Lung & Airway Receptors

Question 1

What receptors are found in the nose, nasopharynx & larynx? What do they do?

Answer 1

Chemo & mechano receptors

Sense & monitor flow, stimulation of there inhibit central controller eg. medullary respiratory centre

Question 2

What are the receptors in the pharynx stimulated by? And what does it cause?

Answer 2

Has receptors that appear to be activated by swallowing- respiratory activity stops during swallowing thereby protecting against risk of aspiration of food or liquid

Question 3

What are the 3 lung receptors?

Answer 3

Slow adapting stretch receptors SASRs
Rapidly adapting stretch receptors RASRs
J receptors

Question 4

Describe SASRs? Where are they found? What are they activated by? What do they do?

Answer 4

Myelinated
Found in smooth muscle airway
Activated by lung distension (stretching of smooth muscle in the airway)
High activity inhibits further inspiration & begins expiration
(ENDS INSPIRATION, STARTS EXPIRATION)

Question 5

Describe RASRs? Where is it found? What is it activated by? What does it produce & cause?

Answer 5

Myelinated 
Found between airway epithelium
Activated by lung distension and irritants
Produce brief burst of energy
High activity causes bronchoconstriction

Question 6

Describe J receptors ? Where is it found? What does it respond to? What does it produce & cause?

Answer 6

Non myelinated
Found in capillary walls or interstitium
Respond to increased lung interstitial pressure because of fluid
Activation = increased respiration
Results = rapid breathing (tachypena), shallow breathing , bronchoconstriction

Question 7

What are the 2 types of chemoreceptors?

Answer 7

Peripheral and central

Question 8

Peripheral chemoreceptors
Where is it located?
What does it detect?
When is it activated?

Answer 8

Located in aortic arch & carotid sinus/body
(Bifurcation of common carotid arteries, high in neck)

Detect change in ppO2 (and [H+])

Only activated when ppO2 is below 60mmHg
Not sensitive to small reductions

Question 9

Why is the carotid sinus/bodies more key?

Answer 9

Measure/monitor oxygen supply to the brain

Question 10

Central chemoreceptors
Where is it located?
What do they detect?

Answer 10

Medulla

Detect changes in ppCO2 (constitutes to respiratory drive)

Changes in pH (H+)

Question 11

How do changed in in CO2 affect resp rate and why?

Answer 11

Constitutes to resp drive

Small changes In CO2 are detected and increase resp rate to compensate

Question 12

How is pH detected by the central chemoreceptors?

Answer 12

CO2 can cross blood brain carrier, H+ can’t
CO2 diffuses info cerebra spinal fluid (CSF)

CO2 + H2O —-> H2CO3 —-> HCO3- + H+

More/less H+ ions enabling central chemoreceptors receptors to detect pH change and increase ventilation

Question 13

Peripheral vs central
Which one is a faster and slower response?
Which is more/less important for breathing?

Answer 13

Peripheral-faster, less important for breathing

Central-slower, more important for breathing