5.5 - Control of Ventilation Flashcards
TRUE OR FALSE
Skeletal muscles can contract spontaneously without being innervated by somatic motor neurons
FALSE
CANNOT CONTRACT SPONTANEOUSLY
What initiates the contraction of the respiratory skeletal muscles?
medulla oblongata (brain)
What is the central pattern generator and what do they do?
its a network of neurons in the medulla oblongata and they have intrinsic rhythmic activity, they fire signals at a rhythmic rate
What is the function of the dorsal respiratory group?
control external intercostal muscles and diaphragm (muscles of inspiration)
the dorsal respiratory group is also known as ____
inspiratory neurons (I neurons)
the ventral respiratory group is also known as _____
active expiratory neurons (E neurons)
Which muscles do the ventral respiratory group neurons control?
internal intercostals and abdominal muscles (active expiration)
What is the function of chemoreceptors?
to modify or adjust the rhythm of the central pattern generator neurons
Peripheral chemoreceptors are found in ____
carotid bodies, glomus cells
Decreased PO2, decreased pH, or increase in PCO2 will lead to ____
increase in ventilation
TRUE OR FALSE:
Peripheral chemoreceptors initiate signals when plasma PO2 changes slightly
FALSE
radical change in plasma PO2 must occur to get a signal
What is the function of peripheral receptors?
sense changes in PO2 and pH of plasma or increase in PCO2
Where are the central chemoreceptors located?
located in the medulla oblongata
TRUE OR FALSE
Peripheral receptors are the most important chemical controller of ventillation
FALSE
central chemoreceptors are most important
What happens if there is an increase in PCO2 in arterial blood?
increased ventilation
What happens when CO2 crosses the blood brain barrier into the cerebrospinal fluid?
activation of central chemoreceptors via changes in pH caused by production of carbonic acid
TRUE OR FALSE
Central chemoreceptors sense changes of H+ in both CSF and arterial blood
FALSE
only in CSF
What is the function of mechanoreceptors?
to control ventilation to protect the lungs
Where are irritant receptors found and what do they do?
located in airway mucosa
triggers parasympathetic neurons which innervate smooth muscles of bronchioles leading to bronchioconstriction
Where are stretch receptors found and what do they do?
found in airway smooth muscle
terminates ventilation if lungs are over inflated (Hering-Breueur inflation reflex)
