Protective Receptors

Question 1

What are nasal receptors sensitive to?

Answer 1

Irritating stimuli mechanical and chemical

Question 2

What does nasal receptor stimulation cause?

Answer 2

Sneezing/apnoea
Bradycardia
Selective vasoconstriction

Question 3

What does laryngeal receptor stimulation cause?

Answer 3

Coughing
slow deep breathing/apnoea
laryngospasm
bradycardia
vasoconstriction

Question 4

What does tracheal receptor stimulation cause?

Answer 4

coughing
slow deep breathing/apnoea
bradycardia
selective vasoconstriction

Question 5

What are the medical importance of these responses?

Answer 5

Prevention of aspiration
intubation and endoscopic procedures
diving reflex
drowning
treatment of supra-ventricular tachycardia

Question 6

What are the 3 intrapulmonary receptors?

Answer 6

Irritant receptors
J receptors
Pulmonary stretch receptors

Question 7

Where are irritant receptors located?

Answer 7

Airway epithelium, myelinated vagal afferents

Question 8

What are irritant receptors sensitive to?

Answer 8

Mechanical and chemical simulation
histamine

Question 9

what does irritant receptor stimulation cause?

Answer 9

Hyperpnoea
Increased tidal volume
bronchoconstriction

Question 10

Where are J receptors located?

Answer 10

Beside pulmonary capillaries
nonmyelinated vagal afferents

Question 11

What are J receptors sensitive to?

Answer 11

Irritant chemicals in pulmonary arterial blood

Question 12

What does J receptor stimulation cause?

Answer 12

Rapid shallow breathing
apnoea
hypotension
bradycardia

Question 13

Where are pulmonary stretch receptors located?

Answer 13

In airway smooth muscle, myelinated vagal afferents

Question 14

What are pulmonary stretch receptors sensitive to?

Answer 14

Lung distension

Question 15

What does stimulation of pulmonary stretch receptors cause?

Answer 15

Inhibition of inspiration
dilation of airways
tachycardia
vasoconstriction

Question 16

What happens to these receptors in a vagotomy?

Answer 16

Low frequency, high tidal volume patterne of ventilation

Question 17

What do cholinergic nerves travel via?

Answer 17

Via vagus to parasympathetic ganglia within airway walls

Question 18

What do postganglionic fibres run to?

Answer 18

airway smooth muscle, epithelium and submucosal glands

Question 19

Where are vagal fibres most dense?

Answer 19

Large airways reduce peripherally

Question 20

What does electrical stimulation of vagus cause?

Answer 20

Bronchoconstriction
Mucus secretion

Question 21

What drug can prevent bronchoconstriction ?

Answer 21

muscarinic antagonist (M3 subtype bronchoconstriction)

Question 22

What do muscarinic receptor antagonists cause in low normal vagal tone?

Answer 22

Minor bronchodilation

Question 23

What do anti-muscarinic agents cause?

Answer 23

Beta2 and M2 receptors on pre-junctional efferent vagal fibres inhibit ACh release

Question 24

What sympathetic receptor is expressed on airway?

Answer 24

Beta2 adrenergic receptors

Question 25

What does adrenaline and noradrenaline cause?

Answer 25

Bronchodilation

Question 26

What is the only neural bronchodilator pathways in humans?

Answer 26

Inhibitory NANC (NO mediated)

Question 27

What does excitatory NANC cause?

Answer 27

Bronchoconstriction (neuropeptide mediated)

Question 28

How is astham treated?

Answer 28

Beta2 agonists - bronchodilation

Question 29

How is COPD treated?

Answer 29

Anti-muscarinics antagonists - bronchodilation

Question 30

What does increased drive to vagal motor tone from airway irritant receptors cause?

Answer 30

Inflammatory mediators
epithelial damage