Pharmacology

Question 1

Where are cell bodies of preganglionic fibres embedded?

Answer 1

In the brainstem

Question 2

Where are the cell bodies of post ganglionic fibres embedded?

Answer 2

In walls of the bronchi and bronchioles

Question 3

What does stimulation of postganglionic cholinergic fibres do to bronchial smooth muscle? what is it mediated by?

Answer 3

It contracts smooth muscle, mediated by M3 muscarinic ACh receptors on ASM cells

Question 4

True/false, mucous secretion increases after stimulation of postganglionic cholinergic fibres

Answer 4

True

Question 5

What does stimulation of postganglionic NONCHOLINERGIC fibres cause? and what is it mediated by?

Answer 5

It causes bronchial smooth muscle relaxation, mediated by nitric oxide (NO) and vasoactive intestinal peptide (VIP)

Question 6

True/false, mucous secretion increases during the sympathetic division

Answer 6

False, mucous secretion decreases

Question 7

True/false, there is no sympathetic innervation in bronchial smooth muscle?

Answer 7

True

Question 8

Which interleukins cause mast cells to express IgE receptors?

Answer 8

IL-4 and IL-13

Question 9

What do activated mast cells release?

Answer 9

Histamines, chemokines, Leukotrienes

Question 10

In sympathetic division, what happens to bronchial smooth muscle when stimulated?

Answer 10

Relaxation

Question 11

Which interleukin causes eosinophils to differentiate and proliferate?

Answer 11

IL-5

Question 12

True/false, mucous secretion is increased when the sympathetic division is active

Answer 12

false, it is decreased as mucociliary clearance is increased

Question 13

Which adreno-receptor mediates bronchial smooth muscle relaxation and what is it activated by?

Answer 13

Beta2-adrenoceptors (β2-ADR) on ASM cells activated by adrenaline released from the adrenal gland

Question 14

Which adrenoreceptor mediates decreased mucous secretion?

Answer 14

Beta2-adrenoreceptor on gland (goblet) cells

Question 15

Which adrenal-receptor mediates vascular smooth muscle contraction?

Answer 15

Alpha1-adrenoreceptors

Question 16

Where does calcium come from that binds to calmodulin?

Answer 16

From extra-cellular, into the cell through Ca channels and (mostly from) the sarcoplasmic reticulum

Question 17

What does the release of calcium into the cytosol cause in smooth muscle cells?

Answer 17

Contraction

Question 18

What happens when GPCR is activated by a transmitter/hormone in smooth muscle?

Answer 18

Phospholipase C is activated by a G protein subunit and it converts PIP2 into IP3 and DAG. IP3 then binds to its receptor on the sarcoplasmic reticulum, its receptor is a calcium channel, so calcium is released into cytosol

Question 19

What happens that initiates contraction of smooth muscle?

Answer 19

Phosphorylation of the regulatory myosin light chain(MLC) in the presence of elevated intracellular Ca (and ATP)

Question 20

What has to happen to initiate relaxation of smooth muscle?

Answer 20

Relaxation results from dephosphorylation of MLC by myosin phosphatase which has constitutive activity

Question 21

What does relaxation require or Ca levels in the cytosol?

Answer 21

Relaxation requires return of intracellular Ca2+ concentration to basal level – achieved by primary and secondary active transport

Question 22

Which hormone relaxes airway smooth muscles?

Answer 22

Adrenaline

Question 23

What does cAMP do in cells?

Answer 23

Activates kinases

Question 24

Which enzyme degrades cAMP to switch off the signalling pathway?

Answer 24

PDE - phosphodiesterase which degrades cAMP into 5’AMP