week 6: respiratory physiology: ventilatory control and pulmonary function assessment

Question 1

signals that indicate whether respiratory system is working effectively

Answer 1

partial pressures of O2 and CO2 in blood

Question 2

normal partial pressures in systemic arterial blood

Answer 2

O2: 100 mm Hg
CO2: 40 mm Hg
indicates appropriate ventilation rate

Question 3

to maintain normal arterial pressure, body has to regulate

Answer 3

minute alveolar ventilation
(vol of air reaching alveolar each minute) by contraction of respiratory muscles

Question 4

how are respiratory muscles stimulated to contract

Answer 4

neural input as they are skeletal muscles

Question 5

diaphragm innovated by

Answer 5

phrenic nerves

Question 6

intercostal muscles innervated by

Answer 6

internal and external intercostal nerves

Question 7

current evidence indicates, respiratory control regions are present in

Answer 7

medulla
pons of brain stem

Question 8

two types of neurones located in respiratory control regions

Answer 8

inspiratory neurons
expiratory neurons

Question 9

sensory inputs into respiratory centres:

Answer 9

central chemoreceptors
peripheral chemoreceptors
pulmonary stretch receptors(smooth muscle of airways)
irritant receptors (lining of respiratory tract)
proprioceptors (muscles and joints)
arterial baroreceptors
thermoreceptors

Question 10

types of chemoreceptors

Answer 10

peripheral chemoreceptors
central chemoreceptors

Question 11

peripheral chemoreceptors

Answer 11

located in carotid body
aortic bodies located in aortic arch

Question 12

central chemoreceptor

Answer 12

located in medulla oblongata

Question 13

PO2 of arterial blood drops below 60mmHg,

Answer 13

peripheral chemoreceptors activated
respiratory control centres
increase ventilation

Question 14

changes in PO2 of arterial blood have little/no effect on

Answer 14

central chemoreceptors

Question 15

PCO2 in arterial blood increases

Answer 15

converted to H+, decreases pH
peripheral chemoreceptors activated
respiratory control centres increase ventilation

Question 16

PCO2 in cerebospinal fluid increases

Answer 16

converted to H+, decreases pH
central chemoreceptors detect and respond
respiratory control centres increase ventilation

Question 17

what type of feedback

Answer 17

negative feedback

Question 18

why do arterial gas concentrations change very little during exercise

Answer 18

feedforawrds control circuits (anticipatory control)
we are aware breathing freq and HR is going to increase
increase in venitaltion before gas concentrations change
negeative feedback according to metabloic demand

Question 19

exercise hyperpnea

Answer 19

increase in minute ventilation due to exercise