Blood

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Slide 1

Blood

By the end of the lesson you should be able to:

State the composition of Blood

State the function of red blood cells and plasma

Explain the function of haemoglobin in the transport of oxygen

State the function of macrophages and lymphocytes

Slide 2

the average human has 5 litres of blood

it is a transporting fluid

it carries vital substances to all parts of the body

Blood

Slide 3

Human blood smear

X 500

Slide 4

plasma (55%)

red blood cells

(5-6-million /ml)

white blood cells

(5000/ml)

platelets

skool blood plasma

Slide 5

x 1000

Slide 6

Plasma

liquid part of blood

plasma transports:-

soluble food molecules

waste products

hormones

antibodies

Slide 7

Red blood cells (RBCs)

transport oxygen

specialised to do this

Also carry some CO2

Slide 8

White blood cells

the bodies “defence”

part of the immune system

much larger than RBCs

far fewer

have a nucleus

4000-13000 per mm3

2 types

phagocytes and lymphocytes

Slide 9

Platelets

if you get cut:-

platelets produce

tiny fibrin threads

these form a web-like

mesh that traps blood

cells.

these harden forming a clot, or "scab."

150,000 to 400,000 per mm3

Slide 10

Red blood cells specialisations

2) no nucleus

 extra space inside

3) contain haemoglobin

 the oxygen carrying molecule

 250million molecules / cell

1) biconcave shape

increases the surface area so more oxygen can be carried

Slide 11

Haemoglobin

gives red blood cells their colour

can carry up to 4 molecules of O2

associates and dissociates with O2

contains iron

Slide 12

When there is a high concentration of oxygen e.g in the alveoli haemoglobin combines with oxygen to form oxyhaemoglobin. When the blood reaches the tissue which have a low concentration of oxygen the haemoglobin dissociates with the oxygen and the oxygen is released into body tissues