1. Life Processes
Circulatory System.

2. The Blood Vessels:
The blood vessels of the circulatory system would be subdivided into
Arteries
Veins
Capillaries

3. Arteries: Things to note: All arteries lead away from the heart
All arteries carry oxygenated blood with the exception of the pulmonary artery.
Arteries have a thick elastic arterial wall that can withstand the pressure of the blood flowing away from the heart.

5. Veins: Things to note: All veins lead toward the heart
All veins carry deoxygenated blood with the exception of the pulmonary vein.
Veins have semi lunar valves that prevent the backflow of blood

8. Differences between arteries and veins.
Arteries carry oxygenated blood, away from the heart except pulmonary artery
These are mostly deeply situated in the body
These are thick-walled, highly muscular except arteries of cranium and vertebral column
These posses narrow lumen
Valves are absent
These are reddish in color
These show spurty movement of blood giving pulse
Blood in arteries moves with pressure
Arteries empty up at the time of death
If arterial wall is injured, the blood comes out like a ‘fountain’ in a large area all around the artery

9. Differences between arteries and veins continued.
Veins carry deoxygenated blood, towards the heart except pulmonary veins
These are superficial and deep in location
These are thin-walled
These posses wide lumen
Valves are present which provide unidirectional flow of blood
These are bluish in color
These show sluggish movement of blood
Blood in veins moves under very low pressure
Veins get filled up at time of death
If venous wall is injured, blood comes out,
collects in a pool in a small area around vein

11. Capillaries:
Capillaries are only one cell thick, they are very leaky. This is ideal since substances e.g. Oxygen and glucose must pass out and carbon dioxide move in

14. The Human Heart:
The human heart is a muscular pump that pushes blood around the body it is made up of a type of muscle called cardiac muscle.