Unit 2 Lecture 15 Flashcards
What type of muscles are respiratory muscles?
skeletal muscles
What type of neurons control skeletal muscles?
motor neurons
What are respiratory muscles controlled by?
autonomic and voluntary controls
Autonomic respiratory muscles depend on what type of neurons?
Inspiratory and expiratory neurons
Where are inspiratory and expiratory neurons found?
medulla oblongata
Where are the inspiratory neurons localized?
Dorsal Respiratory Group (DRG)
Where are the expiratory neurons localized?
Ventral Respiratory Group (VRG)
Where is the DRG in the medulla oblongata?
Bottom left
Where is the VRG in the medulla oblongata?
Bottom right
What specific type of neurons are the DRG and VRG?
pre-motor neurons
*they synapse on motor neurons in the spinal cord
Do expiratory or inspiratory neurons control breathing?
Inspiratory neurons
What group is the inspiratory neurons again?
Dorsal Respiratory Group (DRG)
How do the inspiratory neurons control breathing?
Rhythm-generating “pacemaker-like” neurons that synapse on them
How do expiratory neurons activated for breathing?
Activated when breathing activity must be increased
What muslces does the DRG stimulate?
Diaphragm and External Intercostals
What muscles does the VRG stimulate?
external intercostals (for labored expiration)
Where is the pneumotaxic center in the pons?
Top right
Where is the apneustic center in the pons?
Top left
Where does the pneumotaxic and apneustic center synapse?
The dorsal respiratory group
What effect does the pneumotaxic center have on the DRG?
negative effect
*it inhibits things
What effect does the apneustic center have on the DRG?
positive effect
*it stimulates things
What causes changes in breathing?
Difference in gas
What senses a difference in gas and triggers respiratory neurons?
specialized receptors
What are the 3 receptors for ventilation?
- Pulmonary stretch receptors
- Central chemoreceptors
- Peripheral chemoreceptors
What stimulates the pulmonary stretch receptors?
“when bronchioles are inflated or stretched”
- when lung size changes
What nerve innervates the pulmonary stretch receptor?
Vagus Nerve (CN X)
During inhibition of the pneumotaxic center, what happens to the DRG?
the DRG switches from inspiration to expiration more quickly
What stimulates the central chemoreceptors?
LOW pH and HIGH CO2 levels
What stimulates the peripheral chemoreceptors?
LOW O2 levels
Where are peripheral chemoreceptors located?
Aortic arch and the carotid sinus
What nerves innervate peripheral chemoreceptors?
CN IX and X
Where are the pulmonary stretch receptors found?
Smooth muscle that lines airways, bronchi, and bronchioles
Where are central chemoreceptors found?
Beneath the ventral surface of the medulla
