The document summarizes the circulatory system, including its major components and how it functions. It describes the heart, blood vessels (arteries, veins, capillaries), blood, and the two circuits (pulmonary and systemic). It also discusses the lymphatic system and its role in collecting fluid from tissues and returning it to blood. Key structures of both systems like the heart, blood cells, lymph nodes, and spleen are defined. The document provides an overview of how blood circulates through the body, facilitated by these circulatory and lymphatic components working together.

1. Chapter 11
The Circulatory System
Group 5
Toñacao, Christine
Castillo, Melecia Megan
Cal, Kesler
Calustre, Reian

2. Circulatory System
• “The flow of nutrients, other elements and
water into living organisms which are needed
for growth and reproduction.”
• 3 major structures of this system:
a. Heart
b. Blood Vessels
c. Blood
• 2 major circuit pathways:
a. Pulmonary pathway
b. Systemic pathway

3. Circulation
Two Kinds of Circulatory System:
1. Open Circulatory System
2. Close Circulatory System

4. KINDS OF CIRCULATORY SYSTEM
1. OPEN CIRCULATORY SYSTEM (insects and other invertebrates)
- blood does not remain in the vessels but instead is pumped from the
heart into that open directly into tissue
- OSTIA (openings in heart) is present
- common to molluscs and arthropods
(evolved in crustaceans, insects, mollusks
and other invertebrates)

5. KINDS OF CIRCULATORY SYSTEM
2. CLOSE CIRCULATORY SYSTEM
- blood remains within the vessels throughout its entire circuit
- Ostia is ABSENT

6. THE HUMAN
CIRCULATORY SYSTEM
1. Cardiovascular System
2. Lymphatic Vascular System

7. HUMAN CIRCULATORY SYSTEM
1. CARDIOVASCULAR SYSTEM
- composed of the blood vessels,
the blood and the heart

8. 2. LYMPHATIC VASCULAR SYSTEM
- composed of lymph capillaries,
lymph vessels and collecting ducts.

9. BLOOD VESSELS
VEINS, ARTERIES & CAPILLARIES

10. Blood Vessels

11. Blood Vessels
1. Veins
- carries unoxygentated
blood containing picked
up from body cells
towards the heart.
- flow of blood is slow and
smooth
- walls are thin, don't have
much smooth muscle;
readily distended when
internal pressure is high

12. Venules
- refers to the smallest veins
- walls are only a little thicker
than those of capillaries
- both veins and venules
serve as temporary
reservoir for blood
volume; highly
distensible
- blood volume is high in
these vessels when the
body's metabolic activity
increases
- 50% of total blood volume;
found in veins
- prolonged compression
of the superficial veins in
the legs can contribute
varicose veins

13. Blood Vessels2. Arteries
- carries oxygenated blood away
from the heart where the flow
of blood is pulsating or in
spurts.
- walls are thick and deeply set
with impermeable walls
containing smooth muscles
and distensible tissues.
- composed of three outer and
inner layers that are primarily
connective tissues
- middle layer; made up of
muscle fibers and elastic
connective tissue
- smallest arteries is called
arterioles

14. CONDITIONS
Aneurism
- a birth defect or
injury can cause
the inner wall of
the artery to bulge
Stroke
- a weakened
artery in the brain

15. Three kinds of Arteries
1. ELASTIC ARTERIES
- large arteries leading directly
from the heart; also called
conducting arteries.
2. MUSCULAR ARTERIES
- medium sized with middle coats
that are chiefly muscular; also
called distributing arteries.
3. ARTERIOLES
- smallest arteries connected to
the capillaries that reduce
pressure of blood before
reaching the capillaries.

16. Blood Vessels
3. CAPILLARIES
- smallest blood vessels supplying blood to the
organs and tissues.
- an endothelial tubes that connect arteries and
veins
KINDS OF CAPILLARIES
1. CONTINUOUS CAPILLARIES
- found in muscles connective tissues and
central nervous system
2. FENESTRATED CAPILLARIES
- found in the renal glomeruli, endocrine glands
and intestine
3. SINUSOIDS
- the enlarged capillaries found in the liver, spleen
and bone marrow
- these vessels are so narrow that red blood cells
pass through them in single line.
- the thin walls of capillaries allow the exchange of
dissolved nutrients, wastes, oxygen and other
substances between blood and cells.
- capillary beds are easily destroyed
- high blood pressure can rapture the thin layered
capillaries
CONTINUOUS FENESTRATED
SINUSOIDS

