S8 L1 Micturition

Question 1

Urethra has 2 sphincters, name and draw a diagram, labelling where they are anatomically

Name of the main muscle in the bladder

Answer 1

Question 2

Bladder Pressure

• Draw a graph (Volume infused into the bladder vs Pressure in Bladder)
• Explain the graph
• Explain the two reflexes involved

Answer 2

Storage phase
Voiding phase

Question 3

Storage phase:

• List the neurones involved in this reflex
• Explain this reflex (what happens?) - Briefly, as an overview (will go into more detail in next FC)

Answer 3

Question 4

Storage phase:

1. How is the ‘stretch’ of the bladder sensed?
2. How do we know how ‘full’ our bladder is?
3. Sympathetic role in this reflex?
4. What is another important way of ‘deffering’ micturition?

Consequences of storage reflex

Answer 4

Consequence of Storage reflex:
As volume increases in the bladder, the bladder actively relaxes, meaning the pressure does not increase

Question 5

Voiding phase (2nd Reflex arc)

• Which neurones etc are involved?
• What is this stage?
• Give a brief overview of it (more info on next FC)
• Somatic input?
• (Sympathetic imput?)

Answer 5

As bladder volume increases, bladders pressure starts to increase as well. This will cause the activation of the voiding reflexes.

Question 6

1. How is the ‘stretch’ of the bladder sensed?
2. How do we know how ‘full’ our bladder is?
3. Parasympathetic role in this reflex?

Answer 6

Question 7

• How is it possible for us to decide to miturate? (voluntary control over it…)
• Why babies can’t ‘decide’ to void?

— already know this side of the FC - just here to help with understanding the answer if it is confusing

Answer 7

Question 8

How do these two reflexes communicates?

Why is this important?

• To note with sphincters…

Answer 8

Storage is ‘dominant’ most of the time, the ‘voiding reflex’ steps in here and there

Sphincters:
With sphincters - stop stimulating them, they relax…

Question 9

Receptors and Messengars in Storage reflex

Answer 9

Question 10

Receptors and Messengars in Voiding reflex

Answer 10

Question 11

Medication for:

• Stress urinary incontinence (1)
• Urgency urinary incontience (2)

Answer 11

Question 12

GW:
- Complete the table below (in pic) to show the components of the ANS (Autonomic Nervous system) and the appropriate postganglionic neurotransmitter agonist and receptor type for each branch.

• What investigations would you arrange for someone who has suspected stress incontinece?

Answer 12

L centre is always active until
M centre says not to be…

Stress incontinence:
Urine dipstick
Bladder diary
Ultrasound - Bladder scan (type of
ultrasound, cant see anything, just gives a
number, there is no screen)
Coughing and peeing thingy - see leakage