Pharmacology Of The Uterus

Question 0

Does progesterone induce or inhibit contraction of the myometrium?

Answer 0

Inhibit

Question 1

What are the 3 layers of the myometrium?

Answer 1

Outer longitudinal fibres
Middle figure 8 shaped fibres
Inner circular fibres

Question 2

Does oestrogen induce or inhibit contraction of the myometrium?

Answer 2

Induce

Question 3

What is the innervation of the myometrium?

Answer 3

Sympathetic nerves
Contain both alpha and beta receptors
Alpha - contraction
Beta 2 - relaxation

Question 4

How is synchronous contraction achieved in the myometrium?

Answer 4

Due to pacemaker mechanism –> interstitial cells of cajal (ICCs) which initiate and coordinate contraction

Question 5

Mechanism of contraction in the myometrium

Answer 5

Slow depolarisation produced by ICCs
Slow waves modulated by neuro transmitters
Electrical activity spreads via gap junction (connexins) to smooth muscle cells
Activates action potentials in smooth muscles cells which activates VGCCs which leads to increase in intercellular calcium and hence contraction

Question 6

What is oxytocin used for?

Answer 6

Induction of labour at term

Question 7

What are prostaglandins used for?

Answer 7

Induction of labour before term/abortion

Post partum bleeding

Question 8

What can be used to prevent premature labour?

Answer 8

Beta 2 adrenoceptor agonist such as salbutamol

Calcium channel antagonist such as nifedipine

Question 9

Give non example of an oxytocin

Answer 9

Atosiban