transport

TRANSPORT

• The importance of having a transport system in some multicellular organisms

- to transport oxygen and food to cells and

to remove carbon dioxide and metabolic

wastes from them

THE COMPOSITION OF HUMAN BLOOD

BLOOD CELLS

BLOOD VESSELS

STRUCTURE OFHUMAN HEART

CARDIAC CYCLE The sequence of events that makes up one heart beat, comprise one systole and one diastole

Systole- contraction of heart muscles

Atrial syatole

Ventricular systole

Diastole- relaxation of heart muscles

Atrial systole

Ventricular systole

1 2

3 4

What happen to the atrioventricular valves, the pressure and the blood in atriums and ventricles ?

Ventricular walls relax, dropping its pressure. Pressure in aorta and pulmonary artery is higher, causing the semilunar valves to close

Atrial wall contracts, pressure in atrium is higher than the ventricles, causing the atrioventricular valve to open

Ventricles contract, raising the ventricular pressure exceeding the pressure in atrium, av- valves closes

Semilunar valves open for the outflow of blood from ventricles.

Pressure in atrium drops, the whole heart muscle relaxes. Blood from pulmonary veins and vena cava enter the atriums.

Blood Circulation1. Arterial systole – blood from right

atrium enters the right ventricle.

2. Ventricular systole- ventricle contracts, pushing blood from ventricle into the pulmonary artery and to the lungs

3. Respiratory gaseous exchange in the alveoli of the lungs, blood is reoxygenated

4. Oxygenated blood from lungs enters the left atrium ( during atrial diastole).

5. Blood enters the left ventricle from the atrium and is pumped into the dorsal aorta ( during ventricular systole, whence the semi-lunar valve opens.

6. Oxygenated blood in the aorta is circulated to all over the tissues in the body through arterial system.

7&8.Gaseous exchange in the body tissues. Oxygen is taken up by the cells in the tissue for cell respiration. CO2 is released into the blood .

9&10. deoxygenated blood is carried back to the heart.

11. The blood enters the atrium.

BLOOD CLOTTING