Ureter and Bladder

Question 1

What are the two parts of the urinary bladder?

Answer 1

Body

Bladder neck

Question 2

What is the internal sphincter of the bladder?

Answer 2

The detrusor muscle

Question 3

The natural tone of which sphincter keep urethra empty of urine?

Answer 3

The detrusor muscle

Question 4

Which sphincter is voluntary, the internal or the external?

Answer 4

External

Question 5

What is the motor sensation to the bladder?

Answer 5

Pelvic (S2, S3, S4)

Hypogastric (L1, L2, L3)

Question 6

What are the sensory nerves that supply the bladder/trigone/internal sphincter?

Answer 6

Hypogastric n (L1, L2, L3)
Pelvic nerves (S2, S3, S4)

Question 7

What does the pudendal nerve supply in terms of the bladder?

Answer 7

Both motor and sensory somatic nerve fibers to external sphincter

Question 8

Is the fluid that moves from the kidneys to the bladder via the ureters changed?

Answer 8

no

Question 9

What pushes urine into the ureters?

Answer 9

The walls of the renal calyces, pelvis and ureters have contractile elements that are used to push the fluid into the bladder

Question 10

What controls the smooth muscle contraction of the renal calyces?

Answer 10

Inherent pacemaker activity

Question 11

Are there any real urethral sphincters? What keeps them compressed?

Answer 11

No–the detrusor muscle keeps them compressed

Question 12

What is vesicoureteral reflux?

Answer 12

In some people the ureters’ path through the bladder wall is less oblique and shorter. During urination when the bladder contracts their ureters are not always totally closed. This permits the backward flow of urine into the ureters.

Question 13

What causes the intense pain felt in renal stones?

Answer 13

Ureteral peristaltic contractions

Question 14

What is the ureterorenal reflex?

Answer 14

Sensory nerves to the ureters can sense if there is increased stretch from a blockage, and will stop further urine formation in the kidneys by constricting afferent arterioles

Question 15

As urine enters the bladder, the intravesical pressure rises how?

Answer 15

Quick rise, then slower with additional urine

Question 16

What causes the acute pressure spikes seen in the micturition reflex?

Answer 16

Bladder sends signals to the sacral spinal cord, which sends back parasympathetic impulses to the detrusor to contract. This is a positive feedback loop until the detrusor fatigues. This will happen more often with more urine, thus causing the urge to micturate

Question 17

Is the micturition reflex autonomic or somatic? Can it be inhibited or facilitated by the brain?

Answer 17

Fully autonomic, but can be regulated by the brain

Question 18

What centers of the brain normally inhibit the micturition reflex? What do these do?

Answer 18

Cortical and suprapontine

Send efferent signals to the parasymp nerves in the sacrum to inhibit the nerves that stimulate detrusor muscle

Question 19

What is the sympathetic storage reflex?

Answer 19

As the bladder distends, it sends afferent signals to the spinal cord. There, symp firing via L1-L3 is initiated, decreasing excitatory parasymp inputs to the bladder

Question 20

What is the somatic storage reflex (pelvic to pudendal reflex)?

Answer 20

Afferent activity d/t increased intra abdominal pressure travels to the pelvic nerves. where efferent nerves are activated. These are are usually tonically active, but are suppressed when this reflex arc occurs, to allow for micturition

Question 21

What is the center in the brain that controls urination?

Answer 21

Pontine micturition center

Question 22

When the bladder fills to approx what volume does a person feel the urge to urinate?

Answer 22

150mL

Question 23

Voluntary urination is initiated how?

Answer 23

Partially by voluntary relaxation of the external urinary sphincter and perineal muscles.

Question 24

What is meant by the term neurogenic bladder?

Answer 24

a general term for when the urinary bladder malfunctions because of neurological dysfunction

Question 25

What causes an atonic bladder?

Answer 25

Sensory nerve fibers from the bladder to the spinal cord are destroyed.

Patient cannot have micturition reflex since the sensory signals from the bladder are missing

Question 26

What are the symptoms of an atonic bladder?

Answer 26

the bladder becomes filled to capacity and then overflows a few drops at a time through the urethra.

=”overflow incontinence”

Question 27

What can cause atonic bladder?

Answer 27

Crush injury to sacrum

Tertiary syphilis d/t sacral dorsal root disruption

Question 28

What is an automatic bladder? Are the micturition reflexes intact?

Answer 28

A type of neurogenic bladder caused by spinal cord damage above the sacral region.

Typical micturition reflexes can still occur since all three neural components are intact: sensory nerves from bladder, motor nerves to bladder and area of spinal cord where reflex connections made.

Question 29

What are the symptoms of an automatic bladder?

Answer 29

No voluntary control over micturition, but fully voids.

Question 30

What is a possible complication with automatic bladder?

Answer 30

Patient may develop spastic neurogenic bladder with decreased bladder capacity and reflex hyperactivity

Question 31

What causes an automatic bladder?

Answer 31

the eventual bladder dysfunction caused by a spinal cord lesion above the sacral cord is automatic bladder

Question 32

What is an uninhibited neurogenic bladder?

Answer 32

A type of neurogenic bladder is caused by partial damage in the spinal cord or the brain stem that interrupts most of the descending inhibitory signals but leaves descending facilitory signals intact

Question 33

What are the symptoms of an uninhibited neurogenic bladder? Why?

Answer 33

Frequent, and uncontrolled micturition

Continual excitation of sacral centers makes them so excitable that even a small amount of urine in the bladder elicits an uncontrollable micturition reflex.

Question 34

What is the parasympathetic supply to the bladder?

Answer 34

Pelvic nerves

Question 35

What is the sympathetic supply to the bladder?

Answer 35

Hypogastric nerves

Question 36

What is the nerve supply to the external sphincter?

Answer 36

Pudendal nerve

Question 37

Ureteral peristaltic contractions are due to what innervation?

Answer 37

Parasympathetic innervation

Question 38

Atonic bladder is the result of what? What type of urination?

Answer 38

No sensation to bladder

Leads to dribbling (“overflow incontinence”)

Question 39

Automatic bladder is the result of what? What type of urination?

Answer 39

Total loss of connection with brain (crush injury)

Leads to full expulsion of urine, just uncontrolled by brain

Question 40

Uninhibited bladder is the result of what? What type of urination does this lead to?

Answer 40

Most inhibition gone from the brain, but not all–keeps sacral centers excitable
Frequent, uncontrolled, random urination