Ureters, Urinary Bladder, and Urethra

Ureters

• function

• what are they 

• part of the peritoneum?

passageway from the kidneys to the bladder

are 10-12 in long extensions of the renal pelvis

are retroperitoneal

Ureters

• what type of valve do they have?

• explain

have a physiological valve

as the urinary bladder fills with urine the pressure within causes it to compress the openings into the ureters, preventing the backflow of urine 

Histology: Ureters

• what are the layers?

mucosa, muscularis, and adventitia

(H) Ureters: Mucosa

• what does it consist of?

transitional epithelium: allows stretching

underlying lamina propria

• has lots of collagen, elastic fibers, and lymphatic tissue

(H) Ureters: Muscularis

• what is their major function?

• what does it consist of?

peristalsis, moving urine to the bladder

inner longitudinal muscle

outer circular muscle

(H) Ureters: Adventitia 

• what does it consist of?

• what does it contain?

• function?

layer of areolar CT

• contains BV, LV, and nerves serving the muscularis and mucosa

• also anchors ureters in place

Urinary Bladder

• function

• what type of organ? shape? capacity?

stores and expels urine into the urethra

hollow distensible organ

collapsed when empty, spherical when full

average capacity is 700-800 mL

Is the urinary bladder part of the peritoneum?

no, it is retroperitoneal

(UB) What is the trigone?

• what do its corners contain?

small triangular area in the floor of the urinary bladder

posterior corners contain the 2 ureteral openings 

anterior corner lies the internal urethral surface

Vocab: Internal urethral surface

opening to the urethra

What is the clinical important of the trigone?

frequently a sight of infections

(UB) Histology: What are its layers?

mucosa, muscularis/detrusor muscle, and adventitia 

(UB) Mucosa

• what are its layers?

• what else is present?

transitional epithelium: allows stretching 

underlying lamina propria 

rugae

(UB) Mucosa: Rugae

• what is it? function?

folds of the mucosa 

allow expansion of urinary bladder as it fills 

(UB) Detrusor muscle (muscularis)

• what are its layers?

• function?

inner longitudinal 

middle circular 

outer longitudinal 

contract together for urination 

(UB) Adventitia 

• what are its layers?

• what is it continuous with?

layer of areolar CT, continuous with the ureters

Vocab: Micturition

discharge of urine from the urinary bladder

What is the urethra?

passageway leading from the internal urethral orifice to the exterior urethral orifice

Urethra: Internal urethral sphincter

• where is is found?

• what is formed by?

around the opening of the urethra, formed by circular fibers 

Urethra: External urethral sphincter

• where is is found?

• what is formed by?

inferior to the internal urethral sphincter

• composed of skeletal muscle

Urethra in females:

• how long?

• where is the orifice located?

a short tube (1.5in)

orifice is located between the clitoris and vagina 

Urethra in males:

• how long?

• what are its segments?

has 3 segments, about 8 inches 

prostatic, membranous/intermediate, spongy/penile urethra 

Urethra (M): Prostatic Urethra 

passes through the prostate

Urethra (M): Membranous/intermediate Urethra 

passes through the deep perineal muscles 

Urethra (M): spongy/penile urethra

passes through the penis

Sex differences of Urethra: Length

is 5x longer in males than in females

Sex differences of Urethra: segments

is divided into 3 segments in males, is only a short tube in females

Sex differences of Urethra: systems

urethra is a common duct for the urinary and reproductive system in males

systems are completely separate in females

Urinalysis

An analysis of the volume and physical, chemical, and microscopic properties of urine

Which organs of the urinary system are retroperitoneal?

Kidneys, Ureters, Urinary Bladder