control of ventilation

Question 1

what does ventilatory control require the stimulation of?

Answer 1

skeletal muscle of inspiration

Question 2

what does ventilatory control occurs via?

Answer 2

phrenic (to diaphragm) and intercostal nerves (to intercostal muscles)

Question 3

what are respiratory centres

Answer 3

pons and medulla

Question 4

is ventilatory control subconcious?

Answer 4

yes

Question 5

what is ventilatory control dependent on?

Answer 5

signalling from the brain

Question 6

what do resp centres have their rhythm modulated by?

Answer 6

emotion
voluntary over-ride
mechano-sensory input from the thorax
chemical composition of the blood- detected by chemoreceptors

Question 7

what are the functions of central chemoreceptors in the medulla?

Answer 7

Detect changes in [H+] in CSF around brain

Cause reflex stimulation of ventilation following rise in [H+]

Question 8

what is ventilation inhibited by?

Answer 8

a decrease in arterial PCO2

Question 9

what crosses the blood brain barrier if arterial PCO2 increases?

Answer 9

carbon dioxide not H+

Question 10

where does central chemoreceptors monitor the the PCO2 indirectly

Answer 10

cerebrospinal fluid

Question 11

does decreased arterial PCO2 speed up or slow ventilation rate?

Answer 11

slows

Question 12

what increases ventilation in response to increased arterial PCO2?

Answer 12

feedback via resp centres

Question 13

where are peripheral chemoreceptors located?

Answer 13

carotid and aeortic bodies

Question 14

what is the function of peripheral chemoreceptors?

Answer 14

detect changes in arterial PO2 and H+

Cause reflex stimulation of ventilation following significant fall in arterial PO2 (consider haemoglobin dissociation) or a rise in [H+]

Question 15

does peripheral chemoreceptors respond to arterial PO2 or oxygen

Answer 15

PO2

Question 16

what does an increase in H+ usually follow a rise in?

Answer 16

arterial PCO2

Question 17

does changes in the plasma pH alter ventilation? via what pathway?

Answer 17

yes via the peripheral chemoreceptor pathways

Question 18

what happens to ventilation if plasma pH falls ?

Answer 18

ventilation will be stimulated (acidosis)

Question 19

where would you find central chemoreceptors?

Answer 19

medulla

Question 20

what are the main differences between central and peripheral chemoreceptors?

Answer 20

location- medulla / carotid and aortic bodies

response - directly to H+ / primary to plasma and PO2

ventilatory drive - primary / seconday

Question 21

do central chemoreceptors respond to changes in plasma H+?

Answer 21

no

Question 22

what controles our rate of breathing and depth of respiration?

Answer 22

respiratory centres

Question 23

what are the two respiratory centres?

Answer 23

pons and medulla

Question 24

what are the different types of respiration groups?

Answer 24

dorsal
ventral
pontine

Question 25

what are dorsal resp groups for?

Answer 25

output primarily to inspiratory muscles

Question 26

whats the ventral resp group for?

Answer 26

output to expiratory, some insp,

Question 27

where is resp rhythms modulated by emotion?

Answer 27

limbic system in the brain

Question 28

which chemoreceptor is less sensitive to CO2?

Answer 28

peripheral

Question 29

what is CSF

Answer 29

interstitial fluif in the brain and is very heavily monitored

Question 30

when is there a reflex simulation of ventilation in central chemoreceptors?

Answer 30

following a rise of H+

Question 31

what is hypercapnea?

Answer 31

rise of PCO2

Question 32

what protects the csf?

Answer 32

blood brian barrier

Question 33

what cant pass through blood brain barrier

Answer 33

ions

Question 34

what will happen to resp rate in an anaemic patient with a blood oxygen content half the normal value

Answer 34

stay the same

Question 35

can you override involuntary stimuli such as arterial PCO2 or H+

Answer 35

no

Question 36

how is ventilation inhibited?

Answer 36

increase in arterial PO2 or a decrease in arterial PCO2

Question 37

when is respiration intentionally inhibited?

Answer 37

during swallowing