17. Blood Vessels

18. The Heart
• A large, four-chambered muscular organ
(involuntary muscle)
• Location: slightly to the left of the middle
of the chest cavity
• Function: The right side of
the heart maintains pulmonary
circulation to the nearby lungs while the
left side of the heart pumps blood all the
way to the extremities of the body in the
systemic circulatory loop. The heart
functions by pumping blood both to the
lungs and to the systems of the body.
• No larger than the size of your fist
• Mass: about 300 grams
• 70 beats per minute
• (2.5 billion times in 70 years life span)
• Pumps blood enough to fill 2 large ocean
tankers

19. Parts of the Heart

20. Parts of the Heart

21. Parts of the Heart
ATRIOVENTRICULAR VALVES
(AV Valves)
 tricuspid valve (right)
 bicuspid/mitral valve (left)
SEMILUNAR VALVES
(SV Valves)
 pulmonary artery
 aortic (semilunar) valve
Function:
These flap-like valves
control the direction of the
blood flow inside the heart
(prevent it to flow back)

22. The Cardiac Cycle
• sequence of muscle contractions
and relaxation in the heart
•Two main pumping actions of the
heart:
a. Diastole - relaxation
b. Systole – contraction
•Lub sound – closing of the
atrioventricular valve (AV)
•Dub sound – closure of the
semilunar valve (SV)
• 72 contractions / min (forces 80 ml
of blood into the aorta)
• Stroke Volume – amount of blood
passing through the heart with each
heartbeat
•Cardiac Volume – amount of blood
pumped from the heart each minute
(5-6 liters)

23. The Cardiac Cycle
Right side of the heart (PULMONARY)
1. Blood enters the heart IVC and SVC,
emptying oxygen poor blood from
the body into the RA.
2. As the atrium contracts, blood flows
from your RA into your RV through
the open tricuspid valve.
3. When the ventricle is full, the
tricuspid valve shuts. This prevents
blood from flowing backward into
the right atrium while the ventricle
contracts.
4. As the ventricle contracts, blood
leaves the heart through the
pulmonary valve, into the
pulmonary artery and to the lungs,
where it is oxygenated. The
oxygenated blood then returns to
the heart through the pulmonary
veins.
1
2

24. The Cardiac Cycle
Left side of the heart (Systematic)
1. The pulmonary veins empty
oxygen-rich blood from the lungs
into the left atrium.
2. As the atrium contracts, blood
flows from your left atrium into
your left ventricle through the
open mitral valve.
3. When the ventricle is full, the
mitral valve shuts. This prevents
blood from flowing backward into
the atrium while the ventricle
contracts.
4. As the ventricle contracts, blood
leaves the heart through the
aortic valve, into the aorta and to
the body.
3
4

25. Two Major Pathways

26. Heart Conduction System
 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.

27. Heart Conduction System
Sinoatrial Node (SV node)
- Aka Cardiac Pacemaker
- a small group of specialized muscle in the wall of the RA
- Influenced by the autonomic nerves ( these nerves regulates the
rate of heartbeat; impulses from the vagus nerve slow the
pacemaker)
Atrioventricular Node (AV node)
- Impulses reaches the AV node near the ventricles
- Triggers an impulse that causes the ventricles to contract
Bundle of His
- it transmits impulses from the atrioventricular node, located at the
inferior end of the interventricular septum, to the ventricles of the
heart.
Purkinje Fibers
- Where the signals from the left and right branches pass through
- Connected to the walls of the ventricles

28. Heart Conduction System

29. Heart Conduction System
ECG machine
- An electrocardiogram (EKG or ECG) is a test that checks for problems with the
electrical activity of your heart. An EKG shows the heart's electrical activity as line
tracings on paper. The spikes and dips in the tracings are called waves. The heart is
a muscular pump made up of four chambers

30. Heart Condition
Arrhythmia or Dysrhythmia *wrong spelling sa book
- a disorder of the heart rate (pulse) or heart rhythm. The
heart can beat too fast (tachycardia), too slow (bradycardia)
- “Bad rhythm” in Greek and usually occurs in the upper
chamber of the heart, called the atria

