Transport in Mammals IGCSE for Grade 9.pptx

Transport in Mammals IGCSE for Grade 9.pptx

1. Transport in Humans

2. Why do we need transport system

3. Let’s see closer Do you remember cell? What characteristics of life find in the cell?

4. Activities of the cell Can you name activities of the cell and what they require and released?

5. Transport system in mammals Blood vessel Heart Blood

6. Transport in mammals Closed, the blood always remained in the vessel Double, blood travels twice through the heart on one complete circulation

7. Transport in mammals Double: systemic and pulmonary circulation Systemic circulation, blood pumped out of the left ventricle travel along parts of body and back to the right atrium Pulmonary circulation, The blood pumped out of the right ventricle into the lungs and return it to the left atrium

8. Blood vessels

9. 3 layers of blood vessel an inner endothelium (lining tissue), called the tunica intima , made up of a layer of flat cells (squamous epithelium ) fitting together; this layer is very smooth, minimising friction with the moving blood a middle layer called the tunica media (‘middle coat ’), containing smooth muscle, collagen and elastic fibres an outer layer called the tunica externa (‘outer coat ’), containing elastic fibres and collagen fibres .

10. Cross section of an artery Structure vs function

11. Cross section of a vein Structure vs function

12. Veins Veins contain half-moon valves, or semilunar valves, formed from their endothelium

13. Cross section of a capillary Structure vs function

14. Thickness of the walls is related to their functions

15. The cardiac cycle

16. Atrial systole atrium contracts blood flows from atrium to the ventricle

17. Ventricular Systole Ventricles contract Atrioventricular valves close Semi lunar valves open

18. Diastole whole heart is relaxed

19. Electrical impulses control the pace. These impulses are provided by two electrical nodes: the  sinoatrial (SA) node and the  atrioventricular ( AV) node. Called the natural pacemakers of the heart.

20. Diastole no electrical activity during this phase Atrial Systole Sinoatrial node fires an electrical impulse , it spreads throughout the right and left atria, causing the muscle to contract and push blood into the ventricles. Towards the end of the atrial systole the electrical impulse reaches and triggers the atrioventricular node.

21. Ventricular Systole The atrioventricular node (after a short delay) fires an impulse, it spreads throughout the thick ventricular muscle, causing contraction from the bottom of the ventricles, pushing blood through the lungs and body.

22. Blood Blood is made of blood cells and blood plasma Blood cells  Red blood cell, white blood cell, and platelets Blood plasma  liquid part of blood, contain water, nutrients, protein, hormone .

23. Red Blood Cells (erythrocytes) Bi-concave shape increases surface area and keeps the haemoglobin as close as possible to the membrane Shape makes them flexible to squeeze along capillaries. No nucleus or mitochondria, so more room for haemoglobin. Cannot reproduce, and die after 3 months, so are manufactured in liver, spleen and bone marrow.

24. White blood cells (leucocytes) Two parts: phagocytes and lymphocytes Phagocytes destroy the invaders by phagocytosis Lymphocytes B plasma produce antibody Killer T cells kill the infected cells

25. B cells

26. The action of the T cells Cytotoxic T cell Perforin Granzymes TCR CD8 Class I MHC molecule Target cell Peptide antigen Pore Released cytotoxic T cell Dying target cell 1 . 2 . 3 . lysis

27. BLOOD PLASMA This is the fluid that the cells are surrounded by. It contains Nutrients Waste Products, Plasma Proteins

28. T issue fluid Cells are bathed in tissue fluid Source of nutrients and oxygen Blood at the arterial end is under high pressure which forces water and small molecules out into interstitial spaces (ultrafiltration) Proteins are too big to move so they create an osmotic effect which keeps some fluid in the capillary. The pressure at the venous end is low so water, waste and carbon dioxide move back in to the capillary.

29. Lymphatic system Not all tissue fluid circulates back into the capillary Some drains into the lymphatic system Similar in composition to tissue fluid but has more fatty substances Works in defence system as well.

30. Body Fluids: A Comparison

31. The relationship between Blood, Tissue Fluid and Lymph