ventilation-quiz2 Flashcards
Receives afferent impulses from all other areas in the body
Respiratory control center located in the medulla oblongata
It is here where afferent impulses are interpreted & efferent impulses are initiated
Medulla oblongata
These are 2 areas in the medulla that contain respiratory neurons
Dorsal Respiratory group & Ventral respiratory group
This is where inspiratory efferent impulses originate & then travel to VRG & Spinal Chord
DRG
Inspiration normally a ramp signal, increasing steadily for approx. _______ seconds & then stopping for approx. _______ seconds.
2 seconds
3 seconds
What is the primary controller of the depth & rate of inspiration?
DRG
Name the two centers in the pons that contain afferent respiratory neurons?
Pneumotaxic Center
Apneustic Center
Functions primarily by sending efferent impulses to all expiratory motor neurons during stressed ventilation?
VRG
Axons from the higher brain centers descend into where?
Spinal Cord
Afferent impulses from here fine tune ventilator rhythmic breathing
Pneumotaxic Center
Afferent impulses from here cause a sustained inspiratory pattern with only short expiratory times which is located in the lower pons; if destroyed will cause a rapid, irregular, gasping respiratory pattern.
Apneustic Center
Inhibits length of respiration
Pneumotaxic Center
Important to stressed breathing, they are inactive during normal quiet breathing & is important during exercises; Sends inspiratory efferent impulses during stressed breathing
VRG
Responsible for generating the basic rhythm of inspiration
DRG
Afferent impulses via the vagus nerve originate from what two areas?
Baroreceptors & Pulmonary Reflexes (stretch receptors aka Hering-Breuer Reflex)
Where are stretch receptors located that activate the Hering-Breuer Reflex?
Smooth muscle of conducting airways
What stimulates the hering-breuer reflex?
Lung inflation & increased transpulmonary pressures stiulate the receptors
Where are J-receptors located?
In the walls of pulmonary capillaries
What stimulates J-receptors?
Increased interstitial fluid volume or edema, pulmonary congestion, chemical irritants
What type of breathing occurs when j receptors are stimulated?
Rapid, Shallow breathing
When J-receptors are stimulated it can result in hyper/hypo ventilation?
Hypoventilation
This innervates the peripheral chemoreceptor cells in the carotid bodies?
Glossopharyngeal Nerve
Central/Peripheral chemoreceptors can differentiate between concentrations or pressures of various substances?
Peripheral
Name the 2 groups of peripheral chemoreceptors & what nerve innervates them?
Carotid bodies innervated by glossopharyngeal (cranial IX) nerve;
Aortic bodies innervated by vagus nerve (cranial X)
A compensatory/synergistic response from peripheral chemoreceptors works during hypoxemia and acidosis
Synergistic
Name 2 conditions that have no stimulating effect on ventilation?
Carbon monoxide poisoning & anemia
PaCO2 has a direct/indirect effect on chemoreceptor cells?
Indirect
The magnitude of the response of H+ is greater in chemical/peripheral chemoreceptors?
Chemical chemoreceptors
Stimulation of peripheral chemoreceptors by an increase in H+ causes a decreased/increased RR & increased/decreased tidal volume.
caused increased RR
increased tidal volumes
T or F: A decrease in H+ which stimulates peripheral chemoreceptors dramatically decreases RR & Vt
False, it has a slight decrease in both
Poorly defined groups of cells located near ventrolateral surface of medulla & in contact with CSF & arterial blood?
Central chemoreceptors
CSF is considered to be more/less acidic than arterial pH?
More with an average of 7.336 pH
What is diffusible easily across the blood brain barrier?
CO2
Changes in arterial PH/PCO2 alter diffusion to the CSF
PCO2
Increased PCO2 stimulates/inhibits ventilation whereas decreased PCO2 stimulates/inhibits ventilation.
Increased stimulates
Decreased inhibits
T or F: CO2 content of both venous & arterial blood can influence CSF CO2 levels.
True
T or F: Chronic increases in PaCO2 rapidly cause an increase in CSF PCO2.
