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Flashcards in control of ventilation Deck (55)
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1
Q

what originates in the medulla oblongata of the brainstem

A

rhythmic neural impulses responsible for ventilation

2
Q

what does DRG stand for

A

dorsal respiratory group

3
Q

what does the DRG mainly contain

A

inspiratory neurons

4
Q

what does VRG stand for

A

ventral respiratory groups

5
Q

what does VRG mainly contain

A

intermingled inspiratory and expiratory neurons

6
Q

what provides the main stimulus for inspiration

A

DRG

7
Q

what are the 2 main nerves sending impulses for respiration

A

vagus and glossopharyngeal nerves

8
Q

where do the vagus and glossopharyngeal nerves transmit the sensory impulse to and from

A

to the DRG from the lungs, airways, peripheral chemoreceptors, and joint proprioceptors

9
Q

where are vrg neurons located

A

bilaterally in the medulla in 2 separate nuclei

10
Q

what does the vrg neurons contain

A

both inspiratory and expiratory neurons

11
Q

where can inspiratory vrg neurons send motor impulses through what nerve

A

vagus nerve

12
Q

what does sending inspiratory vrg neurons send motor impulses through the vagus nerve

A

laryngeal and pharyngeal muscles, abducting the vocal cords, and increasing the diameter of the glottis

13
Q

where else does vrg inspiratory neurons transmit impulses

A

diaphragm and external intercostal muscles

14
Q

where do expiratory vrg send impulses

A

internal intercostal and abdominal expiratory muscles

15
Q

what complexes are thought to be responsible for RHYTHMIC breathing

A

botzinger complex and pre-botzinger complex

16
Q

what is the inspiratory ramp signal

A

the signal firing rate increases gradually after expiration ceases, creating a smoothly increasing ramp signal

17
Q

what does the ramp signal lead to

A

progressively stronger contraction of inspiratory muscles, smoothly and gradually filling the lungs instead of an abrupt insp gasp

18
Q

what part of the brain promotes rhythmic breathing

A

the pons

19
Q

what are the 2 groups of neurons in the pons

A

apneustic center

pneumotaxic center

20
Q

what does the apneusis consist of

A

prolonged insp gasp interrupted by occasional expirations

21
Q

what holds the apneusis center in “check”

A

vagal and pneumotaxic center impulses

22
Q

what are the pneumotaxic centers

A

bilateral groups of neurons in the upper pons

23
Q

what do the pneumotaxic centers control

A

the off-switch point of the drg inspiratory ramp signal and control the length of inspiration

24
Q

what do strong pneumotaxic signals cause

A

shorten the insp time and increase the RR rate

25
Q

what do weak pneumotaxic signals cause

A

prolonged insp time and large tidal volumes

26
Q

what is the primary function of the pneumotaxic center

A

limit inspiration and hold apneustic center impulses in check

27
Q

where is the herring-breuer inflation reflex generated

A

stretch receptors located in the smooth muscle of large and small airways

28
Q

why are the herring-breur receptors called slowly adapting

A

bc their activity continues as long as the stimulus persists

29
Q

what happens when the herring-breur receptors are stretched

A

they send inhibitory impulses through the vagus nerve to the DRG neurons which stops further inspiration

30
Q

when is the herring-breuer reflex activated

A

large tidal volumes b/w 800-1000ml

31
Q

when is the herring-breuer reflex most important

A

regulating the respiratory rate and depth during moderate to strenuous exercise

32
Q

what does a sudden collapse of the lung stimulate

A

strong inspiratory efforts and increases the respiratory rate

33
Q

what is the pathway and reflex that effect hyperpnea

A

vagus nerve (pathway) and herring-breuer reflex

34
Q

what reflex is responsible for the hyperpnea for pneumothorax

A

deflation reflex

35
Q

what does head’s reflex do

A

maintains large tidal volumes during exercise and may be involved in periodic deep sighs during quiet breathing

36
Q

what do periodic sighs help prevent

A

alveolar collapse or atelectasis

37
Q

what reflex may be involved in stimulating the first breaths of a new born infant

A

heads reflex

38
Q

where are the rapidly adapting irritant receptors

A

epithelium of the larger conducting airways

39
Q

what sensory nerve fibers do the irritant receptors use

A

vagal sensory nerve fibers

40
Q

what happens when the irritant receptors are stimulated

A

they cause bronchoconstriciton, coughing, sneezing, tachypnea, and narrowing of the glottis

41
Q

what does a vagovagal reflex cause

A

laryngospasm, bronchospasm, coughing, and slowing of the heartbeat

42
Q

what types of things can cause a vagovagal reflex response

A

endotracheal intubation, airway suctioning, and bronchoscopy

43
Q

what are j-receptors

A

c-fibers in the lung parenchyma near pulmonary capillaries

44
Q

how are j-receptors stimulated

A

alveolar inflammatory processes (pneumonia) pulmonary vascular congestion (chf), and edema

45
Q

what does j-receptor stimulation cause

A

rapid shallow breathing, dyspnea, and expiratory narrowing of the glottis

46
Q

where are proprioceptors located

A

muscles, tendons, and joints

47
Q

what happens when the proprioceptors or positional sensors fire off

A

they send impulses to the medullary centers which increases inspiratory activity and hyperpnea

48
Q

what do propriocepters initiate and maintain

A

increased ventilation during exercise

49
Q

what are muscle spindles

A

stretch sensing elements located on muscle fibers

50
Q

what stimulates chemoreceptors

A

increase in blood H+ concentrations NOT co2

51
Q

where do chemoreceptors transmit their impulses

A

to the medulla

52
Q

what do the chemoreceptors cause

A

increase in ventilation

53
Q

how does H+ rise in the cerebrospinal fluid

A

from the reaction b/w dissolved co2 and h2o

54
Q

where are chemoreceptors located

A

carotid arteries and medulla

55
Q

what are the common carotid arteries and the aortic arch indirectly sensitive to

A

hypoxemia and co2