2. Heart
• Heart:- heart is a living pump.
• Location:- it is situated between lungs in our
chest cavity.
• Heart is made of:- Cardiac muscles. These
muscles contract and relax tirelessly throughout
life.
• Speciality of cardiac muscles:- It makes heart
beat continuously and pumps blood into the
arteries to be transported to all parts of the body.
2LIKE, SHARE, COMMENT, SUBSCRIBE
4. - Human heart is 4 chambered.
- It Has 2 auricles or atria. And 2 ventricles.
- Heart is divided into two half by thick muscular
septum. With auricle above and ventricle below.
- Right half of heart has Right auricle and right ventricle.
- Left half of heart has left auricle and left ventricle.
- Right half of heart = deoxygenated blood( blood
coming from body and will be pumped to lungs
for removing carbon dioxide).
- left half of heart = oxygenated blood ( blood coming
from lungs filled with oxygen and will be pumped
to the body parts).
- Septum:- Septum prevents mixing of oxygenated
blood with deoxygenated blood.
LIKE, SHARE, COMMENT, SUBSCRIBE 4
5. Auricles
• Auricles:-
- Auricles are the receiving chambers of the
heart.
- Right auricle receives deoxygenated blood
from the whole body.
- Left auricles receives oxygenated blood from
lungs.
- The walls of auricles are thinner than those of
ventricles.
LIKE, SHARE, COMMENT, SUBSCRIBE 5
6. Ventricles
• Ventricles pumps the blood out in the body.
• Right ventricle:- receives deoxygenated blood
from right auricle. Pumps blood to lungs for
oxygenation.
• Left ventricle:- ( largest heart chamber and
has thickest walls). It receives oxygenated
blood from left auricle. Pumps it to whole
body.
LIKE, SHARE, COMMENT, SUBSCRIBE 6
7. Valves
• There are 4 valves in the heart.
• Function of valve:- to control the flow of
blood in the heart and in blood vessels.
• A tricuspid valve:- guards the opening of right
auricle and right ventricle.
• A bicuspid valve:- guards the opening of left
auricle and left ventricle.
• Semilunar valve:- they are present at the base
of pulmonary Aorta and dorsal aorta.
LIKE, SHARE, COMMENT, SUBSCRIBE 7
8. Working of heart and circulation of
blood
• Auricles gets relaxed and both auricles gets filled
with blood.
• Right auricle receives deoxygenated blood from
body.
• Left auricle receives oxygenated blood from lungs
by pulmonary veins.
• Note:- Veins bring deoxygenated blood from
entire body to heart. But pulmonary vein means
the vein coming from lungs. Pulmonary veins
carry oxygenated blood.
LIKE, SHARE, COMMENT, SUBSCRIBE 8
10. - Both auricle contract and their cuspid valve open up.
- Blood from left auricle comes to left ventricle.
- Blood from right auricle comes to right ventricle.
- Both atrium relax and new blood flow into both
chambers.
- At the same time ventricle contract. The cuspid valves
are slam shut and Semilunar valves open up.
- The oxygenated blood from left ventricle is pumped
into aorta and distributed to all body parts by arteries.
- The deoxygenated blood from right ventricle is
pumped into pulmonary aorta and transported to lungs
for oxygenation by pulmonary arteries.
LIKE, SHARE, COMMENT, SUBSCRIBE 10
11. Pulmonary Vein
• Vein:- Veins are those blood
vessel having their starting
point in capillaries. Veins
coming from body parts
contain deoxygenated blood.
• Pulmonary vein:- The blood
vessels which arise from
capillaries in lungs contain
oxygenated blood. Hence
pulmonary vein carry
oxygenated blood from lungs
to heart. Which is then
circulated in entire body.
LIKE, SHARE, COMMENT, SUBSCRIBE 11
12. Pulmonary artery
• Artery:- Those blood vessels
which divide and re-divide
into smaller units to form
capillaries is called artery.
• Pulmonary artery:- the
blood vessels which divide
itself into smaller units in
lungs contain deoxygenated
blood. Hence pulmonary
artery carry deoxygenated
blood from heart to lungs
for oxygenation.
(oxygenation means adding
oxygen).
LIKE, SHARE, COMMENT, SUBSCRIBE 12
13. Heart beat
• Heart beat:- rhythmic contraction and relaxation of
auricle and ventricle is known as heart beat. ( heart
beats about 72 times per minute.)
• One heart beat:- one heart beat includes a phase of
contraction of heart muscles and a phase of relaxation
of heart muscles.
• Systole:- A phase of contraction of heart muscles.
During this phase auricle contract to push blood to
ventricle. And ventricle contract to circulate blood in
whole body.
• Diastole:- A phase of relaxation of heart muscles.
During this phase heart receives blood.
LIKE, SHARE, COMMENT, SUBSCRIBE 13
14. Heart beat sound
• The heart beat sound is produced by the
contraction of muscles and shutting down of
valves.
• The two phases of heart beat can be heard as Lub
and Dub sounds.
• Lub sound:- produced when the ventricle
contract and cuspid valve close.
• Dub sound:- produces when the pulmonary and
aortic valves close.
• Stethoscope is the instrument use to hear the
heart beat.
LIKE, SHARE, COMMENT, SUBSCRIBE 14