False, acute increases of PaCO2 cause increase in CSF PCO2
T or F: Alveolar ventilation influence CSF CO2y levels.
True
T or F: Increased PCO2 in CSF causes the CSF pH to increase.
False pH will decrease with an increase in PCO2 in the CSF
Chronically elevated PaCO2 results to increased/decreased sensitivity to CO1 changes.
Decreased
T or F: acute decreases in PaCO2 will cause a rapid decrease in PCO2
True
Decreases in plasma pH stimulate peripheral chemoreceptors/chemical chemoreceptors
Peripheral
Peripheral/Chemical chemoreceptors stimulate/inhibit ventilation & central chemoreceptors stimulate/inhibit ventilation
Peripheral stimulate
Chemical inhibit
Hypoxemia stimulates peripheral/central chemoreceptors
Peripheral
Most voluntary control of ventilation is initiated via pons/medulla/cerebral cortex.
Cerebral Cortex
This area of the brain is involved in controlling breathing during emotional behavior?
Thalmus
Name 3 factors that stimulate ventilation
Hypoxemia Hypercarbia Acidosis Fever, infection, sepsis Stimulation of J-receptors Fear, anxiety
Name 3 factors that depress ventilation
Hypocarbia
Alkalosis
Electrolyte imbalance
Fatigue
Breathing pattern which is highly irregular with periods of apnea
Biots
Breathing pattern that includes increasing & decreasing volumes followed by period of apnea
Cheynes-Stokes
Pattern of long sustained inspirations & short expiratory times, seen during injury to pons.
Apneustic breathing
Increased CO2 dilates/constricts cerebral vessels & increases/decreases blood flow
Dilates
Increases
In COPD this is why chronic hyperventilation does not persist when elevated CO2 is chronic.
Kidney compensation & Bicarb returns pH to normal trending acidic but normal so since normal pH it won’t stimulate hyperventilation & receptors
Which type of chemoreceptor react 5x more quickly
Peripheral chemoreceptors
Kidneys retain/secrete HCO3 in response to respiratory acidemia
Retain
Central/Peripheral/both chemoreceptors respond directly to H+
Both central & peripheral respond directly to H+
This controls the off switch of the DRG inspiratory ramp signal to inhibit inspiration
Pneumotaxic center of the brain
A weak signal sent by DRG across inspiratory ramps causes longer/shorter insp times & larger/smaller tidal volumes
longer inspiratory times & larger Vt
This causes prolonged inspiration gasps
Apneustic center
Activated by a large Vt & is important in exercise
Hering Breuer Reflex
This reflex causes laryngospasm, bronchospasm, coughing, & bradycardia
Vavovagal reflex
Receptor that may be responsible for causing the sensation of dyspnea.
J-receptors
PaO2 can affect peripheral/central chemoreceptors
Peripheral
PaCO2 most strongly effect peripheral/central chemoreceptors.
Central
H+ ions & pH stimulates peripheral/central receptors
Peripheral
What are some peripheral chemoreceptors?
Carotid & Aortic bodies
Decreased CO2 dilates/constricts cerebral vessels
Constricts
Stops ventilation when impulses are sent across the vagus nerve when Vt is 800 - 1000 ml Vt
Hering-Breuer Reflex
Respond to increased H+ in CSF, peripheral/central chemoreceptors
central
Nerve impulses travel along vagus/glossopharyngeal/Phrenic nerve causing action on effectors such as diagphragm & muscles of inspiration.
Phrenic
These nerves innervate the diaphragm
Phrenic
What are the 3 basic elements of respiration
Central controller: Pons, Medulla Cortex
Input (sensors like chemoreceptors, pulmonary, etc)
Effectors; resp muscles, diaphragm, accessory muscles
What controls conscious or voluntary breathing
Cerebral Cortex
This part of brain responsible for rage or fear
Thalmus/hypothalamus
Hypothalmus
This part of brain responsible for emotions
thalamus/hypothalamus
Thalmus
This stimulates central chemoreceptors more quickly: elevated PaCO2 or H+
PaCO2
