Regulation Of Respiration

Front 1

how do we ensure PCO2 and PO2 are constant in the blood even when we breath different types of air

Back 1

alter TV and RR

Front 2

where in the brain is breathing controlled normal, override?

Back 2

brain stem normally (medlla
Pons)

BUT we can override it with cerebralcortex

Front 3

what are the 4 components to the control system for RR

Back 3

1. Chemoreceptors: O2, CO2
2. Mechanoreceptors: lungs/loints (irritant/J)
3. control in brainstem: medlla, pons
4. Respiratory MM

Front 4

when you hold your breath what part of brain is controlling

Back 4

cerebral, voluntary controy

**brainstem is more normal, involuntary

Front 5

what respiratory centers are in the Pons

Back 5

1. pneumotaxic: inhibits inspiration

2. Apneustic: abnormal, prolonged inspiration with short expiration (ketamine)

Front 6

what repiratory centers are in the medulla

Back 6

1. Dorsal Respiratory Group: Inhalation

2. Ventral Respiratoyr Group: exhalation (and some inspiration)

3. Rostral ventromedial medulla- DONT NEED TO KNOW

Front 7

what respiratory centers are for Inspiration, expiration, inhibit, abnormal

Back 7

1. Inspiration: dorsal respiratory group (medulla)

2. Expiration: ventral reapiratory group (medulla) (VRG also does some inspiration)

3. Inhibition of Inhalation: pneumotaxic (pons)

4. Abnormal: apneustic (pons)

Front 8

what part of the brain houses the inspiratory respiratory center, what is it called?

what does it control
what nerve
what gives it info

Back 8

in the medulla
dorsal respiratory group (recall the ventral group is mainly expiration but does have SOME inspiration)

*controls rate of inspiration via phrenic to diaphragm

**info from peripheral and mechanoreceptors

Front 9

in what part of the brain does the phrenic receive info to bring to diaphragm, what does it do? where does it receive info from

Back 9

medulla, dorsal respiratory group

**controls RR

**Peripheral Chemosensors: glossopharyngeal, vagus sence O2
**mechanoreceptors in the lung via vagus

Front 10

so the DRG gets infor from where?

Back 10

1. Peripheral Chemoreceptors: sense O2, glossopharyngeal and vagus

2. Lung Mechanoreceptors: vagus, sense distension

Front 11

peripheral chemoreceptors sense what?
where do they send info?
what N do they use

Back 11

Decrease in O2
DRG (inspiratory center in medulla)
Vagus, glossopharyngeal

Front 12

mechanoreceptros in the lungs sense what?
where do they send info?
what N do they use?
Cool thing?

Back 12

sense distension of lungs
send info to DRG (inspiratoy center in medulla)
Vagus

**cause the RR to decrease, ONLY one that does this (herring breuer)

Front 13

what is the herring breuer reflex

Back 13

its the decrease in RR when mechanoreceptors in the lungs sence distension

Front 14

the inspiratory center is what?
what inhibits it?

Back 14

Dorsal respiratoy goup in medulla

**inhibited by pneumotaxis in PONS

Front 15

what does the pneumotaxic brain center do?

Back 15

shortens inspiration
located in teh PONS, inhibits the DRG in the medulla

decreased inspiration decreases TV this then alters RR

Front 16

the DRG has neurons that synapse what mm?

what happens when these neurons fire, cease fire?

Back 16

inspiratory mm, diaphragm, external intercostals, SCM, and scalenes

**fire: mm contract and inspiration occurs

**dont fire: inspiratory mm relax & exhalation occurs

Front 17

we know that the pneunotaxic center is in the pons and inhibits the DRG to inhibit inspiration. how does it do this? what is limited by this (directly, indirectly)

Back 17

limits AP in the phrenic N (reduces inspiration)

Reduced inspiration limits TV directly, this increases RR

Front 18

how does the pneomotaxic center reduce RR

Back 18

1. reduce inspiration
2. reduce TV
3. increase RR

Front 19

the expiratory is made of...

