Physiology Review Slides Lec. 24 Flashcards
J Receptors are sensitive to what?
Pulmonary EDEMA
- Due to Congestive heart failure
Effects of decreased neuronal activity
Results in a Decrease in GAS EXCHANGE
What results when the Ramp signal ceases EARLY?
Shorter the duration
INSPIRATION
And
Expiration
Where are Type I Carotid Body cells located?
Near FENESTRATED Cappilaries
Type I Carotid Body cells
- Glomus cells
- Chemosensors
How many carotid body cell types are there?
2 Total
- Type 1
Glomus cells - Type 2
Sustentacular Cells
Hypercapnia
Increase in CARBON DIOXIDE levels
- decreased activity in most neurons
Stimulation in J receptors results in what?
- Cough
- Tachypnea (fast breathing)
What Establishes the Ramp signal in the Body?
DORSAL Respiratory group
What is mainly associated with INSPIRATION?
Dorsal Respiratory group
Dorsal Respiratory group
- Principal Initiators do the PHRENIC Nerve group
- Receive many fibers from the VENTRAL respiratory group
- Mainly Associated with Inspiration
- Establishes the RAMP Signal
Type II Carotid Body cells
Play a SUPPORT role to GLIAL cells
Where is the Dorsal Respiratory group located?
Locates in the Dorsal portion of the MEDULLA
Hypoxia
Decrease in OXYGEN Levels
- results in decreased activity in most neurons
Type I Carotid Body cells on LOW PO2 levels
- Closes channels and result in DEPOLARIZATION
- Opens Up CALCIUM channels
- NT Release
Type I Carotid Body cells on High PO2 LEVELS
- PO2 Dep K+ channels result in EFFLUX of K+
- Leads to HYPER-POLARIZATION
J receptors travel to the brain via what nerve?
Vagus
A STRONG PRG Signal results in how many breaths per minute?
30-40
Chemoreceptors in the Presence of Hypoxia or Hypercapnia
INCREASE their activity rate
A WEAK PRG Signal results in how many breaths per minute?
3-5
Primary fxn of the PRG
Pneumotaxic Center of the brain
- Controls the “OFF-Switch” point of the INSPIRATORY ramp
Ramp Signal during Heavy Respiration
- Signals Increase RAPIDLY
J Receptor
- Sensory endings (C fibers)
- In the alveolar wall
- Juxtaposition to Pulmonary Capillaries
Ramp Signal
Nervous signals transmitted to the INSPIRATORY Muscles
- Mostly to the DIAPHRAGM
What results in decreased activity in most neurons
- Hypercapnia
- Hypoxia
T/F: J receptor reflexes override the Normal Respiratory control mechanisms
True