5. Micturition Videos

Question 1

What is the renal ureteral reflex?

Answer 1

Reflex in which the renal arterioles are constricted via the sympathetic nervous system in response to the pain of a blockade

Question 2

Through which nerve do the efferent signals of the parasympathetic nervous system run to the bladder?

Answer 2

The pelvic splanchnic nerve

Question 3

Which fibers carry the sensation of bladder fullness?

Answer 3

Alpha Delta fibers (myelinated)

Question 4

Where’s the sacral micturition center located on the spine?

Answer 4

S2 to S4

Question 5

What is the purpose of the periaqueductal gray, and where is it located?

Answer 5

Receives both afferent bladder signals as well as signals from the cerebral cortex to control stimulation of the Pontine Micturition Center.

Located in the Midbrain

Question 6

What is vesicoureteral reflux?

Answer 6

When urine is projected backwards into the ureter via the contraction of the bladder to expel urine

Question 7

What is the function of the Pontine Micturition Center?

Answer 7

It both sends the signal for the external urethral sphincter to relax, as well as increasing parasympathetic outflow to the urinary system (this increases urethral peristalsis and causes detrusor muscle contraction).

This is also the region of the brain that controls the S2-S4 parasympathetic fibers.

Question 8

Which fibers carry the sensation of bladder pain?

Answer 8

C fibers (not myelinated)

Question 9

Through which nerves do the afferent sensory signals of the bladder run?

Answer 9

The pelvic splanchnic nerve, and the hypogastric plexus.

Question 10

Where the 4 anatomic constriction points in the urinary system?

Answer 10

Ureteropelvic junction

Testicular or ovarian artery and vein

External iliac artery and vein

Bladder wall

Question 11

Where do the efferent signals of the sympathetic nervous system come from in the spine?

Which nerve do they run with?

Answer 11

L2

Hypogastric nerve