Respiratory

Question 1

Define Pneumothorax

Answer 1

Loss of subatomic pressure, there is air in the pleural cavity

Question 2

Obstructive lung disease on a spirogram

Answer 2

Expiration is sloped, TLC normal, RV higher

Question 3

What is an obstructive lung disease and examples

Answer 3

Damage to lungs and narrowing of airways makes air come out slower, takes more effort to exhale
Ex. asthma, bronchitis, cystic fibrosis

Question 4

Restrictive lung disease on a spirogram

Answer 4

TLC, VC and IRV lower, reduced normal lung capacity

Question 5

What is restrictive lung disease and examples

Answer 5

Stiffness in lung or anything that restricts lung expansion, capped at 4000 mL volume, cant inhale easily
Ex. Obesity, muscular dystrophy

Question 6

1st Inspiration step

Answer 6

Diaphragm and external intercostal muscles contract, ribs and sternum elevate

Question 7

2nd Inspiration Step

Answer 7

Thoracic cavity expands and increases its volume

Question 8

3rd Inspiration step

Answer 8

Intrapleural pressure decreases, 756 –> 754

Question 9

4th Inspiration step

Answer 9

lung volume increases

Question 10

5th Inspiration step

Answer 10

Alveolar pressure drops, 760 –> 759

Question 11

6th Inspiration step

Answer 11

Air moves from high pressure to low pressure area

Question 12

What is lung elasticity

Answer 12

How easily the lung recoils after being stretched, uses elastin fibres and alveolar surface tension

Question 13

What is lung compliance

Answer 13

How much effort is required to stretch the lungs by a given amount, low compliance = stiff lungs

Question 14

Exercise and Fick’s Law

Answer 14

During exercise, there is increased diffusion, PP gradient gets larger to increase ventilation, SA increases, thickness of membrane reduces, coefficient of D increases

Question 15

Oxygen dissociation curve

Answer 15

Tissues 20-40, Lungs 100, R-state 100 with a high affinity for O2

Question 16

Oxygen curve left shift

Answer 16

Hemoglobin has greater affinity for CO, 200x greater than for O2, does not drop oxygen in tissues and muscles, forced to keep HB in R-state
Ex. CO poisoning

Question 17

Oxygen curve right shift

Answer 17

Hemoglobin drops off more oxygen, decreased affinity for oxygen make it easier to unload

Question 18

3 ways of CO2 transport

Answer 18

1) dissolved in blood, more soluble than O2
2) Bound to hemoglobin, forms HBCO2
3) Turned into bicarbonate HCO3, slowly and via carbonic acid

Question 19

What is V/Q

Answer 19

Ventilation-perfusion ratio, should be 1

Question 20

What happens if V/Q is above 1

Answer 20

usually because Q is too low, not enough blood to pick up O2, low blood pressure, CO2 and ventilation decrease, O2 and perfusion increase

Question 21

What happens if V/Q is below 1

Answer 21

Usually because V is too low, not enough airflow to oxygenate blood, CO2 and ventilation increase, O2 and perfusion decrease