Regulation of Respiration

Question 1

How is it that that the PO2 and the PCO2 in the arterial blood waver minimally?

Answer 1

The nervous system normally adjusts the rate and depth of Alveolar Ventilation almost exactly to the demands of the body

Question 2

Baseline respiratory rate is controlled by the_____

Answer 2

CNS Respiratory center in the brainstem, specifically the Medulla and Pons

Question 3

The sensory component of the vagus and glossopharyngeal nerves terminate on the

Answer 3

DRG

Question 4

What is the DRG responsible for

Answer 4

rhythmical inspiratory discharges that maintain the basic rhythm of subconscious, relaxed breathing

Question 5

The inspiratory ramp signal is transmitted to where

Answer 5

to the inspiratory muscles (mostly diaphragm)

Question 6

Pneumotaxic Center transmits signals to the _____ in the medulla.

Answer 6

lower inspiratory centers

Question 7

Primary function of the Pneumotaxic center

Answer 7

primary role is to control the “switch off” point of the inspiratory ramp, controlling the duration of the filling phase of the lung cycle by either prolonging it or cutting it short.

Question 8

The VRG is essentially totally inactive during ________respiration and does not seem to contribute to the basic rhythmical respiration from the DRG.

Answer 8

normal, relaxed

Question 9

The chemosensitive area is directly sensitive to changes in concentration of ______

Answer 9

H+ and CO2

Question 10

_____ do not readily cross the blood brain barrier (BBB), but _____ can diffuse across as if the BBB does not exist.

Answer 10

H+ ions; CO2

Question 11

An elevated concentration of H+ and CO2 triggers the Chemosensitive Area to activate the DRG, which results in an increase in ______

Answer 11

alveolar ventilation (increased respiratory rate).

Question 12

Increased ventilation rate results in __________, causing what?

Answer 12

increased exhalation of CO2; normalizing PCO2 with time

Question 13

Although we do not completely understand how a low arterial PO2 triggers the glomus cells, we believe Oxygen-sensitive Potassium Channels ______ when the PO2 drops.

Answer 13

Close

Question 14

At the onset of exercise, the alveolar ventilation rate increases almost instantaneously, without ____

Answer 14

an initial increase in PCO2

Question 15

WIth exercise the PCO2 will initially _____

Answer 15

drop, almost as if in “anticipation” of the expected increase in PCO2

Question 16

Once neurogenic control of respiration stops (when exercise stops), _____ control of respiration takes over.

Answer 16

chemical

Question 17

Examples of higher brain centers

Answer 17

Intentional hyper/hypoventilation
Cerebral edema from injury, infection, etc
Pain can increase the respiratory rate
Emotional/Limbic system input
Hypothalamic input (ex: hypothermia)

Question 18

Which receptors are protective against over inflation?

Answer 18

Pulmonary Stretch Receptors

Question 19

Stimulated with an irritant in the airway is present

Answer 19

Airway irritant receptors

Question 20

How is ventilation shifted with exercise?

Answer 20

The neurogenic factor shifts the curve about 20-fold in the upward direction so that ventilation almost matches the rate of CO2 release, thus keeping the arterial PCO2 near its normal value