Physiology Chapter 23 Heart Valves, Sounds, And Valve Defects

Front 1

What event signifies the first heart sound?
Does this occur during systole or diastole?

Back 1

Closure of the atrioventricular valves at the beginning of systole.

Front 2

What signifies the second heart sound?
When during the cardiac cycle does this occur?

Back 2

Closure of the semilunar valves at the end of systole.

Front 3

What are the 2 causes of the first and second heart sounds?

Back 3

- Vibration of taut valves immediately after closure
- Vibration of adjacent walls of the heart and major vessels around the heart

Front 4

When does the 3rd heart sound occur?
What causes the 3rd heart sound?
What initiates it?

Back 4

- Middle third of diastole
- Caused by oscillation of blood back and forth between the walls of the ventricles
- Initiated by inrushing blood from the atria

Front 5

What are the 2 causes of the fourth (atrial) heart sound?

Back 5

Atria contraction and the in rush of blood into the ventricles.

Front 6

What causes most valvular lesions?

Back 6

Rheumatic fever, an autoimmune disease that damages or destroys heart valves

Front 7

What bacteria commonly causes rheumatic fever?
What exactly causes the damage to vessels?

Back 7

- Group A hemolytic streptococci
- Antibodies, intended for the bacteria, reacting with protein tissues of the body

Front 8

What are the 2 most frequently damaged valves as a result of rheumatic fever?

Back 8

Mitral and aortic

Front 9

Stenosis can be described as?

Back 9

- Adhered valve leaflets that retard blood flow

Front 10

What causes regurgitation?
What does it cause?

Back 10

- Valve edges are destroyed by scar tissue preventing complete valve closure as ventricles contract.
- Back flow of blood results

Front 11

What 3 murmurs can be heard during systole?

Back 11

1. IV septal defect
2. Mitral regurgitation
3. Aortic stenosis

Front 12

What 3 murmurs can be heard during diastole?

Back 12

1. Mitral stenosis
2. Tricuspid valve stenosis
3. Aortic regurgitation

Front 13

What murmur can be hear during both diastole and systole?

Back 13

Patent ductus arteriosis

Front 14

What murmur is associated with severe turbulence as a result of significantly increased left ventricle pressure?

Back 14

Aortic stenosis

Front 15

What are the 3 murmur features of aortic and mitral regurgitation?

Back 15

- Blowing
- High pitch
- Swishing quality

Front 16

Where can aortic regurgitation best be heard?

Back 16

- Heard maximally over left ventricle

Front 17

In what direction does blood flow in aortic regurgitation? Mitral regurgitation?

Back 17

- Aorta into left ventricle
- Left ventricle into left atrium`

Front 18

What lesion causes the loudest murmur? the weakest?

Back 18

- Aortic stenosis
- Mitral stenosis

Front 19

What detrimental effect does aortic stenosis/regurgitation cause?
What are the 2 mechanisms for compensating?

Back 19

Decreased net stroke volume output
1. Increased blood volume
2. Hypertrophy of left ventricle

Front 20

What are 3 major types of congenital heart defects of the heart and associated vessels?
What is a special kind of congenital stenosis?

Back 20

- Stenosis
- Left to right shunt
- Right to left shunt

- Coarctation of the aorta

Front 21

A left to right shunt represents failure of what?

What about a right to left shunt?

Back 21

L to R: Failure of blood to flow through systemic circulation
R to L: Failure to flow through the lungs

Front 22

PDA is what kind of shunt?

Back 22

Left to right

Front 23

Teralogy of Fallot is what kind of shunt?

What are its 4 abnormalities?

Back 23

Right to left

1. Aorta originates from right ventricle or overrides a hole in the septum, thereby receiving blood from both ventricles.

2. Stenosed pulmonary artery, reduced amount of blood reaching the blood. Instead, most blood passes into the aorta.

3. Blood from left ventricle flows through a ventricular septal hole into the right ventricle and then into the aorta or directly into the aorta that overrides this hole.

4. Right ventricle hypertrophy

Front 24

What is a common cause of congential anomalies?

Back 24

Viral infection in the mother during the first semester of pregnancy (i.e. German measles).

Front 25

What are 3 reasons that cardiac hypertrophy lead to heart failure?

Back 25

1. Coronary vasculature (vessels) do not increase to the same extent as the cardiac muscle mass.

2. Fibrosis develops in the muscle

3. Ischemia develops as cardiac muscle hypetrophies. Coronary blood flow is insufficient.