mechanisms of breathing (W3) - part 2

Question 1

normal oxygen level terminology

Answer 1

normoxia

Question 2

normal carbon dioxide terminology

Answer 2

normocapnia

Question 3

above normal oxygen level terminology

Answer 3

hyperoxia

Question 4

above normal carbon dioxide terminology

Answer 4

hypercapnia

Question 5

below normal oxygen level terminology - 2 types? what’s the difference?

Answer 5

hypoxia - in tissue
hypoxaemia - in blood

Question 6

below normal carbon dioxide level terminology

Answer 6

hypocapnia

Question 7

central chemoreceptors mechanism

Answer 7

pCO2 from arterial blood transfers across blood brain barrier into cerebrospinal fluid (CSF), causes changes in hydrogen ions, central chemoreceptors (on surface of medulla) cause change in medullary rhythm generator

Question 8

where are central chemoreceptors found

Answer 8

surface of medulla

Question 9

ventilatory response to CO2 in hypoxia

Answer 9

more dramatic response to high CO2 in presence of hypoxia compared to normoxia

Question 10

ventilatory response to CO2 in hyperoxia

Answer 10

less dramatic response to high CO2 in presence of hyperoxia compared to normoxia

Question 11

ventilatory response to hypoxia in hypercapnia

Answer 11

more dramatic response than normocapnia

Question 12

severe COPD result of failure to deliver pO2 and pCO2 requirements the body needs to keep functioning (hypoxia and CO2 buildup)

Answer 12

chronic hypercapnia (cannot keep pushing respiratory rate to clear problem)
leads to loss of sensitivity of central chemoreceptors
relax into respiratory failure

Question 13

what happens if severe COPD patient is given high inspired O2

Answer 13

patient is relying on hypoxia as a drive to breathing, therefore this drive is abolished if the patient is given high inspired O2. this leads to further hypoventilation, further increase in arterial pCO2, leads to CO2 narcosis, acidosis, then potentially death

Question 14

drugs and respiration - depressants?

Answer 14

anaesthetics
analgesics (particularly opioids)
sedatives

Question 15

clinical example of drugs that depress respiration

Answer 15

recreational drug overdose

Question 16

drugs and respiration - stimulants

Answer 16

beta agonists - bronchodilators
eg salbutamol (blue inhaler)

Question 17

breathing pattern disorder triggers

Answer 17

nasal blockage, pain, irritable cough, global pandemics. anything that can affect respiratory system

Question 18

what happens in breathing pattern disorders

Answer 18

voluntary takes over from autonomic. can lead to stacked breath

Question 19

what happens to breathing during sleep

Answer 19

reduction in metabolic rate, reduced input from higher centres such as pons and cortex
loss of tonic neural drive to upper airway muscles (just enough to stay patent)

Question 20

2 types of upper airway muscle activity

Answer 20

phasic
tonic

Question 21

upper airway muscle activity - phasic

Answer 21

contraction of upper airway muscles
opening of upper airway
facilitates inward airflow

Question 22

upper airway muscle activity - tonic

Answer 22

continuous background activity
tends to maintain patent airway
varies with state of alertness

Question 23

name for episode where you do not breath

Answer 23

apnoea

Question 24

what happens in obstructive sleep apnoea

Answer 24

nasal and mouth airflow stop, chest wall movement continues, drop in blood oxygen saturation

Question 25

obstructive sleep apnoea risk factors

Answer 25

obesity, alcohol, nasal obstruction, anatomical abnormalities

Question 26

what can obstructive sleep apnoea cause

Answer 26

daytime sleepiness

Question 27

obstructive sleep apnoea solution

Answer 27

machine CPAP creates air pressure pushing it through the upper airway keeping it open