A small and clear introduction of Heart Anatomy and its function.

1. Anatomy And Physiology Of The Heart
Amrutha Nayaka P,
2nd year Bsc Nursing,
Kidwai College Of
Nursing,
Bengaluru.

2. Contents
• General Features of the Heart
• External Features of the Heart
• Chambers of the Heart
• Circulation of the Heart
• Difference between Artery And Vein
• Cardiac Cycle

3. General Features
• Heart is a pumping organ, that pumps blood to all
parts of the body.
• It is conical in shape with base upwards and apex
below.
• It is 350gms in Males and 250gms in females.
• Heart is appoximately the sixe of a persons closed fist.
• It is located in the chest cavity between the two lungs.
• It is places obliguely behind the sternum, ¼ to the right
of the sternum & ¾ to the left of sternum.
• It extends b/w 2nd to 6th rib on the
left side & is placed over the
diaphragm

4. External features
• Heart consists of 4 chambers, 2 Atrium and 2
Ventricles
• On anterior surface of atria, there is lace like
structure called Auricle.
• Atria are separated from the
ventricles by the AV groove.
• Opening into the right atrium
are;
a) SVC [superior Vena Cava]
b) IVC [Inferior Vena Cava]
c) Opening of the coronary sinus

5. • Opening into left Atrium are 4 pulmonary
veins, two from each lungs.
• Arising from the right ventricle is the
pulmonary trunk, which divides into two
pulmonary arteries near the base of the heart.
• Arising from the Left
Ventricle is the Aorta which
form the arch of Aorta,
near the base of The heart.
• Heart shows the right
border, left border, inferior
border, a base & an apex.

6. Chambers of the Heart:
Right Atrium:
• It forms the right border of
Heart.
• On Anterior surface on the right side,
there is yellow lace like structure called
Auricle, which helps to increase the
capacity of the Right Atrium.
• Cut section shows inside the right atrium there are
important structure,
a) SA Node
b) AV Node
c) Fossa Ovalis

7. Conted……
• Opening into the right Atrium are,
a) SVC (superior Vena Cava)
b) IVC (Inferior Vena Cava)
c) Opening of the common sinus
d) Opening of the right aurical into Right
Ventrical called Right Atrio ventricular
opening, where the opening is guarded
by the right AVV or tricuspid valve.

8. Right Ventricle
• It forms the inferior border
Of the heart.
• Cut section shows right Ventrical is
sepreted from left ventrical by the inter
Ventricular septum.
• Cut section of wall shows 3 layers
a) Outter most pericardium
b) Middle thick Myocardium,
c) Inner most Endocardium.
• Inside the right ventricle there is a rough lower area & smooth
upper area

9. • The rough area is due to a network of muscular
fibres called Trabeculae cornae from which arises
3 pyramid shaped muscular structres called
Papillary Muscles.
• The tips of the papillary muscles give attchment
to one end of a chordae tendinae, the other end is
attached to tricuspid valve.
• From the upper smooth area arises the pulmonary
trunk, the opening of the pulmonary trunk is
guarded by semilunar valve. pulmonary trunk
rises upwards and near the base of the heart, it
divides into 2 pulmonary arteries, one for each
lung.

10. Left Atrium
• It forms a base of the heart
• On the surface of the left side, there is a yellow
lace like structure called auricle, which helps to
increase the capacity of left atrium.
• Inside the left atrium it is very smooth.
• Four pulmonary vein, 2 form each lung open into
the left atrium.
• Left atrium opens into left ventricle through the left
AV opening which is guarded by the bicuspid
value or mitral valve.

11. Left Ventricle
• It forms the left border of the
Heart.
• Cut section shows left ventricle
Is separated from right ventricle,
by the intra ventricular septum.
• Cut section of walls shows 3 layer,
a) Outer most pericardium
b) Middle thick myocardium
c) Inner most endocardium

12. • Inside the left ventricle there is a rough
area , due to a network of muscle fibres
called Trabeculae Cornae, from which
arise two pyramid shaped muscular
structures called papillary muscles.
• The tips of papillary muscles gives
attachment to one end of a chordae
tendinae, while the other end is attached
to the Bicuspid valve.
• From the upper smooth area arises the
Aorta whose opening is guarded by the
Semilunar Valve.

