Cardiovascular System
Aka: The Circulatory System
Structure
• Heart
• Blood Vessels
• Blood
What does it do?
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•
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Moves the blood
Protects the body
Transports nutrients
Removes metabolic
waste
• Regulates body
temperature
Heart Structure
Function
Atrium
Upper Chamber- receives
the blood
Ventricle
Lower chamber – pumps
blood out
Aorta
Brings oxygen rich blood
from left ventricle to the
body
Vena Cava
Brings oxygen poor blood
to the atrium
Pulmonary Vein
Brings oxygen rich blood
from the lungs to the left
atrium
Pulmonary Artery
Brings oxygen poor blood
to the lungs
Valves
Prevent blood from
flowing back
Your Diagram
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•
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1. Aorta
2. Vena Cava
3. Right Pulmonary Artery
4. Pulmonary Veins
5. Right atrium
6. Tricuspid Valve
7. Right Ventricle
8. Lower / Inferior Vena Cava
Your Diagram
9. Left Pulmonary Artery
10. Left Pulmonary Veins
11. Left Atrium
12. Mitral or Bicuspid Valve
13. Aortic Valve
14. Left Ventricle
15. Septum
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)
What allows the heart to keep its
beat?
• The sinoatrial node abbreviated SA node
is the impulse-generating (pacemaker)
tissue located in the right atrium of the
heart, and thus the generator of normal
sinus rhythm.
• It is a group of cells positioned on the wall
of the right atrium, near the entrance of the
superior vena cava.
What allows the heart to keep its
beat?
• http://www.pennmedicine.org/encyclopedia/em_
DisplayAnimation.aspx?gcid=000001&ptid=57
• http://kidshealth.org/parent/medical/body_basics
/heart.html
What allows the heart to keep its
beat?
• The cardiac conduction system is a group of specialized cardiac
muscle cells in the walls of the heart that send signals to the heart
muscle causing it to contract. The main components of the cardiac
conduction system are the SA node, AV node, bundle of His, bundle
branches, and Purkinje fibers. The SA node (anatomical pacemaker)
starts the sequence by causing the atrial muscles to contract. From
there, the signal travels to the AV node, through the bundle of His,
down the bundle branches, and through the Purkinje fibers, causing
the ventricles to contract. This signal creates an electrical current
that can be seen on a graph called an electrocardiogram (EKG or
ECG). Doctors use an EKG to monitor the cardiac conduction
system’s electrical activity in the heart.
2 Phases of a Heart Beat
• In the diastole phase, the heart ventricles
are relaxed and the heart fills with blood.
• In the systole phase, the ventricles
contract and pump blood to the arteries.
• One cardiac cycle is completed when the
heart fills with blood and the blood is
pumped out of the heart.
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
Pulse
• Rhythmic contractions
of arteries can be felt
through the skin.
• Keeps pace with
heart beat.
• A way to measure
vital health statistics
Types of Vessels
Arteries
Veins
Capillaries
transports
blood away
from the
heart
transports
blood from
various
regions of
the body to
the heart
exchange
materials
with their
surroundings
Cross
Sectional
View
Function
Structure of the Blood
Plasma
Red Blood
Cells
White Blood Cells Platelets
water (90%)
proteins,
glucose,
clotting factors,
minerals
hormones and
carbon dioxide
No nucleus
cytoplasm
contains
hemoglobin
which binds
to oxygen
derived from
hematopoietic
stem cells.
Complex
nucleus,
lysosomes,
histimine
No nucleus,
fragment of a
megakaryocyte
Function Transportation
medium
Deliver
Oxygen
defend the body
against disease
and foreign
materials
Blood clotting
Where
is it
made?
Bone Marrow
Bone Marrow
Bone Marrow
Diagram
Key
Parts
H2O portion is
absorbed by
capillaries,
blood cell in
bone marrow
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
How blood circulates….
• Closed system
of blood vessels
• Four chambers
of the heart
• http://www.youtu
be.com/watch?v
=xagOnC6sZEU
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
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.
Arteries to Arterioles to
capillaries
• Veins: Carry deoxygenated
blood to heart. Capillaries –
Venuoles – Veins
• Capillaries: gas exchange
and absorb metabolic waste