Pelvic Floor

Question 1

Direction of levator ani fibres

Answer 1

Downward and inward

Question 2

Innervation of levator ani

Answer 2

S3,S4

Question 3

Periurethral levator ani

• voluntary or involuntary?
• action during straining?

Answer 3

Voluntary

Contracts

Question 4

Initiation of voiding

Answer 4

As bladder fills to functional capacity signals from detrusor to higher cortical centres to initiate emptying

Question 5

Action of urethral and detrusor muscles in normal voiding

Answer 5

Urethral muscles relax
before (inhibition of contraction of proximal sphincter)
detrusor contracts (inhibition of sympathetic relaxation)

Question 6

Nervous control of levator ani and external urethral sphincter during voiding

Answer 6

Inhibition of sacral and pudendal efferents causes relaxation

Question 7

Innervation, neurotransmitter and receptors causing detrusor contraction

Answer 7

Parasympathetic, ACh, cholinergic receptors

Question 8

Effects of rectal distension

Answer 8

Internal anal sphincter relaxes, sampling reflex stimulated

Question 9

Deferral of defacation

Answer 9

Voluntary contraction of external anal sphincter and levator ani

Question 10

Muscle action at time of defecation

Answer 10

External anal sphincter, levator ani and puborectalis relax