Bladder

Question 1

What is the two main roles of the bladder

Answer 1

Temporary storage of urine

Assists in the expulsion of urine

Question 2

How does the bladder act as a temporary storage of urine

Answer 2

Hollow organ with distensible walls

Folded internal lining - rugae - allows to accommodate 400-600mL of urine in healthy adults

Question 3

How does the bladder assist in expulsion of urine

Answer 3

Musculature of the bladder contracts during micturition

Question 4

Describe the trigone

Answer 4

Triangular area which marks the orifices

Question 5

Why does the trigone different from the rest of the internal bladder with smooth walls

Answer 5

Has a different embryological origin

Question 6

What is the specialised smooth muscle of the bladder

Answer 6

Detrusor muscle

Question 7

How does the detrusor muscle maintain structural integrity when stretched

Answer 7

Fibres are orientated in multiple directions

Question 8

What innervation does the bladder receive

Answer 8

Parasympathetic and sympathetic

Question 9

What are the muscular sphincter located in the urethra

Answer 9

Internal urethral sphincter

External urethral sphincter

Question 10

Describe the internal urethral sphincter in males

Answer 10

Consists of circular smooth muscle fibres

Under autonomic control

Question 11

Describe the internal urethral sphincter in females

Answer 11

Functional sphincter

Formed by bladder neck and proximal urethra

Question 12

Describe the external urethral sphincter

Answer 12

Skeletal muscle

Voluntary control

Question 13

What is the arterial supply of the bladder

Answer 13

Internal iliac vessels

Superior vesical branch of the internal iliac artery

Obturator and inferior gluteal arteries may contribute small branches

Question 14

In males what is the arterial supply of the bladder supplemented by

Answer 14

Inferior vesical artery

Question 15

In females what is the arterial supply of the bladder supplemented by

Answer 15

Vaginal arteries

Question 16

What is the venous drainage of the bladder

Answer 16

Vesical venous plexus

Drains into the internal iliac veins

Question 17

What innervation does the bladder receive

Answer 17

Autonomic

Somatic

Question 18

Describe the sympathetic innervation of the bladder

Answer 18

Hypogastric nerve (T12-L2)

Causes relaxation of the detrusor muscle - promotes urine retention

Question 19

Describe the parasympathetic innervation of the bladder

Answer 19

Pelvic nerve (S2-4)

Increased signals cause contraction of the detrusor muscle

Stimulates micturition

Question 20

Describe the somatic innervation of the bladder

Answer 20

Pudendal nerve (S2-4)

Innervated external urethral sphincter - provides voluntary control over micturition

Question 21

What is the role of sensory (afferent) nerves in the bladder

Answer 21

Found in bladder wall

Signal the need to urinate when bladder becomes full

Question 22

What is the bladder stretch reflex

Answer 22

Primitive spinal reflex

Micturition is stimulated in response to stretch of the bladder wall

Question 23

Describe the reflex arc

Answer 23

Bladder fills with urine. Stretched. Sensory nerves detect. Transmit information to spinal cord

Spinal cord relay signals to the parasympathetic efferent

Pelvic nerve acts to contract the detrusor muscle - stimulates micronutrition