CIRCULATION Blood and Blood Vessels

Transcription

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2 CIRCULATION Blood and Blood Vessels Blood Vessels The 5 Main Types 1. Arteries 2. Arterioles 3. Capillaries 4. Venules 5. Veins

3 Arteries:

4 1) Arteries Function Transport blood AWAY from the heart Structure Thick, elastic walls Location Usually deep, along bones Notes Walls can expand Arteries have very high Blood Pressure Expansion is the pulse we feel

5 Arteries of the Human Body

6 2) Arterioles Function Control blood flow to capillaries Structure Smaller in diameter than arteries, thinner walls Have pre-capillary sphincters Location Leading towards all capillaries Notes pre-capillary sphincter muscles to regulate blood pressure

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9 Problems with arteries/arterioles: Arteriosclerosis - hardening of the arteries - reduces elasticity of artery walls Atherosclerosis = fatty deposits in arteries - reduces blood flow if in brain = stroke if in heart = heart attack Aneurysm - Weakening of artery wall

10 3) Capillaries Function Connect arteries to veins Structure Very thin walls (1 cell thick) Location Everywhere; within a few cells of each other Site of capillary-tissue fluid exchange O 2 CO 2

11 4)Venules Function Drain blood from capillaries Structure Thinner walls than veins Location Often near the surface Notes Takes blood tom veins

12 5) Veins Function Transport blood TOWARDS the heart Structure Inelastic walls, contain one-way valves Location Often near to surface Notes Blood pressure & velocity is much lower than in arteries Valves prevent blood from flowing backwards Surrounded by skeletal muscle, squeezes blood along

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15 Veins of the Human Body

16 Problems with Veins: varicose veins valves become weak and allow the pooling and backflow of blood varicose veins of the rectum are called hemorrhoids

17 How Does It All Fit Together? Arteries: Carry blood away from the heart Elastic Capillaries: Very thin tubes Connect arteries to veins Can close down or open up to regulate blood flow GAS EXCHANGE Veins: Bring blood towards the heart Have valves to stop blood from moving backwards

18 Size/Structure summary Arteries Veins Capillaries

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20 1. To summarize your notes, complete table comparing arteries and veins use p and your notes, if needed YOUR TASK

21 Comparison Chart Arteries Veins Carry blood the heart Carry blood the heart Strong, thick and muscular walls Weak, thin and non-muscular walls Contain blood at (low/high) Contain blood a (low/high) blood pressure: pressure: Have (pulse/no pulse) Have (pulse/no pulse) Carry oxygenated/deoxy blood, Carry oxygenated/deoxy blood, bright red blood, except in the bluish blood, except the pulmonary (arteries/veins) pulmonary (arteries/veins) Contain valves/no valves as blood Contains valves/no valves as BP is pressure is and blood. The valves depend on moves in direction muscles in order to work Are found deep/near the surface Are found deep/near the surface

22 Fluid Exchange Across the Walls of Capillaries ARIS; Inquiry; 12 th ed: Ch 12

23 CAPILLARY-TISSUE FLUID EXCHANGE Exchange due to difference between BP & OP

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25 Your task Underneath your Capillary-tissue fluid exchange diagram, explain what is occuring at the a) arteriole side, b) capillary and c) venule side

26 PLO C7: The Lymphatic System A system of thinwalled vessels with valves that drain fluids from bodies tissue spaces

27 Functions of the Lymphatic System 1. Take up excessive tissue fluids from the ECF 2. Transport fatty acids and glycerol (from intestines to subclavian vein) 3. Fight infection (lymphocytes) 4. Trap and remove cellular debris

28 Structures of the Lymphatic System 1. Lymph Veins and Capillaries Lymph capillaries drain and collect excess fluids from ECF which drains into a lymph vein Lymph vein also contains valves to prevent backflow Cleansed lymph travels through lymph vein to the subclavian vein

29 Structures of the Lymphatic System 2. Lymph Nodes cleanse lymph

30 3. Lacteals absorb/transport fatty acids & glycerol in the villi of the small intestine. 4. Other Lymphoid Organs Tonsils, Appendix, Spleen, and Thymus gland

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33 The Major Blood Vessels of the Body Cranial vein VENA CAVA

34 Cranial artery AORTA Brachial artery

35 1. Aorta Biggest Artery Carries O 2 rich blood from heart (left ventricle) to body systems

36 2. Coronary Arteries/Capillaries/Veins Very first branch off the aortic arch Blood vessels that FEED the heart muscle Why can t the heart just get its oxygen and nutrients from the blood that passes through it?

37 3. Carotid Arteries Branch off the aortic arch to take the blood to the head close to the surface pulse can be taken here

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39 4. Jugular Veins Take blood out of head region to the heart (via superior vena cava) These veins DO NOT contain any valves! Blood flows down them because of gravity only Try standing on your head for a while!

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41 5. Subclavian Arteries/Capillaries/Veins Arteries branch off of aorta Branch to fed chest wall/arms Lymphatic vessels join circulatory system at the subclavian veins before returning to the heart

42 Mesenteric Arteries Associated with the small intestine Mesentary

43 Mesenteric Arteries

44 6. Hepatic Portal Vein Hepatic = Liver; Portal = capillary bed on either end This vein transports blood rich in nutrients directly from the intestines to the liver Remember the liver functions?? Significant functions for the circulatory system: regulation of blood [glucose] Destroys old RBC s detoxification of blood

45 HEPATIC PORTAL VEIN

46 7. Hepatic Veins Carries the blood from liver to inferior vena cava 8. Renal Arteries/Cap/Veins Renal arteries bring blood to kidneys Renal veins take blood from kidneys to heart (via inferior vena cava)

47 9. Iliac Arteries/Veins aorta branches into two iliac arteries which go down each leg Iliac veins return blood to inferior vena cava

48 10. Pulmonary Arteries/Capillaries/Veins deo 2 blood collected from the body is pumped into the pulmonary artery from the heart Pulmonary artery brings deo 2 blood to lungs Blood picks up O 2 in the alveoli of lungs Pulmonary vein takes high O 2 blood back to the heart Pulmonary Artery Pulmonary Vein

49 11. Vena Cava Largest vein Carries deo 2 blood from body to the heart Superior vena cava - from head, chest & arms to the heart Inferior vena cava from lower body to the heart Superior vc Inferior vc

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