The circulatory system
10
The circulatory system Our body’s public transport system
description
For IGCSE O-Level Biology students Chapter 9
Transcript of 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
