Control of breathing Oct5 M1

Question 1

2 resp control neurons aggregates and location

Answer 1

medulla. VRG and DRG

Question 2

what DRG does

Answer 2

inspiration, situation beyond normal tidal breath

Question 3

what VRG does

Answer 3

inspiration and expiration, normal breathing

Question 4

what controls phrenic nerve mainly

Answer 4

DRG (NTS)

Question 5

DRG components (1)

Answer 5

NTS (nucleus tractus sollitarius)

Question 6

VRG components (2)

Answer 6

nucleus ambiguous
retrofacial nucleus (pre botz complex and botz complex)

Question 7

what pre botz complex does and location in VRG

Answer 7

pacemaker. (all others are modulators)

rostral end of VRG

Question 8

botz complex function

Answer 8

involved in expiration

Question 9

ninth and tenth cranial nerve name + job

Answer 9

glossopharyngeal. vagus. carry info on PO2, PCO2, pH and BP from aorta and carotid bodies to central controller

Question 10

what additional info vagus nerve carries

Answer 10

stretch receptors (PSRs), C-fibers, juxta-capillary receptors) in the lugns

Question 11

3 cell types in carotid bodies and important one and why

Answer 11

type 1: glomus cell (important senses O2)
type 2: sustentacular cells
NF: fibres of carotid sinus nerve

Question 12

central chemoreceptors location and mechanism

Answer 12

ventrolateral surface of medulla. sense pH

Question 13

location of CO2 chemoreceptors in the brain

Answer 13

retrotrapozoid nucleus (RTN) or retrofacial nucleus,

Question 14

RTN nucleus closely related to what nucleus

Answer 14

pre-botz complex

Question 15

how ventilation changes with O2 drop if eucapnic vs hypercapnic

Answer 15

greater increase of ventilation for same O2 drop if hypercapnic

Question 16

chemoreceptor activation mechanism (in carotid body)

Answer 16

hypoxia: hemoxygenase 2 (HO 2) shuts off, no more CO prod, CSE not inhibited anymore and can produce hydrogen sulfide, opens K+ channel, opens Ca channel, ntr vesicles release

Question 17

response to hypoxia and why

Answer 17

rapid shallow breathing: stay in linear portion of PV curve

Question 18

response to hypercapnia and why

Answer 18

slow deep breathing to minimize deadspace ventilation (Vd over VT) and optimize CO2 elim

Question 19

sensors other than chemo and pulmonary

Answer 19

chest wall receptors (golgi tendons, muscle spindles)

upper airway dilator muscle sensors

Question 20

def of hyperventilation

Answer 20

reduced PaCO2

Question 21

causes of hyperventilation

Answer 21

metabolic acidosis
drugs
CNS problem
lung disease
psychogenic

Question 22

ultimate consequence of increase in PACO2

Answer 22

generalized acidosis and syncope

Question 23

why high FiO2 worsens high PaCO2 (3)

Answer 23

• blunts ventilatory drive
• blunts hypoxic vasoconstriction in poorly ventilated regions
• more HbO2, less HbCO2, more CO2 in blood

Question 24

how treat high PaCO2

Answer 24

controlled supp O2 91-93%

Question 25

hypoventilation def

Answer 25

high PaCO2

Question 26

causes of hypoventilation

Answer 26

metabolic
drugs
CNS
chest wall deormities
neuromuscular
parenchymal disease
congenital central hypovent syndrome

Question 27

Ondine’s curse or congenital central hypoventilation syndrome

Answer 27

impaired CO2 chemosensitivity, no air hunger, sleep ane

Question 28

congenital central hypoventilation syndrome cause

Answer 28

mutation in Phox2b