learningobjectives At the end of the lesson, you should be able to: - Humans Explain the need for a transport system in multicellular

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Collin Hart
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1 transport in humans

2 learningobjectives At the end of the lesson, you should be able to: - Humans Explain the need for a transport system in multicellular organisms Identify the parts of the human circulatory system and their respective functions o Identify 4 heart chambers o Identify 3 main blood vessels and explain their functions o Identify and explain function of blood components State how diffusion facilitates the transport of substances in animals (e.g. diffusion of digested food molecules and oxygen from blood to tissues)

3 funfact It would take about 1,200,000 mosquito bites to completely drain the average human of blood. (Discover magazine, August 2007)

4 whytransport? If you stay within 500 m 1 km of the school, you probably would not mind walking to school

5 whytransport?

6 whytransport? BUT if you stayed at Bedok, Woodlands, or even Boon Lay You would probably take a form of public transport. (or go to a school within walking distance ) WHY?

7 whytransport?

8 whytransport? Likewise, in unicellular organisms, The cell is in direct contact with the external environment. Diffusion alone is enough to: - transport essential materials such as oxygen and nutrients to the cell - remove waste such as carbon dioxide rapidly

9 whytransport?

10 whytransport? In multicellular (complex) organisms, Cells are far from the external environment. Diffusion alone is too slow to: - transport essential materials such as food to the various organs - remove waste products efficiently

11 whytransport? Thus, a transport system is developed to move these substances eg. Blood system in humans This will ensure - a continual supply of nutrients, oxygen and other useful materials for metabolism - the removal of toxic waste products produced by metabolism

12 circulatorysystem The human circulatory system consists of three parts: heart (pumps blood around the body) blood (liquid which carries materials) heart blood vessels blood blood vessels (tubes which carry blood around the body)

13 theheart right atrium left atrium left ventricle right ventricle

14 theheart

15 theheart pumps blood around the body all mammals have hearts that are similar in structure human heart is about the size of our fists made up of cardiac muscles comprises 4 chambers 2 upper chambers called atria (left and right) 2 lower chambers called ventricles (left and right)

16 theheart right side of heart pumps blood to lungs only (which are a short distance from the heart) left side of heart pumps blood around the body (which are further away from the heart) hence left ventricle has thicker muscular walls than the right ventricle

17 theheart The blood is then De-oxygenated This blood pumped passes from the blood from the body Oxygenated blood from the left ventricle right out of enters the right atrium heart the from rest the lungs enter ventricle then out into and then into the of the body the left atrium and the lungs right ventricle flow into the left ventricle Right atrium Right ventricle Left atrium Left ventricle

lungs The blood is then pumped from the left ventricle out of the heart to the rest of the body

18 theheart De-oxygenated blood from the body enters the right atrium and then into the right ventricle Right atrium Right ventricle This blood passes from the right ventricle then out into the lungs The blood is then pumped from the left ventricle out of the heart to the rest of the body Oxygenated blood from the lungs enter the left atrium and flow into the left ventricle Left atrium Left ventricle

19 bloodcirculation In mammals, blood flows through the heart twice in one complete circuit. This is known as double circulation.

20 bloodcirculation From the heart to the lungs and back to the heart, In the lungs, the blood collects oxygen and releases carbon dioxide. Blood that returns to the heart is now rich in oxygen, called oxygenated blood.

21 bloodcirculation From the heart to the rest of the body and back to the heart, As blood passes the small intestine, it collects digested food. The blood supplies all the cells of the body with this digested food together with oxygen picked up in the lungs. After oxygen is deposited in body tissues, the blood now has little oxygen, called deoxygenated blood.

