Control of ventilation- chemoreceptors

Question 1

how respiratory motor movements are affected by the CNS

Answer 1

nerves act on skeletal muscle and contract for inspiration and relax for expiration. they reside in ill defined centres located in the pons and medulla. subconscious. dependent on signalling from brain

Question 2

two classes of chemoreceptors

Answer 2

central and peripheral

Question 3

nerves that act on external intercostal muscles

Answer 3

intercostal

Question 4

how do peripheral chemoreceptors become important during hypoxia

Answer 4

respond to changes in oxygen partial pressure so are critical during hypoxia

Question 5

dorsal respiratory group works on

Answer 5

inspiratory muscles via phrenic and intercostal muscles

Question 6

ventral respiratory group works on

Answer 6

tongue, pharynx, larynx, expiratory

Question 7

central chemoreceptors

Answer 7

found in medulla, respond to hydrogen ions, give primary ventilatory drive

Question 8

peripheral chemoreceptors

Answer 8

found in carotid and aortic bodies, respond to PO2 and plasma, secondary ventilatory drive

Question 9

increased partial pressure of carbon dioxide in blood is called

Answer 9

hypercapnea

Question 10

central chemoreceptors

Answer 10

found in medulla, respond to hydrogen ions and PCO2 in plasma, give primary ventilatory drive

Question 11

how does CO2 affect acid-base balance

Answer 11

broken down into bicarbonate and hydrogen which leaves hydrogen ions which alter pH

Question 12

how can respiratory system create acid base disturbances

Answer 12

if you start off with normal resting level of hydrogen ion levels in plasma and this changes to abnormal levels by hyper or hypo ventilation

Question 13

how can respiratory system compensate for acid base disturbances

Answer 13

if plasma pH falls then ventilation will be stimulated, if plasma pH increases then ventilation will be inhibited

Question 14

pH is proportional to

Answer 14

bicarbonate over carbon dioxide