Respiratory disorders

Question 1

What is the endocardium?

Answer 1

-the lining of the interior surface of the heart chambers, which consists of endothelial cells and connective tissue

Question 2

What is LaPlace’s Law?

Answer 2

-law that relates the pressure on a vessel wall to the transmural pressure and the radius of the vessel

Question 3

What is the after load?

Answer 3

-the physical forces acting on the cells during contraction or the pressure the heart must work against to eject blood

Question 4

What is a myofibril?

Answer 4

-an elongated contractile thread found in striated muscle

Question 5

What is the ejection fraction?

Answer 5

-the ratio of the volume of blood ejected from the left ventricle per beat to the volume of blood in the left ventricle at the end of diastole

Question 6

What is the chordae tendinae?

Answer 6

-fibrous bands of connective tissue that connect the heart valves to the papillary muscle

Question 7

What is the preload?

Answer 7

-the physical forces acting on the cells before contraction or the volume of blood within the heart at the end of diastole

Question 8

What is Starling’s Law?

Answer 8

-the law that relates initial fibre length to strength of contraction

Question 9

What effect does exercise have on cardiac output?

Answer 9

• increases cardiac output
• due to reduction in after load due to decreases in vascular resistance
• but exercise can also increase preload

Question 10

What effect does heart failure have on the the cardiac output?

Answer 10

• reduced cardiac output

- due to increase i after load due to reduction in cardiac muscle contractility

Question 11

What will happen to the following structures after prolong hypertension?

• the resistance vessels
• the heart

Answer 11

• the resistance vessels will thicken due to increased pressure
• the overall radius should remain the same but the lumen is likely to get smaller

Heart:
-complex series of events but the increased afterload (pressure) will require increased force of systole -> thickening of left ventricle

Question 12

What 2 things can cause an increase in stroke volume?

Answer 12

• increase in contractility

- increase in preload

Question 13

Which 2 factors can affect heart rate?

Answer 13

• autonomic NS (sympathetic and parasympathetic)

- baroreceptor reflex

Question 14

What 3 factors affect stroke volume?

Answer 14

• preload
• afterload
• contractility

Question 15

What is the pleura?

Answer 15

-serous membrane that lines the thorax and lungs

Question 16

What is dead space?

Answer 16

-the volume of breath that does not participate in gas exchange

Question 17

What is the FEV1 ?

Answer 17

-the volume of air that can be forced out in 1 second after taking a deep breath

Question 18

What is the FVC?

Answer 18

-the maximum amount of air that can be exhaled following a deep inhalation

Question 19

How is alveolar ventilation calculated?

Answer 19

(breathing rate x tidal volume) - dead space

Question 20

What happens to the flow-volume loops in a restrictive disease?

Answer 20

• displaced to the right due to reduction in lung compliance

- narrower curve due to reduction in tidal volume

Question 21

What happens to the flow-volume loops in a fixed airway obstruction?

Answer 21

-blunted inspiratory curve and expiratory curves, due to reduced capacity to inspire and expire