3. Review
What are the 3 parts of the cardiovascular system?
heart – blood – blood vessels
What do arteries do?
Take blood AWAY from the heart
What are the 3 layers of an artery?
What do veins do?
Bring blood TOWARD the heart
What do veins have that arteries don’t?
VALVES – (veins & arteries both have the same layers
except the muscular layer is smaller)
Tunica externa /connective tissue (elastin) – tunica
media/smooth muscle – tunica intima/endothelium
4. What exchanges material between blood and the body’s cells?
CAPILLARIES
How big are they?
microscopic in size
What is the outer membrane of the heart called?
Pericardium
What is the function of the pericardium? (there are 3)
1. protection
2. anchors heart to other structures
3. provides lubrication for heartbeat
5. What are the 3 layers of the heart wall?
1. Epicardium – outside layer
2. Myocardium – middle layer (cardiac muscle)
3. Endocardium – inner layer
What are the 4 chambers of the heart?
1. Right Atria
2. Left Atria
3. Right Ventricle
4. Left Ventricle
What does the septum do?
Divides the heart into right and left sides
6. What is the function of the right atria?
receives blood from inferior & superior vena cava (oxygen poor)
What is the function of the left atria?
receives blood from pulmonary veins (oxygen rich blood from
the lungs)
What does the function of the left ventricle ?
receives blood from left atria & pumps it to the body (through
the aorta)
What is the function of the right ventricle?
receives blood from the right atria and pumps it to the lungs
(through the pulmonary arteries)
7. Where is the tricuspid valve located?
between right atria and right ventricle
Where is the bicuspid (mitral) valve located?
between left atria and left ventricle
Where is the pulmonary semilunar valve located?
between pulmonary artery and right ventricle
Where is the aortic semilunar valve located?
between aorta and left ventricle
8. • PHYSIOLOGY OF THE
HEART
• The Conducting
System (electric)
1. Sinoatrial Node (SA) • PACEMAKER OF HEART – starts
each heartbeat
• located in wall of right atrium
• made of specialized myocardial
cells
• sends impulse to both atria,
causing them to contract
• called an intrinsic conduction or
“nodal” system of specialized tissue
9. 2. Atrioventricular
Node (AV node)
• located at base of right atrium –
receives impulse from SA node
SA Node
AV Node
10. • Atrioventricular
Bundle
• Location: middle of septum
• Direction of Heart
Beat
• impulse from AV node goes down
bundle to base of heart
• it then travels up the sides of the
ventricles through the PURKINJE
NETWORK causing the ventricles to
contract from the bottom up
Atrioventricular
Bundle
11. • RATE OF HEART
BEAT
• Factors affecting
heart rate
• age, sex, physical activity,
temperature, thought processes,
chemicals (natural and otherwise)
• rate high at birth (100 – 140 bpm) –
then declines steadily until average is
reached (70 – 80 bpm)
• heart rate faster in females –
slower in trained athletes
12. • CARDIAC CYCLE • the events of one complete heartbeat
• length of cycle (heartbeat) is about
0.8 sec
• atria contract at the same time – as
they relax, the ventricles contract
• SYSTOLE • contraction of ventricle
• DIASTOLE • relaxation of ventricle
• Cardiac Output • amount of blood pumped out of each
side of the heart in 1 minute
• heart rate X stroke volume
13. • PULSE & BLOOD
PRESSURE
• Pulse
• expansion & contraction
of an artery as the left
ventricle contracts
• normal is 70 – 80 bpm
(there are exceptions to
this)
• pulse can be found at
many sites on the body
14. • Blood Pressure • pressure blood exerts on the inner
walls of blood vessels
• Measuring BP • BP is a measure of the systolic
pressure (ventricles contracting) OVER
the diastolic pressure (ventricles relaxing)
• Example: • 110/70 is in normal range
• Factors affecting
BP
• nervous system, blood volume
(kidneys), temp, chemicals, diet, exercise
