Cardiovascular System
Blood vessels, heart
and blood
Functions
• Transport
oxygen,
nutrients, waste,
hormones
• White blood
cells fighting
disease
• Temperature
regulation
Blood vessels; Arteries
• Arteries carry blood away from the heart
• Most carry oxygen-rich blood (bright red)
• except the pulmonary artery
• Walls are thick and muscular
• Arteries expand and relax as the heart beats
• The pulse: pulse points on body surface
• Arteries have high pressures
Blood vessels: Veins
• Veins carry blood back to the heart
• Carry deoxygenated blood; little oxygen (dark reddish/blue)
• except the pulmonary veins
• Walls of veins are thin and pressures are low
• Valves to prevent back flow of blood
Blood Vessels; Capillaries
• Capillaries; smallest blood vessels
• Connect arteries and veins
• Very thin walls – one cell layer
• Diffusion of substances (e.g. oxygen) occurs through the
walls
Lymph Vessels
• Lymph vessels travel near
the veins
• carry blood-like fluid; no
red blood cells
• These vessels empty into
large veins
• Lymph vessels pass
through lymph nodes; of
filter the lymph
Heart
• “cardia-” = heart
• Location; slightly left of center in chest cavity; lungs on
each side
• Striated involuntary muscle; myocardium
Heart myths
• #1: I would know if I had high blood pressure or high
cholesterol
• #2: Heart disease treats men and women the same
• #3: Younger Women Aren't at Risk
• #4: Exercise is too risky if you have heart disease.
• #5: Aspirin and Omega-3 fatty Acids Are All Good
• #6: Once I Have Heart Disease, That's It
Heart chambers contain blood
• Left and right atrium (atria pl.); upper
• Left and right ventricle; lower
Heart valves
• One way valves prevent blood back flow
• As valves close, makes “lub-dupp”
sound of the heart beat
• Found between the atria and ventricles
• Found between the ventricles and the
arteries
Normal Heart Sound
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Heart murmur!
valve doesn’t close properly
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Aortic stenosis!
narrowing of the aortic valve
19
Blood flow through heart
• Superior & Inferior
Vena Cava
• Right atrium
• Right ventricle
• Pulmonary artery
to lungs
• Pulmonary veins
• Left atrium
• Left ventricle
• Aorta to the body
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• Vena Cava; deoxygenated
blood
• Pulmonary artery;
deoxygenated
• Pulmonary vein;
oxygenated
• Aorta; oxygenated
Coronary arteries
• These supply the heart muscle with oxygen and nutrients
• What would happen if a coronary artery gets blocked?
Heart Physiology
• SA node is the
pacemaker of the heart
• Location; wall of the right
atrium
• SA node cardiac cells
contract fastest
• All cardiac cells are
interconnected.
• SA node sets the pace of the
entire heart
• about 60-80 beats per
minute at rest.
Heart Physiology
• Heart muscle contraction is electrical
• Monitored with electrodes
• Recorded as an ECG or EKG - ElectroCardioGram
Cardiac Cycle
• One complete heart
beat.
• Systole =
contraction phase
– blood is ejected
from the
ventricles
• Normal systolic
pressure = 120 mm
Hg
Cardiac Cycle
• Diastole = relaxation
phase
• Chambers refill with
blood
• Diastolic pressure is
low in the heart
• Normal is 80 mm Hg
30
Cardiovascular Pathology
• Hypertension is continuous high blood
pressure.
• > 160/95 mm Hg
• Affects 20 % of American Population
Hypertension
• Causes
–
–
–
–
–
heredity
Obesity
Stress
Smoking
Diet
• Arteriosclerosis is “hardening” of the
arteries
• Associated with hypertension
• Increased risk of an unwanted blood clot in
the arteries
Aneurysm
• Weakening and
ballooning of an
artery
• Associated with
hypertension
• Can lead to a
burst artery
Coronary Artery Disease
• Excessive cholesterol build up in the arterial wall
– especially the coronary arteries
• Associated with saturated fats in the diet
• Atherosclerosis
– fatty plaques in the wall of an artery
Heart Attack
• Coronary arteries
blocked; heart muscle
dies from lack of
oxygen and nutrients
• Treatments
– “clot busting”
drugs
– angioplasty to
open up clogged
arteries;
– bypass surgery
around the
blockage
Angina
• Chest pains due to lack of oxygen in heart
muscle cells
• Often occurs after physical exertion
• Forewarning of a possible heart attack
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Varicose Veins
• Damaged veins become distended
• Damage to valves
• Varicose veins near the anus are called
hemorrhoids
• Treatments
–
–
–
–
anti-inflammatory drugs
rest
vein injections
surgery