Download Respiratory Regulation - Warner Pacific College

Regulation of
Respiration
(Chapter 41)
Taylor Clark
Lindsay Loe
Respiratory Center
○
○
Located bilaterally in the medulla
oblongata and pons in the brain
stem.
Divided into three collections of
neurons:
1. Dorsal Respiratory Group
2. Ventral Respiratory Group
3.
Pneumotaxic Center
Dorsal Respiratory Group
○
Plays most fundamental role in the control of respiration
○ Located in the Nucleus of the Tractus Solitarius (NTS)
○ Sensory input from the vagal and glossopharngeal
nerves
1. Chemorecetors
2. Baroreceptors
3. Receptors in the lungs
○ Inspiratory Center
○ Sets respiratory rhythm
○ Ramp Signal
1. During heavy respiration, ramp increases
therefore fills lungs rapidly
2. Limiting point which ramp suddenly ceases
therefore shorter duration of inspiration or an
abrupt stop (expiration)
Ventral Respiratory Group
○ Found in the nucleus ambiguus and nucleus
retroambiguus
○ Inactive during normal quiet respiration
○ do not participate in basic rhythmical
oscillation that controls respiration
○ increased pulmonary ventilation becomes
greater than normal
○ neurons contribute to both inspiration and
expiration
Pneumotaxic Center
○ Located dorsally in the nucleus
parabrachialis of the upper pons
○ Controls the “switch off” point of the
inspiratory ramp
○ Primary function is to limit inspiration
Not a Clicker Question:
Which portion of the respiratory
center plays the primary role in
respiratory function?
Hering-Breuer Inflation Reflex
○
When the lungs become inflated, stretch receptors activate
a feedback that ”switches off” the respirator ramp and stop
further inspiration
○ can also increase the rate of respiration
Not activated until tidal volume increases
Can appear to be a protective mechanism for preventing
lung inflation
Stretch receptors in bronchiols-> vagi-> DRG
Chemical Control
○ Goal of respiration is to maintain concentrations of
oxygen, carbon dioxide, and hydrogen ions
○ Excess of carbon dioxide of hydrogen ions in the
blood acts directly on the respiratory center itself
○ Oxygen acts on peripheral chemoreceptors on
carotid and aortic bodies
-Hydrogen Ions are the most direct stimulus for the chemoreceptive
area
-Carbon Dioxide plays an indirect role in stimulation of the
chemoreceptive area by supplying the hydrogen ions
Carotid Bodies: Glossopharyngeal nerves -> Dorsal respiratory
group
Aortic Bodies: Vagi -> Dorsal respiratory group
*Stimulated by drop in arterial oxygen concentration OR increase in
carbon dioxide/hydrogen ions
Not a Clicker Question:
True or False: Blood Oxygen
levels are the primary stimulus
for respiration
Carbon Dioxide, Blood pH,and
Regulation of Breathing
Effects of Low Oxygen