Biology - Chapter 8:Heart and Circulation

How is the shape of a red blood cell is related to its function

It is biconcave shape for increased surface area

flexible to can flow through easily

no nucleus to carry more oxygen

Explain why red blood cells cannot be stored in pure water

swell up and burst

lower water conc. inside than surroundings

water would diffuse inside and burst

Artery

Transports blood away from heart

withstand high pressure

carry oxygenated blood

elastic fibres to help it stretch and recoil with each surge of blood

endothelium layer reduces friction

collagen - protection

Vein

Transports blood to the heart

Carry deoxygenated Blood

have valves

thin walls

Cardiac output

Volume of blood by heart into system in one minute

Stroke volume

Volume of blood pumped each time left ventricle beats

Leukocytes

digests and destroys pathogens also produce antibodies

Erthocytes

Transports oxygen, removes carbon dioxide takes it to lungs to exhale

Role of haemoglobin

bind to oxygen

why can red blood cells not be stored in pure water

swell up and burst (lysis)

lower concentration of water molecules inside than outside it surroundings

water molecules differ inside

Give one reason why the wall of the left ventricle is thicker than the right.

Need to pump blood throughout the whole body .

right only need to pump to lungs so shorter distance