Autonomics of Respiration

Question 1

Sympathetic Receptors

Answer 1

1. Nicotinic receptors (ACh) –> located on adrenal medulla –> cause actiavtion and release of Epi
2. Alpha 1 receptors (Epi=NE»»iso) –> contraction of VSM –> stimulates phospholipase C –> IP3 –> elevated Ca2+
3. Beta-2 receptors (iso>Epi»»>NE) –> relaxation of smooth muscle, glycogenolysis (Epi is natural stimulus for B-2 receptors in lung)

Question 2

Location in body with greatest amount of nicotinic receptors?

Answer 2

Skeletal muscle –> cause contraction

Question 3

Parasympathetic Receptors

Answer 3

1. Nicotinic receptors (ACh) –> located on postsynaptic surface of postganglionic nerve –> causes activation of postganglionic nerve
2. Muscarinic receptors (ACh) –> all end-organ responses –> activate PLC or suppress AC

Question 4

Where do parasympathetic nerves in lung originiate?

Answer 4

Medulla Oblongata

Question 5

Where do sympathetic nerves to lung originate?

Answer 5

Thoracic Spine

Question 6

Sympathetics function

Answer 6

constrict vasculature via alpha 1 receptor (decongestants)

dilate bronchioles via beta-2 receptors

Question 7

Parasympathetics function

Answer 7

constrict bronchioles via muscarinic receptors and increase secretions
(anti-muscarinics dilate bronchioles –> “tropiums”)

Question 8

Most common initial treatment for asthma?

Answer 8

Albuterol (SABA)

Question 9

Beta-2 Agonists

Answer 9

All given via inhalation –> restricts activity to lung tissue –> good
Major S.E. = tachycardia and palpitations (beta-1), tremor (beta-2), headache

Question 10

Epi

Answer 10

• constricts vasculature, relaxes bronchioles
• used for anaphylaxis
• metabolized by MAO, COMT

Question 11

Iso

Answer 11

• synthetic catecholamine stimulated beta-receptors
• relaxes beta-2 receptors
• metabolizes COMT not MAO

Question 12

Ephedrine

Answer 12

partial beta-2 agonists (treat bronchospasm)

- releases NE which has direct effects (increase BP, relaxes bronchioles)

Question 13

Pseudoephedrine

Answer 13

stereoisomer of ephedrine commonly used to treat nasal congestion

Question 14

Phenylephrine

Answer 14

alpha 1 agonist

Question 15

Muscarinic receptor antagonists

Answer 15

Ipratropium, tiotropium

bronchodilator and dries up secretions

Question 16

Phosphodiesterase 4 inhibitor

Answer 16

Roflumilast –> bronchodilator for COPD –> improves FEV1

major side effect –> Nausea

Question 17

alpha blockers

Answer 17

cause mucosal stuffiness –> block alpha 1 receptors in vasculature

Question 18

beta blockers

Answer 18

increase airway resistance (bronchoconstriction) –> particularly in asthmatics (olol’s)

Question 19

Based on efficacy of anatagonists, which of following are likely to cause asthma?

Answer 19

NOT HISTAMINE!!!!

- leukotriene more likely

Question 20

Zafirlukast effective for asthma, whats causing asthma?

Answer 20

Leukotriene

Question 21

If diphenhydramine is not effective in asthma, asthma most likely?

Answer 21

Not caused by histamine!!!!

Question 22

Which is best for treating anaphylaxis

Answer 22

EPI –> constricts vasculature via alpha 1 and relaxes bronchioles via beta-2

Question 23

Best decongestant?

Answer 23

Alpha 1 agonist –> phenylephrine

Question 24

Most likely mechnism for beneficial effects of ipratropium in COPD?

Answer 24

bronchodilation (little)

suppressing secretions