control of lung function

Question 1

name the 4 regions in the medulla oblongata

Answer 1

Dorsal respiratory group
Ventral respiratory group
Apneustic centre
Pneumotaxic centre

Question 2

what is the dorsal respiratory centre

main function

Answer 2

Inspiratory centre
Main ‘controller’ of inspiration
Set the ‘rate’

Question 3

where is it

Answer 3

posterior in the brainstem

Question 4

Ventral respiratory group

function

Answer 4

Expiratory centre

Question 5

how active/inactive is it during quiet breathing

Answer 5

Inactive during quiet breathing

Question 6

what does the ventral re gr act on

Answer 6

Inhibit apneustic centre

Question 7

where is it

Answer 7

posterior to the DRG

Question 8

what is Apneustic centre

associated wuth

Answer 8

inspiration

Question 9

what does it stimulate

Answer 9

DRG

Question 10

how is it inhibited

Answer 10

Inhibited by pulmonary afferents

VRG

Question 11

what is Pneumotaxic centre

associated with

Answer 11

expiration

Question 12

what is the main function of the Pneumotaxic centre

Answer 12

The ‘inspiratory off switch’

Regulates depth & frequency

Question 13

DIVE

Answer 13

Dorsal inspire

Ventral expire

Question 14

how does the Pneumotaxic centre inhibit the apneuustic centre

Answer 14

apneustic centre stimulated DRG
action potential increases to a certain point/threshold then the Pneumotaxic centre
stops the ap

Question 15

where do the phrenic (controlling diaphragm) nerves originate from

Answer 15

c3 4 5 nerves become

Question 16

what are the external intercostal. muscle responsible for

Answer 16

inspiration

Question 17

what are the internal intercostal muscle responsible for

Answer 17

expiration

Question 18

difference between normal cappiliries and the blood brain barrier

Answer 18

normal capilliries are continous as are blood brain

difference is that BB have tight junctions help more tightly pack

Question 19

what does that mean

Answer 19

the substances that can get into the csf from the blood are heavily restricted

Question 20

how do protons and hco3- diffuse across the lipid bilayer

Answer 20

they can’t pass thru thr BBB
but co2 can and will as it is highly lipid soluble
once in the csf it will undergo the same reactions in the blood e.g. h20 + c02-> h+ +hco3-

Question 21

which molecule out of those reacts with afferent fibres in the medulla

Answer 21

h+

Question 22

what happens

Answer 22

project signals to dorsal respiratory group/nucleus to determine what type of rate or rhythm should be created

Question 23

what receptors are there in the airways

Answer 23

Irritant receptors
Stretch receptors
J-receptors

Question 24

where are Irritant receptors

Answer 24

Afferent receptors embedded within and beneath airway epithelium

Question 25

function and what is it

Answer 25

Leads to cough: which involves forceful expiration against a closed glottis with sudden glottal opening & high velocity expulsion of air

Question 26

what activates Stretch receptors

Answer 26

Excessive inflation of lungs activates pulmonary stretch receptors

Question 27

what affect in the medulla

Answer 27

Afferent signals to respiratory centres inhibit DRG and apneustic centre and stimulate pneumotaxic VRG

Question 28

what is thus the function

Answer 28

Inspiration inhibited & expiration stimulated

Question 29

what are j receptors sensitive to

Answer 29

Sensitive to oedema and pulmonary capillary engorgement

Question 30

what function do they carry out

Answer 30

Increases breathing frequency

Question 31

what occurs when you hold your breath for a prolonged period of time

Answer 31

``` (when ventilating your arterial o2 and arterial co2 are stable) Not replenishing o2 o2 decreases co2 increases accumalation of h+ beyong the BBB stimulate the medulla to breathe in ```

Question 32

does the blood buffer

Answer 32

The blood has an ENORMOUS buffering capacity that can react almost IMMEDIATELY to imbalances

Question 33

Alkalaemia

Answer 33

Refers to high-than-normal pH of blood

Question 34

Acidaemia

Answer 34

Refers to lower-than-normal pH of blood

Question 35

Alkalosis

Answer 35

Describes circumstances that will decrease [H+] and increase pH

Question 36

Acidosis

Answer 36

Describes circumstances that will increase [H+] and decrease pH

Question 37

so alkalosis causes

Answer 37

alkalaemia

Question 38

what are ventilatory distubances

Answer 38

changes in breathing that then cause a change in ph | then corrected by the kidneys

Question 39

what are metabloic disturbaces

Answer 39

any non lung cause of change in ph (normally corrected by the lungs)

Question 40

what is the time scale for changes in ventialtion

Answer 40

Changes in ventilation can stimulate a RAPID compensatory response to change CO2 elimination and therefore alter pH

Question 41

describe the timescale for changes made by the kidneys

Answer 41

Changes in HCO3- and H+ retention/secretion in the kidneys can stimulate a SLOW compensatory response to increase/decrease pH

Question 42

can emotion change breathing

Answer 42

yep

Question 43

can exercise change breathing

Answer 43

yes, anything shortening you muscle stimulates increase ventilation even if you move somelse e.g cycle their legs

Question 44

what can immersing the body in cold water do

Answer 44

causes deep breathing Ventilator Inspiratory gasp/ hyperventilation

Question 45

what pattern do respitory pacemakers display

Answer 45

Respiratory pacemaker displays a ‘ramp potential’ pattern

Question 46

which 2 main nuclei are responsible for inspiration

Answer 46

Dorsal respiratory group and apneustic centre control inspiration

Question 47

and expiration

Answer 47

Ventral respiratory group and pneumotaxic centre control expiration

Question 48

what stimulates inspiration

Answer 48

Central H+ concentration, juxtacapillary oedema/pulmonary engorgement, motor control, limbic system, peripheral O2 concentration, peripheral proprioceptors and skin thermoreceptors

Question 49

what causes expiration

Answer 49

Airway stretch receptors, limbic system, motor control | Coughing stimulated by airway irritant receptors

Question 50

what ph is the blood between

Answer 50

Blood pH is tightly regulated between 7.35 and 7.45