Back 19

its the Ventral Respiratory Group in the medulla

1. nucleus retrofacialis
2. nucleus retroambigious
3. nucleus ambigous

Front 20

does the ventral respiratory group only do expiration

Back 20

NO

SOME inspiration also

Front 21

is the VRG pretty active

Back 21

nope, usually expiration is PASSIVE

Front 22

when is the VRG active

Back 22

diring ACTIVE exhalation, exercise etc

Front 23

what are the nuclei in the VRG and what do they do?

Back 23

we know the VRG is in the medullay and mainly does expiration but also some inspiration

1. Nucleus Ambiguous: insp & expir. innervates laryngeal & pharyngela mm

2. Nucleus Retroambiguous:
-inspir: external intercostals
-expir: internal intercostals & abd mm

3. Nucleus Retrofacialis: inhibit inspiration in DRG

Front 24

what does the nucleus retrofacilis do? where is it

Back 24

its in the VRG in the medulla

*It inhibits the inspiration of DRG

**pnemotaxic also inhibits inspiration

Front 25

what inhibuts inspiration (2)

Back 25

1. pnemotaxic in pons
2. nucleus retrofacilis in the VRG in the medulla

Front 26

what nucleus is responsible for innervating pharyngeal and laryngeal mm

Back 26

nucleus ambiguous (part of VRG)

**does inspiration and expiration

Front 27

what nucleus is responsible for innervating the intercostals? any other mm?

Back 27

nucleus retroambiguous

**the expiratory neurons innervate the internal intercostals and the abd mm

Front 28

what happens when the apneustic center inthe brain is stim?

when do you see this?

whta is going on in the other brain centers

Back 28

prolonges inspiration, breif expiration

**ABNORMAL, ketamine induced

Apneustic excites the inspiratory center of the DRG in the medulla, prolonged AP in the phrenic N --> prolonged contraction of diaphragm

Front 29

why is there prolonged inspiration when the apneustic center is stim

Back 29

well the Apneustic causes the inspiratory DRG to fire prolonges AP's in the phrenic N
leads to increased diaphragm contraction
leads to increased inspiration

Front 30

what is housed in the medullary respiratory center

Back 30

1. DRG: inspiration
2. VRG: expiration (and some inspiration, also inhibition of inspiration via nucleus retrofacialis)

Front 31

when we say the RR and TV are regulated to keep PCO2 normal, what is normal

Back 31

40mmHg

** in the arterioles

Front 32

what can overide brain stem centers of respiration

is this permanent

Back 32

cerebral cortex

nope

Front 33

when we use our cerebral cortex to hyperventalate what is happening to PaCO2 and pH

Back 33

PaCO2 is decreased
pH is increased

**we breath really fast to get out all of the CO2

**again, the cerebral cortex can be overcome, with lots of hypervent hte CO2 gets so low you pass out and then breath normal with the brainstem mechs

Front 34

what is hypoventalation, what happens to PaCO2 and pH, what part of the brain

can you elongate hypoventalation

Back 34

breath less (hold breath)

PaCO2 increases, pH decreases

cerebral cortex

**a period of HYPERVENT, before you hold breath helps you hold your breath longer

Front 35

why can you hold your breath longer if you hyperventalate first

Back 35

hypervent will decrease CO2, this gives you longer before CO2 builds up and your forced to breath

Front 36

what happens to vent rate if PaCO2 is 35

Back 36

nothing really, a PaCO2 that is less than 40 (40 is normal) wont really alter RR

BUT a PaCO2 more than 40 will make you increase RR

**the Reticular Activating System controls this

Front 37

what is the reticular activating system

Back 37

its what increases your RR if you PaCO2 is more than 40,

**OFF when you sleep. less sentsitive to changes in CO2

Front 38

what shifts the PaCO2 to the right?

