Physiology Revision

Question 1

Which of the following is correct about Functional Residual Capacity?

Is usually increased in obese subjects
Is measured by spirometry
Is decreased in spirometry
Is normally about 40% of total lung capacity
Is approximately about 20% of vital capacity

Answer 1

Is normally about 40% of total lung capacity

Question 2

Residual capacity is decreased in obese patients why is this?

Answer 2

In obese pressure there is increased pressure exerted by the diaphragm thus more air expired out so residual capacity decreased

Question 3

Answer 3

85%

Question 4

Answer 4

60%

Question 5

Outline FEV1 and FVC in normal lungs, restrictive lung disease and obstructive lung disease

Answer 5

In obstructive disease need more time to bring air out of lungs compared to restrictive lung disease or normal lungs

Question 6

In COPD post bronchodilator, FEV1/FVC will be…

Answer 6

<70%

Question 7

Outline spirometry results in normal lungs and different lung diseases

Answer 7

Question 8

Answer 8

Increased central and autonomic arousal

Question 9

Answer 9

A low PO2 causes pulmonary vasoconstriction

• opposite to systemic circulation where low pO2 will cause vasodilation

Question 10

Answer 10

Reduced pulmonary compliance and impaired gas diffusion

Question 11

Answer 11

Dynamic airway compression is likely to occur during active expiration

Question 12

Answer 12

The pulmonary compliance is increased

Question 13

Compliance is….

Answer 13

How easy it is to stretch the lungs

• thus in diseases that reduces elasticity of the lung there is increased compliance as lesser effort to stretch the lungs

Question 14

Answer 14

Patient is likely to be hypotensive

Question 15

Answer 15

90%

Question 16

Answer 16

Saturation 99%, PO2 13.1 kPa

• having a low Hb will not affect saturation and PO2

Question 17

Answer 17

pH 7.26 PCO2 3.2 HCO3- 8 PO2 12

Question 18

Answer 18

Increased total lung capacity, decreased lung diffusion capacity, and decreased FEV1/FVC ratio

Question 19

Answer 19

IV furosemide + start nitrate infusion

Question 20

Answer 20

Thyroid function tests

Question 21

Answer 21

Reduced pulmonary compliance and impaired gas diffusion

• He has pulmonary fibrosis (dry cough)

Question 22

Answer 22

A. pH 7.6 PCO2 2.6 HCO3- 26 PO2 12.8

Question 23

Answer 23

%Saturation: 90%, PO2: 8.3, and PCO2: 4.8

Question 23

Answer 23

Ventilation perfusion mismatch

Question 24

Answer 24

pH 7.1 PCO2 7.1 HCO3- 26 PO2 6.2

Question 25

Answer 25

pH 7.36; PCO2 6.8; PO2 6.9; HCO3- 38

Question 26

Answer 26

Decreased total lung capacity, decreased lung diffusion capacity, normal or increased FEV1/FVC ratio

Question 27

Answer 27

A 28 year old man with type 1 diabetes, admitted semi-comatose with blood glucose 32mmol/L

Question 28

Answer 28

Reduced oxygen carrying capacity of the blood

Question 29

Hyperventilation causes ______________ and ______________. This results in decreased ____________________ so more ______________. The decreased in ________________ results in increased ________________ and hence __________________

Answer 29

Wash out of CO2
Respiratory alkalosis
Ionised (free) calcium
Calcium will bind to albumin if the pH increases
Ionised calcium
Nerve excitability
Numbness and tingling