Respiratory Control

Question 1

Medullary respiratory centers

Answer 1

Dorsal respiratory group- inspiratory
Ventral respiratory group- Inspiratory and expiratory
Pontine respiratory group- Inspiratory
Pre-Botzinger complex- Associated with generating respiratory rhythm

Question 2

Groups determining respiratory rate

Answer 2

Pre-botzinger complex is important for determining rhythm, with help from the pontine respiratory group
PRG helps control length of respiration, if it is lesioned you lose the ability to turn off respiration- known as apneusis

Question 3

Dorsal/ventral respiratory group

Answer 3

DRG- 95% of axons activate the phrenic nerve
Helps control the depth of breathing, slow/long/deep breaths or short and fast (tidal volume)
VRG- Rostral region (inspiratory) - premotor to phrenic, other inspiratory muscles
Caudal region- premotor to upper airway, other muscles of expiration

Question 4

Apneusis effects vs apnea effects

Answer 4

Apneusis: Slight delay, but then increased CO2, decreased O2, death if not supported
Apnea: Same but no delay- results from medullary or spinal damage

Question 5

What causes increased firing of chemoreceptors in respiratory system

Answer 5

Increased CO2
Decreased O2
Increased H+

Question 6

Central chemoreceptors

Answer 6

Indirectly sensitive to CO2 in blood; do not care about O2 or pH
CO2 crosses BBB and reacts with water via carbonic anhydrase, causing release of hydrogen ion, which the chemoreceptors are directly sensitive to
-It is believed these chemoreceptors are responsible for creating the “drive” to breath

Question 7

Neurotransmitter used in carotid body

Answer 7

Dopamine

Question 8

Carotid body and aortic arch are sensitive to

Answer 8

O2
CO2
H+

Question 9

Peripheral chemoreceptors send signals mainly to

Answer 9

Botzinger complex, maybe PRG

This is to increases breathing frequency and tidal volume

Question 10

Central vs Peripheral responses to CO2 and pH

Answer 10

Peripheral responses are much faster

Question 11

Peripheral chemoreceptors

Answer 11

Directly sensitive to CO2, O2 and H+ (pH)
Increase respiratory rate and depth in response to hypercapnia, hypoxia or acidosis (or decrease rate in opposite scenarios)

Question 12

Slowly adapting pulmonary stretch receptors

Answer 12

Located in smaller airways
Fibers travel to brain in vagus nerve
Inhibit inspiration and prolong expiration
Important for controlling respiration in infants, as well as adults during exercise
Can fire for longer periods of time on breath by breath basis

Question 13

Rapidly adapting pulmonary stretch receptors

Answer 13

Fire for short periods of time
Sensitive to irritation, foreign bodies; stretch
Fibers travel to brain in vagus nerve
Cause caugh

Question 14

Juxtacapillary receptors (J receptors)

Answer 14

Located near blood vessels of alveoli
Sensitive to pulmonary edema
Fibers travel to brain in vagus nerve
Cause caugh, tachypnea