The document outlines the structure and function of the circulatory system, focusing on the heart, major blood vessels, and their roles in transporting blood, gases, and nutrients. Key components include the heart's four chambers and valves, the differences in blood circulation through arteries and veins, and various heart-related conditions like coronary artery disease and congestive heart failure. It also addresses practical applications and the impact of cardiovascular health on overall well-being.

1. The Circulatory System

2. The Circulatory System
1. Know the basic structure of the heart and relate this to
its function
2. Know the different valves of the heart and how they
function.
3. Know the positions, functions, and names of the major
blood vessels.

4. Cardiovascular System
• Heart, vessels, blood
• Function: transport
gases, nutrients,
wastes, hormones

5. The Heart
• Size of a fist; less than a
pound
• In thorax; flanked by
lungs; rests on diaphram
• Top: base
• Bottom: apex

6. Pericardium
• Double-layered sac
covering the heart
• Outer layer
anchors heart in
chest
• Inner layer
(epicardium)
attached to heart
wall
• Lubricating fluid in
pericardial space
(between layers)
reduces friction

7. Pericarditis
Decrease in
fluid causes
layers to
cling & rub
against each
other
resulting in
pain &
decreased
efficiency of
heart

8. Pericardial Tamponade
• Bleeding into
pericardial space
after chest trauma
• Excess blood
restricts expansion
of heart during
pumping
• Causes shock or
death if not
corrected

9. Heart Wall
3 layers:
• Epicardium: outer wall joined with pericardium
• Myocardium: the actual cardiac muscle that
contracts
• Endocardium: lines heart chambers & vessels

10. Heart Chambers
Four chambers:
• 2 atria: top of
heart – receive
blood from
veins
• 2 ventricles:
bottom of heart
– pump blood
through arteries

11. Heart Chambers
• Septum: divides
left from right
heart
• Valves: keep
blood flowing in
one direction
• Four valves:
– 2 AV valves,
– 2 semilunar valves
Heart sounds (Lupp-
dupp) from valves closing

12. Atrioventricular
Valves
AV valves: between atria
and ventricles
• Bicuspid (mitral) valve:
on the left
• Tricuspid valve: on the
right
• When valves are open blood drains from atria into
ventricle
• When ventricle contract, valve flaps are forced shut,
blocking blood from reentering atria

13. Semilunar Valves
• Located in arteries leaving
ventricles
• Pulmonic valve: at base of
pulmonary artery
• Aortic valve: at base of aorta
• When ventricles contract, valves are forced
open & let blood flow
• When ventricle relaxes, backflow of blood fills
flaps of valve & forces them to shut

15. Blood Vessels
• Arteries: carry
blood away
from the heart
• Veins: carry
blood to the
heart
• Capillaries:
connect
arteries to
veins &
exchange
gases with
tissues

16. Arteries
• Carry blood at high
pressure
• Very thick, stretchy walls
that expand in size
• Most carry oxygenated
blood (red)
• Damaged arteries spurt
in time to heart beat

17. Arteries
• Aorta: largest
vessel (diameter of
a garden hose) –
receives blood
from left ventricle
• Arteriole: smaller
vessels connecting
arteries to
capillaries

18. Veins
• Carry blood at low
pressure
• Have valves to
prevent backflow of
blood against gravity
• Most carry de-
oxygenated blood
(purple)
• Damaged veins ooze
blood

19. Veins
• Vena Cava: dump all
blood from the body into
the right atria
– superior vena cava:
receives blood from
upper body
– inferior vena cava:
receives blood from
lower body
• Venules: smaller
vessels connecting
veins to capillaries

21. Capillaries
• Connect arteries and veins
• Walls are one cell thick
• Allow exchange of gases through thin walls
– Drop off oxygen delivered from heart by arteries
– Pick up CO2 and send it to the heart thru veins

22. How Blood Travels thru Vessels
heart artery arteriole capillary venule vein heart

23. • Narrowing of
vessel lumen due
to plaque/fat
formation on
inside of walls
• Causes: diet high
in fat, cholesterol,
salt; inactive
lifestyle; smoking
• Risks: high BP,
enlarged heart,
embolus blocking
circulation; stroke
Atherosclerosis

24. Coronary
Artery
Disease
• When Atherosclerosis affects the arteries that
supply the heart muscle
• Symptoms: short of breath after simple
exertion, angina (chest pain)
• Risk: MI, cardiac arrest, death

25. How is CAD
treated?
• Medication
• Angioplasty
(balloon surgery) –
balloon is inserted
and inflated in
blocked vessel to
compress fatty
mass against the
artery wall

26. How is CAD Treated?
• Stent – wire mesh inserted into the artery to expand its
lumen
• Coronary Artery Bypass – arteries are removed from
leg and grafted into the heart to restore circulation

27. Vessel Disorders
Varicose Veins:
twisted, dilated
veins resulting
from pooling of
blood due to long
periods of
standing, obesity,
or inactivity

28. Vessel Disorders
Thrombophlebitis:
inflammation of a
vessel due to clot
formation & poor
circulation. Clot
can become an
embolus if freed.

29. Aneurysm
• Weaking in the wall of a vessel, causing it to
balloon outwards.
• Rupture of the site causes
– Stroke (if in the brain)
– Death (in a large artery – aorta).

30. Cardiac
Circulation
• Coronary arteries exit the aorta & supply
oxygen/blood to heart muscle (myocardium)
• Coronary veins pick up & return deoxygenated
blood from myocardium

31. Defects in
Coronary
Circulation
• Angina Pectoris: impaired circulation to myocardium
causes oxygen deprivation & pain
• Myocardial infarction: “heart attack” – blockage of
circulation to section of myocardium causes the
muscle to infarct (die)

32. Pulmonary Circulation
• Right ventricle pumps deoxygenated blood
through pulmonary artery to the lungs
• The blood picks up O2 from the lungs and
dumps CO2 into the lungs
• Oxygenated blood is returned to the left
atrium thru the pulmonary vein

34. Systemic
Circulation
• Oxygenated blood
is pumped from
left ventricle thru
aorta to the body
• Blood dumps
oxygen into
tissues and picks
up CO2
• Deoxygenated
blood travels from
body to vena cava
to the right atrium

36. Congestive Heart Failure
• Heart is ‘worn out’ from hypertension,
multiple MI, atherosclerosis, or age
• Heart pumps too weakly to meet tissue
needs
• If one side is weaker than the other, blood
will back up in system

37. Congestive Heart Failure
• Left ventricle is failing:
– Pulmonary congestion
– Pulmonary edema
(blood in lungs)
causes suffocation
• Right ventricle is
failing:
– Peripheral congestion
– Edema in distal body
parts (ankles, feet)

38. Pulmonary
Edema
Pulmonary
edema (A);
normal lung
(B)

40. Group Activity
Instructions:
1.Group by 4
2.Discuss and answer the given questions
3.10 mins will be given for each group to
finished the task
4.One representative will discuss about the
given questions

41. Questions
1.Can you name the four chambers of the
heart and describe their locations?
2.What are the four main valves of the heart?
3.Describe the pathway of blood through the
heart starting from the vena cava.
4.How does oxygenated blood differ from
deoxygenated blood in terms of their
pathways in the heart?

42. Daily Practical Applications
How does the circulatory
system interact with other
systems in the body?

43. Daily Practical Applications
What would happen if one
part of the heart or a
major blood vessel
stopped working properly?

44. Daily Practical Applications
How can we use our
knowledge of the
circulatory system to
improve overall health and
wellbeing?