Lecture 20: Regulation

Question 1

respiratory muscles controlled by

Answer 1

motor neurons

Question 2

respiratory muscles are sepcial because

Answer 2

they are under automatic AND voluntary controll

Question 3

automatic resp control depends on neurons in

Answer 3

medulla oblongata

Question 4

DRG

Answer 4

dorsal resp group
inspiratory neurons
basic rythm of resp
active or not: active to inhale, not to exhale

Question 5

for normal breathing

Answer 5

just need DRG activated

only active to inhale

Question 6

VRG

Answer 6

expiratory neurons
ventral resp group
not always active, chilling during resting breathing

Question 7

VRG and DRG neurons are…

Answer 7

pre motor neurons
synapse on resp neurons
sent out of medulla

Question 8

rythmic breathing

Answer 8

depends on pacemaker like activity of brainstem

spontaneous depol

Question 9

pacemaker like cells

Answer 9

are in brainstem
control DRG
alternatively turn inspiratory neurons on and off
deopl, rest, repeat

Question 10

expiratory neurons at rest…

Answer 10

normally silent

Question 11

expiratory neurons when breathing increased

Answer 11

activated

VRG used

Question 12

why is DRG always active

Answer 12

because of rythm gen neruons with pacemaker like activity

Question 13

pneumotaxic center

Answer 13

to protect you
will inhibit DRG
if breathing too fast to slow you down

Question 14

apneustic center

Answer 14

promote breathing in
when we need more O2
stims DRG

Question 15

when you stimulate breathing out forcefully

Answer 15

you’ll also breathing in forcefully

Question 16

during normal quiet breathing DRG is….

Answer 16

active for 2 seconds

rests for 3 second

Question 17

receptors involved in breathing

Answer 17

pulmonary stretch receptors
central chemoreceptors
peripheral chemoreceptors

Question 18

respiratory neurons depend on info from

Answer 18

various specialized receptors

inform neurons about body’s need for ventialtion

Question 19

Pulmonary stretch receptors in general

Answer 19

alert to how stretch lungs are and how much we are pulling thm
if lungs inflated too high, we can damage tissues

Question 20

Central chemo-receptors

Answer 20

monitor conc of CO2 ONLY

Question 21

Peripheral chemo-receptors

Answer 21

monitor conc of O2 (mostly)

also sensitive CO2 and pH

Question 22

when DRG is active

Answer 22

2 secs
contract diaphragm and external intercostals
inhilation (normal)

Question 23

when DRG inactive

Answer 23

3 secs
diaphragm and external intercostals relax
elastic recoil of chest wall and lungs
exhilation (normal)

Question 24

when VRG active

Answer 24

internal intercostals, abdominal muscules contract

forecefull EXHILATION

Question 25

Forceful breathing

Answer 25

coordination between DRG and VRG

Question 26

Forceful inhilation

Answer 26

VRG SENDS message to DRG toINHALE harder

internal intecauses diaphragm, sternocleidomastoid, scalenes to contract

Question 27

pulmonary stretch receptor locations

Answer 27

smooth muscle of
some large conducting airways
bronciloes
bronchi

Question 28

pulm stretch receptors stimulated when

Answer 28

broncioles inflated/stretch
main stim is rate of change of lung stretch
more stretch=more trigger

Question 29

pulm stretch receptors innervated by

Answer 29

axons in Vagus nerve (X)

Question 30

if you try to breath in too fast

Answer 30

body freaks because you change stretch too quickly

Question 31

central chemo-receptors located

Answer 31

right below ventral surface of medulla

Question 32

central chemo-receptors respond to

Answer 32

inc H+ ion conc in CSF
inc H+ is result of CO2 that diffuses into CSF from blood and forms of H+ ions

NOT OXYGEN

Question 33

when conc of H+ goes up

Answer 33

an alarm signal is sent to the central chemo-receptors

Question 34

peripheral chemo-receptors located

Answer 34

aortic arch

carotid sinus

Question 35

peripheral chemo-receptors respond to (mainly)

Answer 35

low O2 levels in arterial blood
elevated H+ ion conc
elevation in CO2

Question 36

peripheral chemo-receptors respond WEAKLY to

Answer 36

elevated H+ ion conc

elevation in CO2

Question 37

peripheral chemo-receptors innervated by

Answer 37

axons from cranial nerves IX and X (glossopharyngeal and vagus)

Question 38

peripheral chemo-receptors synapse on

Answer 38

neurons in DRG

Question 39

pulmonary stretch receptor influences ______ center

Answer 39

pneumotaxic center

Question 40

pulmonary stretch receptor influence on pneumotaxic center

Answer 40

inhibits DRG
      inhibits inhalation 
protective function
this means cells switch from inspiration in expiration more quickly
      lung inflation stops
      deflation strongly encouraged

Question 41

When CO2 (central chemoreceptors) receptors are set off..

Answer 41

we breathe in more

trigger inspiration area

Question 42

response to change in conc of CO2, O2 and pH

Answer 42

negative feedback loop

Question 43

result of breathing in more because central chemorecptors told us to

Answer 43

increase conc of O2
more air comes in
blow off more CO2

Question 44

when there central chemoreceptors are set off

Answer 44

too much CO2

negative feeback loop

Question 45

why peripheral monitor O2 in arterial blood

Answer 45

its on its way to the brain

Question 46

if peripheral measure high O2

Answer 46

less frequent breathing

Question 47

if peripheral measure LOW O2

Answer 47

more rapid breathing

Question 48

irritant receptors

Answer 48

protect lung from changing shape too fast