Mirconitiron Flashcards
What are some of the features of the internal urethral spincther?
Is composed of smooth muslce (autonomic innervation) and prevents retrograde ejaculation in men
What are some of the features of the external urethral spincther?
Is voluntary, and is what you hold when physically holding in a wee
What do the sensory neruones respond to?
Stretch receptors in the bladder wall
Where do the sensory fibres synaspe on the sympatheic fibres in the stroage phase?
T10- L2
Which nervous systems are involved in the storage of bladder?
The sympatheic nervous system and the somatic (motor nervous system)
What is the effects of sympatheic activiation on the bladder?
Causes exciation and then ionhbitorn of the setrusor muscle, and then contraction of the internal spincther
What is the cerebral centre involved in the storage of urine?
The L centre
What is the action of the L centre?
Stimulates motor neurones, and caused contraction of the external spincthers.
What is the nerve and the nerve roots involved in contraction of the external spinther?
The peudenal nerve, S2 3 4
Describe the reflex arc involved in voiding the bladder?
Sensory fibres synaspe directly onto the parasympathiec fibres, in teh S2 to S4 region and this causes stimulation of the detrusor muscle
What is the cerebral centre involved in voiding the bladder?
The m centre
What stimulates the M centre?
High frequency aactivity in the sensory neurone p?
What are the influences of the cortex on the M centre?
Cortex can send inhbitory projections on the M centre, and coretex can also send excitart prjections?
Even when the M centre is operational, what still needs to happen to faciliatate voiding?
Even at high storage leves the L centre needs to be switched off and then inhibited when voidng, and this helps two relax the different spincthers (espeically the external p)
