Download Right Ventricle

HEART
Introduction :
• It is conical, hollow muscular organ situated
in the medial medistinum and enclosed within
the pericardium
• It pumps blood to various parts of the body to
meet their nutritive requirements
Situation :
• It is placed obliquely behind the body of sternum
and adjoining parts of costal cartilages, so that
1/3rd of it lies to the right and 2/3rd to the left of
median plane.
Measurements:
Length : 12 cm
Breadth : 9 cm
Weight : 300 gm in Males
250 gm in Females
Features :
Four chambered heart
External Features :
Apex –
• It is formed by left ventricle and
directed downwards, forwards
and to the left.
• It is overlapped by the anterior
border of left lung.
• Situation – It lies in the left fifth
intercostal space 9 cms lateral
to the mid-sternal line
External Features :
Base –
• It is formed mainly by the left
atrium and small part of right
atrium
• It shows openings of four
pulmonary veins and superior &
inferior vena cavae
• It is related to the T5 to T8
thoracic vertebra
Borders of the Heart :
Upper Border –
• Slightly oblique and is formed by
two atrium
Right Border –
• It is more or less vertical and is
formed by right atrium
Inferior Border –
• It is nearly horizontal and is
formed mainly by right ventricle
and small part of left ventricle near
at its apex
Borders of the Heart :
Left Border –
• It is oblique and curve and formed
mainly by the left ventricle and
partly by the left auricle
Surfaces of the Heart :
Sternocostal Surface –
• It is mainly formed by right atrium,
right ventricle and partly by left
ventricle and left auricle.
• Most of the surface is covered by
lungs but a part of it that lies behind
the cardiac notch of the left lung
is uncovered.
Surfaces of the Heart :
Inferior Surface –
• Rest on the central tendon of the
diaphragm and it is formed in it’s
left 2/3 rd by the left ventricle and
in it’s right 1/3 rd by the right
ventricle
Left Surface –
• Formed mostly by the left
ventricle and at the upper end
by the left auricle
Chambers of the Heart :
Right Atrium –
• It is a quadrilateral chamber
situated behind and to the right
side of right ventricle from which
it is separated externally by the
right part of atrio-ventricular
groove.
Extent –
• It extends from the orifice of
superior vena cava behind the
third right costal cartilage to the
orifice of inferior vena cava behind the sixth right costal
cartilage
Chambers of the Heart :
Right Atrium – External Features
• A hollow conical muscular projection
known as right auricle arises from
the antero-superior part of atrium
• A shallow verticle groove known
as sulcus terminalis runs along
the right border of the heart and
extends between the orifices of
superior and inferior vena cavae
Interior of Right Atrium:
• It consists of posterior smooth part known as sinus venarum
and anterior rough part known as atrium proper. Two parts
are separated by a smooth muscle ridge the crista terminalis
Smooth Part
Rough Part
Sinus Venarum:
Opening of
Superior Vena
Cava
Opening of
Inferior Vena
Cava
Foramen
Venarum
Minimarum
Opening of
Coronary
Sinus
Atrium Proper:
Musculi
Pectinati
Crista
Terminalis
Limbus
Fossa Ovalis
Fossa
Ovalis
Right Ventricle:
Introduction:
It is triangular chamber
which receives blood from the
right atrium and pumps it to the
lungs through the pulmonary
trunk and pulmonary arteries.
Right Ventricle:
Features :
It has two parts:
1)the inflowing part
It is rough due to presence of
muscular ridges called trabeculae
carneae.
2) the outflowing part /infundibulum
It is smooth and forms the upper
conical part of the right ventricle which
gives rise to pulmonary trunk
Right Ventricle:
Features :
Trabeculae carneae is of three types:
1) Ridges : which are fixed elevations
2) Bridges: having two fixed ends,
but with a free centre.
3) Pillars/Papillary Muscles: one end
attached to the ventricular wall,
and the other end connected to
the cusps of the tricuspid
valve
Anterior
by chordae tendinae. Posterior
Septal
Right Ventricle:
Features :
The interior shows 2 orifices:
1. The right atrioventricular orifice
(or) tricuspid valve
2. The pulmonary orifice which is
guarded by the pulmonary valve.
Left Atrium
 It is quadrangular chamber, situated posteriorly and
receives the oxygenated blood from lungs through
pulmonary veins and pumps it into left ventricle through
the left atrioventricular orifice which is guarded by
bicuspid valve.
Left Atrium
 Its appendage left auricle projects anteriorly to
overlap the infundibulum of the right ventricle.
Left Atrium
Features:
 Two pulmonary veins open into left
atrium on each side of posterior wall.
 Most part of the atrium is smooth
walled, and musculi pectinati is
present only in the auricle..
Left Ventricle
 The left ventricle receives oxygenated blood from
the left atrium and pumps into aorta.
Left Ventricle
Features:
The interior is divisible into 2 parts:
1. the lower rough part
trabeculae cornea
2. the upper smooth part gives
origin to the ascending aorta
Left Ventricle
Features:
The interior presents 2orifices
1. the left atrioventricular
orifice/bicuspid valve/mitral valve
2. the aortic orifice guarded by the
aortic valve
Left Ventricle
Features:
•
They are two papillary muscles:
anterior and posterior
•
The wall is 3 times thicker than
the right ventricle.
Blood Supply
Arterial Supply of the Heart
The heart is supplied mostly by two coronary
arteries, right and left.
Only the inner 75-100um of endothelial surface
gets nutrition directly from the blood in the cardiac
chambers.
