"The Circulatory System The Circulatory System"
The Circulatory System By: Bianca Calderone Jenna Kosmo Allie Hedlund and Hollis Toussaint Overall Function Body’s delivery system. Blood flowing from the heart delivers oxygen and nutrients to every part of the body. Blood going back to the heart picks up waste products so that the body can dispose of them Main Features Blood • Transports nutrients, waste, O2, CO2, hormones 2 pumps (in heart) • One to pump deoxygenated blood to lungs • Other to pump oxygenated blood to other organs and tissues Blood vessel system • Distributes blood Organs for exchange of materials between blood & external environment Functions: Transporting Materials Gases • O2 goes from lungs to cell • CO2 goes from cells to lungs Other nutrients • Glucose transported through body (goes to liver) Other cell waste Hormones • To help maintain internal conditions Functions continued Has cells to fight infection Helps stabilize pH and ionic concentration of body fluids Helps maintain body temp. by transporting heat The Systems Path 1. From body, through veins, blood is full of CO2 2. Into right atrium 3. Into right ventricle 4. Through pulmonary arteries 5. Into lungs, CO2 is replaced with O2 6. From lungs, blood is now full of O2 7. Through pulmonary veins 8. Into left atrium 9. Into left ventricle 10. Through Aorta 11. Into body, through arteries Blood Animation http://www.argosymedical.com/flash/th e_blood/landing.html Heart One to pump deoxygenated blood to lungs Other to pump oxygenated blood to other organs & tissues http://www bostonscientific.com/templatedata/imports/HTML/lifebeat online/winter2007/learning.shtml Veins Diameter of veins > diameter of arteries Blood pressure in veins =so low so valves in veins help prevent backflow Contraction of skeletal muscle during normal body movements, squeezes veins/assists with moving blood back to heart Vena cava returns blood to right atrium of heart from body Varicose veins develop when valves weaken Veins act as blood reservoirs, contain 50% to 60% of blood volume Smooth muscle in walls of veins expand/contract to adjust flow volume returning to heart and make more blood available when needed. Vein Animation http://www.simquest.com/animations/v eins.html Venules Capillaries merge to form venules Venules merge into veins Can constrict due to contraction of smooth muscle When constricted, more fluid loss in capillaries (increased pressure) Arteries Carry blood away from heart Thick, elastic layer to stretch & absorb pressure (stretches & recoils in response to pumping) Elastic layer surrounded by circular muscle to control diameter & rate of blood flow Act as pressure reservoirs by maintaining (storing) pressure Outer layer of connective tissue provides strength Arterioles Smooth muscle surrounding arteries Control distribution of blood (blood vessels dilate when O2 levels decrease or wastes accumulate) – allows more blood into area to bring oxygen and nutrients or removes wastes Capillaries Smallest blood vessels (>1 mm long) • red blood cells travel single file Vasodilation/vasoconstriction = dilation/constriction of blood vessels Sphincter muscles control flow of blood to capillaries Rate of blood flow (velocity) is low (blood pressure is highest in arteries, reduced in capillaries, lowest in the veins) Interstitial Fluid Exchange of substances between blood and body cells occurs in capillaries Specialized for exchange of substances with interstitial fluid No cell in body is more than 100 micrometers from capillary Surrounds and bathes the cells Continually being replaced with fresh fluid from blood in circulatory system Body cells take up nutrients from fluid and empty wastes into it Blood pressure forces fluid out and intro surrounding tissues Blood flows through, fluid moves out, blood that remains behind becomes more concentrated (osmotic pressure = greater near venule end, results in increase in amount of fluid moving into capillary) Portal Veins Connect one capillary bed with another Hepatic portal vein connects capillary beds in digestive tract with capillary beds in the liver Endothelial Cells Cells lining the blood vessels are called endothelial cells Their structure is flat, which forms pavement like patterns on the inside of vessels Good for function: keep the vessels from leaking Acts as a selective barrier Surface molecules act as receptors and interaction sites Picture Bibliography http://www.nhlbi.nih.gov/health/dci/images/at her_lowres.gif http://www.uic.edu/classes/bios/bios100/lect uresf04am/bloodvessels_1.gif http://www.scifly.co.uk/client_files/AQA%20A dditional%20Science/diffusion_into_capillary _3.jpg http://www.southdartmoor.devon.sch.uk/pe/3 00px- Diagram_of_the_human_heart_cropped.svg. png Bibliography Gregory, Michael. "Circulatory System". Clinton CC. Nov 9, 2009 <http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio 102/Bio 102 lectures/Circulatory system/circulat.htm>. Abdallah, Hasan. "How the Heart Works: Blood Flow Diagram". Children's Heart Institute. Nov 9, 2009 <http://www.childrensheartinstitute.org/educate/heartwrk/bloodflw.htm>. Bailey, Regina. "Capillary". About.com. Nov 9, 2009 <http://biology.about.com/od/anatomy/ss/capillary.htm>. McGeachie, John. "Blue Histology - Vascular System: Blue Histology - Vascular System." School of Anatomy and Human Biology - The University of Western Australia. 02/09/98. The University of Western Australia, Web. 6 Nov 2009. <http://www.lab.anhb.uwa.edu.au/mb140/MoreAbout/Endothel.htm>. U.S. National Institutes of Health, . "Classification & Structure of Blood Vessels." SEER Training Modules. 2008. National Cancer Institute, Web. 6 Nov 2009. <http://training.seer.cancer.gov/anatomy/cardiovascular/blood/classification.ht ml>. "Capillaries." Web. 6 Nov 2009. <http://www.bbc.co.uk/schools/gcsebitesize/pe/images/capillaries.gif>.