Control of Respiration

Question 1

What is diffusing capacity?

Answer 1

Diffusion=(Change in PressureAreaSurface)/(distance*sqrt(MW))

Question 2

What is the equation for DLco?

Answer 2

DLco=(Va60)/((Pb-47)T)*Ln(FACOi/FACOe)

Va=alveolar volume
Pb=barometric pressure
47=water pressure at 37 degrees celsius
T=breath hold time
FACOi=fractional conccnetration of alveolar CO at start of breath hold
FACOe= fractional concentration of alveolar CO expired at the end of breath hold

Question 3

What is the equation fro Va?

Answer 3

Va=Vi/(FECH4/FiCH4)

FiCH4=fractional concentration of inspired CH4
FECH4=fractional concentration of expired CH4
VI=inspired volume at STPD

Question 4

What is the equation for Dl?

Answer 4

D/change in pressure

Question 5

What are type I cells in the aortic and carotid bodies?

Answer 5

type I cells are glomus

Question 6

What are type II cells in aortic and carotid bodies?

Answer 6

type II cells are sheath cells

Question 7

where are the central chemoceptors located?

Answer 7

located in brainstem, including the ventral medullary surface, near the nucleus tractus solilatrus and near the locus ceruleus

Question 8

In respiratory distress, sternocleidomastoid muscles are contracting what ishappening ot the abdomen?

Answer 8

sternocleidomastoid muscles contracting; abdomen move inwards. Keep rib cage elevated and allow for ventilation

Question 9

What is the diaphragm used for?

Answer 9

quite tidal breathing

Question 10

What senses high PaCO2?

Answer 10

both central and peripheral chemoreceptors

Question 11

What senses a low PaO2?

Answer 11

sensed by peripheral chemoreceptors

Question 12

Low PaO2 plus high PaCO2?

Answer 12

increases ventilation by increasing the depth and frequency of breathign. Effectively, acessory muscles are recruited.

Question 13

What are the accessory breathing muscles?

Answer 13

sternocleidomastoids, scalenes, and the abdominus recti

Question 14

What are the inputs to the brainstem, other than peripheral and central chemoreceptors?

Answer 14

focus on input to the brainstem. Mechanoreceptors in the nose, in the lungs, feedback from hypothalamus and important voluntary control

Question 15

Small airways collapse leading to incomplete aveolar emptying in what?

Answer 15

COPD or other obstructive lng disease

Question 16

What is the consequence of chronically elevated PaCO2?

Answer 16

PaCO2 rises leads to compensatory HCO3. Increase pH
consequentially respiratory drive decreases
chronic hypercapnia such as occurs in COPD, respiratory drive is not maintained by CO2 anymore but rather b PaO2

Question 17

In a pt with chronic hypercapnia what is respiratory drive maintained by?

Answer 17

bc of chronic hypercapnia

respiratory drive not maintained by CO2 but rather by PaO2

Question 18

What is the 2nd reason why too much O2 bad for severe COPD other than PaO2 repressing respiratory drive?

Answer 18

pt with alveolar damage from COPD blod gets diverted away from bad portion of lung, when you give thm lots of O2 blood flow was diverted away is now vasodilated. V/q mismatch and has worsened hypercapnia

Question 19

In COPD when blood is divereted away from bad portion fo lung what is this called?

Answer 19

hypoxic vasoconstriction

Question 20

What is a thrid mechanism that makes O2 bad for COPD?

Answer 20

hemoglobin normally acts as a buffer for carbon dioxide

but in COPD pts with 100% oxygen because binding sites are all taken up
haldane effect CO2 cant be bufered leads to an increase of PaCO2

Question 21

What is the haldane effect?

Answer 21

buffering of CO2 by hemoglobin during gas exchange

Question 22

What happens to abdomen when diaphragm is fatigued or not working?

Answer 22

paradoxical abdominal breathingg

Question 23

What is maximum expiratory pressure less than 60 cm H20 predicts what?

Answer 23

weak cough

Question 24

What is maximum inspiratory pressure less than 30 % predict?

Answer 24

respiratory failure

Question 25

What is vital capacity less than 55% predict?

Answer 25

respiratory failure

Question 26

In brainstem you should be aware of 2 large groups of neurons

Answer 26

first located in medulla are the dorsal and ventral respiratory group of neurons.

Question 27

What group is responsible for quite breathing?

Answer 27

dorsal group

Question 28

What group of neurons has 6 divisions and are ultimately responsible for breathing during exercise and responible for not so quite breathin, responsible for both inspiration and expiratory changes?

Answer 28

medulla is the ventral respiratory group

Question 29

What does the pontine group inhibit what?

Answer 29

central pattern generator

Question 30

What is the function of the pontine group?

Answer 30

function is to limit inspiration. created using a ramped signal and this group of neurons act to shut off inspiration.

Question 31

What nervous group is used to limit inspiration

Answer 31

pontine group

Question 32

If the central pattern generator is damaged in a medullary stroke what hapens to breathing?

Answer 32

becomes ataxic; amplitude and frequency are both altered

Question 33

What is the result of a pontine stroke it results in what sorta breathing?

Answer 33

apneustic breathing, long period of inspiration followed by a burst of expiration

Question 34

What is lastly medication such as opiates and barbs have on central pattern generator?

Answer 34

inhibitory effect, on central pattern generator central pattern generator function is inhibited by morphine and so the effectors do not receive the signal to increase ventilation

Question 35

What is primary alveolar hypoventilation?

Answer 35

ondine's curse; all autonomic functions leading to a respiratory drive are gone. pt has to Remember to breathe

Question 36

What is polysomnography used for?

Answer 36

useful for OSA and periodic limb movment disorder determination

Question 37

What can we learn from a sleep study?

Answer 37

sleep disordered breathing -evaluation and treatment movement disorder of sleep parasomnias

Question 38

What is sleep diary used for?

Answer 38

quantifying sleep and assessing patterns of sleep