Ureters/Bladder/Urethra Anatomy

Question 1

ureters

Answer 1

• thin muscular tubes that carry urine from kidneys to bladder
• begin as continuation of renal pelvis, descend all the way to bladder where bring urine via ureteral orifices
• walls have 3 layers of different tissue

Question 2

ureterovesical valves

Answer 2

• located at ureteral orifices

- let urine into bladder and keep urine from flowing back into kidney (helped out by downward flow of urine)

Question 3

inner lining of ureters

Answer 3

• made up of transitional epithelium (specialized for cellular expansion to absorb fluid)
• continuous with lining of kidney

Question 4

middle lining of ureters

Answer 4

• 2 layers of muscle: longitudinal + circular

- distends as urine enters ureter which causes muscle contraction –> pushes urine thru ureter

Question 5

outer lining of ureter

Answer 5

• aka adventitia layer

- fibrous connective tissue

Question 6

urinary bladder

Answer 6

• hollow muscular elastic pouch
• stores urine excreted by kidneys before disposed via urethra
• opens at base to send urine into urethra
• wall has 3 layers of tissue

Question 7

male bladder

Answer 7

• base of bladder located in front of rectum / just behind pubic symphysis
• higher max capacity than female bladder

Question 8

female bladder

Answer 8

• sits below uterus / in front of vagina

- presence of uterus/vagina give it lower max capacity

Question 9

trigone

Answer 9

smooth triangular center of bladder

Question 10

bladder when empty

Answer 10

collapses into pyramidal shape

Question 11

bladder when fills with urine

Answer 11

• swells and rises in abdominal cavity to become pear shaped

- muscular wall stretches and thins to hold urine without major increase in internal pressure

Question 12

layers of tissue of bladder wall

Answer 12

• outer + inner layers = same tissues as ureters
• muscular layer has inner AND outer longitudinal layers plus an inner circular layer
• wall has folds that help increase internal capacity

Question 13

bladder capacity

Answer 13

• moderately full: ~500ml

- max capacity: ~1000ml

Question 14

urethra

Answer 14

• thin walled muscular tube
• carries urine from urinary bladder outside of body
• contains 2 sphincters: internal + external
• different in males + females

Question 15

female urethra

Answer 15

• shorter
• only carries urine
• more prone to bringing bacteria to bladder (causing UTI)

Question 16

male urethra

Answer 16

• 5x longer than female
• 3 regions (prostatic, membranous, spongy)
• carries urine and semen

Question 17

internal urethral sphincter

Answer 17

• involuntary
• located near bladder
• keeps urethra closed to prevent urine from leaving bladder

Question 18

external urethral sphincter

Answer 18

• under voluntary control

- skeletal muscle that surrounds uretha as it travels thru pelvic floor

Question 19

urge to urinate

Answer 19

• caused by visceral reflex arc
• can be consciously resisted with control of external urethral sphincter unless bladder fills to 100% capacity –> external sphincter forced open

Question 20

visceral reflex arc

Answer 20

• caused by distention of bladder walls when bladder has ~200 ml of fluid
• reflex arc causes detrusor muscle to contract + internal sphincter to relax –> urge to urinate