1. Circulatory System
Take a look at a skeleton and see how well a heart is protected — open heart surgery takes breaking a body to get to the heart.

2. Feeding Energy Needs
Why do we need a circulatory system?

3. Blood & blood cells Blood is a tissue of fluid & cells plasma cells
liquid part of blood
dissolved salts, sugars, proteins, and more
cells
red blood cells (RBC)
transport O2 in hemoglobin
white blood cells (WBC)
defense & immunity
platelets
blood clotting

4. Hemoglobin
Protein which carries O2 O2 O2 O2 O2

5. emergency repair of circulatory system
Blood clotting
chemical emergency signals
platelets seal the hole
protein fibers build the clot
Inherited defect in any step of the clotting process causes hemophilia, characterized by excessive bleeding from even minor cuts & bruises

6. Vertebrate Heart 4-Chambered heart atria (atrium) ventricles thin wall
collection chamber
receive blood
ventricles
thick wall pump
pump blood out
left atrium
right atrium
right ventricle
left ventricle

7. Lub-dub, lub-dub 4 valves in the heart Heart sounds Heart murmur
flaps of tissue
prevent backflow of blood
Heart sounds
closing of valves
“Lub”
force blood against closed AV valves
“Dub”
force of blood against semilunar valves
Heart murmur
leaking valve causes hissing sound SL AV AV

8. Arteries: Built for their job
blood flows away from heart
thicker walls
elastic & stretchable

9. Veins: Built for their job
Blood flows
toward heart
Veins
blood returns back to heart
thinner-walled
Open valve
Closed valve

10. Structure-function relationship
Capillaries
very thin walls
allows diffusion of materials across capillary
O2, CO2, H2O, food, waste
body cell
waste
CO2 O2
food

11. Blood vessels arteries arterioles capillaries venules veins veins
artery
arterioles
venules
arterioles
capillaries
venules
veins

12. Circulation of Blood 2 part system Circulation to lungs
blood gets O2 from lungs
drops off CO2 to lungs
brings O2-rich blood from lungs to heart
Circulation to body
pumps O2-rich blood to body
picks up nutrients from digestive system
collects CO2 & cell wastes
lungs
heart
body
Circulation to body

13. Vertebrate circulatory system
2 part system
lungs
artery to lungs
vein from lungs to heart
heart
vein from body to heart
artery
to body
body
St. Joseph's Aspirin Commercial

14. Electrical signals heart pumping controlled by electrical impulses
stimulates ventricles to contract from bottom to top, driving blood into arteries
allows atria to empty completely before ventricles contract
heart pumping controlled by electrical impulses
signal also transmitted to skin = EKG

16. atria empty into ventricles fill (minimum pressure)
Cardiac Cycle
How is this reflected in blood pressure measurements?
chambers begin to fill
pump (peak pressure)
__________________
fill (minimum pressure)
The cardiac cycle. For an adult human at rest with a pulse of about 75 beats per minute, one complete cardiac cycle takes about 0.8 second.
During a relaxation phase (atria and ventricles in diastole), blood returning from the large veins flows into the atria and ventricles.
A brief period of atrial systole then forces all remaining blood out of the atria into the ventricles.
During the remainder of the cycle, ventricular systole pumps blood into the large arteries. Note that 7/8 of the time—all but 0.1 second of the cardiac cycle—the atria are relaxed and are filling with blood returning via the veins.
110 80
______
ventricles pump

17. Measurement of blood pressure
if top number > 150 or
if bottom number > 90
hypertension = (high blood pressure)

18. Coronary artery bypass
bypass surgery

19. Cardiovascular disease
Atherosclerosis & Arteriosclerosis
deposits inside arteries (plaques)
develop in inner wall of the arteries, narrowing their channel
increase blood pressure
increase risk of heart attack, stroke, kidney damage
normal artery
hardening of arteries

20. Cardiovascular health
bypass surgery
Risk Factors
genetics
diet
high animal fat
exercise & lifestyle
smoking
lack of exercise

21. Have a heart? Ask Questions!!