Bladder

Question 1

How does the urine get to the bladder and how?

Answer 1

Urine flows through the ureters to the bladders

Propelled by contractions of the ureter wall smooth muscle

Question 2

What are the walls of the bladder made of?

Answer 2

Detrusor muscles

Question 3

What nerves supply the detrusor muscle?

Answer 3

Parasympathetic nerve-pelvic splanchnic (S2,3,4)

Question 4

What is the first sphincter that urine goes through?
What is it made of?
Nerve supply?

Answer 4

Internal urethral sphincter
Smooth muscle
Sympathetic nerve - hypogastrics T1 to L2

Question 5

What is the last sphincter that urine goes through?
What is it made of?
Nerve supply?

Answer 5

External urethral sphincter
Skeletal muscle
Somatic motor - pudendal (S2,3,4)

Question 6

What happens in bladder filling?

Answer 6

Parasympathetic input to detrusor muscle (relax)

Internal and external sphincter (contracts- closes)

Question 7

What happens when you urinate?

Answer 7

As bladder fills, Pressure increases, stimulated stretch receptors
Detrusor contract
Internal and external urethral sphincter relaxes and opens

Question 8

What is the primitive bladder stretch reflex?

Answer 8

Peeing (until childhood) is a spinal reflex to increased bladder filling

Question 9

What happens if the bladder stretch reflex continues to adulthood?

Answer 9

Incontinence syndrome

Question 10

What is the function of the urinary tract?

Answer 10

Store pee at low pressure
Fill to comfortable volume (receptive relaxation)
Voluntary initiate peeing