7. Transportation

7.2 Transport in humans

• Describe the circulatory system as a system of tubes with a pump and valves to ensure one way flow of blood

• Describe the double circulation in terms of a low pressure circulation to the lungs and a high pressure circulation to the body tissues and relate these differences to the different functions of the two circuits

7.2.1 Heart

• Describe the structure of the heart including the muscular wall and septum, chambers, valves and associated blood vessels

• Describe the function of the heart in terms of muscular contraction and the working of the valves

• Investigate, state and explain the effect of physical activity on pulse rate

• Describe coronary heart disease in terms of the blockage of coronary arteries and state the possible causes (diet, stress and smoking) and preventive measures

7.2.2 Arteries, veins and capillaries

• Name the main blood vessels to and from the heart, lungs, liver and kidney

• Describe the structure and functions of arteries, veins and capillaries Supplement

• Explain how structure and function are related in arteries, veins and capillaries

• Describe the transfer of materials between capillaries and tissue fluid

7.2.3 Blood

• Identify red and white blood cells as seen under the light microscope on prepared slides, and in diagrams and photomicrographs

• List the components of blood as red blood cells, white blood cells, platelets and plasma

• State the functions of blood

• red blood cells – haemoglobin and oxygen transport

• white blood cells – phagocytosis and antibody formation

• platelets – causing clotting (no details)

• plasma – transport of blood cells, ions, soluble nutrients, hormones, carbon dioxide, urea and plasma proteins Supplement

• Describe the immune system in terms of antibody production, tissue rejection and phagocytosis

• Describe the function of the lymphatic system in circulation of body fluids, and the production of lymphocytes

• Describe the process of clotting (fibrinogen to fibrin only)

[Type here]Ms. Binoli Herath

Blood and it’s components

1.Blood is a bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells.

2. When it reaches the lungs, gas exchange occurs when carbon dioxide is diffused out of the blood into the alveoli and oxygen is diffused into the blood.

3. This oxygenated blood is pumped to the left hand side of the heart in the pulmonary vein and enters the left atrium.

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4. From here it passes through the bicuspid valve, through the ventricle and taken all around the body by the aorta.

5.Blood contains antibodies, nutrients, oxygen and much more to help the body work.

6.Blood is a constantly circulating fluid providing the body with nutrition, oxygen, and waste removal.

7.A liquid called plasma makes up about half of the content of blood.

8.Plasma contains proteins that help blood to clot, transport substances through the blood, and perform other functions.

9.Blood plasma also contains glucose and other dissolved nutrients.

10.About half of blood volume is composed of blood cells:

• Red blood cells, which carry oxygen to the tissues• White blood cells, which fight infections• Platelets, smaller cells that help blood to clot

[Type here]Ms. Binoli Herath

11.Blood is conducted through blood vessels (arteries and veins).

12.Blood is prevented from clotting in the blood vessels by their smoothness, and the finely tuned balance of clotting factors.

Blood performs many important functions within the body including:

Supply of oxygen to tissues (bound to hemoglobin, which is carried in red cells) Supply of nutrients such as glucose, amino acids, and fatty acids (dissolved in the blood or bound to plasma

proteins (e.g., blood lipids)) Removal of waste such as carbon dioxide, urea, and lactic acid Immunological functions, including circulation of white blood cells, and detection of foreign material by

antibodies Coagulation, the response to a broken blood vessel, the conversion of blood from a liquid to a semi-solid

gel to stop bleeding. Messenger functions, including the transport of hormones and the signaling of tissue damage Regulation of body pH Regulation of core body temperature

[Type here]Ms. Binoli Herath

[Type here]Ms. Binoli Herath