Muscle And Innervation

Question 0

Treat hypotension

Answer 0

Relax vascular smooth muscle to dilate arterioles
–> reduces vascular resistance to blood flow
Eg L-type calcium channel antagonists (nifedipine)

Question 1

Duchenne muscular dystrophy

Answer 1

Most severe form
Results from an absence of dystrophin protein - mutation on ac chromosome
Lose dystrophin –> lose function of every protein it binds to
Symptoms from age 5, life expectancy 20s
Main cause of death is respiratory/cardiac failure
Progresses from loss of legs –> arms –> trunk
Result of early termination codon –> out of frame
–> very little protein produces
Huge gene –> too large for viral vector unless condensed and all muscle have to be targetted
Utrophin is homologue, tightly regulated as only found at NMJ and in immature muscle –> develop drugs to switch of utrophin gene

Question 2

Treat Asthma

Answer 2

Relax bronchial smooth muscle to dilate airways

B2 adrenoreceptors agonists (salbutamol), ACh muscarinic receptor antagonist eg ipratropium

Question 3

Treat erectile dysfunction

Answer 3

Sildenatil - Viagra
(Blocks second messenger breakdown)
Alters smooth muscle tone, to relax for an erection

Question 4

Scarring of smooth muscle

Answer 4

Loses elastic properties

Eg autoimmune hepatitis –> cirrhosis

Question 5

Muscle cramp

Answer 5

Imbalance of calcium

Question 6

Myocardial infarction

Answer 6

Heart contraction must be synchronised

Otherwise arrhythmic –> myocardial infarction