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Flashcards in Ctrl of Breathing Deck (16):
1

How does the pneumotaxic center contribute to respiration?

regulates respiratory rate

2

How does the apneustic center contribute to respiration?

prolongs inspiration

3

Where are the pneumotaxic and apneustic center located?

pons

4

When the medulla triggers rhythm generating neurons, (inspiration/expiration) occurs; when the signal stops, (inspiration/expiration) occurs.

inspiration
expiration

(these signals trigger motor nerves that activate muscles involved in respiration)

5

Where are gamma efferents located?

muscle

6

How do baroreceptors affect respiration?

signal to medulla to increase respiration when decreased BP sensed

7

Alveolar ventilation is regulated in response to:

arterial PCO2, pH and PO2

8

What is sensed to regulate minute to minute stability of arterial gases and pH?

partial pressure of arterial CO2
(metabolism relative to ventilation)

9

How do high CO2 levels in the blood affect ventilation?

--In the extracellular fluid, CO2 forms bicarb and H ions, which are sensed by H sensitive neurons.
--Medulla senses pH changes
--Respiration is increased in response

CO2 freely diffuses across BBB?

10

How do chemosensitive cells react to long term elevations in PCO2?

reset themselves to the new nml:
--bicarb is pumped into BBB via transport protein
--medulla senses the increased pH and lowers respiratory drive

11

If the respiratory drive is too high (COPD) in response to chronically elevated PCO2, you will see metabolic (acidosis/alkalosis) in response to respiratory (acidosis/alkalosis)

alkalosis
acidosis

**the medulla is sensing decreased pH, which increases respiratory rate; high bicarb crosses BBB to reset ventilation to function at a higher CO2 level

12

What type of channels are present in carotid bodies? How do they work?

O2 sensitive K channel

--decreased O2 inhibits the channel
--this depolarizes the cell and increases excitability
--excitatory neurotransmitters are released to the glossopharyngeal nerve

13

What is sensed by the carotid bodies?

arterial PO2 (not content)

14

Carotid bodies are (fast/slow) responders to gas changes

fast

15

How are central chemoreceptors reset at high altitude (chronic hypoxia)?

--arterial PO2 decreased due to altitude = carotid body increases alveolar flow (ventilation)
--this decreases arterial PCO2 which raises pH in brain
--central chemoreceptors block increased respiratory drive
--bicarb moves out, which lowers/resets the pH

16

How does the body compensate for respiratory alkalosis?

decreasing plasma bicarb

**this sentence in his notes was confusing