Male Reproductive Anatomy Flashcards
what are the male reproductive organs?
testes
accessory reproductive organs?
vas deferens
seminal glands
prostate
penis
how long is the male urethra?
approx 20cm
what divides the pelvis and perineum in males?
levator ani
deescribe the path of the male urethra?
internal urethral orifice in bladder (contains internal urethral sphincter) > through prostate (“prostatic urethra”) > through external urethral sphincter (voluntary) > enters corpus spongiosum in penis > exits penis at external urethral orifice
position if bladder in pelvis?
most anterior pelvic organ
lies posterior to pubic bone when empty
above prostate gland
in front of rectum
what is the trigone?
triangle shape on internal aspect of bladder
- 2 ureteric orifices
- internal urethral orifice
most common site of transition cell tumour
what forms bladder wall?
detrusor muscle mainly
fibres encircle ureteric orifices and tighten when bladder contracts to prevent urine reflux
what forms the internal urethral sphinter muscle and what does it do?
detrusor muscle around the neck of the bladder
contracts during ejaculation to prevent retrograde ejaculation
how do the testes develop and move?
originate on the posterior abdominal wall
by birth they have descended into the scrotum through the anterior abdominal wall via the inguinal canal
(vas deferens follows testis into the scrotum and almost connects the testis to the urethra)
what follows the testis into the scrotum through the inguinal canal, what does this mean?
testicular artery testicular vein vas deferens lymphatic vessels nerves - autonomic (vas deferens) - somatic (cremaster muscle)
means blood supply, drainage and lymphatics all relate back to the abdomen
what is contained within the spermatic cord?
vas deferens testicular artery pampinoform venous plexus cremasteric artery artery to the vas nerve to cremaster sympathetic nerves lymphatics
what forms the spermatic cord?
the 3 layers of coverings gained as the testis passes through the inguinal canal + the structures contained within
what layers does the testis pass through on descent?
//
position of the testis in the scrotum?
sit within a sac called the tunica vaginalis
- testis pushes into tunica vaginalis
what is excess fluid in the tunica vaginalis called?
hydrocele
temp for sperm production? what helps control this?
1 degree below core body temp
dortos muscle helps by controlling ascent and descent of testes in scrotum
how many sperm produced per second and how long does it take?
1500 every second
take 64 days to mature
path of sperm?
produced in seminiferous tubules
pass into rete testis
then into head of epididymis
epididymis then becomes vas deferens
vas passes superiorly in spermatic cord to deep inguinal ring
at deep inguinal ring, vas turns medially into the pelvis and loops around back of bladder and combines with seminal vesicle tubule to from ejaculatory duct
ejaculatory duct combines with urethra in prostate gland forming prostatic urethra
what allows the testes and epididymis to be mobile within the scrotum?
attached to the spermatic cord superiorly only
- risk of twisting (torsion) which can disrupt blood supply
position of epididymis?
posterior aspect of testis
its proximal end is located at posterior aspect of superior pole of testes
are the vas deferens and epididymis palpable?
epididymus - not really when normal
vas - palpated within spermatic cord in scrotum superior to testes
blood supply/drainage to testes?
supply = gondal arteries arise from lateral aspect of abdominal aorta
drainage = left testicular vein > left renal vein > IVC, right testicular vein > IVC
all pass via inguinal canal
where are the seminal glands?
on top of prostate either side
feed into vas deferens in prostate to form ejaculatory duct
position and function of bulbourethral gland?
either side of urethra in penis
secretes mucus which lubricates urethra and neutralises acidity
position of prostate?
walnut shaped gland which surrounds prostatic urethra
sits below the bladder
inferior aspect in contact with levator ani muscle
zones in the prostate?
peripheral zone either side connecting round the back
central zone
transition zone (contains urethra)
anterior/fibromuscular zone
which zone do most prostatic cancers arise in?
peripheral
- part felt on digital examination
what is a vasectomy?
vas transected and its lumen sutured closed bilaterally
anatomical position of penis?
erect
what is paraphimosis?
retraction of the prepuce (foreskin) causing constriction of the neck of the glans causing the glans to swell
how is paraphimosis managed?
circumcision
where is the penis found?
within the perineum
root laterally attached to ischium of pelvis
what are the 3 cylinders of erectile tissue in the penis which become engorged with blood at arterial pressure to cause an erection?
corpus cavernosum (R and L)
- sit posteriorly
- transmit deep arteries of penis
corpus spongiosum
- sits anteriorly
- transmits spongy urethtra
- expands distally to form the glans penis
what is the superficial perineal pouch?
area below perineal membrane
contains root of penis
- bulb (corpus spongiosum) and crura (corpus cavernosa)
- associated muscles (bulbospongiosus and ischiocavernosus)
also contains proximal spongy urethra, superficial transverse perineal muscle and branches of internal pudenal vessels and pudenal nerve
blood supply to penis and scrotum?
supply = deep arteries of the penis (branches from internal pudenal artery from the internal iliac)
supply to scrotum = internal pudenal and branches from external iliac
lymphatic drainage of penis and scrotum?
superficial inguinal nodes (in superficial fascia of groin)
- not the glans
lymphatic driainage of testes?
lumbar nodes (around abdominal aorta)
