Transcript document

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
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From body, through veins, blood is full of CO2
Into right atrium
Into right ventricle
Through pulmonary arteries
Into lungs, CO2 is replaced with O2
From lungs, blood is now full of O2
Through pulmonary veins
Into left atrium
Into left ventricle
Through Aorta
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
00pxDiagram_of_the_human_heart_cropped.svg.
png
Bibliography
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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
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<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>.