respiratory - topic 7 Flashcards
what is the general information transport for respiration?
sensors (chemoreceptors, lungs) give info to central controller (pons, medulla, etc) which sends impulses to effecters (respiratory muscles)
what is the pontine respiratory centre?
pneumotaxic (upper ponds) and apneustic (lower pons) areas
what is the pneumotaxic area?
sends signals to DRG to stop or shorten inspiration
what happens when the pneumotaxic area is more active?
more breathing, but isn’t necessary for normal rhythm
what is the apneustic area?
makes long deep inspiration, normally overridden by pneumotaxic area
what is the DRG?
controls the basic rhythm by setting the frequency of inspiration
what does the DRG do during breathing?
sends AP bursts for two seconds (inspiration) and is inactive for three seconds (expiration)
what is the VRG?
fires during inspiration or forced expiration
what are chemoreceptors?
sensory receptors that respond to chemical changes (O2, CO2, [H+])
what are central chemoreceptors?
respond to PCO2 in brain extracellular fluid
important for rapid control of breathing based on pH
where are the central chemoreceptors?
ventral surface of the medulla
what do the central chemoreceptors do in response to pH?
increased pH - decreased breathing rate (low CO2)
decreased pH - increased breathing rate (too much CO2)
what are peripheral chemoreceptors?
sense what is happening in blood going to brain and increase breathing rate (low PO2 or high PCO2)
where are peripheral chemoreceptors?
aortic arch and carotid bodies
what is the process when there isnt enough O2 in body?
decrease in inspired PO2
decrease in alveolar PO2
decrease in arterial PO2
peripheral chemoreceptors increase firing
respiratory muscles increase contractions
ventilation increases
what is the process when the arterial CO2 is too high?
increase in alveolar PCO2
increase in arterial PCO2
increase in arterial [H+] AND increase in brain fluid PCO2 and [H+]
peripheral AND central chemoreceptors increase firing
respiratory muscles increase contraction
ventilation increases
what is the process when plasma [H+] increases?
increased production of non-CO2 acid
increase in arterial [H+]
increase in peripheral chemoreceptor firing
increase in respiratory muscle contractions
increase in ventilation
what are the types of sensory receptors?
irritant receptors/rapidly adapting pulmonary stretch receptors
slowly adapting pulmonary stretch receptors
juxta-alveolar capillary receptors (J-receptors)
somatic receptors
what are rapidly adapting pulmonary receptors?
in trachea and large airways
react to noxious gas, smoke, dust, etc to cause airway resistance, reflex apnea, and cough
what are slowly adapting pulmonary stretch receptors?
respond to mechanical stimulation from lung inflation (to inflate lungs)
increased lung volume in COPD stimulates these to delay inspiration
what are J receptors?
in alveolar walls and are activated by engorgment of pulmonary capillaries with blood and increased intersitial fluid volume to increase breathing rate
what is dyspnea?
feeling like you aren’t getting enough air
what are somatic receptors?
in intercostals, rib joints, accessory muscles
notice changes in respiratory muscle length and tension to provide info about lung volume to stop inspiration
