University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

288

Pages:

9
Author:

Mariam A. A.

Urinary bladder ● ● ● ● ● ● ● ● ● Located on the floor of the pelvic cavity Hollow collecting vessel Muscular Receives all of the urine produced by the kidney In the true pelvis (below the pelvic inlet) Posterior to the anterior inferior wall Superior to the pelvic floor muscles Sub peritoneal organ Anterior to the uterus in females Anatomy ● Detrusor muscle (muscular sac, squeezed when the bladder is full to remove urine) ● Lots of rugae on the internal section to stretch and recoil in size (muscles in different directions) [presence of rugae = empty bladder] ● 3 openings - Ureters (paired L and R) - Urethra (single structure that takes urine away from the body) ● Trigone - Joining these three regions = the trigone - No rugae - Has stretch receptors in the wall - Sensitive to the filling of the bladder (determines when the bladder is full, trigger urge to go to the toilet) Urethra ● Where the body expels the urine ● Single tube Female ● 3-4cm long ● Starts from the neck of the bladder to the external urethral orifice (in the vestibule of the external genitalia of the female) ● Sphincter and opening 1 ○ Internal opening bounded by internal urethral sphincter inside the wall of the origin of the urethra ○ Involuntary muscle ○ Controls flow of urine from inside the bladder to the urethra activated during the micturition reflex ● ● Sphincter and opening 2 ○ External opening ○ Located within the pelvic floor ○ Outside of the urethra and bladder ○ Squeezes the urethra ○ Under conscious control to stop the flow of urination In females, relationship between bladder and uterus affects position of tubes ○ Bladder is anterior to the uterus ○ Urethra is anterior to the vagina (positioning of their openings) Internal opening External opening Male urethra ● Transports urine and seminal fluids from the body ● 18cm long ● 3 regions: prostate, membranous, spongy ● 2 sphincters: internal and external Prostatic urethra ● Passes through the prostate gland (2.5cm) ● Goes from neck of bladder to just above the pelvic floor ● Internal sphincter associated with this tube at the wall of the bladder/origin of the urethra activated during micturition reflex which controls the flow of urine from the bladder to the urethra (circled in green) ● Role in ejaculation - prevents seminal fluid from going into the bladder during ejaculation, needs to be closed to prevent any infection or bacteria entering into the urinary tract/urinary organs Membranous urethra ● Shortest (0.5cm) ● Passes through the pelvic floor through the external urethral sphincter - under voluntary control to contract during urination Spongy urethra ● Passes through the erectile tissue (corpus spongiosum) of the male penis ○ Note: penis is made up of two different spongy tissues