Anatomy of the Lower Renal Tract Flashcards
what are the 2 regions of the pelvis and what separates them?
true pelvis and false pelvis
separated by the pelvic rim/inlet
- above = false
- below = true
describe the path of the urinary tract through the cavities
pass from the retroperitoneum through the false pelvis and into the true pelvis
ureters enter bladder in the true pelvis
urethra passes from true pelvis through pelvic floor into the perineum
what is contained in each region of the pelvis?
false = abdominal viscera (part of abdominal cavity) true = pelvic viscera (part of pelvic cavity)
what sits below the true pelvis and what separates them?
perineum
separated by levator ani muscle (pelvic diaphragm) - AKA pelvic floor
where is the perineum?
between pelvic floor and skin of genitalia
anatomical features of the pelvic floor?
formed by the bowl shaped pelvic diaphragm
- made up of muscles including levator ani
openings for distal parts of alimentary, renal and reproductive tracts to pass from pelvic cavity to perineum
describe the specific route of the ureters
pass anterior to the common iliac vessels to enter the false pelvis
pass anteriorly on lateral walls of pelvis
turn medially at the level of the ischial spine to enter the posterior bladder in an inframedial direction
route is completely subperitoneal (below peritoneal cavity)
what is the significance of the inferomedial change in direction of the ureters?
prevents reflux of urine back into the ureters when the bladder contracts
what is the most dependant (deep) part of the peritoneal cavity in males and females when lying supine?
males = rectovesicle pouch females = rectouterine pouch (of douglas)
what does the round ligament of the uterus do and where is it found?
attaches uterus to the perineum via the inguinal canal
attaches to uterus below attachment of the uterine tube (fallopian tube)
anatomical relations of the ureters in the female pelvis?
ureter runs inferiorly to and underneath the uterine tubes and the uterine artery
“water under the bridge”
- important during gynae surgery (e.g hysterectomy which requires ligation of uterine artery)
anatomical relations of the ureters in the male pelvis?
ureters run inferiorly and underneath the vas deferens
pelvis blood supply in females?
mainly branches from internal iliac
- vesical arteries
- uterine arteries
- middle rectal artery
- vaginal artery
pelvis blood supply in males?
mainly branches of internal iliac - vesical arteries - middle rectal artery - prostatic arteries all pass under vas deferens
where is the prostate found?
directly inferior to the bladder
what are the 3 openings into the bladder and where are they found?
left and right ureteric orifices = where ureters enter bladder
internal urethral orifice = opening into urethra where the bladder empties
openings form a triangle with the 2 ureteric orifices at the top and the urethral orifice at the bottom
what is the triangle formed by the bladder orifices called?
trigone
what muscle forms the main bulk of the bladder wall?
detrusor muscle
contracts to empty the bladder
secondary function of the detrusor muscle?
has fibres which encircle the ureteric orifices and contract around them, blocking them off and preventing reflux of urine
what function of the detrusor muscle is only found in males?
forms the internal urethral sphincter muscle (smooth muscle) around the neck of the male bladder which contracts during ejaculation to prevent semen entering bladder during ejaculation
anatomical relations of the bladder in females?
empty bladder is tucked behind pubic symphysis
body of uterus sits on top of bladder (= anteflexed position)
vagina is immediately posterior to the bladder
what structure bears most of the weight of the uterus?
bladder
anatomical relations of the bladder in males?
prostate lies directly inferior
rectum lies posterior
how does the position of the bladder change depending on volume?
completely within true pelvis when empty
extends superiorly as it fills and extends out of the true pelvis and into the false pelvis, superior to the pelvic bone
the bladder is covered in peritoneum, true or false?
false
only covers the superior surface
what are the 2 methods of catheterisation?
urethral (via urethra, most common)
suprapubic (via anterior abdominal wall, avoiding peritoneal cavity)
how must a suprapubic catheterisation be performed?
cannot be performed on an empty bladder as it would pierce the peritoneum
how long is the female urethra?
4cm
secondary function of levator ani muscle?
acts like a sphincter as the urethra must pass through it to reach the exterior of the body
internal vs external urethral orifice?
internal = smooth muscle external = voluntary
how long is the male urethra?
20cm
where in the penis does the urethra pass through?
corpus spongiosum
- urethra known as spongy urethra here
what is the path of sperm from production to vas deferens?
made in seminiferous tubules of testicles
stored in epididymis
passes into vas deferens
path of the vas deferens?
passes through inguinal canal
enters abdominal cavity
passes behind bladder
joins duct of seminal gland (which produces semen) forming the ejaculatory duct
passes through prostate and joins with urethra forming prostatic urethra
passes through corpus spongiosum
terminates at external urethral orifice
how do the testes move during development?
originate on the posterior abdomen
descend through the inguinal canal to the scrotum
what is the spermatic cord and what does it contain?
collection of structures which the testes drag down with them as the descend during development
- testicular artery
- testicular vein
- vas deferens
- lymphatic vessels
- nerves (autonomic and somatic)
what surrounds the testes in the scrotum and how does this develop?
surrounded by a sac called the tunica vaginalis (similar relationship as pericardium surrounding heart)
testicle pushes into tunica vaginalis like a fist into a balloon so never actually enters it
what is hydrocele?
excess fluid within the tunica vaginalis
blood supply to the testes?
testicular arteries
venous drainage of the testes?
pampiniform venous plexus
- drains into testicular veins
what is torsion and what can this cause?
twisting of the spermatic cord
can compromise blood supply to the testes causing severe pain and potentially necrosis of testicles
where do the gonadal (uterine/testocular) arteries arise from?
aorta
where do the gonadal veins drain to?
right = IVC left = left renal artery > IVC
what passes into/out of the inguinal canal via the deep inguinal ring?
testicular artery testicular vein vas deferens lymphatics nerves
where does the vas deferens begin?
inferior pole of the testicle
where is the epididymis palpated?
posterior aspect of the testicle proximal end (head) = at posterior aspect of the superior pole of the testes
where is the vas deferens palpated?
within the spermatic cord
within the scrotum
superior to the testes
feels like a thick piece of string
the spermatic cord enters the abdominal cavity via what structure?
deep ring of inguinal canal
- vas deferens then turns medially into the pelvis and the rest continues upwards
what openings are found within the prostatic urethra?
opening of ejaculatory duct
openings of several small prostatic ducts for secretions from prostate
anatomical relations of prostate?
surrounds prostatic urethra
inferior aspect is in contact with levator ani muscle
what are the zones of the prostate and which ones can be palpated during digital examination? is this enough?
central zone and peripheral zone
digital examination palpates peripheral zone
- most cancers occur in peripheral zone
the penis is within the perineum, true or false?
true
the root of the penis attaches where?
ischium of the pelvis
what are the 3 parts of the penis?
root
body
glans (tip)
what are the 3 tubes of erectile tissue?
right and left corpus cavernosum (contain deep arteries of penis) corpus spongiosum (contains urethra)
what causes an erection?
engorgement of blood in the deep arteries of the penis
- internal iliac > internal pudenal > deep artery of penis
scrotal blood supply?
dual blood supply
- branches from internal and external iliac
lymphatic drainage of penis and scrotum?
superficial inguinal nodes
lymphatic drainage of testicles?
lumbar nodes (due to embryological origin of testes)
