Anatomy of the valves

Question 1

What is the tricuspid orifice?

Answer 1

• It is a large oval opening connecting the right atrium with the right ventricle
• It is surrounded by a fibrous tissue ring giving attachment to the tricuspid valve
• It lies behind the 4th intercostal space

Question 2

What is the anatomical thorax relation of the tricuspid orifice?

Answer 2

4th intercostal space

Question 3

Describe the tricuspid valve

Answer 3

• It is a valve that guards the tricuspid orifice formed of a fibrous ring and three cusps:

1) Anterior cusp: Between the tricuspid orifice and the infundibilem of the RA

2) Posterior cusp: At the inferior wall of the right ventricle

3) Septal cusp: Attached to the interventricular septum

Question 4

What are the features of the tricuspid valve cusps?

Answer 4

1) Made of two layers of endocardium with a fibrous tissue in between

2) The cusp is avascular except at the circumference

3) The atrial surface of the cusp is smooth, while the ventricular surface is rough and has attachments for the chordae tendenae

Question 5

What is the mitral orifice?

Answer 5

• It is an opening surrounded by a fibrous ring between the LA and the LV
• It is smaller than the tricuspid orifice
• It lies at the 4th costal cartilage

Question 6

What is the anatomical relation of the mitral orifice in regard to the thorax?

Answer 6

It lies at the 4th costal cartilage

Question 7

What is the mitral valve?

Answer 7

It is the valve that guards the mitral orifice formed of two cusps:

1) Anterior cusp: It is larger than the posterior one, lies at the anterior and towards the right

2) Posterior cusp: Smaller and lies posteriorly towards the left

Question 8

What are the features of the mitral cusps?

Answer 8

• It consists of a double endocardium layer with fibrous tissue in between
• Its base is attached to a fibrous ring
• Its atrial surface is smooth while the ventricular surface is rough, the ventricular surface is attached to two papillary muscles in the ventricles which are fewer and stronger than those of the right ventricle

Question 9

Describe the aortic and pulmonary (semilunar) valves

Answer 9

• It is guarded by three semilunar cusps
• In the aortic valve, one cusp is anterior (right), and ONE IS LEFT THE THIRD IS POSTERIOR
• In the pulmonary trunk, one cus is posterior and 2 are anterior (LEFT & RIGHT)

Question 10

Describe the structure of the semilunar cusps

Answer 10

• The cusp is cup-shaped
• The cusps are projected into the arterial wall
• Their free edge is thickened forming the lunule
• Each lunule has an angulated free edge with a central fibrous nodule

Question 11

What is the significance of the sinus in the aortic semilunar valve?

Answer 11

The wall of the artery is slightly dilated in each cusp preventing the cusp from sticking into the blood vessel, and thus failing to shut

• The Right anterior cusp has a right coronary artery opening, while the left posterior cusp has a left coronary artery opening

Question 12

What is meant by aortic stenosis?

Answer 12

It is a condition where the valve cusps are fused, narrowing the central opening, which will require extra work from the heart that might lead to hypertrophy of the LV

Question 13

What is meant by aortic incompetence?

Answer 13

It is when the aortic cusps fail to close completely, leading to the backflow of blood into the ventricles

Question 14

Describe the skeleton of the heart

Answer 14

• They are fibrous rings that surround the AV canals and the AORTA & PULMONARY TRUNKS
• Right and Left Fibrous Triagones form connections between the rings
• It forms the membranous part of the interventricular septum

Question 15

What is the function of the skeleton of the heart?

Answer 15

1) Keeps the tricuspid and mitral orifices patent all the time

2) Prevents the over-distention of the orifices

3) It provides attachment for the myocardium and the cusps of the valves

4) Acts as an electrical insulator between the atria and the ventricles so that they can contract independently

Question 16

Describe the surface anatomy of the heart and its relation to the thorax

Answer 16

1) Apex:

• Left 5th intercostal space, 3.5 inches from the midline

2) Base:

• 5-8 while sitting, 6-9 thoracic vertebra while standing

3) Left border:

• From the lower border of the 2nd left costal cartilage, 1.5 inches from the median plane, till the apex (5th…)

4) Upper border:

• From the second left costal cartilage to the 3rd right costal cartilage

5) Right border:

• From the third right costal cartilage to the 6th right costal cartilage (0.5 inch from the sternal margin)

6) Lower border:

• From the sixth right costal cartilage till the apex (5th intercostal)

Question 17

What are the surface anatomy of the valves of the heart?

Answer 17

• Papa (Pulmonary), A7san (Aortic), Men (Mitral) Teta (Tricuspid)

1) Papa (Pulmonary):

• Left 3rd costal cartilage

2) A7san (Aortic):

• right to the pulmonary valve but left of the chest at the 3rd intercostal space

3) Men (Mitral):

• Left to the sternum, 4th costal cartilage

4) Teta (Tricuspid):

• 4TH INTERCOSTAL SPACE AT THE MEDIASTINUM

Question 18

What are the auscultatory locations of the valves?

Answer 18

• Blood carries the sound in the direction of its flow, and remember the aorta is going to the right side while the pulmonary is going to the left side

1) Pulmonary

• 2nd left intercostal space

2) Aortic Valve:

• 2nd right intercostal space

3) Mitral Valve:

• Superficial to the apex beat (5th intercostal space)

4) Tricuspid Valve:

• Inferior to the body of the sternum at the left side