BLOOD VESSELS

Arteries take blood away from the heart.

BLOOD VESSELS

Arteries take blood away from the heart. Artery walls are thickened with connective tissue to

withstand blood pressure, yet elastic enough to expand and contract to even out pressure from each heart beat.

BLOOD VESSELS

Arteries take blood away from the heart. Artery walls are thickened with connective tissue to

withstand blood pressure, yet elastic enough to expand and contract to even out pressure from each heart beat.

When arteries lose their elasticity (eg. Because of poor diet, or from disease) high blood pressure develops, which puts strain on the heart, aff ects kidneys and can even cause arteries to burst.

**Add picture of human**

BLOOD VESSELS

Arteries divide into smaller vessels called arterioles, which supply blood to capillaries.

BLOOD VESSELS

Arteries divide into smaller vessels called arterioles, which supply blood to capillaries.

Capillaries are the smallest blood vessels; their walls are only one cell thick, allowing rapid exchange of materials between the blood and individual cells.

BLOOD VESSELS

Arteries divide into smaller vessels called arterioles, which supply blood to capillaries.

Capillaries are the smallest blood vessels; their walls are only one cell thick, allowing rapid exchange of materials between the blood and individual cells.

Blood enters capillaries under pressure, forcing fluid and useful materials out of capillaries to surrounding cells.

BLOOD VESSELS

Arteries divide into smaller vessels called arterioles, which supply blood to capillaries.

Capillaries are the smallest blood vessels; their walls are only one cell thick, allowing rapid exchange of materials between the blood and individual cells.

Blood enters capillaries under pressure, forcing fluid and useful materials out of capillaries to surrounding cells.

Fluid containing waste products or cell secretions is drawn into the venule end of a capillary by osmosis and diff usion.

** now stick in the ‘blood movement through…” diagram**

BLOOD VESSELS

The reduction in the volume of blood fluid, and friction between blood cells and capillary walls, causes blood pressure to drop, so that blood flowing through veins is of very low pressure.

VEINS

The reduction in the volume of blood fluid, and friction between blood cells and capillary walls, causes blood pressure to drop, so that blood flowing through veins is of very low pressure.

Veins carry blood back to the heart – they have thinner walls than arteries.

VEINS

The reduction in the volume of blood fluid, and friction between blood cells and capillary walls, causes blood pressure to drop, so that blood flowing through veins is of very low pressure.

Veins carry blood back to the heart – they have thinner walls than arteries.

The lumen (in picture) of a vein is wider than that of an artery – valves are present in veins.

VEINS

The reduction in the volume of blood fluid, and friction between blood cells and capillary walls, causes blood pressure to drop, so that blood flowing through veins is of very low pressure.

Veins carry blood back to the heart – they have thinner walls than arteries.

The lumen (in picture) of a vein is wider than that of an artery – valves are present in veins.

**Glue in vein diagram**

VEINS

The reduction in the volume of blood fluid, and friction between blood cells and capillary walls, causes blood pressure to drop, so that blood flowing through veins is of very low pressure.

Veins carry blood back to the heart – they have thinner walls than arteries.

The lumen (in picture) of a vein is wider than that of an artery – valves are present in veins.

Blood moves through veins towards the heart by:- The squeezing of muscles against the walls of veins

VEINS

The reduction in the volume of blood fluid, and friction between blood cells and capillary walls, causes blood pressure to drop, so that blood flowing through veins is of very low pressure.

Veins carry blood back to the heart – they have thinner walls than arteries.

The lumen (in picture) of a vein is wider than that of an artery – valves are present in veins.

Blood moves through veins towards the heart by:- The squeezing of muscles against the walls of veins- Gravity- Pressure in the chest cavity during inspiration

‘pulling’ blood into the heart.

VEINS

The reduction in the volume of blood fl uid, and friction between blood cells and capillary walls, causes blood pressure to drop, so that blood fl owing through veins is of very low pressure.

Veins carry blood back to the heart – they have thinner walls than arteries.

The lumen (in picture) of a vein is wider than that of an artery – valves are present in veins.

Blood moves through veins towards the heart by:- The squeezing of muscles against the walls of veins- Gravity- Pressure in the chest cavity during inspiration ‘pulling’

blood into the heart.- Some (very low) blood pressure helping push blood

through the veins. ** Now glue in vein diagram**

VEINS