control of ventilation

Question 1

what originates in the medulla oblongata of the brainstem

Answer 1

rhythmic neural impulses responsible for ventilation

Question 2

what does DRG stand for

Answer 2

dorsal respiratory group

Question 3

what does the DRG mainly contain

Answer 3

inspiratory neurons

Question 4

what does VRG stand for

Answer 4

ventral respiratory groups

Question 5

what does VRG mainly contain

Answer 5

intermingled inspiratory and expiratory neurons

Question 6

what provides the main stimulus for inspiration

Answer 6

DRG

Question 7

what are the 2 main nerves sending impulses for respiration

Answer 7

vagus and glossopharyngeal nerves

Question 8

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

Answer 8

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

Question 9

where are vrg neurons located

Answer 9

bilaterally in the medulla in 2 separate nuclei

Question 10

what does the vrg neurons contain

Answer 10

both inspiratory and expiratory neurons

Question 11

where can inspiratory vrg neurons send motor impulses through what nerve

Answer 11

vagus nerve

Question 12

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

Answer 12

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

Question 13

where else does vrg inspiratory neurons transmit impulses

Answer 13

diaphragm and external intercostal muscles

Question 14

where do expiratory vrg send impulses

Answer 14

internal intercostal and abdominal expiratory muscles

Question 15

what complexes are thought to be responsible for RHYTHMIC breathing

Answer 15

botzinger complex and pre-botzinger complex

Question 16

what is the inspiratory ramp signal

Answer 16

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

Question 17

what does the ramp signal lead to

Answer 17

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

Question 18

what part of the brain promotes rhythmic breathing

Answer 18

the pons

Question 19

what are the 2 groups of neurons in the pons

Answer 19

apneustic center

pneumotaxic center

Question 20

what does the apneusis consist of

Answer 20

prolonged insp gasp interrupted by occasional expirations

Question 21

what holds the apneusis center in “check”

Answer 21

vagal and pneumotaxic center impulses

Question 22

what are the pneumotaxic centers

Answer 22

bilateral groups of neurons in the upper pons

Question 23

what do the pneumotaxic centers control

Answer 23

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

Question 24

what do strong pneumotaxic signals cause

Answer 24

shorten the insp time and increase the RR rate

Question 25

what do weak pneumotaxic signals cause

Answer 25

prolonged insp time and large tidal volumes

Question 26

what is the primary function of the pneumotaxic center

Answer 26

limit inspiration and hold apneustic center impulses in check

Question 27

where is the herring-breuer inflation reflex generated

Answer 27

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

Question 28

why are the herring-breur receptors called slowly adapting

Answer 28

bc their activity continues as long as the stimulus persists

Question 29

what happens when the herring-breur receptors are stretched

Answer 29

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

Question 30

when is the herring-breuer reflex activated

Answer 30

large tidal volumes b/w 800-1000ml

Question 31

when is the herring-breuer reflex most important

Answer 31

regulating the respiratory rate and depth during moderate to strenuous exercise

Question 32

what does a sudden collapse of the lung stimulate

Answer 32

strong inspiratory efforts and increases the respiratory rate

Question 33

what is the pathway and reflex that effect hyperpnea

Answer 33

vagus nerve (pathway) and herring-breuer reflex

Question 34

what reflex is responsible for the hyperpnea for pneumothorax

Answer 34

deflation reflex

Question 35

what does head's reflex do

Answer 35

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

Question 36

what do periodic sighs help prevent

Answer 36

alveolar collapse or atelectasis

Question 37

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

Answer 37

heads reflex

Question 38

where are the rapidly adapting irritant receptors

Answer 38

epithelium of the larger conducting airways

Question 39

what sensory nerve fibers do the irritant receptors use

Answer 39

vagal sensory nerve fibers

Question 40

what happens when the irritant receptors are stimulated

Answer 40

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

Question 41

what does a vagovagal reflex cause

Answer 41

laryngospasm, bronchospasm, coughing, and slowing of the heartbeat

Question 42

what types of things can cause a vagovagal reflex response

Answer 42

endotracheal intubation, airway suctioning, and bronchoscopy

Question 43

what are j-receptors

Answer 43

c-fibers in the lung parenchyma near pulmonary capillaries

Question 44

how are j-receptors stimulated

Answer 44

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

Question 45

what does j-receptor stimulation cause

Answer 45

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

Question 46

where are proprioceptors located

Answer 46

muscles, tendons, and joints

Question 47

what happens when the proprioceptors or positional sensors fire off

Answer 47

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

Question 48

what do propriocepters initiate and maintain

Answer 48

increased ventilation during exercise

Question 49

what are muscle spindles

Answer 49

stretch sensing elements located on muscle fibers

Question 50

what stimulates chemoreceptors

Answer 50

increase in blood H+ concentrations NOT co2

Question 51

where do chemoreceptors transmit their impulses

Answer 51

to the medulla

Question 52

what do the chemoreceptors cause

Answer 52

increase in ventilation

Question 53

how does H+ rise in the cerebrospinal fluid

Answer 53

from the reaction b/w dissolved co2 and h2o

Question 54

where are chemoreceptors located

Answer 54

carotid arteries and medulla

Question 55

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

Answer 55

hypoxemia and co2