Test Bank For Porth Pathophysiology: Concepts of Altered
Health States 2nd Edition By Ruth Hannon
What are the centers of the pons? What are they responsible for? - ANSWER:
•Pneumotaxic and Apneustic centers - modifications/adjustments
•Chemosensitive center - responds to changes in pH, PaO2 and PaCo2
What is the medulla responsible for? - ANSWER: •Dorsal respiratory group -primarily
inspiration
•Ventral respiratory group - inspiration & expiration
•sends signals via the phrenic nerves to the diaphragm and external and intercostal
muscles
•Autonomic control of rate and rhythm
How is the phrenic nerve involved in respiration? - ANSWER: control each side of the
diaphragm
How is the vagus nerve involved in respiration? - ANSWER: -sensory feedback from
the throat and lungs
-muscles in the neck -inspiration and expiration
-bronchoconstrition or dilation
What muscles do the thoracic nerves (T1-T11) affect? - ANSWER: internal and
external intercostals, and accessory muscles
What are the 3 essential receptors? - ANSWER: 1) Irritant receptors
2) Stretch Receptors
3) J-Receptors
Where are irritant receptors located? - ANSWER: epithelium (inner lining) of the
conducting airways
What do irritant receptors do? - ANSWER: •Sensitive to noxious aerosols, gases, and
particulates in the air
•Initiate the coughing reflex
•Cause bronchioconstriction and increased respiratory rate
Where are stretch receptors located? - ANSWER: smooth muscles of the airways
What do stretch receptors do? - ANSWER: •Sensitive to the volume of air in the
lungs
•Decrease rate and volume when stimulated
Where are J receptors located? - ANSWER: near capilliaries in the aveoli
, What do J receptors do? - ANSWER: •Sensitive to increased pulmonary pressure
•Initiate rapid shallow breathing, slows heart rate, vasodilation
Where are central chemoreceptors located? - ANSWER: near respiratory center
(medulla)
What do central chemoreceptors do? - ANSWER: -measure and sense changes of pH
in CSF (normal = 7.35-7.45)
-responds to high or low pH and adjust respiratory rate and depth
*extremely sensitive
Why measure the pH in CSF? - ANSWER: -pH of CSF reflects pH of arterial blood due
to rapid CO2 diffusion
-CO2 combines with H2O to form carbonic acid -> H+ ions
-acidic = More CO2
Where are peripheral chemoreceptors located? - ANSWER: carotid bodies
What do peripheral chemoreceptors do? - ANSWER: -Sense/monitor PaO2 (oxygen
levels in arterial blood)
-increase respiration when PaO2 is low
*not very sensitive
*become more dominant when central receptors are less sensitive (COPD)
Why are peripheral chemoreceptors located in carotid bodies? - ANSWER: -Close to
lungs
-good to tell how well lungs are working and how efficiently we are bringing O2 into
the body
-Carotid is before the O2 gets distributed to tissues in the rest of body
What is hypercapnia? - ANSWER: Increased PaCO2
What is hypoxemia? - ANSWER: low PaO2
examples of acute and chronic hypercapnia - ANSWER: Acute
•Low ventilation rate (sedation, overdose)
•Pneumonia (limits diffusion, shallow breaths)
Chronic
•COPD - air trapping due to poor elastic recoil and low compliance (stiff lungs)
Examples of acute and chronic hypoxemia - ANSWER: Acute
•Asthma attack
•High altitudes - low o2
Chronic
•Sleep apnea
•Heart valve problems - mixing of venous and arterial blood
Health States 2nd Edition By Ruth Hannon
What are the centers of the pons? What are they responsible for? - ANSWER:
•Pneumotaxic and Apneustic centers - modifications/adjustments
•Chemosensitive center - responds to changes in pH, PaO2 and PaCo2
What is the medulla responsible for? - ANSWER: •Dorsal respiratory group -primarily
inspiration
•Ventral respiratory group - inspiration & expiration
•sends signals via the phrenic nerves to the diaphragm and external and intercostal
muscles
•Autonomic control of rate and rhythm
How is the phrenic nerve involved in respiration? - ANSWER: control each side of the
diaphragm
How is the vagus nerve involved in respiration? - ANSWER: -sensory feedback from
the throat and lungs
-muscles in the neck -inspiration and expiration
-bronchoconstrition or dilation
What muscles do the thoracic nerves (T1-T11) affect? - ANSWER: internal and
external intercostals, and accessory muscles
What are the 3 essential receptors? - ANSWER: 1) Irritant receptors
2) Stretch Receptors
3) J-Receptors
Where are irritant receptors located? - ANSWER: epithelium (inner lining) of the
conducting airways
What do irritant receptors do? - ANSWER: •Sensitive to noxious aerosols, gases, and
particulates in the air
•Initiate the coughing reflex
•Cause bronchioconstriction and increased respiratory rate
Where are stretch receptors located? - ANSWER: smooth muscles of the airways
What do stretch receptors do? - ANSWER: •Sensitive to the volume of air in the
lungs
•Decrease rate and volume when stimulated
Where are J receptors located? - ANSWER: near capilliaries in the aveoli
, What do J receptors do? - ANSWER: •Sensitive to increased pulmonary pressure
•Initiate rapid shallow breathing, slows heart rate, vasodilation
Where are central chemoreceptors located? - ANSWER: near respiratory center
(medulla)
What do central chemoreceptors do? - ANSWER: -measure and sense changes of pH
in CSF (normal = 7.35-7.45)
-responds to high or low pH and adjust respiratory rate and depth
*extremely sensitive
Why measure the pH in CSF? - ANSWER: -pH of CSF reflects pH of arterial blood due
to rapid CO2 diffusion
-CO2 combines with H2O to form carbonic acid -> H+ ions
-acidic = More CO2
Where are peripheral chemoreceptors located? - ANSWER: carotid bodies
What do peripheral chemoreceptors do? - ANSWER: -Sense/monitor PaO2 (oxygen
levels in arterial blood)
-increase respiration when PaO2 is low
*not very sensitive
*become more dominant when central receptors are less sensitive (COPD)
Why are peripheral chemoreceptors located in carotid bodies? - ANSWER: -Close to
lungs
-good to tell how well lungs are working and how efficiently we are bringing O2 into
the body
-Carotid is before the O2 gets distributed to tissues in the rest of body
What is hypercapnia? - ANSWER: Increased PaCO2
What is hypoxemia? - ANSWER: low PaO2
examples of acute and chronic hypercapnia - ANSWER: Acute
•Low ventilation rate (sedation, overdose)
•Pneumonia (limits diffusion, shallow breaths)
Chronic
•COPD - air trapping due to poor elastic recoil and low compliance (stiff lungs)
Examples of acute and chronic hypoxemia - ANSWER: Acute
•Asthma attack
•High altitudes - low o2
Chronic
•Sleep apnea
•Heart valve problems - mixing of venous and arterial blood
