Excretory System

Where are the ureters located?

retroperitoneal medial side of kidney, extend from hilus into pelvic cavity, enter posterior inferior region of urinary bladder

The outer layer of the ureters is made of?

fibroelastic connective tissue

Describe the middle layer of the ureters

three separate layers of smooth muscle

Describe the inner layer of the ureters

mucous membrane containing transitional epithelium

What is the function of the ureters?

move urine from kidneys to urinary bladder

What moves urine through the ureters?

smooth muscle peristaltic contractions

Where is the urinary bladder located?

retroperitoneal in pelvic cavity behind the pubic symphysis

The top, outer layer of the urinary bladder is made of?

parietal peritoneum

The sides and bottom of the outer layer of the urinary bladder is made of?

fibroelastic tissue

Describe the middle layer of the urinary bladder

three layers of smooth muscle (detrusor muscle)

What allows the urinary bladder to stretch without tearing?

inner layer of mucous membrane with transitional epithelium

Where is the trigone?

inner layer of urinary bladder

What forms the trigone?

boundaries of two ureteral openings and the urethral opening

What is the trigone?

stabilized area to maintain normal orientation of ureteral openings

Describe the inner or internal sphincters associated with urinary bladder and urethra

smooth muscle around urethra at the base of the urinary bladder, involuntary

Describe the outer or external sphincters associated with urinary bladder and urethra

skeletal muscle around urethra distal to inner sphincter, voluntary

Where is the external urinary sphincter in females?

adjacent to urethral orifice

Where is the external urinary sphincter in males?

inferior to prostate gland

What are the functions of the urinary bladder?

reservoir for urine and micturition

Approximately how much urine can the bladder hold?

300 ml

What is the first step in micturition?

stretch receptors in bladder send sensory impulses to spinal cord

What is the second step in micturition?

motor impulses come back to the bladder and stimulate contraction of the detrusor muscle with relaxation of the internal sphincter

What is the third step in micturition?

external sphincter relaxes and urine flows

Where is the urethra located in the female?

anterior to vagina

Where is the urethra located in the male?

passes through prostate gland and penis

Where does the urethra terminate?

urethral orifice

What is the function of the urethra in both sexes?

conducts urine from urinary bladder to outside

What is the function of the urethra in males?

conducts seminal fluid to outside

Kidney stones are also called?

staghorn calculus

Why are kidney stones difficult to pass?

attach to smooth muscle