The document discusses the anatomy and structure of the heart valves, conducting system, blood supply, innervation, and applied anatomy. It notes that the heart contains two pairs of valves - atrioventricular and semilunar - which ensure one-way blood flow. The right and left atrioventricular valves have different numbers of cusps. The aortic and pulmonary valves are semilunar in shape. The conducting system initiates and spreads cardiac impulses, while the coronary arteries supply blood to the heart muscle. Applied anatomy discusses common causes of ischemic heart disease.

1. Valves of the heart
• Provides unidirectional flow of blood.
• 2 pairs: atrioventricular valve & semilunar
valve
• A.V. valve:
• Right a.v. valve is known as tricuspid valve
because of 3 cusps(anterior, posterior &
septal)
• Left a.v. valve(mitral) is known as bicuspid
valve due to 2 cusps.(anterior/aortic
&posterior)
• Both valves have following components:
1.Fibrous ringor annulus to which cusp attach
2.Leaflet or cusp
3.Chorda tendinae-connects upper free margin
of the cusp to papillry muscle
4.Papillary muscle-whose contraction makes the
valve competant.

2. Semilunar valve
• Aortic & pulmonary valve are
semilunar valves-cusps are
semilunar in shape.
• Each valve has 3 cusps which
are attached to the fibrous
scallop of the orifice by convex
margin.
• Free margin shows fibrous
nodule (nodule of Arantius ) at
the centre with 2 thin lunule at
the side.
• Opposite the cusp, vessel walls
are dilated to form aortic &
pulmonary sinuses.
• Applied anatomy: stenosis,
valvar incompetence leading
to regurgitation (murmur)

3. Skeleton of the heart
• It consists of 4 fibrous rings around
A.v. orifice, pulmonary & aortic orifices
• Pulmonary & aortic rings are
• connected by fibrous septum
called tendon of infundibulum.
• Right & left A.V. rings are united by
trigonum fibrosum dextrum.
• Aortic & left A.V. rings are connected
by trigonum fibrosum sinistrum.
• These interconnected fibrous rings
provide attachment to cardiac
muscle & supports the valve
• It disturbs the continuity between atrial &
ventricular muscle. So impulses are
propagated through conductng system of
the heart

4. Conducting system of the Heart
• They are the specialized
myocytes for initiation &
conduction of cardiac
impulses. It includes:
• Sinuatrial node(S.A node)
• Atrioventricular Bundle & its
2 limbs
• Subendocardial plexus of
purkinje fibers.
• Heart beat is myogenic.

5. Conducting system of the Heart

6. Blood supply of the heart
• Heart is supplied by 2 coronary arteries-
rt.&lt. arising from ascending aorta.
• coronary is derived from the word
`crown’which encircles the base of ventricle
as a crown
• Each coronary artery is vasvasorum
• Right coronary artery:
• Arises from ant. Aortic sinus & passes
forward to the right betn pulmonary trunk
& rt auricle.
• Then runs in the rt. Coronary sulcus to the
junction of rt. & inferior border of the
heart.
• It winds around the inferior border to reach
diaphragmatic surface of the heart. Here it
runs backward & to the left to reach
posterior iv groove & terminates
anastomosing with left coronary artery.

7. Blood supply of the heart

8. Contd..
• Left coronary artery: Larger than right coronary artery.
• Arises from left posterior aortic sinus .
• Pecularities:
• Sometimes left coronary artery may arise from pulmonary
trunk.
• Sympathetic stimulation constricts the epicardial artery & dilate
intramuscular arteries.
• It is the only vessel where blood flows in diastole.
• Cardiac & extracardiac anastomosis
• 85% of Inter- atrial anastomosis takes place in precapillary level
&15% in capillary level. So they are not typical end arteries but
functionally behave like end arteries.

9. Inter-atrial anastomosis
• Sites of anastomosis are:
• Kugel’s artery: artterial branch of both coronary arteries
communicates at ant. atrial wall.
• Anastomosis between anterior & posterior interventricular artery
near to the apex.
• Annulus of Vieussens- anastomosis betn rt. & left conal artery
around the infundibulum.
• In the intervenricular septum
• Near the crux of the heart
• Coronary perdominance:
• Most case right coronary predominance where posterior
interventricular artery is derived from right coronary artery(70%).
• Minority of population has left coronary predominance-from left
coronary artery.
• In balanced pattern branches of both run in or near the sulcus.

10. Venous drainage of the heart
• Great cardiac vein
• Middle cardiac vein
• Small cardiac vein
• Oblique vein of left atrium(of
Marshal)
• Left marginal vein
• Anterior cardiac vein
• Venae cordis
minimae(Thebesian vein)
• All veins excep last two drain
into coronary sinus which
open into rt. Atrium.

11. Contd..

12. Nerve supply of the heart
• Derived from cardiac plexus formed by
sympathetic (T1-T4/T5) &
parasympathetic(vagus) nerves.
• Cardiac plexus suprficial-below the arch of
aorta
deep-infront of bifurcation
of trachea

13. Applied anatomy
• Common cause of death in developed
countries-ischaemic heart disease
• Sudden obstruction of major branch of
coronary vessels lesd to myocrdial infarction.
• Common branches for occlusion are:
• Anterior interventricular artery
• Rt. coronary artery
• Circuflex branch of left coronary artery