Cardiovascular System
Aka: The Circulatory System
What does it do?
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Moves the blood
Protects the body
Transports nutrients
Removes metabolic
waste
• Regulates body
temperature
Structure
• Heart
• Blood Vessels
• Blood
Blood
Blood is made of…
• Erythrocytes (RBC)
• Leukocytes (WBC)
• Platelets
• Plasma
Differentiated Blood Cells
Erythrocytes
• Red Blood Cells (RBC)
• Transport Oxygen and
Carbon Dioxide
• Flattened Doughnuts
with depressed center
for increased surface
• Flexible to get through
vessels
• No nucleus – last 120
days broken down in
spleen
Leukocytes
• White Blood Cells
(WBC)
• Protects body from
foreign microbes and
toxins
• Found in blood
stream and some
tissue
• Last 18-36 days
• Three types
Types of Leukocytes
• Lymphocytes: Immune function
• Granulocytes: Destroy bacteria, viruses, parasites
• Macrophages: Break down old blood cells and foreign
matter like dust and asbestos
Platelets
• Aka: Thrombocytes
• Clot blood
• Release coagulating
chemicals
• No nucleus
• Fragments of
Megakaryocytes
• Stimulate Immune
System and Fight
Infections
Plasma
• Clear liquid protein and
salt part of the blood
• 55% of our blood volume
• 95% of plasma is H2O
• Contains: nutrients,
clotting factor, hormones,
antibodies, vitamins,
lipids, sugars, other
proteins, metabolic waste
Blood Formation - Hematopoiesis
• Bone Marrow
produces red blood
cells, most white
blood cells and
platelets
• All blood cells
originate from stem
cells
• Production is based
on body need such
as infection or
bleeding
The Heart - Structure
• Four cavities that fill
with blood
• Two are Atria
(Upper “Round” Half)
• Two are Ventricles
(Lower “pointed”
Half)
• Points to left side of
chest at the bottom
• Size of fist
• Pumps 4300 gallons
/ day
Four Steps of Circulation
• Step 1: From right side of heart to lungs to
collect O2 turning blood bright red and CO2
leaves the capillaries through diffusion.
• Step 2: Oxygenated blood returns to the left
side of the heart. (Pulmonary Circulation)
• Step 3: Blood is pumped to all parts of the body
distributing O2 and nutrients
• Step 4: Blood returns to the right side of the
heart a reddish-blue color to be oxygenated
again (Systemic Circulation)
How blood circulates….
• Closed system
of blood vessels
• Four chambers
of the heart
• Review the
steps from the
previous slide
Heart - Function
• Connects to Aorta at
the top. Main artery
carrying blood away
• Pulmonary Artery
connects heart to lungs
• Two largest veins =
Carry blood into heart
are superior vena cava
and inferior vena cava.
Heart - Function
• Cardiac Muscle
• Contracts 70-80 times
per minute
• Nerves connected to
the heart regulate
speed of muscle
contraction
Blood Vessels - Structure
• Three Types:
1. Arteries - thick and
flexible due to
forceful bloodflow
2. Veins- appear blue,
thinner walls than
arteries, less forceful
flow
3. Capillaries – tiniest
vessels, connect
arteries and veins.
Very thin walls
Blood Vessel - Function
• Arteries: Carry oxygenated
blood from heart to tissues.
Large to small: Arteries to
Arterioles to capillaries
• Veins: Carry deoxygenated
blood to heart. Small to
large: Capillaries to
Venuoles to Veins
• Capillaries: gas exchange
and absorb metabolic waste
Pulse
• Rhythmic contractions
of arteries can be felt
through the skin.
• Keeps pace with
heart beat.
• A way to measure
vital health statistics
Blood Pressure
• The force of blood
pushing against artery
walls
• Strongest when heart
contracts (systolic or the
higher number)
• Weakest when heart
relaxes (diastolic or the
low number)
• 120/80 is considered
normal BP
http://www.youtube.com/watch?v=E
5huVSebZpM
• http://depts.washington.edu/learncpr/video
demo/two-step-cpr.html