Lecture 25: Regulation of Respiration Flashcards
What makes up the medullary respiratory centers?
dorsal respiratory group
ventral respiratory group
Where is the dorsal respiratory group located?
nucleus of the tracts solitarius
What makes up the pontine respiratory centers?
apneustic center
pneumotaxic center
what does the dorsal respiratory group do?
sets basic rhythm of respiration
What are most of the neurons of the dorsal respiratory group located?
in the nucleus of the tracts solitarius (NTS) and medulla reticular substance
What nerves are the sensory termination of the NTS?
vagal and glossopharyngeal
Where does the NTS receive information from?
peripheral chemoreceptors
baroreceptors
several types of receptors in the lungs
During heavy respiration the rate of the increase ramp signal _____ rapidly
increase
What is the ramp signal?
nervous signals transmitted to the inspiratory muscles during normal respiration
What is the usual method for controlling rate of respiration?
- Control limiting point at which ramp suddenly ceases
- The earlier the ramp ceases, the shorter the duration of inspiration and
- Thus, the primary function of the PRG (Pneumotaxic center) is to control the “switch-off” point of the inspiratory ramp.
- A strong PRG signal results in 30-40 breaths per minute.
- A weak PRG signal results in 3-5 breaths per minute.
Where is the pneumotaxic center located
superior pons
What does the pneumotaxic center do?
mainly controls rate and depth of breathing, transmit signals to the inspiratory center (DRG)
Lesions to the PRG result in the loss of what?
ability to turn off inspiration
Where is the apneustic center located?
inferior pons
Loss of function in the apneustic center results in what?
prolonged inspiratory gasping
What is the normal function of the apneustic center?
limit lung expansion
Where is the ventral respiratory group located?
ventrolateral portion of the medulla
What is the pre botzinger complex?
small area in the rostral part of the VRG
What does the pre botzinger complex do?
believed to be the site which generates the timing of the respiratory rhythm
What does the hering-breuer reflex do?
protective mechanism to prevent excess inflation of the lungs
An increase in carbon dioxide (hypercapnia) or a decease in oxygen (hypoxia) results in what?
decreased activity in most neurons
Chemoreceptors _____ their rate of activity when hypoxia or hypercapnia occur
increase
What are the two types of chemoreceptors?
central
peripheral
What chemoreceptor is located on the ventral surface of the medulla and indirectly sensitive to carbon dioxide levels in blood (based on pH)
central
What chemoreceptor is sensitive to concentrations of oxygen, carbon dioxide, and hydrogen ions?
peripheral
What chemoreceptors are the receptor sin the aortic arch and the carotid body receptors?
peripheral
How do the kidneys increase blood bicarbonate levels
- reduces plasma and CSF (H+)
- bicarbonate ions diffuse through the blood brain barrier
What are peripheral receptors more sensitive to?
changes in oxygen levels in the blood
What are peripheral receptors less sensitive to?
changes in plasma concentrations of carbon dioxide and hydrogen ions
