nervous system breathing Flashcards
What is the area from which nerve impulses are sent to the respiratory muscles to control respiratory rate? Where is this located?
- Respiratory Center
- Pons and Medulla Oblongata
What generates nerve impulses establishing basic rhythm of quiet normal breathing?
Dorsal Respiratory Group (DRG)
formally known as Inspiratory area
Dorsal Respiratory Group (DRG)
Impulses innervate what (muscles) via the phrenic nerve and what (muscles) via the intercostal nerves causing contraction.
Diaphragm via the phrenic nerve
Intercostal Muscles…. via intercostal nerves
Neurons of this area supply nerve impulses for forceful exhalation and remain inactive during quiet breathing.
Ventral Respiratory Group (VRG)
formally known as Expiratory Area
What respiratory group:
Active during inhalation and exhalation. Transmits nerve impulses to the DRG in the medulla. Plays a role in both inhalation and exhalation by modifying the rhythm of breathing generated by the VRG as when exercising, speaking, or sleeping.
Pontine Respiratory Group (PRG)
formally known as the Preirrhotaxic Area
What allows us to hold our breath voluntarily?
cerebral cortex’s connection to the respiratory center
Voluntarily holding breath:
When blood concentrations of Co2 and H+ becomes too elevated. the inspiratory area becomes stimulated and _____
breathing resumes
True/False
It is possible to kill one’s self by holding breath.
False
Even if person faints breathing will resume.
What CNS structures also stimulate inspiratory center, allowing emotional stimuli to alter respirations, i.e. laughing or crying.
Hypothalamus and limbic system
What receptors:
Located in the medulla, respond to changes in H+ and PCO2 levels in the cerebrospinal fluid in the CSF.
Central Chemoreceptors
What receptors:
Located in the aortic arch common carotids are sensitive to levels of PO2, H+ and PCO2 in the blood.
Peripheral Chemoreceptors
_______ participate in a negative feedback system that regulates the levels of CO2, O2 and H+ in the blood
Chemoreceptors
How do chemoreceptors respond to increased PCO2 or decreased Po2 levels?
- They cause the inspiratory area to become highly stimulated.
- Rate and depth of respiration will increase(Hyperventilation); allows for exhalation of CO2 until PCO2 and H+ levels are normalized
Hypercapnia is defined as?
An increase in the arterial PCO2, even slightly above the normal 40mmhg.
Hypoxia is defined as….
A deficiency in O2. If the PO2 falls from normal levels (100 mmHg) to about 50 mmHg
