• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/56

Click to flip

56 Cards in this Set

  • Front
  • Back
The respiratory center is made up of several groups of neurons located bilaterally in the
medulla oblongata and pons of the brain stem
The respiratory center is divided into three parts
1. DRG - dorsal respiratory group - inspiration
2. VRG - ventral respiratory group - expiration
3. Pneumotaxic center - located in pons - controls rate and depth of respiration
DRG - dorsal respiratory group extends the length of the
medulla oblongata
DRG - most of its neurons are located in the nucleus of the
tractus soltarius
The tractus soltarius area is the location where the sensory termination of the
vagus and glossopharyngeal nerves transmit signals into the respiratory center from the peripheral chemoreceptors, baroreceptors, and other lung receptors
The DRG controls the
rhythmicity of respiration
How does the DRG control the rhythmicity of respiration
By ramping up over a period of a couple seconds, then shutting down
DRG - the ramping allows for
diagphragmatic stimulation and allows time for elastic passive lung pressure recoil
DRG - ramp up time is shorted during
heavy breathing or exercise and the expiratory phase is shortened
Overstretching of the stretch receptors in the bronchi and bronchioles is called
Hering-Breuer inflation reflex
HB Inflation Reflex
Overstretch results in
vagal stimulation, which transmits to the DRG switching off the ramp time phase
HB Inflation Reflex protects the lungs from
excessive lung inflation and barotrauma
What populations have the HB Inflation Reflex
kids and babies
The pneumatic center is located in the
pons
Primary function of the pneumatic center is to
control the switch off point of the inspiratory ramp
If pneumatic center signal is strong - inspiration lasts for a
shorter period of time
If pneumatic center signal is weak - inspiration lasts for a
longer period of time
If pneumatic center signal can increase rate up to ______ or as low as ______
30-40BPM, 3-5BPM
VRG is located in the
medulla in the nucleus ambiguous
VRG is located near the
DRGs
VRG
If respiratory drive increases, then the
signals spill over into the VRG area and the VRG is contributory to the DRG
VRG
Stimulation may either lead to
inspiration or expiration
VRG
These neurons also provide powerful signals to the
abdominal muscles to help with exhalation during heavy breathing
The ultimate goal of respiration is
homeostasis of O2, CO2, and pH
The respiratory center is sensitive to changes in the
chemical concentrations
Excessive CO2 affects the central respirtatory center and
increases inspiration and expiration mechanisms
Does O2 impact the respiratory center
no
O2 acts on the peripheral chemoreceptors located in
the carotid and aortic bodies
Does CO2 directly stimulate DRG, VRG or pneumatic center
no
How does CO2 indirectly stimulate DRG, VRG or pneumatic center
there are chemosensitive neurons located near these centers
The area around the DRG, VRG, and pneumatic enter is sensitive to
changes in PaCO2 and hydrogen ions
The area around the DRG, VRG, and pneumatic enter is more sensitive to changes in PaCO2 or hydrogen ions
hydrogen ions
Is the area around the DRG, VRG, and pneumatic center within the blood brain barrier
no
Do hydrogen ions cross the blood brain barrier
no
Does CO2 cross membranes
yes
How does CO2 indirectly stimulate the chemosensitive area
quickly crosses membrane - combines with H2O to from carbonic acid - then dissociates in bicarb and hydrogen ions
CO2 + H2O --> H2CO3 --> HCO3 + H
What stimulates the chemoreceptors
hydrogen ions
Does CO2 impact the respiratory system
yes - huge impact
How long does CO2-driven stimulation of the chemoreceptors last
just a couple of days
How does the body compensate for high hydrogen levels
the kidney retains more HCO3 that binds the hydrogen
For what population does the CO2-driven stimulation of central chemoreceptors disappear after a couple days
COPD
Stimulation of central chemoreceptors leads to an increase in
minute ventilation
Under normal circumstances, hemoglobin has the ability to
shift affinity right or left to deliver adequate O2 despite ventilation UP TO A POINT
Can ventilation impact oxygen concentration
yes, to some degree
What is most affected by ventilation changes
CO2 concentration
What two factors affect CO2 concentration
TV and RR
When tissue lacks O2, the body has what special mechanism for respiratory control
peripheral chemoreceptors located in the aortic and carotid bodies
When PaO2 falls below 70 torr
the peripheral chemoreceptors are stimulated - signal sent through glossopharyngeal and vagus nerves to DRG
The chemoreceptor stimulus is especially important when PaO2 falls between
30-60 torr
Glossopharyngeal nerve is associated with
carotid body
The vagus nerve is associated with
the aortic body
Between 20-60 torr - the oxyhemoglobin dissociation curve
unloads and loads very quickly
At SpO2 of 100% - PaO2 is
90 torr
At SpO2 of 90% - PaO2 is
60 torr
At SpO2 of 60% - PaO2 is
30 torr
At SpO2 of 50% - PaO2 is
27 torr