Unit 7: Circulatory System

1. Unit 7: Circulatory System Absorption & Circulation

2. A. Absorption 1. Where in the body are nutrients and materials absorbed by the body? a. Lungs – O2

3. b. Small Intestine - nutrients = amino acids, glucose, lipids

4. B. Circulation Distribution of materials 1. Cells - need to live in a watery environment - circulate the material around the cell - single celled organisms and even the cells in your body have to stay moist

5. 2. Human Circulatory System a) Blood – liquid transport material made of 4 parts: 1) Red Blood Cells (RBC) – - use hemoglobin to carry oxygen - red in color because of iron Fe - made in bone marrow - destroyed by the liver and spleen (last for 3 months) - most numerous cell in the body

6. 2) White Blood Cells (WBC) – - large cells – not very numerous - many different kinds of WBC (we will learn about this later) - fight infection – make more WBC

7. 3) Platelets - small cell fragments - made in bone marrow - clot blood = stop bleeding

8. 4) Plasma - liquid part of blood - made mostly of H2O - Yellow in color - Carries – urea, CO2, glucose, amino acids

9. b) Blood Vessels tubes that carry blood 1) Arteries - Carry blood away from the heart - Usually carry oxygenated blood Pulmonary artery carries deoxygenated blood - thick walled and muscular - Pulse = muscular contractions to push blood - Aorta = largest artery in the body

10. 2) Vein - Carry blood to the heart - Usually carry deoxygenated blood - Pulmonary veins carry oxygenated blood - thinner wall than arteries - have valves – stop back flow of blood Valve Animation

11. 3) Capillary - Smallest blood vessels - one cell thick - Found in every part of the body - Diffusion of materials - Blood flows from arteries to capillaries to veins

12. b) Veins - thinner and less muscle than arteries - carry blood back towards the heart - generally carry deoxygenated blood except for pulmonary veins - oxygenated - contain one way valves to keep blood flowing in one direction - blood flow is helped by skeletal muscle Valve Animation

14. c) Capillaries - site where materials are exchanged between cells and blood - 1 cell thick – allows for diffusion - blood passes through 1 cell at a time – single file

15. 3. Heart a) Structure - hollow organ with thick muscular walls - myocardium - muscle = cardiac muscle * specialized muscle tissue Make a fist demo

16. - the heart is divided into 4 chambers * atrium = upper chamber (left and right) * ventricle = lower chamber (left and right) pumps blood out of the heart - divided into the left and right sides by the septum prevent the mixing of blood right side – deoxygenated blood left side – oxygenated blood

17. b) Blood Flow Through the Heart - acts as two pumps in one - 1 pump - right side – deoxygenated blood pumps to the lungs - other pump – left side – oxygenated blood pumps to the body - Atria  Valve  Ventricle  Artery right side - tricuspid valve left side - bicuspid valve

19. c) Blood Circulation - Pulmonary Circulation - circulation to the lungs carbon dioxide leaves the blood, oxygen enters deoxygenated  oxygenated - Systemic Circulation - circulation to the body renal, hepatic, neural, etc. oxygen leaves the blood, carbon dioxide enters oxygenated  deoxygenated

20. Blood returns to the heart through the vena cava  right atrium  tricuspid valve  right ventricle  pulmonary artery  capillaries in the lungs (drop off CO2 pick up O2) – the blood has become oxygenated  pulmonary vein  left atrium  bicuspid valve  left ventricle  aorta  arteries  capillaries in the body (drop off O2 pick up CO2) – the blood becomes deoxygenated  veins  vena cava – to do it all again! Heart  Lungs  Heart  Body it takes ~7 minutes for a red blood cell to complete the trip

21. d) Heart Rate / Heartbeat - heart has its own “pace maker” – bundle of nerves to control and time the rhythm of the beats - sinoatrial node (SA) – causes atria to beat first - artioventricular node (AV) – cause ventricle to beat second two beats more efficient - need for oxygen changes heart rate

22. e) Blood Pressure - because it is a closed circulatory system – there is a force exerted on the heart and arteries - sphygmomanometer – measures blood pressure normal: 120/80 120 – systolic pressure = pressure of ventricle contractions 80 – diastolic pressure = pressure when heart is relaxed

23. 4. Disorders of the Circulatory System a) Atherosclerosis – fatty deposits build up on the artery walls - obstruct blood flow, make arteries less elastic - causes majority of circulatory system diseases b) Hypertension = High Blood Pressure - “silent killer” - a narrowing of the arteries and/or more viscosity to the blood - Damages the heart by making it work harder to pump Blood, could also cause your arteries to rupture – Increases the risk of heart attack and stroke - Causes: excess sodium intake, poor diet, saturated fats, smoking, alcohol, caffeine, obesity, stress, aging, not enough exercise - Treatment / cure: medication, diet, lifestyle

24. c) Heart Attack = Coronary Thrombosis - blockage in the coronary arteries (arteries that bring blood to the heart muscle) - heart muscle begins to die - symptoms: nausea, shortness of breath, chest pain, intense pressure - Treatment – clot dissolving drugs, bypass surgery

25. d) Stroke - blood clots break free and get stuck in a blood vessel in the brain - causes brain cells not to get O2 - lose brain function – depends where it happens e) Anemia - blood lacks ability to carry oxygen - not enough iron