Respiratory Control

Question 1

what are the 5 major Medullary respiratory centers

Answer 1

DRG: Dorsal respiratory group
-part of nucleus solitaris tractus

VRG: Ventral respiratory group
-contains nucleus ambiguus and dorsal motor nucleus of Vagus

PRG: Pontine respiratory nucleus
-parabrachial nuclei, colorcofuse nuclei

Botzinger complex
-retrofacial nucleus

Pre-Botxinger Complex

Question 2

Pre-Botzinger complex function

Answer 2

is believed to be the site which generates the timing (frequency) of the respiratory rhythm

more noticeable in babies and gets more complicated the more we get older

More for inspiration since expiration is passive

Question 3

when does the phrenic nerve fire

Answer 3

Fires during inspiration (activating muscles)

quiet during expiration

Question 4

Apneusis

Answer 4

failure to turn off inspiration

lesion in the PRG makes it so the Phrenic nerve is constantly firing leaving the body stuck in inspiration

hard to notice this

slight delay, but then increase in CO2, decrease in O2, death if not supported

Question 5

what is the function of the Pontine respiratory group

Answer 5

important in turning respiration off, part of the network that controls the length of inspiration under normal circumstances

Question 6

what is the function of the Dorsal respiratory group

Answer 6

DRG (found dorsal, and at the midline by the CN X, and XII

95 percent premotor to phrenic
-recieves lots of sensory info

-Allows it to generate a pattern appropriate to the circumstances in determining the depth (pattern) of the breath (Vt)

Question 7

what is the function of the Ventral respiratory group

Answer 7

found more lateral and ventrally

Rostral part: premotor to phrenic and most to inspiratory muscles

Caudal part: premotor to upper airway and other muscles of expiration (most muscles of expiration are passive except in the upper airway)

important in the depth of the breath (Vt)

Question 8

Apnea

Answer 8

apsence of respiratory effect (no inspiration)

damage to the medullary or spinal damage

instant increase in CO2 and decrease in O2, and death if not supported

Question 9

function of a chemoreceptor and what they respond too

Answer 9

since normal neurons will turn off in an hypoxic event, need a neuron that will fire under certain bad circumstances to continue the respiratory cycle (kick in the but)

the chemoreceptors fire for an increase in CO2, decrease in O2 and a increase in H+
-hypercapnia, hypoxia

Question 10

what are the two sets of chemoreceptors and where are they located

Answer 10

Central chemoreceptors: In brain

Peripheral chemoreceptors: in carotid and aorta

Question 11

Central chemoreceptor function

Answer 11

located on ventral surface of medulla

sensitivity indirectly to CO2 in blood

• CO2 will cross BBB
• CO2 reacts with water (Carbonic anhydrase) (making H+ and HCO3-)

due to the decrease in pH (directly activates) this will activate the chemoreceptor

this will give the drive to breath sensation and make you breath regularly

Question 12

function of the peripheral chemoreceptors

Answer 12

found in carotid body and aortic arch

sensitive to decrease in O2
increase in CO2
increase in H+
(seperate cells in the body controls this)

send signal to the Pre-BotC and stimulate increased Frequency of breathing and Tidal volume

Peripheral chemoreceptors are faster than the Central

Question 13

what is the Neurotransmitter that the peripheral chemorecepter uses

Answer 13

Dopamine

Question 14

Location, What are they sensitive to, influence, and effects: Central Chemoreceptor

Answer 14

Location: Ventral surface of brainstem

What are they sensitive to: Directly: pH of CSF
indirectly: CO2 in plasma

Influence: respiratory drive or drive to breathe

Effects: increase respiratory rate/depth in response to hypercapnia (slower than peripheral)

Question 15

Location, What are they sensitive to, influence, and effects: Peripheral chemoreceptors

Answer 15

Location: aortic arch and carotid body

what are they sensitive to: Directly: O2, CO2, and H+ (pH)

Influence: acute gas changes in blood

effects: increase respiratory rate/depth in response to hypercapnia, hypoxia or acidosis

Question 16

Location, and effect of the Slowly adapting Pulmonary Stretch receptors

Answer 16

located in airways

sensitive to: stretch of airways directly proportional to lung volume

Fibers travel to brain via Vagus nerve

Effect: inhibition of inspiration (inspiration termination) and prolongation of expiration
-very minimal effect on frequency

Question 17

what are the circumstances that slowly adapting pulmonary stretch receptors important for controlling respiration in?

Answer 17

Infants: in utero dont want to use the lungs for very long or at all (occurs every breath)

Adults during exercise due to the increased tidal volume

Not too important for adults during rest

Question 18

location, function of the Rapidly adapting pulmonary stretch receptors

Answer 18

located in airways

sensitive to: irritation, foreign bodies in airway, and stretch

fibers travel to brain in Vagus nerve

Effect: cough much deeper and is not elicted by the larynx, more for influuenza or bronchitis

helps protect the gas exchange surface

protective (not every breath)

Question 19

what is the function and location of the J (juxtacapillary) receptors

Answer 19

Located near blood vessesl of alveoli

sensitive to Pulmonary edema (lung behaves very stiff and restrictive)

fibers travel to brain via vagus N

Effect: cough, tachypnea
-increased breathing that is fast and shallow

protective (not every breath)

Question 20

Cortical Influences on breathing

Answer 20

Cortical influences do control breathing as well during talking, or holding breath

cortex will bypass the medullary centers and sending input directly to the muscles of inspiration