31. Regulation of Blood Pressure and Flow of Blood
• Blood Pressure (BP)
- The force against the arterial walls that moves
blood from the heart through the body
- Generated by heart contractions to keep blood
circulating
- Blood always flow from high to low pressure
- Blood flowing through the pulmonary and
systematic circulation
- BP is commonly measured in the brachial artery
with a device known as sphygmomanometer
- Normal BP in adult is 120/80 mm hg
- BP ↑ during exercise and times of stress
- High blood pressure or hypertension is a
medical condition and the cause of high BP is
arteriosclerosis (hardening of the arteries:
accumulation of cholesterol or fatty materials
around the walls of arteries → narrow and walls
are rigid → pressure increases →if untreated =
stroke/heart attack)

32. Examples of Blood Clot
Cerebrovascular accident. The picture
above shows a portion of the brain that
has been compromised due to lack of
blood supply. This patient has a stroke
because in this case, the blood flow to the
brain was stopped because the vessel was
occluded by a clot.

33. Blood Cells
1. RBC
2. WBC
3. Platelets

35. Differences between RBC, WBC & Platelet

36. THE CLOTTING PROCESS
Platelets, Thromboplastin, Fibrin

37. The Clotting Process
• Aka Blood Coagulation
• an important process that prevents excessive
bleeding when a blood vessel is injured.
• Platelets (a type of blood cell) and proteins in
your plasma (the liquid part of blood) work
together to stop the bleeding by forming
a clot over the injury.
• The expected range for clotting time 4 – 10
mins

38. Blood Type
• Four types: O, A, B and AB
• Variation are due to two antigens on the surface
of the red cells, symbolized as A and B
• Antigens are proteins that increase the
manufacture of the anti-body (one or two other
types of proteins found in the blood plasma; Anti-
A and Anti-B)
• Blood Type O are universal donors because they
have no antigens
• Blood Type AB are universal recipients because of
having no antibodies in the plasma

39. Blood Clot illustration

40. Examples of Blood Clot
Venous thrombus. A blood clot (thrombus) that forms within the vein. The pictures
above is a condition called deep vein thrombosis (DVT) or sa bisaya “Barikos”. There
is blood clot in the deep veins of the leg.

41. The Lymphatic System
Principal Functions:
collects and transports fluid from the intercellular spaces of the tissues
and returns it to the blood by way of lymph vessels, immune mechanism and
the lymph system absorbs fats from the villi of the interstitial tract and
transports them to the bloodstream
Consists of:
 Lymph
 Lymphocytes
 Lymphatic Vessels
 Lymph Nodes
 Tonsils
 Spleen
 Thymus

42. The Lymphatic System
• The system of vessels that connects with the
veins of the cardiovascular system
• Transports lymph (colorless interstitial fluid of
the blood) – a watery solution does not contain
RBC which remain in the closed circulatory loop
because they are too large to pass through the
capillary membranes
• before, it is the plasma in the blood, but if its in
the lymphatic circulation it is called lymph,
leaving the red blood behind
• Tonsils, Thymus and Spleen are like lymph
nodes, they produce lymphocytes (similar to
wbc for immune)
• Lymphocytes release the macrophage (large
cells that engulfs target cells) or activate
general immune system when they encounter
foreign invaders or bacteria/virus

43. The Lymphatic System consists of:
Lymph Capillaries
- Have no openings but is permeable to
all substances dissolved in the interstitial
fluid
Collecting Ducts
- drains into veins in the lower back
Lymph Vessels
- open-ended vessels (has valves)
- drain the lymph from around the
cells to the lymphatic trunks and
ducts and, eventually, to the
subclavian veins.

44. Lymphoid Organs
1. Lymph Nodes
- are small, bean-shaped glands
throughout the body. They are part of
the lymph system, which carries fluid
(lymph fluid), nutrients, and waste
material between the body tissues and
the bloodstream.
2. Spleen
- largest organ of lymphatic system
- Oblong and flattened shape and darkish
purple color
- located below the diaphragm
- in the spleen, the lymphoid tissue filters
out bacteria and worn-out blood cells from
the blood
3. Thymus gland
- located in the mediastinum behind
the sternum
- Age 25: decrease size and old age:
diminish/disappear entirely

45. Lymphoid Organs
4. Tonsil
- masses of lymphoid tissues embedded in
mucous membrane
- disk-like shape and become smaller
during puberty
5. Patches of lymphoid tissues in the small
intestine
- The lymph nodes that become inflamed
are in a membrane that attaches
the intestine to the abdominal wall.
These lymph nodes are among the
hundreds that help your body fight
disease. They trap and destroy
microscopic "invaders" like viruses or
bacteria. Mesenteric lymphadenitis often
causes abdominal pain.

46. Thank you for listening!
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