Lecture 11 - Challenges to normal respiration Flashcards Preview

Respiratory physiology > Lecture 11 - Challenges to normal respiration > Flashcards

Flashcards in Lecture 11 - Challenges to normal respiration Deck (14)
Loading flashcards...
1

How much oxygen do we need at rest

4.8L/kg/min
200 ml/min

2

Effect on alveolar O2 at altitude

oxygen constant at 21%
atmospheric pressure at sea level - 100
PO2 - 21 pKa
Inspired O2 at alveolar level is less
inspired O2 alveolar level is less - 6.3 kPa
Partial pressure of inspired O2 = 0.21 (Patm - 6.3)kPa

3

Alveolar gas equation

PAO2 = [FiO2 x (Patm - PH2o] -(PACO2/R)
13.3 kPa

4

What does hyperventilation and respiratory alkalosis result in?

increased DPG and cause better unloading of oxygen
right shift
Polycythaemia - slow to develop
bicarbonate excretion from CSF and kidneys
Diuresis and hyponatraemia
Acetazolamide

5

Acute mountain sickness

Headache
nausea
loss of apetite
difficult sleeping/exercising
amnesia/dizziness

6

What does sever mountain sickness result in

Cheyne stokes respiration - is an abnormal pattern of breathing characterized by progressively deeper and sometimes faster breathing, followed by a gradual decrease that results in a temporary stop in breathing called an apnea.

cerebral and pulmonary oedema

7

What happens to pressure with an increase in altitude

pressure decreases

8

What stays the same and what changes

Fraction concentration of oxygen stays the same but partial pressure of inspired oxygen changes

9

What does acclimatisation involve

sever physiological changes to help reduce hypoxia

10

Why is deep sea diving possible when snorkelling below 1.6 metres is impossible?

at greater depth, helium-oxygen used
2% O2 sufficient
enables removal of N2
tissue solubility bends
high density at pressure
increased work of breathing
nitrogen narcosis above 40 m

11

Decompression sickness

a condition that results when too rapid decompression causes nitrogen bubbles to form in the tissues of the body.
call it the bends ), and can cause pain in the muscles and joints, cramp, numbness, nausea, and paralysis.

12

Dive reflex

In mammals, overrides homeostatic responses
causes a brain -heart connection as all blood supply directed towards limbs
- causes vasoconstriction
-02 conserved to heart, lungs and brain
reflex vagal bradycardia
suppressed ventilation drive

13

What happens to atmospheric pressure under water

increases. Partial pressure of inspired Oxygen also increases

14

When is deep diving possible?

if lower FiO2 is used to keep PiO2 normal.