Back 38

sleep
Excessive EtOH and drugs

Front 39

when you sleep is the slope of the PaCO2/vent curve when you sleep vs awake

Back 39

Awake: steeper
Sleep: decreased slope, less sensitive to changes in PaCO2

Front 40

what is the most important chemoreceptor in normal breathing and where is it located
what nerves

Back 40

central chemoreceptors

**in the front of the medulla, near inspiratory center (DRG)

**glossopharyngeal and vagus

Front 41

what do central chemoreceptors sence? where are they

Back 41

sence [H] in CSF
in the medulla (near the DRG) inspiratory center

**glossopharyngeal and vagus

Front 42

what type of receptor communicates with the inspiratory center

Back 42

central chemoreceptors

Sence [H] in the CSF

Front 43

what is the response when there is increased H in the CSF

Back 43

the pH is decreased
this increases the RR (hyperventilate)

Front 44

what is the response when there is less H in the CSF

Back 44

increased pH, decreased RR

Hypoventilate

Front 45

how does H increase in the CSF, what sences it

Back 45

central chemoreceptors

**when PaCO2 increases >40mmHg the CO2 from blood diffuese into the CSF, in the CSF the CO2 turns into HCO3 and H+

Front 46

central chemoreceptors sense what

Back 46

H in CSF

**reflection of PaCO2

Front 47

where are peripheral chemoreceptors, what do they sence

Back 47

carotid and aortic arch

**O2 (MOST IMPORTANT)
CO2
H, in carotid only

Front 48

when peripheral chemoreceptors sence a change in CO2 O2 or H (only in carotid) whar N carries the info. where do they carry them to, what changes

Back 48

change in CO2 O2 (most important) H sensed in carotid or aortic body
carried via glossopharyngeal and vagus into the Medularry inspiratory center
Changes RR

Front 49

what increases the RR? peripheral chemoreceptors

Back 49

increased CO2
Decreased O2 (MOST IMPORTANT)

**in Carotid only, a decrease in pH

Front 50

are peripheral chemoreceptors sensitive to changes in PaO2

Back 50

nope,

they are good at around 60-100, so they are relatively insensitive but they do respond to changes in PaO2

PaO2, is the most important molecu;e detected by peripheral chemoreceptors

**respond to changes less than 60

Front 51

what must PaO2 must fall below in order to initiate peripheral chemoreceptors

Back 51

less than 60 mmHg

Front 52

what receptor is most important in detecting PaCO2

Back 52

central chemoreceptors (H in the CSF)

Front 53

in the herring breuer reflex how is RR decreased

Back 53

by making expiration longer

**mechanoreceptors in the lungs sense distension and decreases RR

Front 54

what are Joint and mm receptors, where are they, what activates them, what do they do to RR when they are activated?

Back 54

in joints and mm
activated by limb movements to increase the RR

(NOT the same as J receptors)

Front 55

what receptros are important in early ventilation

Back 55

the Joint/mm receptors in joints and mm
they are activated by limb movement and cause the RR to increase

(NOT the same as J receptors)

Front 56

what are irritant receptors, where are they and what does it do to RR

Back 56

they are in the lings and detect pollen/dust, etc

constricts the SM and increases RR

**asthmatic response

Front 57

what are J cells
activated by what? what does it do to RR

Back 57

cells in alv walls that detect engorgement of capillaries they increase RR

Front 58

central chemoreceptors respond to
peripheral chemoreceptors respond to

Back 58

central: CO2 (needs to be more than 40?)
Peripheral: O2 (needs to be less than 60)

Front 59

the medularry respiratory control has how many nuclei

Back 59

3


DRG
VRG (ambiguous, retroambiguous, retrofascilis)
rostral ventromedial medulla

Front 60

is the ventral center always active?

Back 60

nope,

**the expiratory center in NOT active during passive expiration

Front 61

what receptros decrease the RR

Back 61

lung mechanoreceptors

Front 62

describe pneumotaxis

Back 62

Pneumotaxic limits firing of action potentials in the phrenic to the diaphragm

thus contraction of the key inspiratory muscle will be shortened

inspiration will shorten

tidal volume will be reduced, less air brought in.

a decrease Tv will indirectly increase respiratory rate