lect26-Reg of Respiration Flashcards
what does the dorsal respiratory group do
sets basic rhythm of respiration
prinicipal initiator of phrenic nerve activity
receive many fibers from VRG
receives lots of sensory info via the nucleus tracts solitaries
mainly associated with inspiration: ESTABLISHES RAMP SIGNAL
what is the NTS
sensory termination of both the vagal and glossopharyngeal nerves in the DRG and receives info from peripheral chemoreceptors, baroreceptors, and several receptors in the lungs
what is the primary function of the PRG
control the switch off point of the inspiratory ramp
what do lesions of the PRG result in
loss of the ability to turn off the inspiration without additional input from vagus nerves
what does the PRG mainly do
controls rate and depth of breathing
transmits signals to the inspiratory center
what happens when there is a loss of function in the apneustic center
causes prolonged inspiratory gasping
what is the normal function of the apneustic center
limit lung expansion
define apneusis
failure to turn off inspiration
what is the botzinger complex associated with
coordinating VRG output
what is the intermediate part of VRG associated with
dilation of the upper airway during inspiration
describe pre-botzinger complex
site which generates the timing (frequency) of the respiratory rhythm (central pattern generator
decides length of inspiration and expiration and also determines frequency
define hering-breuer inflation reflex
protective mechanism to prevent excess inflation of the lungs
what do chemoreceptors do when hypoxia or hypercapnia occur
rate of activity increases
what are central chemoreceptors sensitive to
indirectly to CO2 levels (H+) based on pH
what are peripheral chemoreceptors sensitive to
oxygen
what are examples of peripheral chemoreceptors
receptors in aortic arch
carotid body receptors
describe type 1 (glomus) cells of carotid bodies
chemosensors
effected by PO2 (K+ channels open when high and close when low)
describe type 2 (sustentacullar cells)
play a support role similar to glial cells
what PO2 are chemoreceptors exposed to
PO2 of arterial blood not venous
how do signals from slow-adapting pulm stretch receptors travel and what do they do
in vagus nerve to medulla
terminate inspiration and prolong expiration
what do rapidly-adapting pulm stretch receptors sign
signals travel in vagus nerve to brain and elicit cough (override normal respiratory control mechanisms)
what do J receptors do
sensitive to pulmonary edema
signals travel from these receptors to brain via vagus nerve and stimulate cough and tachypnea (override normal respiratory control mechanisms)
define hyperpnea
increasingly deeper and rapid breathing
