Week 3 urinary system Flashcards
what are the ureters?
they are narrow tubes with thick muscular walls that convey urine from the kidneys to the bladder (around 1,200 ml a day) the upper half resides in the abdomen whereas the lower half sits in the pelvis
Where do the ureters lie?
the ureters lie in the retroperitoneal areolar tissue and adhere to the peritoneum
cross down psoas
pass down on psoas
cross genitofemoral nerve
leave psoas at bifurcation of the common iliac joint
pass over SIJ
enter pelvis
terminate at the posterior lateral aspect of the bladder
How is urine propelled?
urine is propelled by peristaltic contractions of muscle as well as filtration pressure of the glomeruli
what is the arterial supply to the ureters?
Upper part: Uteric branch of the renal artery Middle part: Branches from the abdominal aorta gonadal artery common iliac artery internal iliac artery Lower part: Branches from the superior and inferior vesicle arteries and uterine arteries
What is the nerve supply to the ureters?
Sympathetics:
(T10-L1) via coeliac and hypogastric plexuses
Parasymptathetics:
Parasympathetic pelvic splanchnics (S2-S4)
what Is the structure of the ureters?
smooth muscle lined by mucous membrane
they have an inner and longitudinal layer of muscle
have a middle circular layer
are lined by transitional epithelium
why is transitional epithelium labelled the way it is?
It is named this way as it has some features which are transitional between stratified cuboidal and stratified squamous epithelium
In a relaxed state the epithelia appears 4 to 5 cell layers thick
What is the bladder?
Hollow organ with strong muscular walls
temporary store for urine
varies in size and shape in regards to other organs
when empty, sits in pelvic cavity
when full, can stretch into abdominal cavity
What are the surfaces of the bladder?
inferior/ posterior surface = base
Inferior/lateral surface
superior surface
what structures are found in the empty bladder?
Apex
Body
Neck
Uvula
how is the bladder separated from the pubic bones?
By a potentilal retropubic space
What is the body of the bladder?
The body is the part of the bladder between the apex and the fundus
How is the base (or fundus) of the bladder formed?
The base or fundus is formed by the posterior wall of the bladder and is convex
how is the neck of the bladder formed?
It is formed where the fundus, base and inferloateral surfaces of the bladder meet
What pierces the bladder?
The urethra at the internal urethral orifice
What is the trigone of the bladder?
a triangular region at the base of the bladder
lies between the two urethral orifices and the internal urethral orifice
it is smooth unlike the rest of the bladder and remains fixed
What is the uvula of the bladder?
the uvula of the bladder is a slight projection of the trigone of the bladder
formed by the convergence of muscle fibres terminating in the urethra
the bladder is usually more prominent in males due to pushing down from the prostate
what is the bladder surrounded in?
fascia known as vesicle fascie
what separates the bladder from the uterus in females?
the uterovesicle pouch
What is the blood supply to the bladder?
Branches of the internal iliac artery:
superior vesicle
inferior vesicle (M)
vaginal (F)
What is the nerve supply to the bladder?
Parasympathetics:
pelvic splanchnic nerves (S2-4)
Sympathetics:
(T11-L2)
What is the structure of the bladder?
Contain three layers of smooth muscle: inner layer outer layer middle layer lined with transitional epithelium
What is the male urinary/ reproductive function?
longer than the female urethra
approx. 20 cm long
extends from the bladder neck to the tip of the penis
passes through the prostate and the entire corpus spongiosum
What are the parts of the male urethra
preprostatic
prostatic
intermediate
spongy
What is the prostatic urethra?
the part of the urethra that runs closer to the anterior surface of the gland.
receives openings of the ejaculatory ducts (union of the vas deferens)
What is the intermediate urethra?
shortest section of the urethra (1-2cm)
begins at the apex of the prostate and ends at the bulb of the penis
What is the spongy urethra
The longest region of the urethra
passes through the bulb and corpus spongiosum of the penis
starts at the end of the intermediate part of the urethra and ends at the external urethral orifice
What is the external urethral sphincter?
an external sphincter that is composed of striated muscle and is under voluntary control. Contains mainly slow twitch fibres. it maintains constant muscular tone and only relaxes during micturition
