Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Biology: Circulatory System
Transcript of Biology: Circulatory System
System Heart Blood
Vessels Blood STRUCTURE Double Circulation - pulmonary circulation to the lungs and systemic circulation to the rest of the body. DOUBLE CIRCULATION SYSTEM BLOOD PRESSURE The chambers of the heart contract, blood is forced out into the arteries, the Heart is in SYSTOLE.
The chambers of the heart relax, they fill with blood, the Heart is in DIASTOLE.
Blood pressure changes in the arteries, when thr heart empties and fills.
Normal systolic blood pressure is 120mmHg. Normal diastolic blood pressure is 80mmHg. ARTERIES thick muscle walls to smooth out the pulses of blood flow from the heart.arteries carry oxygenated blood away from the heart. the only exception is the pulmonary artery, which carries deoxygenated blood to the lungs. VEINS large to carry blood under low pressure back to the heart. veins carry deoxygenated blood back to the heart. the only exception is the pulmonary vein which carries oxygenated blood from the lungs to the left atrium. CAPILLARIES very thin walls so the blood can exchange dissolved food and gases easily with the cells by diffusion. substances diffuse in and out of the blood in the capillaries. PLASMA-
yellow liquis - transports disssolved food molecules, carbon dioxide, urea, all blood cells. mostly water. RED BLOOD CELLS-
biconcave - transport oxygen, contain haemoglobin. WHITE BLOOD CELLS-
defend the body against attack by microbes. LYMPHOCYTES-
white blood cells - produce antibodies to destroy microorganisms. memory lymphocytes give us immunity to specific diseases. PHAGOCYTES-
white blood cells - engulf and digest microorganisms. PLATELETS-
cell fragments which help clot the blood. BLOOD CLOTTING-
injury -> platelets arrive -> platelets break open -> if CALCIUM IONS present THROMBIN formed -> thrombin acts on FIBRINOGEN to turn it into FIBRIN -> fibrin forms a mass of insoluble protein threads which forms a clot and then a sscsab as red blood cells become trapped in it. IMMUNE RESPONSE-
white blood cells protect the body against pathogens. 70% are phagocytes. pathogens have antigens on their cell surfaces. lymphocytes make antibodies in response to these antigens. the antibodies stick to the antigens and destroy the pathogen by:
1) make pathogens stick together so phagocytes can engulf more easily.
2) acting as abel so phagocytes can recognise the pathogen more easily.
3) causing bacterial cells to burst open.
4) neutralising toxisn produced by bacteria.