Physiology RESP Book

Question 1

What lung volumes cannot be measured by spirometry

Answer 1

FRC,RC

Question 2

What is FRC

Answer 2

Volume left in lung after passive expiration

Question 3

What is ERV

Answer 3

Volume that can be expired further after passive expiration

Question 4

Define anatomical dead space

Answer 4

Air in conducting airways

Question 5

Where is surfactant produced

Answer 5

Lamella of type 2 alveolar epithelial

Question 6

Main constituent of surfactant

Answer 6

DPPC main
Remainder proteins, phospholipids

Question 7

Causes of reduced surfactant production

Answer 7

Cigarette smoking
Cardiac surgery
Occlusion of main bronchus
Long term 100% O2

Question 8

Elastance and compliance relationship

Answer 8

Reciprocal relationship

Compliance is the ability of a hollow organ (vessel) to distend and increase volume. It is the reciprocal of “elastance” which is a measure of the tendency of a hollow organ to recoil toward its original dimensions upon removal of a distending or compressing force.

Question 9

When is compliance greatest in respiration

Answer 9

In expiration

Question 10

Main transport of CO2

Answer 10

As bicarbonate

Question 11

Physiological changes at higher altitude

Answer 11

Decreased PO2
Tachypneoic
Resp alkalosis

Increase in Hb due to EPO
Increased 2,3 DPG - decreased affinity- aiding unloading

Question 12

Causes of pulmonary vasoconstriction

Answer 12

Hypoxia
Acidosis - increase in CO2I

Question 13

Increase in pulmonary circulation in systole or diastole

Answer 13

Systole

Question 14

Areas in the brain controlling respiration

Answer 14

Medulla- inspiratory and expiratory
Pons- apneustic and pneumotaxic - affect inspiration
Cerebral cortex- voluntary
Limbic- extreme states of emotion

Question 15

Chemoreceptors affecting respiration

Answer 15

Central- close to medulla- sensitive to change in PCO2
- triggered by H+

Peripheral- carotids- respind to O2 when very low <8

Question 16

What shifts the O2 curve to the right

Answer 16

Acidosis
High Temp
High DPG
Low CO

Question 17

Chemoreceptors

Answer 17

Peripheral mainly sensitive to PO2
Central within BBB- sensitive to pH indirectly through CO2

Question 18

What shift O2 curve to the left

Answer 18

Low temp
Low CO2
Low DPG
High pH
High CO

Question 19

Cause of sigmoid curve

Answer 19

Binding of first O2 molecule increases affinity on next

Question 20

What Oximetry measures and cannot measure

Answer 20

The saturation of Hb using red and infrared light- difference between oxygen and deoxy absorption

Doesn’t give good measure of ventilation - PCO2 better
If CO poisoning cannot differentiate

Question 21

Composition of Haemoglobin molecule

Answer 21

4 haem- bind to 1 O2 molecule
4 globin- 2 a and 2 b

Question 22

Causes of type 1 resp failure

Answer 22

Pulmonary oedema
Pneumonia
ARDS
PE