TRANSPORTATION AND CIRCULATION THE CIRCULATORY SYSTEM

Transcription

1 TRANSPORTATION AND CIRCULATION THE CIRCULATORY SYSTEM 1

2 1. Moves nutrients to and waste from cells 2. Pathway for disease fighting agents and hormones 3. Control of body temperature homeostasis 2

3 The Circulatory System The network of organs and vessels that is responsible for the flow of blood, nutrients, hormones, oxygen and other gases to and from cells. 3

4 Unicellular and Simple Multicellular No need for organized transport All cells remain in direct contact with the environment Diffusion allows movement of oxygen in and waste out 4

5 Three cell layers means that the middle layer (mesoderm) does not come in direct contact with circulating fluids Complex Multicellular Need a circulation system to bring them into contact with oxygen and nutrients 5

6 Open Circulatory System Blood carrying oxygen and nutrients is pumped into body cavities where it bathes the cells directly No distinction between blood and interstitial fluid (the fluid that occupies spaces between cells) Commonly found in snails, insects and crustaceans 6

7 Closed Transportation System Encloses blood in tubes or vessels Blood is pumped around the body through this network Fluid only circulates in one direction, passing through the gas exchange system 7

8 The Heart 8

9 2 Chambered Fish Blood travels through the heart only once during each complete circuit around the body (single loop) 1) deoxygenated blood enters the atrium and exits the ventricle 2) oxygenated at the capillaries in the gills 3) oxygenated blood travels to the organs (uses up the oxygen) 4) deoxygenated blood returns to the atrium 9

10 3 Chambered Reptiles/Amphibians Blood travels through the heart twice before a circuit around the body (double loop) 1) deoxygenated blood from the body enters the right atrium 2) oxygenated blood from the lungs enter the left atrium 3) mixing of blood occurs in the ventricle 4) this blood is then pumped to the body 2 Atria (Right and Left), 1 Ventricle 10

11 4 Chambered Mammals/Birds Blood travels through the heart twice before a circuit around the body (double loop) 1) deoxygenated blood from the body enters the RA and then the RV 2) deoxygenated blood from the RV gets sent to the lungs 3) oxygenated blood from the lungs enters the LA and the the LV 4) oxygenated blood from the LV gets sent to the body 2 Atria, 2 Ventricles 11

12 There are three primary closed cycles: 1) Cardiac circulation pathway of blood within the heart 2) Pulmonary circulation blood from the heart to lungs and back 3) Systemic circulation blood from the heart to the rest of the body There are three main elements to a circulatory system: 1) Transport medium fluid that transports materials throughout the body 2) Transport vessels a network of tubes in which the fluid circulates 3) A pumping mechanism pump that pushes fluid through the tubes 12

13 There are three primary closed cycles: 1) Cardiac circulation pathway of blood within the heart 2) Pulmonary circulation blood from the heart to lungs and back 3) Systemic circulation blood from the heart to the rest of the body There are three main elements to a circulatory system: 1) Transport medium fluid that transports materials throughout the body 2) Transport vessels a network of tubes in which the fluid circulates 3) A pumping mechanism pump that pushes fluid through the tubes 13

14 Check your pulse! Place you index finger and middle finger on either 1) your neck to the side of your windpipe 2) on your wrist between the bone and the tendon (thumb side) Count the number of beats in 15 seconds and multiply this by 4. 14

15 What is a pulse? Often confused with the heart rate but refers instead to how many times per minute the arteries expand and contract in response to the pumping action of the heart. The pulse rate is exactly equal to the heartbeat, as the contractions of the heart cause the increases in blood pressure 9n the arteries that lead to a noticeable pulse. Taking the pulse is, therefore, a direct measure of heart rate. Pulse is often measured by feeling the arteries of the wrist or neck. 15

16 ARTERIES Arterioles Take blood away from the heart at high pressure Strong thick walls (muscles, elastic fibers and fibrous tissue)* Lumen narrow (varies as a pulse of passes through) 16

17 CAPILLARIES Supplies cells with their requirements & take away waste products Only one cell thick Brings blood into close contact with body tissues allowing diffusion 17

18 VEINS Venules Return blood to the heart at low pressure Thin walls, mainly fibrous tissues Wide lumen Valves to prevent back flow 18

19 Arteries are red Veins are blue NOPE! 19

20 So why do veins look blue? 20

21 Check your pulse! Jog in place for a minute, do jumping jacks or do some other SAFE form of exercise for 1 minute. Immediately sit down and count the number of beats in 15 seconds and multiply this by 4. Compare your resting pulse to your pulse just after exercising. 21