Biology Unit 3 Continued
- Created by: Leah Gibbons
- Created on: 02-05-12 16:39
How the small intestine is adapted for the absobtion of food
Very long (plenty time for absorption)
Many Villi (large surface area)
villi, no blood capillaries (food to pass into)
Villi have lacteals (fat absorption)
Villi Walls, one cell think (easy absorption of food molecules)
Exchance surfaces in animals
alveoli, small 'sacs', end of bronchioles, gas exchange takes place, maximise diffusion of oxygen + carbon dioxide
gas/solute exchange, depends on large surface area, moist surfaces, short diffusion distances, large concentration gradient
The Circulatory System
transport substances e.g. oxygen & glucose, to cells where used, removes waste, e.g. carbon dioxide, urea
made up of 3 parts:
- the heart
- the blood vessels
- the blood
The Heart
cardian muscle, two pumps, right side pumps blood to lungs, left side pumps blood round the body, top chambers = atria, lower chambers…
Comments
No comments have yet been made