Transcript Circulatory System

Circulatory System
SBI 3U
Ms. Raper
Open circulatory system
• Found in many
insects
• Blood returns to the
heart via the
movement of the
animal’s body.
• inefficient
http://fajerpc.magnet.fsu.edu/Education/2010/2010_INDEX.HTM
Closed Circulatory System
• Found in some
invertebrates such as
worms and in fish,
reptiles, birds and
mammals
• Blood never leaves a
system of tubes
• Heart pumps blood
around the body
William Harvey 1568 -1657
• Was a physician trained
in Italy.
• Was the first to accurately
describe the action of the
heart pumping blood
around the body.
• He confirmed the
presence of valves in the
veins to prevent the
backflow of blood.
• He confirmed his theories
by carrying out
http://www.bbc.co.uk/history/historic_figures/harvey_william.shtml
dissections.
Blood Vessels
• Arteries – carry blood AWAY from the heart.
• Veins – carry blood back to the heart –
blood returns VIA the veins.
• Capillaries – CONNECT arteries and veins, it is here
that substances are loaded and unloaded into the
blood by diffusion.
http://www.owensboro.kctcs.edu/gcaplan/anat2/notes/Notes5%20Circulatory%20Anatomy.htm
Arteries
•Thick elastic muscular walls
•Small lumen
•Carry oxygenated blood
(except pulmonary artery)
•Carry blood away from the
heart.
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookcircSYS.html
Veins
• Have thin walls
•Large lumen
•Carry deoxygenated
blood (except pulmonary
vein)
•Have valves to prevent
backflow of blood
•Carry blood back to the
heart
Circulatory System
Blood vessels
Arteries
• Have a smaller lumen than
veins
• Have thick Muscular walls.
• Carry oxygenated blood
(except the Pulmonary artery)
• Have a pulse
• Carry blood away from the
heart
• Have blood under high
pressure
• Blood is BRIGHT red
• A cut artery spurts with the
heart beat.
• Main artery is the AORTA
Cross section through an artery.
Capillaries
• Connect arteries and
veins.
• Are found in organs.
• Are where substances
are dropped off or picked
up from the cells
• Are only one cell thick.
• Red Blood Cells must
travel through in single
file.
• Low pressure
• Cut capillaries ooze
Cross section of a capillary
• Veins have thinner muscular
walls than arteries,
• Have a large lumen,
• Have valves to prevent
backflow of blood
• Carry blood back to the heart
• Carry deoxygenated blood
(except the pulmonary vein)
• Have blood that is DARK red.
• Low pressure
• A cut Vein will gushes.
• Main vein is the VENA CAVA
Blood Vessels.
http://iws.ccccd.edu/mweis/Images/Histology/2402%20histology/Circulatory%20Histo/labeled%20circ%20histo/circ_vess
els_av_compare_heading.png
Exchange in Capillaries
Coronary Arteries
http://www.patient.co.uk/showdoc/Pilsinl/112.gif
Peripheral Arteries
http://www.patient.co.uk/showdoc/Pilsinl/101.gif
3 parts to the Circulatory System
• Cardiac - blood supply to and through the
heart.
• Pulmonary – blood flow through the lungs.
• Systemic – blood flow through the body other
than the lungs and heart.
• Because blood flows through the heart twice for
every complete circuit, it is referred to as a
DOUBLE circulation.