Circulatory System

By Allie Hale, Eileen Monagle and Caroline Kelly

The Heart

http://www.heart-valve-surgery.com/Images/Human-Heart-Diagram-Picture.gif

Lungs

http://www.himho.com/wp-content/uploads/2010/12/Lungs-1.gif

Red Blood Cells

• Erythrocytes; from stem cells in bone marrow 2,5

• Stem cells can divide to form other types of cells 5

• Biconcave disks5

• Binds to hemoglobin2,5

• No nucleus5

• 120 day lifespan5

• Dent = more surface area5

http://www.fi.edu/learn/heart/blood/images/red-blood-cells.jpg

White Blood Cells• Leukocytes, from stem cells2

• Defense, patrol tissues5

• 5 types5:o neutrophilso eosinophilso basophils o monocyteso lymphocytes

http://seys-science.wikispaces.com/file/view/www.sciencehelpdesk.com%3Aimg%3Abg3_2%3AWhiteBloodCell_Bacteria.jpg/97294120/www.sciencehelpdesk.com%3Aimg%3Abg3_2%3AWhiteBloodCell_Bacteria.jpg

Platelets• megakaryocytes → giant cells5, shed fragments wrapped in bits of

plasma membrane called platelets (thrombocytes)2

• 5 to 9 day lives5

• hundreds of thousands circulating in the blood5

• release substances to clot blood2

http://upload.wikimedia.org/wikipedia/commons/thumb/5/5f/Giant_platelets.JPG/250px-Giant_platelets.JPG

Plasma• straw colored liquid, transport medium for cellular part of

blood and dissolved substances2,5

• 91%-92% water as solvent5

• 7%-8% plasma proteins5

• 1%-2% miscellaneous molecules5

http://www.beltina.org/pics/plasma.jpg

Blood Vessels• Vascular or Vasculature means blood vessels• The three types of blood vessels are:

o Arterieso Capillarieso veins

Function:• Complex system of tubes• Carry blood to every part of the body.• “Drop off” nutrients and oxygen• "Pick up” waste

o After exchange blood is returned to the heart

Arteries• Function

o Carry oxygen-rich blood to body4

• Structureo Appear red4

o Thick walls4

o Smooth muscle fibre1

o Thick and flexible walls1

o Grow smaller and smaller1

• Arterioleso Arteries in tiny branches that lead to capillaries4

o Function → To regulate blood flow and blood pressure by constricting and dialateing1

Veins

• Function• Carry oxygen-poor blood back to the heart4

• Transport blood BACK to the heart4

• Carry blood flowing at lower pressure then blood in arteries1

• Structureo Appear blueo Thinner walls than arteries4

o Three layers of tissue4

o Valves help aid the blood flow back to the heart → prevents blood from flowing in reverse direction1

Capillaries• Function

o Connect arteries to veins4

o Carry blood4

o Exchange and carry away waste1

o Supplied with blood from arterioles and venules1

• Structureo 1 Cell thick1

o Tiniest blood vessels1

o Oxygen and Carbon Dioxide pass through1

o Comparison to cell membrane1

Endothelial cells• Line blood vessels with thin layer5

• Closely packed5

• Line entire circulatory system5

http://www.lab.anhb.uwa.edu.au/mb140/moreabout/MoAbPics/JMcGendo.jpg

http://oac.med.jhmi.edu/res_phys/Encyclopedia/Alveoli/AlveoliDrawing.GIF

Alveoli• Tiny air sacs in

lungs• Gas exchange

occurs between alveoli and endothelial cells

Diffusion Gas Exchange

• Oxygen and Carbon Dioxide transported5

• Occurs at capillary beds5

• Velocity decrease allows for more time for exchange5

• Diffusion occurs5

http://www2.estrellamountain.edu/faculty/farabee/biobk/gasexch_2.gif

http://www.youtube.com/watch?v=Z1h29R82mVc

What prevents gas from being exchanged at non-optimal places?

• Capillaries are optimal place5

• Arteries are too thick5

• Contain smooth muscle and elastic tissue5

• Not thin enough for diffusion to occur5

• Capillary = just membrane and endothelium5

Artery Capillaryhttp://www.web-books.com/eLibrary/Medicine/Physiology/Cardiovascular/artery.jpg

http://www.biosbcc.net/doohan/sample/images/CO%20and%20MAP/bulk%20flow.jpg

Blood Pressure

• Blood pressure = fluid pressure imparted to blood by heart contractions5

• Blood rubs against vessel's inner wall - friction causes energy loss5

• Blood pressure is higher at beginning of vessel5

• Veins transport blood back to heart5

• Vein walls have smooth muscle which contracts5

• Moving limbs cause skeletal muscles to bulge against veins5

• Breathing alters pressure gradient5

Bibliography 1. “Blood Vessels - Vascular System.” ivy-rose. N.p., 1 Oct. 2011. Web. 21 Oct. 2011. <http://ivy-rose.co.uk/ HumanBody/ Blood/ Blood_Vessels.php>.2. Dr. Dennis, O’Neil. “Blood Components.” Human Blood: An Introduction to its Components and Types. N.p., 19 Aug. 2011. Web. 22 Oct. 2011. <http://anthro.palomar.edu/ blood/ blood_components.htm>.3. Heart Valve Surgery. N.p., n.d. Web. 22 Oct. 2011. <http://www.heart-valve-surgery.com/ Images/ Human-Heart-Diagram-Picture.gif>.4. “Intro to Blood Vessels.” Boston Scientific. Boston Scientific Corporation or its affiliates, 1 Jan. 2009. Web. 21 Oct. 2011. <http://www.bostonscientific.com/ templatedata/ imports/ HTML/ CRM/ heart/ vessel_intro.html>.5. Starr, Cecie, and Ralph Taggart. Biology: The Unity and Diversity of Life. Ed. Kristin Milotich and Daniel Lombardino. Pacific Grove: Brooks/ Cole, 2001. Print.