Respiratory Control Flashcards
Minute Ventilation =
Frequency X Tidal Volume
Inspiration occurs when what nerve is active?
Phrenic N.
What are the 4 respiration control centers in the brain?
- Pre-Botzinger Complex
- Pontine Respiratory Group (PRG)
- Dorsal Respiratory Group (DRG)
- Ventral Respiratory Group (VRG)
Pre-Botzinger Complex
Generates the core timing (frequency) of the respiratory rhythm
What brain center generates the core timing (frequency) of the respiratory rhythm?
Pre-Botzinger Complex
What brain center helps control the respiratory rhythm frequency by stopping inspiration?
Pontine Respiratory Group (PRG)
Pontine Respiratory Group (PRG)
Helps control the frequency of the respiratory rhythm by STOPPING INSPIRATION
What occurs when the PRG is lesioned?
Apneusis - failure to stop inspiration
Apneusis
Failure to stop inspiration
Failure to stop inspiration
Apneusis
What areas of the brain contribute to determining the timing/frequency of the respiratory rhythm?
Pre-Botzinger Complex
Pontine Respiratory Group
Dorsal Respiratory Group (DRG)
95% premotor to Phrenic N.
= Generates a pattern appropriate to the circumstance
What brain center contains 95% premotor to Phrenic N.?
Dorsal Respiratory Group (DRG)
Ventral Respiratory Group (VRG)
Premotor to other inspiratory and expiratory muscles
What are the regions of the VRG?
Rostral - Premotor to inspiratory muscles
Caudal - Premotor to expiratory muscles
What areas of the brain contribute to determining the depth of the respiratory rhythm (tidal volume)?
Dorsal Respiratory Group
Ventral Respiratory Group
Apnea
Failure to turn off expiration (NO inspiration)
Failure to turn off expiration (NO inspiration)
Apnea
Damage to ____ causes Apneusis
Pons
Damage to ____ causes Apnea
Medulla or spinal cord
What do chemoreceptors do?
Neurons that INCREASE firing rate in response to a chemical change
Where are central chemoreceptors located?
Ventral surface of medulla
What do central chemoreceptors come into contact with?
CSF - cerebrospinal fluid
What molecule crosses the blood-brain barrier and contacts the central chemoreceptors?
CO2
– increased CO2 means there is decreased O2 and we need to breathe
What is the central chemoreceptors response based on?
PaCO2 in the blood
Describe how the central chemoreceptors increase their firing rate as CO2 reaches the CSF at the ventral surface of the medulla
- CO2 reaches CSF and is mixed with H2O
- Carbonic Anhydrase is present and creates H2CO3
- H2CO3 dissociates to H+ and HCO3-
- H+ activates the central chemoreceptor increase firing rate!!!
What molecule activates the central chemoreceptor to increase firing rate?
H+
Where does the axon of the central chemoreceptor go to?
Pre-Botzinger Complex
Once the axon of the central chemoreceptor reaches the Pre-Botzinger Complex, then what is the cascade of the signal?
Pre-Botzinger
DRG/VRG
Phrenic N.
Diaphragm
What chemoreceptors respond with quick changes?
Peripheral chemoreceptors
Where are the majority of the peripheral chemoreceptors?
Carotid Body
What senses O2 in the peripheral chemoreceptors?
Type 1 Glomus cell
When the peripheral chemoreceptors sense the low O2, what do they increase/decrease?
ROS, Lactate and decrease ATP
When Peripheral chemoreceptors increase ROS, lactate and decrease ATP what does this cause?
K+ leaky channels SHUT
– Cells depolarize!
As the peripheral chemoreceptors are starting to depolarize once the leaky K+ channels shut, then what enters the cell?
CALCIUM
– Cells depolarize further and generate an action potential
What do peripheral chemoreceptors end up releasing?
Dopamine
With what nerve can peripheral chemoreceptors send action potentials?
CN IX
What are the mechanoreceptors?
Pulmonary Stretch Receptors
Where are slowly and rapidly adapting pulmonary stretch receptors located?
Airways
Describe how slowly adapting pulmonary stretch receptors stop inspiration
Increased size of lungs
Increases the stretch in the airways
Sends an action potential via vagus nerve
STOPS inspiration
When are slowly adapting pulmonary stretch receptors critical?
Infancy
Adults when exercising
What activates rapidly adapting pulmonary stretch receptors to produce a cough?
Airway irritation via CN X
Rapidly adapting pulmonary stretch receptors are ______
Protective
Slowly adapting pulmonary stretch receptors are used for _____
Normal breathing
Where are juxtacapillary (J) receptors?
By alveolar capillaries
What activates J receptors?
Pulmonary edema
When the J receptors are active, what do they cause to happen?
Dry cough and rapid/shallow breathing
How does the Cortex influence breathing?
BYPASSES the medullary centers and directly contacts muscles of respiration
