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
o
o
o
o
neutrophils
eosinophils
basophils
monocytes
lymphocytes
http://seysscience.wikispaces.com/file/view/www.sciencehelpdesk.com%3Aimg%3Ab
g3_2%3AWhiteBloodCell_Bacteria.jpg/97294120/www.sciencehelpdesk.co
m%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_plate
lets.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 Arteries
o Capillaries
o 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
• Structure
o Appear red4
o Thick walls4
o Smooth muscle fibre1
o Thick and flexible walls1
o Grow smaller and smaller1
• Arterioles
o 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
• Structure
o Appear blue
o 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
• Structure
o 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
Alveoli
• Tiny air sacs in
lungs
• Gas exchange
occurs between
alveoli and
endothelial cells
http://www.lab.anhb.uwa.edu.au/mb140/moreabout/Mo
AbPics/JMcGendo.jpg
http://oac.med.jhmi.edu/res_phys/Encyclopedia/Alveoli/
AlveoliDrawing.GIF
Diffusion Gas Exchange
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•
•
•
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?
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•
•
•
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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
http://www.webbooks.com/eLibrary/Medicine/Physiology/Cardiovascular/artery.jpg
Capillary
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.heartvalve-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/​ve
ssel_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.