1. Amity Institute Of
Biotechnology
Plant Animal Physiology
Compiled By:
Priti Pal
M.Sc. BT
A7100213018

2. Pulmonary And Systemic
Circulation

3. Circulatory System
• Three basic
components:
• Heart: The pump
• Blood vessels: The
passageways
• Blood: The transport
medium

4. THE CIRCUIT OF BIOOD FIOW
• Right half of heart
receives blood
• Left half receives and
pumps oxygenated blood
• Blood returning from the
systemic circulation
(deoxygenated) enters
the right atria via two
large veins: superior and
inferior venae cavae

5. • The deoxygenated blood from the• The deoxygenated blood from
the right atrium then gets
pumped into the right ventricle
• From there, it’s pumped out
through the pulmonary artery
– It immediately forms two
branches, one going to each
lung
• In the lungs, blood picks up O2
and drops off CO2
• Then it’s returned to the left
atrium via the pulmonary veins
• **Only case where veins carry
oxygenated blood and arteries
carry deoxygenated blood**
• Aorta is the single large artery
carrying blood away from the left
ventricle to the body organs
The Circuit of Blood Flow

6. • Right side of heart receives blood from the
systemic circulation and pumps it into the
pulmonary circulation
• Left side of heart receives blood from the
pulmonary circulation and pumps it into the
systemic circulation
The Circuit of Blood Flow

8. Pulmonary circulation
• Blood enters superior and inferior vena cava which is then received
by right atrium.
• The opening of inferior vena cava into right atrium has valve but the
opening of superior vena cava does NOT have a valve. This is because
the inferior vena cava must work against gravity whereas the blood in
superior vena cava is moved by the help of gravity.
• Blood from right atrium is DIRECTED into right ventricle by opening of
tricuspid or right atrioventricular valve. The pulmonic valve is closed
at this time.
• Blood from right ventricle is then DIRECTED into pulmonary trunk via
pulmonic valves that are open. At the same time, the tricuspid valve
is closed. The closing of this valve is directed by muscles in right
ventricle (called papillary muscles).
• Blood from pulmonary trunk moves through pulmonary arteries to
lungs. Note that the blood in pulmonary artery is deoxygenated. The
oxygenated blood is picked up by pulmonary veins and returned to
left atrium.

10. Systemic Circulation
• (from previous slide)…blood in left atrium is oxygenated. This
blood is directed into left ventricle by mitral or bicuspid valve.
During this stage the aortic valve is closed and right ventricle is
filling with blood (diastole).
• Blood from the left ventricle is then directed into aorta by aortic
valve (open during ventricular systole). The mitral valve is close at
this time so that left atrium may collect blood from pulmonary
veins.
• The aorta has three parts: Ascending part, Arch, and Descending
part.
• The ascending part delivers blood to the heart itself via the
coronary arteries.
• The arch of aorta delivers blood to head, neck, and upper
extremity.
• The descending part delivers blood to everything below the level
of heart.
Consider: How would the pressure in systemic circulation differ from
pressure in pulmonary circulation? Is there any difference?

12. Differentiate between systemic and
pulmonary circulation
• The pulmonary circulation takes
deoxygenated blood from the
right ventricle to the air sacs of
the lungs and returns oxygenated
blood from the lungs to the left
atrium
• The systemic circulation takes
oxygenated blood from the left
ventricle through the aorta to all
parts of the body, including some
lung tissue (but does not supply
the air sacs of the lungs) and
returns the deoxygenated blood
to the right atrium.

13. Different between systemic and
pulmonary circulation
• The pulmonary and systemic circulations differ from
each other in several more ways.
– Blood in the pulmonary circulation is not pumped so
far as in the systemic circulation and the pulmonary
arteries have a larger diameter, thinner walls, and less
elastic tissue.
– resistance to blood flow is very low meaning that less
pressure is needed to move blood through the lungs.
– normal pulmonary capillary hydrostatic pressure is
lower than systemic capillary hydrostatic pressure
which tends to prevent pulmonary edema

14. Thank you