Lecture 9

Question 1

Sympathomimetics

Answer 1

Alpha and beta adrenoreceptor agonists

Adrenaline
Beta 1 - Dobutamine - cardiogenic shock
Beta 2 - salbutomal - Asthma

Question 2

Adrenoreceptor antagonists

Answer 2

alpha 1 -
Prazosin
Anti-hypertensive
Vasodilation

Beta adrenoreceptor
Propranolol
Decrease HR and force of contraction - B1
Bronchoconstriction - B2

Atenolol - B1 selective so less risk of bronchconstriction

Question 3

Parasympathetic NS

Answer 3

Spinal nerves exit at the cranial and sacral regions

Question 4

Sympathetic NS

Answer 4

Spinal nerves exit the thoracic and lumbar region

Question 5

Sympathetic pre and post ganglion

Answer 5

Pre ganglion - short and myelinated
- synapses on Ach nicotinic receptor
Post ganglion - long and unmyelinated
- noradrenaline receptors but can be Ach or ATP

Question 6

Parasympathetic pre and post ganglion

Answer 6

Pre ganglion - long and myelinated 
- synapses on Ach nicotinic receptor 
- vagus nerve 
Post ganglion - short and unmyelinated 
- muscarinic Ach receptors (GPCR) 
- on epicardium surface or within myocardium at SAN and AVN

Question 7

Noradrenaline inotropic effect

Answer 7

Acts on beta 1 receptors in the myocardium

• increased cAMP
• activates PKA

1. Phosphorylation of Ca2+ channel increases Ca2+ entry during plateau
2. Increased uptake of Ca2+ in sarcoplasmic reticulum
3. More cross bridges can form increasing contraction

Question 8

Pharmacological dose of adrenaline

Answer 8

• activates alpha 1 receptors

- causes vasoconstriction

Question 9

Circulating adrenaline

Answer 9

Acts on beta 2

- vasodilation