L15: Control of Respiration 1/2/3 Flashcards
What is rhythmic breathing
Breathing that we do automatically
Inspiration
Expiration, active breathing
Intercoastal nerves
2
1. internal intercostal nerve–> involved in active expiration
2. external intercostal nerve –> inspiration
Phrenic nerve
During quiet breathing which nerves will be active?
Phrenic nerve
External intercostal nerve
What type of neurons regulate breathing of respiratory muscles
Motor neurons that are bundled together in nerves
Quiet breathing versus active ventilation?
Active ventilation
- More AP in all nerves
- AP in internal intercostal nerve seen
- AP are not in sync
—–EX. External vs internal nerve AP’s
- Tension in inspiratory and expiratory muscle greater
- Expiratory muscle tension is contracting during active ventilation and relaxed during quiet breathing
- Lung volume, tidal volume, the air the moves in and out of the lungs, is greater than quiet breathing
Tidal volume
What are the 6 things that we can look at to see differences in quiet breathing vs. active breathing
Action potentials in:
1. phrenic nerve
2. External intercostal nerve
3. Internal intercostal nerve
Muscle Tension in:
4. Inspiratory muscles
5. Expiratory muscles
Tidal volume:
6. Lung volume
Which 2 centers in the brain control rhythmic breathing?
- Pons
- Medulla
Pontine respiratory group (PRG)
Cluster of nerves in pons that control rhythmic breathing
Ventral respiratory group (VRG)
Nerve cluster in Medulla that control breathing
-contains both expiratory and inspiratory neurons
Dorsal respiratory group (DRG)
Nerve cluster in Medulla that control breathing
- contains mainly inspiratory neurons
Inspiratory neurons
- Active during inspiration
- Hypothesized to control motor neurons to inspiratory muscles
Expiratory neurons
- Active during expiration
- Hypothesized to control motor neurons to expiratory muscles and/or inhibit inspiratory neurons
Central pattern generator, where is it and what are the functions?
- in medulla
- inside the VRG, pre-botzinger complex
- responsible for creating repeating pattern of neural activity which then creates respiratory rhythm
What are the 2 hypotheses in how rhythm is generated? Which one is accurate?
- pacemaker
- neural network
Both of hypotheses can work side-by-side to create rhythm
What is the pacemaker hypotheses?
Neurons have intrinsic pacemaker activity
- spontaneously depolarize generating action potentials in a cyclical manner
What is the neural network hypotheses?
Complex interactions between network of neurons generate rhythm
Respiratory control centers of medulla, what nerves are contained and what does it influence?
- Contains inspiratory and expiratory neurons, central pattern generator and pre-motor neurons
- Pre-motor neurons influence activity of motor neurons of phrenic and intercostal nerves
Respiratory control centers of pons, what nerves are contained and what does it influence?
- Contains inspiratory, expiratory, and mixed neurons
- May regulate transitions between inspiration and expiration
Focus: How is rhythmic breathing modulated?
Focus: How do chemoreflexes regulate blood pH?
