The circulatory system

The circulatory system

Our body’s public transport system

Our transport systemBlood

Blood cells Blood plasma

Red BiconcaveNo nucleushaemoglobin White

IrregularContain nucleusSome produce antibodiesSome swallow bacteria

PlateletsCell fragmentsResponsible for blood clotting

Contains: water, CO2, Glucose, amino acids, salts, urea, hormones.

Blood vessels

Blood flow

Comparing blood vesselsfeature artery Vein Capillary

Function

Wall thickness

Do the walls contain elastic

fibers?

How wide are the vessels?

Valves

Blood pressure

transport blood from transport blood from allows exchange heart to all organs organs to heart of substances Thickest thinner thinnest-1cell thick Yes less no

Narrow widest narrowest

No yes no

Highest lowest lower

Heart structure

Exchange of substances between blood & body cells

Heart disease

Factors causing heart disease:

1. lack of exercise2. diet rich in animal fat (cholesterol).

3. eating too much salt4. stress5. genetic factors6. smoking