Lecture 25: Regulation of Respiration

Question 1

What makes up the medullary respiratory centers?

Answer 1

dorsal respiratory group

ventral respiratory group

Question 2

Where is the dorsal respiratory group located?

Answer 2

nucleus of the tracts solitarius

Question 3

What makes up the pontine respiratory centers?

Answer 3

apneustic center

pneumotaxic center

Question 4

what does the dorsal respiratory group do?

Answer 4

sets basic rhythm of respiration

Question 5

What are most of the neurons of the dorsal respiratory group located?

Answer 5

in the nucleus of the tracts solitarius (NTS) and medulla reticular substance

Question 6

What nerves are the sensory termination of the NTS?

Answer 6

vagal and glossopharyngeal

Question 7

Where does the NTS receive information from?

Answer 7

peripheral chemoreceptors
baroreceptors
several types of receptors in the lungs

Question 8

During heavy respiration the rate of the increase ramp signal _____ rapidly

Answer 8

increase

Question 9

What is the ramp signal?

Answer 9

nervous signals transmitted to the inspiratory muscles during normal respiration

Question 10

What is the usual method for controlling rate of respiration?

Answer 10

• Control limiting point at which ramp suddenly ceases
• The earlier the ramp ceases, the shorter the duration of inspiration and
• Thus, the primary function of the PRG (Pneumotaxic center) is to control the “switch-off” point of the inspiratory ramp.
• A strong PRG signal results in 30-40 breaths per minute.
• A weak PRG signal results in 3-5 breaths per minute.

Question 11

Where is the pneumotaxic center located

Answer 11

superior pons

Question 12

What does the pneumotaxic center do?

Answer 12

mainly controls rate and depth of breathing, transmit signals to the inspiratory center (DRG)

Question 13

Lesions to the PRG result in the loss of what?

Answer 13

ability to turn off inspiration

Question 14

Where is the apneustic center located?

Answer 14

inferior pons

Question 15

Loss of function in the apneustic center results in what?

Answer 15

prolonged inspiratory gasping

Question 16

What is the normal function of the apneustic center?

Answer 16

limit lung expansion

Question 17

Where is the ventral respiratory group located?

Answer 17

ventrolateral portion of the medulla

Question 18

What is the pre botzinger complex?

Answer 18

small area in the rostral part of the VRG

Question 19

What does the pre botzinger complex do?

Answer 19

believed to be the site which generates the timing of the respiratory rhythm

Question 20

What does the hering-breuer reflex do?

Answer 20

protective mechanism to prevent excess inflation of the lungs

Question 21

An increase in carbon dioxide (hypercapnia) or a decease in oxygen (hypoxia) results in what?

Answer 21

decreased activity in most neurons

Question 22

Chemoreceptors _____ their rate of activity when hypoxia or hypercapnia occur

Answer 22

increase

Question 23

What are the two types of chemoreceptors?

Answer 23

central

peripheral

Question 24

What chemoreceptor is located on the ventral surface of the medulla and indirectly sensitive to carbon dioxide levels in blood (based on pH)

Answer 24

central

Question 25

What chemoreceptor is sensitive to concentrations of oxygen, carbon dioxide, and hydrogen ions?

Answer 25

peripheral

Question 26

What chemoreceptors are the receptor sin the aortic arch and the carotid body receptors?

Answer 26

peripheral

Question 27

How do the kidneys increase blood bicarbonate levels

Answer 27

• reduces plasma and CSF (H+)

- bicarbonate ions diffuse through the blood brain barrier

Question 28

What are peripheral receptors more sensitive to?

Answer 28

changes in oxygen levels in the blood

Question 29

What are peripheral receptors less sensitive to?

Answer 29

changes in plasma concentrations of carbon dioxide and hydrogen ions