Transport in blood

• All will know the composition of blood

• Most will be able to describe and explain the role each part of our blood has

• Some will be able to suggest the benefits of haemoglobin

Transport in blood

• What is the function of blood?

• How much blood does an average adult human have?

5.5 litres 5.5 litres

blood cells(45% ofvolume)

plasma (55% ofvolume)

red blood cell

white blood cell

platelet

Human blood smear

X 500

Blood components

Blood component Function/facts

Plasma

RBC

WBC

Platelet

Plasma

liquid part of blood

plasma transports:-

• soluble food molecules

• waste products (CO2, urea)

Red blood cells

• transport oxygen

• specialised to do this

White blood cells

• the bodies “defence”

• part of the immune system

• have a nucleus

Platelets

• Small fragments of cells

• No nucleus

• Help blood clot when you cut yourself

Features of a red blood cell

Disc-shaped, witha dent on each side,

creates a large surface area for gas

exchange.

A large surface area compared to volume, so oxygen is always close to the surface.

No nucleus - more space for

haemoglobin and so more oxygen.

Contains haemoglobin,

a special pigmentthat combines/carries

oxygen.

haemoglobinhaemoglobin

Red blood cells and haemoglobin

Oxyhaemoglobin makes red blood cells appear bright red.

oxygenoxygen

++ oxyhaemoglobinoxyhaemoglobin

++oxygenoxygen

haemoglobinhaemoglobin

Oxygen is then able to diffuse into the body’s cells.

Why do red blood cells appear a dull red colour when oxygen is released?

oxyhaemoglobinoxyhaemoglobin