22 circulatorysystem The human circulatory system consists of three parts: heart (pumps blood around the body) blood (liquid which carries materials) heart blood vessels blood blood vessels (tubes which carry blood around the body)

23 bloodcomponents

24 BLOOD Has two main functions: To carry materials round the body. These materials include nutrients, oxygen, carbon dioxide and other waste substances. To protect us against diseases. BLOOD plasma red blood cells white blood cells platelets

25 bloodcomponents BLOOD plasma red blood cells (erythrocytes) white blood cells (leukocytes) Platelets (thrombocytes) PLASMA Pale yellowish liquid Contains mainly water (90%) Contains mainly dissolved substances like nutrients (digested food), hormones, antibodies and waste products (carbon dioxide and urea).

bloodcomponents BLOOD plasma red blood cells (erythrocytes) white blood cells (leukocytes) Platelets (thrombocytes) Contains haemoglobin gives RBC red

26 bloodcomponents BLOOD plasma red blood cells (erythrocytes) white blood cells (leukocytes) Platelets (thrombocytes) Contains haemoglobin gives RBC red colour when combined with oxygen; or purplish colour when combined with carbon dioxide combines reversibly with oxygen so RBC can transport oxygen around the body

27 bloodcomponents BLOOD plasma red blood cells (erythrocytes) white blood cells (leukocytes) Platelets (thrombocytes) Does not contain nuclei More space to contain haemoglobin for oxygen transport

28 bloodcomponents BLOOD plasma red blood cells (erythrocytes) white blood cells (leukocytes) Platelets (thrombocytes) WHITE BLOOD CELLS

29 bloodcomponents BLOOD plasma red blood cells (erythrocytes) white blood cells (leukocytes) Platelets (thrombocytes) WHITE BLOOD CELLS Much bigger in size than RBC Fewer in number than RBC Colourless (no haemoglobin) Contains a nucleus

30 bloodcomponents BLOOD plasma red blood cells (erythrocytes) white blood cells (leukocytes) Platelets (thrombocytes) WHITE BLOOD CELLS Two types: Phagocytes Ingests foreign particles by phagocytosis Lymphocytes Produces antibodies that neutralise bacteria and viruses

31 bloodcomponents BLOOD plasma red blood cells (erythrocytes) white blood cells (leukocytes) Platelets (thrombocytes) PLATELETS Cell fragments (not complete cells) No nucleus Involved in the process of blood clotting

32 circulatorysystem The human circulatory system consists of three parts: blood heart heart blood vessels blood blood vessels

33 bloodvessels The blood vessels are a network of tubes to carry blood around the body. Namely the artery, vein & capillary

34 Artery Vein Capillary Thick muscular wall to withstand high pressure in artery. Elasticity allows artery wall to stretch and recoil to push the blood in spurts along the artery. Thin muscular wall as blood moves more slowly and smoothly in the vein at low pressure. One-cell thick wall to allow rapid diffusion to take place between the blood and surrounding tissues. (Note: Capillary wall is one-cell thick; capillary is NOT one-cell thick)

35 Artery Vein Capillary Valves are absent. Valves are present to prevent backflow of blood. Valves are absent.

36 Artery Vein Capillary Small lumen Larger lumen Small lumen (thinnest wall)

37 Artery Vein Capillary Always transports blood away from heart to the rest of the body. Transports mainly oxygenated blood (except pulmonary artery and umbilical artery). Always transports blood from body towards the heart. Transports mainly deoxygenated blood (except pulmonary vein and umbilical vein). Always carry blood from small arteries (arterioles) to small veins (venules). Allow exchange of materials between blood and body tissues via diffusion.

38 bloodvessels - summary Artery Vein Capillary Structure Thick, elastic, muscular walls Thinner, less elastic, less muscular walls One-cell thick endothelium Functions Transports blood away from the heart Transports blood towards the heart Transports nutrients & waste materials Blood Pressure High blood pressure from heart Lowest blood pressure Low blood pressure

Multicellular Organisms. Sub-Topic 2.6 Transport Systems in Animals

Multicellular Organisms. Sub-Topic 2.6 Transport Systems in Animals Multicellular Organisms Sub-Topic 2.6 Transport Systems in Animals On completion of this sub-topic I will be able to state that: In mammals a transport system is required to deliver essential substances