Regulation of Breathing Flashcards
What is the apneustic center?
An anatomically ill-defined, localized collection of neurons in the pons located at the level of the vestibular area that moderates the rhythmic activity of the medullary respiratory centers.
What is Biot respirations?
Breathing characterized by irregular periods of apnea alternating with periods in which 4 or 5 breaths of identical depth are taken.
What are chemoreceptors?
Sensory nerve cell activated by changes in the chemical environment surrounding it; the chemoreceptors in the carotid artery are sensitive to PCO2 in the blood, signaling the respiratory center in the brain to increase or decrease ventilation.
What is Cheyne-stokes respiration?
Abnormal breathing pattern with periods of progressively deeper breaths alternating with periods of shallow breathing apnea.
What is the Hering-Breuer inflation reflex?
The parasympathetic inflation reflex mediated via the lungs stretch receptors that appears to influence the duration of the expiratory pause occurring between breaths.
What is the pneumotaxic center?
Bilateral group of neurons in the upper part of the pons that rhythmically inhibits inspiration.
What are vagovagal reflexes?
Reflexes caused by stimulation of parasympathetic receptors in the airways that can result in laryngospasm, bronchoconstriction, hyperpnea, and bradycardia.
What stimulates vagovagal reflexes?
They are often associated with mechanical stimulation, as during procedures such as tracheobronchial aspiration, intubation, or bronchoscopy.
What Controls Ventilation?
- Control of ventilation will begin in the respiratory center in the medulla
- The respiratory center will receive impulses from the lungs and airways and will send motor impulses to the
- Diaphragm
- Intercostals
- Accessory muscles
- SCM
- Scalene
- Pecs
- Abdominals
- Accessory for expiration
Medullary Respiratory Center
- Rhythmic cycle of breathing originates in medulla
- Higher brain centers, systemic receptors, & reflexes modify medulla’s output
- No truly separate inspiratory & expiratory centers
- Medulla contains several widely dispersed groups of respiratory-related neurons
- These form dorsal & ventral respiratory groups
Medulla Oblongata
Located in the brainstem, immediately above the start of the spinal cord
The Foramen magnum is the opening that landmarks the beginning of the Medulla Oblongata from the spinal cord
High transection of the spinal cord will lead to inability of the patient to breathe
Dorsal Respiratory Groups (DRG)
- Composed mainly of inspiratory neurons located bilaterally in the medulla
- Neurons send impulses to the phrenic nerve & external intercostal muscles
- DRG nerves extend into VRG but few VRG nerves extend into DRG
- Vagus & glossopharyngeal nerves bring sensory impulses to DRG from lungs, airways, peripheral chemoreceptors, & joint proprioceptors
- Input modifies breathing pattern
Proprioceptor
- A sensory receptor, found chiefly in muscles, tendons, joints, and the inner ear, that detects the motion or position of the body or a limb by responding to stimuli
Dorsal Respiratory Groups (DRG)
Consists of 2 Neuron Groups
- Inhibited deep lung inflation causing cessation of inspiratory effort
- Excited lung inflation causing continued inspired effort-Neurons are involved in Herring Breuer and Head reflexes
Ventral respiratory groups (VRG)
- Contain both inspiratory & expiratory neurons located bilaterally in medulla
- VRG sends inspiratory impulses via vagus nerve to:
- Laryngeal & pharyngeal muscles
- Diaphragm & external intercostals
- Other VRG neurons send expiratory signals to abdominal muscles & internal intercostals
- Neurons are involved in Herring Breuer and Head reflexes
