The circulatory system transports nutrients, water, oxygen, and waste throughout the body using blood, blood vessels, and the heart. Oxygen-rich blood is carried from the heart to body cells via arteries and returns to the heart via veins as oxygen-poor blood. The heart pumps blood in two separate circuits - the pulmonary circulation transports blood to the lungs to receive oxygen and the systemic circulation transports oxygenated blood to all body tissues before returning to the heart.

1. Th
e
Circulatory
System
By Nitesh Sharma
X – C
golu1098@gmail.com

2. • The Circulatory System is responsible for
transporting materials throughout the
entire body.
• It transports nutrients, water, and oxygen
to your billions of body cells and carries
away wastes such as carbon dioxide that
body cells produce.
• It is an amazing highway that travels
through your entire body connecting all
your body cells.

3. Components
• Heart
• Blood
• Vessels
– Arteries
– Veins
– Capillaries
Heart
Blood
Arteries
Veins

4. • Which gases are transported to and from the body’s cells
by the blood flowing in the circulatory system?
carbon
dioxide
oxygen
Oxygen is the gas needed for respiration and is
transported to the body’s cells.

5. • The circulatory system carries two types of blood
• Arrangement of the circulatory system means that these
two types of blood do not mix.
Oxygen-rich
blood
c
De-Oxygen rich
blood
 Blood travelling
to the body cells
 High oxygen content
 Low carbon dioxide content
 Blood travelling
away from the body cells
 Low oxygen content
 High carbon dioxide content

6. • The heart is the organ at the centre of the circulatory
system. It pumps blood around the body.

7. • The inside of the heart is divided into two sections so
that the two types of blood (oxygen-rich and oxygen-
poor) are kept apart
Oxygen-poor
blood
Right side
of the heart
Oxygen-rich
blood
Left side
of the heart

9. • The right and left sides of the heart are separated by a septum,
or wall.
• The septum prevents the mixing of oxygen rich and oxygen
poor blood.
• On each side of the septum are two chambers.
• The upper chamber (receives blood) is the atrium.
• The lower chamber (pumps blood out of heart) is the ventricle.

10. • Four chambers
– Two Atria
• Upper chambers
• Left and right
• Separated by interatrial
septum
– Two Ventricles
• Lower chambers
• Left and right
• Separated by interventricular
septum
Right Ventricle
Right Atrium
Left Ventricle
Left Atrium

11. • The chambers of the heart have different functions:
blood to
the body
blood from
the body
blood to
the lungs
blood from
the lungs
The Atria collect
blood that enters
the heart.
The ventricles
pump blood
out of the
heart.

12. • The valves between the atria and ventricles are connected
to the inner walls of the heart by tough tendons.
valve open

13. • The tendons allow the valves to close and hold the valve flaps
in place. They prevent the valves from flipping up and turning
inside out
valve open valve closed

14. • A valve acts like a door that only opens in one direction.
• In the heart, the tendons holding the valve are like the
arm holding the door.
• One end of each tendon is fixed to the wall of the heart
and so the valve can only open in one direction.

15. • The heart can pump blood because it is made of muscle. Muscle
tissue works by contracting (squeezing) and relaxing.

16. • All the parts of the heart on
either side, work together in a
repeated sequence.
• The two atria contract and relax;
then the two ventricles contract
and relax.
• This is how blood moves through
the heart and is pumped to the
lungs and the body.
• One complete sequence of
contraction and relaxation is
called a heartbeat.

17. • As blood moves through the
circulatory system it moves
through 3 types of blood vessels:
– Arteries: Carry blood away from
the heart .
– Capillaries: Link arterioles to
veins.
– Veins: Carry blood towards the
heart

18. Arteries
 Large vessels
• Carry blood from heart to tissues of body.
• Carry oxygen rich blood, with the exception of pulmonary arteries.
• Thick walls-need to withstand pressure produced when heart pushes
blood into them.
 Smallest blood vessels
 Walls are only one cell thick and very narrow.
 Important for bringing nutrients and oxygen to tissues and
absorbing CO2 and other waste products.
Capillaries

19. • Once blood has passed through the capillary systems it must
be returned to the heart. Done by veins
• Walls contains connective tissue and smooth muscle.
• Largest veins contain one way valves that keep blood flowing
toward heart.
• Many found near skeletal muscles. When muscles contract,
blood is forced through veins.

21. • The heart produces pressure
• The force of blood on the wall of the arteries
is known as blood pressure.
• Blood pressure decreases as the heart relaxes,
but the rest of the circulatory system is still
under pressure.

22. • When blood pressure is taken, the cuff is wrapped around
the upper portion of the arm and pumped with air until
blood flow in the artery is blocked.
• As the pressure in the cuff is relaxed, 2 numbers are
recorded.
– Systolic pressure- the first number taken, is the force felt in the
arteries when the ventricles contract.
– Diastolic pressure- the second number taken, is the force of the
blood on the arteries when the ventricles relax.

23. Blood
• What percent of your body is blood?
• How much blood do we contain?
– On average 4-6 liters
– We contain about a pint of
blood for every 15 pounds
of body weight
• Composition of Blood:
– What percent of your blood is
cellular?
– What percent of your blood is
plasma?
8%
45%
55%

24. • Composed of plasma and blood cells
• Types of Cells are:
– Red Blood Cells
– White Blood Cells
– Platelets
 Plasma
Straw colored
90% water
10% dissolved gases, salts, nutrients, enzymes,
hormones, wastes, and proteins.

25. • Plasma proteins
– 3 Types: Albumins, globulins and fibrinogen.
– Albumins and Globulins- transport substances such as fatty acids,
hormones and vitamins.
– Fibrinogen- Responsible for blood’s ability to clot
Most numerous type
Transport oxygen
Get color from hemoglobin
Disk shaped
Made in red bone marrow
Circulate for 120 days

26. – Guard against infection, fight parasites, and attack bacteria
– Number of WBC’s increases when body is fighting
– Lymphocytes produce antibodies which fight pathogens and
remember them
 Platelets
Aid the body in clotting
Small fragments
Stick to edges of broken blood cell and secrete clotting factor to
help form clot.

27. Blood has 3 main
Functions
– Transport
– Protection
– Temperature
Regulation
Plasma
Red Blood
Cells
Platelets
White Blood
Cells

28. Nitesh Sharma
golu1098@gmail.com