Lecture 15 Unit 2 Flashcards

1
Q

how do respiratory and skeletal muscles contract?

A

by the action of motor neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

unlike other skeletal muscles, the respiratory muscle are under both______?

A

automatic and voluntary control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what does automatic respiratory muscle control depend on?

A

groups of inspiratory and expiratory neurons in the medulla oblongata

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

where are phrenic motor neurons located?

A

C3-C5 spinal segments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

where are inspiratory neurons localized into?

A

a functional group known ad the dorsal respiratory group (DRG)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

where are expiratory neurons located?

A

ventral respiratory group (VRG)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are pre motor neurons?

A

they synapse on and excite motor neurons to respiratory muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

since breathing is rhythmic, what does it depend on?

A

“pacemaker like” activity in brain stem neurons that alternately turn the inspiratory neurons on and off

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

when are expiratory neurons activated?

A

when breathing activity must be increased

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what happens in the pneumotaxic center

A

negative effect (inhibition)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what happens in the apneustic area?

A

positive effect (stimulation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

where are the DRG and VRG located in the brain

A

pons and medulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the various specialized receptors that inform the neurons about the body’s needs for ventilation?

A
  1. pulmonary stretch receptors
  2. central chemoreceptors
  3. peripheral chemoreceptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

where are pulmonary stretch receptors located?

A

in the msotth msucle that lines some of the large conducting airways, bronchi, and bronchioles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what do pulmonary stretch receptors respond to?

A

when bronchioles are inflated or stretched

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

the pulmonary stretch receptors are innervated by axons from what nerve?

A

vagus (CN X)

17
Q

what is the influence of stretch receptors?

A

the DRG switches from inspiration to expiration more quickly - lung inflation stops and lung deflation begins

18
Q

where are central chemoreceptors located

A

beneath the ventral surface of the medulla

19
Q

what do central chemoreceptors respond to?

A

low pH and high P(CO2) in CSF

20
Q

what is low pH in the CSF the result of?

A

CO2 that diffuses into the CSF from the blood and forms hydrogen ions

21
Q

where are peripheral chemoreceptors located?

A

in the aortic arch and in the carotid sinus

22
Q

what do peripheral chemoreceptors mainly respond to?

A

low oxygen levels in arterial blood

23
Q

what do peripheral chemoreceptors weakly respond to?

A

low pH and high CO2 levels

24
Q

peripheral chemoreceptors are innervated by axons that travel from where?

A

glossopharyngeal nerve and vagus nerve (cranial nerves IX and X)

25
Q

where do axons that control peripheral chemoreceptors synapse?

A

on neurons in the DRG