Control of Breathing Flashcards
The dorsal and ventral respiratory groups are located where in the brain? What’s another name for them?
The medulla.
The dorsal respiratory group = inspiratory center
Ventral = expiratory
The inspiratory center sends its afferent signals out through which nerve?
Phrenic - controls the diaphragm and the diaphragm controls breathing.
What nerves send signals to the inspiratory (dorsal) center of the medulla?
CN IX (glossopharyngeal) and X (vagus) from mechanoreceptors
The lung sends information to the inspiratory center via which nerve?
Vagus (X)
When is the ventral respiratory center (expiratory) active?
Exercise.
Expiration is usually a passive process so there are no effector signals from the expiratory center unless needed.
What does the Apneustic center of the brain do?
It causes inspiratory gasps - increases the length of inspirations via prolonging the contraction of the diaphragm.
Long breaths with a short expiratory period in between.
What does the Pneumotaxic center of the brain do?
Turns off inspiration by limiting the burst of action potentials in the phrenic nerve.
What center of the brain allows you to consciously control your breath?
Cerebral Cortex - allows you to voluntarily hyperventilate or hold your breath (hypo ventilate)
Which sensory receptors are in charge of the minute- to minute control of breathing?
Central chemoreceptors
Central chemoreceptors detect what stimulus? Explain.
Decrease in the pH of CSF.
When arterial CO2 increases, the ECF also gains more CO2. CO2 is lipid soluble and can cross the BBB, so it is transferred from the ECF to the CSF. The CSF does not have a good CO2 buffering system like the blood and ECF do, so the pH decreases very quickly.
Central chemoreceptors detect this and communicate directly with the inspiratory center (since they’re located adjacent to one another in the medulla) and increases the respiratory rate.
An increase in the pH of the CSF will cause an Increase/Decrease in the RR?
Decrease
Which is responsible for inspiration? The dorsal or the ventral respiratory group?
Dorsal.
” you use a DOOR to go IN”
Information relayed from the carotid bodies to the DRG (dorsal respiratory group) travel along which nerve?
CN IX and X.
Glossopharyngeal and Vagus.
The carotid bodies are especially sensitive to levels of what substance in arterial blood?
O2 levels.
Especially at high altitudes when the PO2 falls.
Causes increase in respiratory rate.
What is the Hering- Breuer Reflex?
Pulmonary stretch receptors sense the inflation of the lung with inspiration and prevent over-stretching.
They do this by inhibiting the vagal fibers that trigger inspiration.