Right Coronary Artery
Right Coronary Artery
Origin:
It arises from the anterior aortic sinus of the ascending
aorta just below the supravalvular ridge.
Right Coronary Artery
Branches are divided into two groups:
1. those branches arising from first segment of artery
i.e. upto inferior border
2. those branches arising from the second segment
i.e. upto the crux.
Right Coronary Artery
Branches from the first segment:
Ventricular Rami
Right Conus Artery
Right Anterior Ventricular Rami
Right Marginal Artery
Atrial Rami
Sinu-Atrial Nodal
Artery
Branches from the first segment:
Ventricular Rami:
1. Right conus artery: It usually first branch of right
coronary artery and supplies the infundibulum of
right ventricle.
2. Right anterior ventricular rami: These are 3-4 in
number arises right angles to main trunk of coronary
artery and supplies sternocostal wall of the right ventricle.
3. Right marginal artery: It is longest of ventricular ramus
follows the inferior border of the heart towards the apex
and supplies adjoining surfaces of the right ventricle.
Branches from the first segment:
Atrial Rami:
• Sinu-Atrial Nodal artery:
It belongs to atrial rami and supplies the SA-node
Branches from the second segment:
Right posterior ventricular rami
Posterior inter-ventricular branch
Right posterior atrial rami
Branches from the Second Segment:
1. Right posterior ventricular rami
It arises from trunk of right coronary artery in
posterior ventricular groove and supplies diaphragmatic
surface of the right ventricle.
2. Posterior ventricular branch:
It arises from right coronary artery and anastomoses
with anterior interventricular branch of left coronary artery
near the apex. It supplies diaphragmatic surface of the
right ventricle and left ventricles.
3. Right posterior atrial rami:
It supplies posterior surface of both right and left atria
Left Coronary Artery
Left Coronary Artery
Origin:
It arises from left posterior aortic sinus of the ascending
aorta..
Left Coronary Artery
Branches are divided into two groups:
1. Anterior interventricular artery
2. Circumflex artery
Anterior
Interventricular Artery
Circumflex Artery
Anterior Interventricular Rami
Atrial and Ventricular Rami
Left Conus Artery
Septal Rami
Left Marginal Artery
Anterior interventricular artery:
It is continuation of left coronary artery and descends
in the anterior ventricular groove and anastomoses with
the posterior interventricular branch of right coronary
artery.
Branches:
Anterior interventricular rami: It supplies right and left
ventricles.
Left conus artery : It is a branch of anterior ventricular
rami and supplies the infundibulum of right ventricle.
Septal rami: Supplies antero-superior 2/3rd of the
ventricular septum.
Circumflex Artery:
It passes along the left part of atrioventricular groove,
winds round the left border of heart and occupies the
posterior part of atrioventricular groove and anastomoses
with the right coronary artery
Branches:
Atrial and Ventricular rami:
Supplies adjoining surfaces of left atrium and left
ventricle.
Left marginal artery:
It follows the left border of heart towards the apex
Venous Drainage :
About 60% of the venous blood of the heart drains
into the right atrium through coronary sinus.
The remaining 40% of the blood drains into the heart
through venae cordis minimi and anterior cardiac veins.
Coronary sinus conveys the grater part of blood
from the left coronary artery.
Anterior cardiac veins drain most of the blood of the
right coronary artery.
Venous Drainage :
Veins which donot join the coronary sinus are:
1) Anterior cardiac vein: 3-4 in number, drains the
infundibulum of the right ventricle and end directly
into the right atrium through foramen minimarum.
2. Venae cordi minimi: These veins open into different
chambers of heart through the foramin minimarum
3. Some times right marginal vein instead of joining the
small cardiac vein, opens directly into right atrium.
Coronary Sinus:
It is wide venous channel, about 2-3cms long
situated in the posterior part of the atrio-ventricular groove
and receives about 60% venous blood of the heart.
Tributaries : Coronary Sinus
1. Great Cardiac Vein
3. Oblique Vein of the
Left Atrium
5. Small Cardiac Vein
2. Middle Cardiac Vein
4. Posterior Vein of the
Left Ventricle
Nerve Supply :
Nerves of the heart are derived from cardiac
plexus which are formed by parasympathetic fibers.
Parasympathetic: By vagus
These are cardio inhibitory, on stimulation they
slow down the heart rate.
Sympathetic: Derived from the upper 4-5 thoracic
segments of the spinal cord.
These are cardioacceleratory, and on stimulation
increases the heart rate, and also dilate the
coronary arteries.
Both parasympathetic and sympathetic nerves
forms cardiac plexus.
Cardiac Plexus :
It consists of two parts –
 Superficial and
 Deep
Superficial Cardiac Plexus :
Situation :
It is situated below the arch of aorta and in front
of pulmonary artery
Formation:
 By the cardiac branch from the superior cervical
ganglion of the left sympathetic trunk
 By the inferior cervical cardiac branches of the
left vagus
Branches of the superficial cardiac plexus:
- To the deep cardiac plexus
- The right coronary artery
- The left anterior pulmonary plexus
Deep Cardiac Plexus :
Situation :
In front of bifurcation of trachea above the division of
pulmonary trunk and behind arch of aorta
Formation:
 By the cardiac branches of superior, middle and
inferior cervical ganglia and upper 4 (or) 5 thoracic
ganglia of both sympathetic trunks
 By the cardiac branches of vagus and recurrent
laryngeal nerves of both sides.
 Except the braches of superficial cardiac plexus.
Branches of the Deep cardiac plexus:
- To the Coronary plexus
- To the Pulmonary plexus