Dasguppta - Control Of Respiration Flashcards
The central chemoreceptors are located inside the brainstem on the other side of the BBB. They are sensitive to fluctuation of ____ in the brain interstitium.
CO2
The peripheral chemoreceptors can be found in the carotid sinus. They respond to ?
Arterial [H]
Arterial pCO2 (only because of the effect it has on[H+])
Arterial pO2 (but only when very low, below 60mmHg)
For a normal person, fluctuation in _____ is the main drive for respiration
CO2
Chronic exposure to ____ can cause adaptation of central chemoreceptors
CO2
Hypoxia _______ central chemoreceptors
Does not drive
Central chemoreceptors can be stimulated by a very small increase in PaCO2, around ______ mmHg, and / or increases in H+ concentration in CSF
42-43mmHg
Normal range is 35-45mmHg
Why is the overall buffering system in the CSF very slow, causing rapid increases in [H+] and making the receptors there very sensitive?
CSF lacks hemoglobin and carbonic anhydrase and has a relatively low bicarbonate and protein level.
PaO2 about 60mmHg and lower leads to _________ of peripheral chemoreceptors
Activation
The driving force for ventilation that comes from the aortic arch and carotid bodies is ?
Fluctuation in pO2
There is no adaptation for hypoxia
Hypoxic stimulation of ventilation is exclusively mediated by __________
Peripheral chemoreceptors
The most powerful stimulus known to influence the respiratory components is the ________.
Mediated solely by peripheral chemoreceptors
Concentration of [H+] ions
There must be _______ hypoxia before pO2 causes any increase in ventilation
Moderately severe
Hypoxic response of the carotid bodies is _________ _by increasing pCO2
Very strongly enhanced
Does the response to hypoxia ever adapt?
No
The neurons in the medulla have both inspiratory and expiratory activity, and this region of the medulla is referred to as the ?
Central pattern generator
During exercise or patients of lung disease, accessory muscles (internal intercostal and abdominal muscles) are used for EXPIRATION, where is innervation for these muscles from ?
Nerves in the lumbar region and near the thoracic vertebrae
The motor act of inhalation is mostly innervated by what?
Phrenic nerve innervation to the diaphragm.
In the “respiratory center of the medulla” the intrinsic respiration is controlled by which 2 groups of neurons?
The dorsal respiratory groups
The ventral respiratory groups
Receives inspiratory impulses from several different specialized monitoring systems throughout the body, including central chemoreceptors, peripheral chemoreceptors, stretch receptors, and higher brain centers. Send neural impulses every few seconds to the muscles of inspiration. Believed to be responsible for the basic rhythm of breathing. Trigger inspiration at rate of 12/15 breaths/min
Dorsal respiratory groups
Contains both inspiratory and expiratory neurons
Control constituent muscles of upper airway, regulating diameter during breathing. Stimulates the muscles of the upper airway to expand in inspiration. Also controls muscles of expiration and the accessory mm. Of inspiration during stress and heavy exercise
The ventral respiratory group
Located in pons
Normal respiration cut-off switch
Continually sends neural impulses to stimulate inspiratory neurons of DRG and VRG
Apneustic center
Located in pons
Major function; prevent apneusis, enhance and fine tune the rhythmicity of breathing
Pneumotaxic centers
An abnormal pattern of breathing characterized by deep, gasping inspiration with a pause at full inspiration followed by a brief, insufficient release
Apneustic respiration
Central pattern generator inoperative
Insensitivity of chemoreceptors to O2, CO2 or pH
Respiratory drive only voluntary
Tracheostomy needed so they can plug into ventilator when they sleep because otherwise respiratory drive is gone when asleep
Congenital Central Hypoventilation Syndrome (CCHS)
Drugs that depress CNS and alter respiratory control system in medulla. Cause respiratory depression and dampen the normal ventilatory response to increase of CO2
Alcohol
Opiates
Benzodiazepines
Barbiturates
Anesthetics
Drugs that increase respiratory drive by stimulating the respiratory control center in the medulla
Cocaine
Amphetamine
Caffeine
Fever _____ ventilation
Increases
Mild hypothermia _____ ventilation
Increases
Due to stimulation of sympathetic nervous system as the body works to preserve heat
Also have shivering, tachycardia, and vasoconstriction
Deep hypothermia ________ ventilation
Depresses
{probably through general depression of neural activity}
Depression of CNS activity due to brain injury or drug overdose and _____ ventilation
Depress
Painful stimuli can cause ______ in ventilation
An increase
Panic can result in _
Hyperventilation
10-30 seconds of apnea followed by gradual increase in volume and frequency of breathing until another period of apnea comes.
Found in patients of cardiac failure or brain damage
Cheyne-Stokes breathing
What kind of illness is Cheyne-Stokes breathing associated with ?
Cardiac failure
Brain damage
Rhythmic but deep respiration movements which alternate (at approximately regular intervals) with long respiratory pauses (from few seconds to half a minute)
Occurs in meningitis patients, disorders of cerebral circulation, and damage to the respiratory center from trauma, stroke and opioid use
Biot’s respiration
What conditions are associated with Biot’s respiration?
Meningitis
Disorders of cerebral circulation.
Damage to the respiratory center from trauma, stroke, or opioid use
Type of breathing; inspiratory process intact.
Upper airway obstructed bc too much fat around the pharynx; pharyngeal muscles do not contract properly.
Absence of airflow due to an occlusion in the upper airway that lasts at least 10 seconds in spite of continual effort to breathe.
Obstructive sleep apnea
How are the types of sleep apnea different from Cheyne-Stokes respiration?
No hyperventilation and waning of ventilation
Pattern of breathing characterized by a normal deep inspiratory cycle interchanged with complete cessation of breathing.
Typically caused by problems with how the brain controls breathing rather than an occlusion
Absence of airflow for at least 10 seconds
Central sleep apnea
Hyperventilation, gasping, deep and labored respiration, usually seen in DKA, kidney failure, diabetic coma, or other states with high degree of acidossi
Kussmaul’s respiration
What types of conditions are associated with Kussmaul’s respiration?
DKA
Diabetic Coma
Renal Failure
States characterized by high degree of acidosis
Symptoms associated with ARDS:
Tachypnea, tachycardia, diahporesis, cyanosis, dyspnea, diffuse crackles ,+/- cough and cp,
(Onset of symptoms usually 6-72 hours after inciting event)
Static compliance of the lung is determined by ?
PV slope at FRC
Pathophysiology of ARDS:
Alveolar injury —> cytokine release
Recruit neutrophils to lungs (releases ROS and proteases)
Damage capillary endothelium (lymph drainage overwhelmed)
Damage alveolar epithelium (no more tight junctions)
Ventilation = __
CO2
Where are the apneustic center and pneumotaxic center located?
The pons
