Ventilation Control Flashcards
types of neurons in VRG
inspiratory and expiratory, project to phrenic, intercostal and abdominal motor neurons
contains pre botzinger complex
fn of pre botzinger complex
origin of normal breathing rhythm, output in roots of hypoglossal nerve
types of neurons in DRG
mainly inspiratory and sensory
sensory from peripheral receptors
location and fn of pneumotaxic and apneustic centers
in pons, PRG
ap- causes gasping, prolonged inspiration
penumo-promotes rhythmic breathing
3 major effectors of respiration
phrenic nerve to diaphragm
thoracic motor neurons to intercostals
lumbar motor neurons to abdominals
locaiton of peripheral chemoreceptors
common carotid body and in the aortic arch
stimulus and mechanism of transmission for carotid body
low O2, transmitted to brain via nerve IX glossopharyngeal
describe anatomy of carotid body
very vascular, glomus cell surrounded by sustentacular cells (glia) and smooth muscle
autonomic efferents and CN IX afferents
contrast peripheral and central chemoreceptors
peripheral= O2 sensors
central (medulla)= CO2 and H+
why is CSF around the brain responsive to CO2
BBB is permeable to CO2 but not ions, susceptible to swings in CO2
low protein content decreases buffering capacity, more responsive to pH change
contrast ventilation response to high CO2 to low O2
high CO2 - more gradual increase in ventilation and decrease as normal conditions return- from slower equilibriation of CSF pH
low O2- rapid increase in ventilation, pause of apnea to allow for recalibration on return to normal conditions
location and role of pulm stretch receptors
airway smooth muscle, afferent via vagus
inhibit ventilation to protect from overinflation (hering breuer reflex) when stretched
slow adapting- fire the whole length of stimulus
result of severing vagus on respiration
cuts off pulm stretch receptor inhibition, increased tidal volume
where and what are pulm irritant receptors
b/w airway epithelial cells- rapidly adapting receptors (desensitize even while stimulus remains) that respond to gases, smoke, dust, cold air
innervation and function of pulm irritant receptors
afferent via vagus
increase ventilation, bronchoconstriction, coughing
histamine stim in asthma
where are J receptors and what to they respond to
Juxta capillary receptors
external wall of pulm capillaries, respond to blood borne stuff, pulm congestion or edema
innervation and effect of J receptors
via non myelinated vagus
causes apena followed by rapid shallow breathing, bronchoconstriction, mucus secretion
involved w/ dyspnea w/ heart failure and ILD
what causes the uncomfortable feeling that stimulates ventilation w/ held breath
altered proprioception- input from mechanoreceptors
describe change in ventilation when both O2 and CO2 are changed
ventilation will be increased more if the other gas is abnormal: ie high CO2 will induce a stronger response to low O2 and vice versa
describe changes in ventilation, blood gases and pH during exercise
ventilation increases dramatically but NOT from changes in blood gas or pH- thought to be from cortex or muscle signalling
gases and pH stay flat until anaerobic conditions are met, metabolic acidosis occurs which stimulates more dramatic ventilation change to compensate
