Respiration parts 7 - 10 Flashcards
a rhythmic pattern of breathing is established by cyclic ______ activity to the respiratory mm.
neural
what are the 3 respiratory centers of the brain stem and which is the primary center?
- medulla (primary)
- Apnustic center
- Pneumotaxic center(influences output from the medulla)
the medulla is composed of 2 groups (clusters) what are they and what are they composed of?
- Dorsal Resp group (DRG) - the inspiratory center composed of inspiratory neurons.
- Ventral Resp Group (VRG) - the expiratory center and also composed of inspiratory neurons. - DRG has connections to it.
the inspiratory center receives input from ______ _______ via CN IX (glossopharyngeal) in the carotid aa. and the ________ via CN X (vagus nerve) in the lungs
peripheral chemoreceptors
machanoreceptors
the DRG sends motor output to the _______ via CN VII (phrenic nerve) and to the external intercostal mm via ________ nerves.
diaphragm
intercostal nerves
the result of the DRG simulating contraction of the diaphragm and external intercostal mm is what?
the active process of inhalation occurs - air if forced to flow in
the VRG is responsible for _______ but is inactive during quite breathing because it is a passive process.
exhalation
air is forced out of the lungs by a reverse in the ____ _____ between the lungs and the atmosphere until the system achieves an equilibrium point.
pressure gradient
the VRG is activated by the ______ as an overdrive mechanism during periods when demand for ventilation are increased.
DRG - creates active exhalation
Only during _____ expiration do the expiratory neurons stimulate the motor neurons supplying the expiratory mm. (internal intercostals & abdominal)
active
the _______ center is responsible for the activation of the expiratory center involvement when ventilation demand is high.
inspiratory center
the Pneumotaxic & Apnustic Centers located in the Ponds of the brain stem help to ______ ______ the medulla/DRG to produce a normal smooth inspiration and expiration.
Fine tune
The pneumotaxic center transmits ____ _____ to the DRG that help limit the volume of air inspired per breath.
inhibitory impulses
the Apneustic center is responsible for making sure the _______ ______ are never switched off. thus, provides a boost to the inspiratory center’s drive.
inspiratory neurons
in a check-&-balance system, the pneumotaxic center is _______ over the apneustic center, helping to bring inspiration to a halt and allowing expiration to occur normally
dominate
the medullary respiratory center, in response to changing metabolic O2 & CO2 needs can adjust the _______ & _______ of respiration to keep arterial gas values WNL.
rate & depth
what are the 3 most important factors that increase ventilation?
- increase in arterial PO2
- increase in arterial PCO2
- increase in H+ conc
the body has two sets of chemoreceptors what/where are they?
peripheral chemoreceptors in carotid aa & aortic arch
central chemoreceptors in the medula
chemoreceptors are specialized ______ that respond to changes in chemical levels the body.
Organs
________ chemoreceptors are not sensitive to modest reductions in arterial PO2. thus, to activate this receptor PO2 must fall below 60mmHg.
peripheral
________ chemoreceptors link changes in PCO2 to compensatory adjustments in ventilation.
central
T/F
central chemoreceptors monitor CO2 directly.
False biotch!
they monitor CO2 induced H+ concentrations in the ECFof the brain that baths them
a decrease in pH of CSF will _________ breathing rate.
increase
which chemoreceptor play a role in adjusting ventilation in response to alterations in arterial [H+] unrelated to fluctuations in PCO2?
peripheral
- [H+] can rise from fat –> ketone breakdown. the H+ produced this way can NOT cross the BBB thus the drop in pH from the rising [H+] will activate the peripheral chemoreceptor and increase ventilation
