Respiratory Centers of the Brain
What structure is known as the primary respiratory control center?
the medulla oblongata
How would the Hering-Bauer Reflex be affected in an individual with emphysema?
-a person with emphysema would have an impaired Hering-Bauer reflex due to a loss of pulmonary stretch receptors
What is involuntary respiration?
-any form of respiratory control that is not under direct, conscious control -in control by mainly the medulla and the pons
What is voluntary respiration and include an example?
-any type of respiration that is under conscious control -ex. blowing out a candle
What is the deflation reflex?
-as inspiration stops, expiration begins, and the lungs begin to deflate, and the stretch receptors are deactivated
What is the function of the pons in regards to respiration?
-controls the rate or speed of involuntary respiration
Carotid body- what changes does it detect?
-detects changes in blood oxygen, carbon dioxide, and pH (ALL 3)
How do chemoreceptors regulate breathing?
-does so by a negative feedback loop --> goal of the system is to keep blood pH in a normal range
peripheral chemoreceptors
-includes the aortic body and carotid body
vagus nerve- what is it and what is its function?
-innervates the diaphragm as well as movements in the larynx and pharynx -provides parasympathetic stimulation for the heart and digestive system -major autonomic nerve!!
Voluntary respiration involves what?
-involves higher functions that are controlled by the cerebral cortex -the motor cortex within the cerebral cortex is what is controlling voluntary respiration
What is the Hering-Bauer Reflex?
-it is a reflex that prevents the over-inflation of the lungs during inspiration -stretch receptors: a sensory receptor that sends an action potential when it detects pressure, tension, stretch, or distortion (sends an AP to the medulla and pons thru the vagus nerve)
central chemoreceptors
-located on the ventrolateral surface of the medulla and detect changes in the pH of spinal fluid
What portion of the cerebral cortex controls exhalation?
-posterior region of the primary motor cortex
Apneustic center
-send signals for inspiration for long and deep breaths -controls intensity of breathing and inhibited by stretch receptors of the pulmonary muscles -increases tidal volume
What is the main function of the medulla in regards to respiration?
-send signals to the muscles that allow breathing to occur
Pneumotaxic center
-sends signals to inhibit inspiration, which limits the activity of the phrenic nerve and inhibits signals of the apneustic center -finely control the respiration rate -decreases tidal volume
How does the cerebral cortex initiate any voluntary respiratory muscle movement?
-sends signals to the spinal cord and then signals to the muscles controlling voluntary respiration, which include the diaphragm and intercostal muscles -the pathway above is called the ascending neural pathway
posterior thoracic nerves- what is it and what is its function?
-stimulate the intercostal muscles -considered to be part of a larger group of intercostal nerves that stimulate regions across the thorax and abdomen -somatic nerves!!
Ventral respiratory group in the medulla
-stimulates expiratory movements
Dorsal respiratory group in the medulla
-stimulates inspiratory movements
Phrenic nerves- what is it and what is its function?
-stimulates the activity of the diaphragm -composed of two nerves, the right and left phrenic nerve --> pass thru the left and right side of the heart -autonomic nerves!
Aortic body- what changes does it detect?
-the aortic body detects changes in blood oxygen and carbon dioxide, but does NOT detect changes in pH
What is the inflation reflex?
-the pneumotaxic center of the pons sends signals to inhibit the apneustic center of the pons
Where does the initiation of the voluntary contraction and relaxation of the internal or external intercostal muscles take place?
-the superior portion of the cerebral cortex