The Cardiovascular
System Chapter 13
By the end of today, you should
be able to:
•Describe the 3 major elements
of the cardiovascular system.
•Contrast the 2 “circuits” or
“routes” that blood takes
throughout the cardiovascular
system.
•Relate the effects of
activity/exercise to the
cardiovascular system
The Closed Circulatory System
•Humans have a closed circulatory system
(blood confined to vessels).
•The heart pumps blood into large vessels
that branch into smaller ones leading into
the organs.
(arteriesarteriolescapillaries)
•Materials are exchanged by diffusion b/w
blood and the fluid bathing the cells
(interstitial fluid)
The Cardiovascular System
•Three Major Elements –
Heart, Blood Vessels, &
Blood
•1. The Heart
• cardiac muscle tissue
• highly interconnected
cells
–4 chambers
•Right atrium
•Right ventricle
•Left atrium
•Left ventricle
•Pulmonary circuit
–Sends oxygen-depleted (deoxygenated) blood to
lungs to pick up oxygen & unload CO2
•Systemic circuit
–Sends oxygen-rich (oxygenated) blood &
nutrients to all body cells and remove wastes
Circuits
The Cardiovascular System
•
2. Blood Vessels -A network of tubes
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All blood vessels in body, joined end to end,
would stretch 62,000 miles (2.5 times
around the Earth)
Arteriesarterioles
Move blood away from the heart
Elastic Fibers
3 layers (endothelial tissue, smooth
muscle, connective tissue)
Carries blood under relatively high
pressure from heart to arterioles
Largest artery = aorta (diameter of
garden hose)
Blood Vessels
• Capillaries
• where gas exchange takes
place
• Materials diffuse thru slits
(openings) in capillary walls
• Single layer of epithelial
tissue
• Connect arterioles to venules
• Serve the Respiratory System
FYI--(There is always 1/5 of our blood supply
in the lungs)
Blood V essels
• VeinsVenules
• Move blood towards the
heart
• 3 layers (similar to arteries
except middle layer poorly
developed)
• Carries blood under low
pressure
• Many have valves that
prevent backflow of blood
• Largest vein = inferior vena
cava
• heart anatomy video model
The Cardiovascular System
3. The Blood
• RBCs (erythrocytes)
• WBCs (leukocytes)
• Platelets
(thrombocytes)
• Plasma
Exercise
• CV System adapts to exercise
• Increase in heart pumping efficiency, blood
volume, blood hemoglobin concentration, # of
mitochondria in muscle fibers
• All of these improve oxygen delivery to and
utilization by muscle tissue
• Good=Slow, steady buildup of exercise
frequency & intensity
• Bad=suddenly shoveling snow, running 3
miles when body isn’t used to it
Inside the Human body video – 48 min
Anatomy of the human body 1
Plastination, Heidelberg, Germany