13. Circulation Of the Heart
3 main circulations play an important
role in blood circulation of the heart,
They are;
1. Systemic Circulation
2. Pulmonary Circulation
3. Portal Circulation

14. 1. Systemic Circulation:
 Pure blood flows from the left
Ventricle, pusses out through
The Aorta & distributed to all the
Tissues in the body, where it
Burst Up into 5 blood capillary.
 All the capillaries in the tissue, joins to
form veins, that carry impure blood &
return it to the right Atrium.

15. 2. Pulmonary Circulation:
Impure blood from the right
atrium enters the right
Ventricle is carried forward by
the pulmonary Trunk & to the
pulmonary artery enters the lungs. In the
lung the blood gets oxygenated & pure
blood is brought back from the lungs to the
atrium, through four pulmonary veins, two
from each lung.

16. 3.Potal Circulation
• It is the special type of
circulation of blood , seen only in
human beings,
• In this type of circulation there are 2 sets of
capillaries, one in the intestine and one in the liver.
• All the digested food, drugs are absorbed in the
intestine by the superior and inferior misentric veins.
• These 2 veins rises upwards & open into the splenic
vein coming from the spleen, to form the portal vein.

17. • Portal vein runs horizontally towards the right, rises
upwards to enter the liver.
• Before entering the liver, cystic vein and left gastric vein
from the stomach, opens into the portal vein.
• Inside the liver, portal vein breaks up into the second set of
capillaries.
• All the capillaries joint to form 4 to 5 hepatic veins that open
into the Inferior vena cava on the posterior surface of the
liver.
• By this portal circulation of blood, all the harmful
substances, drugs, alcohol removed or detoxified in the
liver and purified blood is sent into general circulation.

18. Difference Between Artery And Veins
Sl
No.
Feature Artery Veins
01 Valves Absent Present
02 Direction Blood towards the
heart
Away from the heart
03 Lumen size Small Large
04 Type of blood Oxygenated blood Dioxygenated blood
05 Tunica media Thicker thinner
06 Location Always deep Superficial or deep
07 Pressure in the blood
vessles
Pressure present No pressure
08 Flow of blood Towards gravity Against Gravity

19. Cardiac Cycle
Definition:
The changes taking place in the heart
during one beat, it is repeated in the same
order, beat after beat, this is called Cardiac
Cycle.
Cardiac cycle time is 0.8 sec.

20. 1} On set of ventricular contraction:
Just before the ventrical are
going to contract, AVV close producing 1st sound ‘S1’
2} Isometric Contraction Period:
Semilunar valve will not open,
until the pressure in the ventricles is very high, then that in the
aorta or pulmonary trunk, until the ventricles are contracting as
closed cavities, this is called Isometric contraction period.
3} Maximum ejection period:
After sometimes the pressure in
the ventricles is more, then that in the aorta or pulmonary
trunk, i.e. SLV open & blood rushes out, this is called Maximum
Ejection period.

21. 4} Isometric Relaxation Period:
Once the blood goes out into the aorta
and pulmonary trunk, pressure inside the ventricles falls, as a result,
blood tries to fall back into the ventricle, but SLV are like pockets which
closes
And Produce ‘S2’ . AVV will not open until the presser in the
ventricle is very low, as there relaxing, mean while pressure is
build up in the Atria as they are getting filled up with blood, i.e.
the ventricles are relaxing as close cavity, this is called Isometric
Relaxation period.
5} 1st Rapid Filling Period :
After some time, the pressure in the
Aorta is very high, then that in the ventricles , AVV open and
blood rushes into ventricles produces 3rd sound that is ‘S3’ .
This is called 1st rapid filling period.

22. 6} Last rapid filling period:
Any remaining blood in the
Atria is pushed into ventricles
Producing 4th sound ‘S4”.
This is called last rapid filling period.
Now AVV close and cycle is repeated.