Urinary system

Question 1

3 ways you move urine;

Answer 1

1. Peristaltic contractions
2. Hydrostatic pressure
3. Gravity

Question 2

Urinary back flow

Answer 2

Urinary backflow from the bladder up the ureters is prevented by

• Pressure exerted on the ureters as the bladder fills with urine
• One-way valve between each ureter and bladder

Question 3

Three layers :

Answer 3

• Inner mucosa of transitional epithelium
• Middle smooth muscle coat (DETRUSOR MUSCLE)
• Outer adventitia

Question 4

Outline the process of micturition (describing the voluntary and involuntary pathways).

Answer 4

Definition: The act of emptying the bladder (urination or voiding)

Involuntary:
Stimulus
- Stretch receptors of bladder wall activated by filling of urine
Pathway
- Sensory neurons carry action potential to sacral spinal cord (S2-S4)
- Motor nerves carry action potentials from spinal cord to bladder
Effector
- Detrusor muscle contracts
- Internal urethral sphincter relaxes
- Urination occurs

Voluntary:
Stimulus
- Stretch receptors of bladder wall activated by filling of urine
Pathway
- Sensory neurons carry action potential to sacral spinal cord (S2-S4) and on to cerebral cortex to create the urge to urinate
- Motor nerves carry action potentials from cerebral cortex and spinal cord to bladder
Effector
- Detrusor muscle contracts and internal sphincter relaxes but external sphincter constricts to consciously prevent urination
- Urination is prevented until a conscious decision is made to urinate
- Motor impulses continue to increase to detrusor and internal sphincter and motor impulses decrease to external sphincter
Urination occurs.

Question 5

Incontinence

Answer 5

Urinary incontinence is a lack of voluntary control over micturition

Question 6

Identify types of Incontinence.

Answer 6

Functional incontinence
- Impaired mobility, dexterity and cognition causes a person to become unable to use a toilet

Nocturnal enuresis
- Involuntary loss of micturition control during sleep

Post-micturition dribble
- Leakage of urine following voiding (common in older men)

Stress incontinence
- Involuntary leakage of urine during exertion, laughing, sneezing
- Common in pregnancy, obesity and older men post-prostate surgery

Urge incontinence
-Involuntary leakage of urine accompanied by or immediately preceding urgency.

Question 7

Two age related changed to the urinary bladder

Answer 7

1. urinary retention from prostate enlargement obstructing flow of urine in males
   2.decreased elasticity of bladder wall prevents the bladder from holding as much urine leading to more frequent urination