the rest of the body

Why does the left side of the heart have a thicker wall?

to help pump oxygenated blood back to the rest of body

What are the three different type of blood vessels?

artery, vein, capillary

What is the role of arteries?

transport blood away from the heart to the organs

- they all carry oxygenated blood (except the pulmonary artery)

What is the role of capillaries?

They are a smaller branch of arteries

- they allow exchange of gases, nutrients, hormones between blood and tissues

What adaptations does arteries have?

- elastic fibres to stretch

- thick layers of muscles to stay strong due to the high pressure when pumping blood

What are the adaptations of capillaries?

- thin walls and pass very close to body cells

= more efficient exchange of waste products (CO2) and glucose/oxygen

What is the role of veins?

carry deoxygenated blood to the heart (except the pulmonary vein)

What are the adaptations of veins?

- thinner walls due to a lower blood flow pressure

- wider cross-section to counteract the low pressure limiting blood flow

- valves to prevent backflow of blood

Define pulmonary

relating to the lungs

Pulmonary vein - transports oxygenated blood from lungs to heart

Pulmonary artery - transports deoxygenated blood from heart to lungs

What is the role of valves in the heart?

prevent backflow of blood

calculate heart rate

Heart rate = cardiac output ÷ stroke volume

calculate stroke volume

stroke volume = cardiac output ÷ heart rate

calculate cardiac output

cardiac output = stroke volume x heart rate

calculate rate of blood flow

the rate of blood flow = volume of blood / number of minutes