ANATOMY - MALE REPRODUCTIVE SYSTEM Flashcards
What are the 3 parts of the penis?
Root, body, glans
What is the most proximal section of the penis?
Root
What structure is the root of the penis within?
Superficial pouch of pelvic floor
What 5 muscles and tissues does the root of the penis comprise of?
2 x crura + 1 x bulb = erectile tissues
ischiocaverosus + bulbospongiosus = mm
What is the ‘free’ part of the penis called
Body of penis
What bone is the body of the penis suspended from?
Pubic symphysis
What is the most distal section of the penis?
Glans
Shape of glans penis
Conical
What tissue is the glans penis the distal expansion of?
Corpus spongiosum
What tissue does the crus in the penis become?
Corpus cavernosum
What tissue does the bulb in the penis become?
Corpus spongiosum
What structure travels through the bulb of the penis?
Urethra
What are the 4 muscles of the penis?
2 x bulbospongiosum
2 x ischiocavenrosus
What part of the penis is the bulbospongiosum associated with
Bulb
Role of bulbospongiosum muscle (2)
Contracts to empty urethra
Increases pressure within bulb to maintain erection
What structure do the ischiocavernosus muscles surround?
Crura
Role of ischiocavernosus muscle
Forces blood from crura to corpus cavernosa
(to maintain erection)
Name of 3 fascia of penis
External Colles fascia
Deep Bucks fascia
Tunica Albuginea
What is the Colles fascia of the penis an extension of?
Scarpas fasica abdomen
Which fascia of the penis holds the erectile tissues together?
Bucks fascia
What structure does the tunica albunigea encapsulated?
Caverosum
What does the suspensory ligament of the penis connect?
Erectile bodies to pubic symphysis
Fundiform ligament penis structure
From the linea alba - forms a sling around the penis and connects to the pubic symphysis
arterial supply penis (3)
Dorsal aa penis
Deep aa penis
Bulboarethral aa
What are the penile arteries branches of?
Internal pudendal aa
What is the internal pudendal aa a branch of?
Internal iliac aa
Venous supply penis - cavernous bodies
Deep dorsal veins
Where do the deep dorsal veins of the penis drain into?
Prostatic venous plexus
Venous supply penis - skin/cutaneous tissue
Superficial dorsal veins
Innervation of the penis - nerve roots
S2-4
Sympathetic innervation of the penis
Dorsal nn of the penis (branch pudendal nn)
MALE Parasympathetic innervation of the penis
Periprostatic nn plexus
Role of testes (2)
Sperm production
Hormone synthesis
Role of epididymis
Storage sperm
Which testicle lies lower?
Left
What cells line the semineferous tubules?
Sertoli cells
Role Sertoli cells
Spermatozoa maturation
Role of interstitial tissue testes
Support semineferous tubules + produce testosterone
Route of spermatozoa from semineferous tubules to epididymis
semineferous tuubules –> rete testes –> efferent tubules –> epididymis
What covers the testes?
Tunica vaginalis
What fibrous structure protect the testicular parenchyma?
Tunica albuginea
3 parts of the epididymis
Head
Body
Tail
Nerve innervation testes
Testicular plexus (from renal/aortic plexi)
3 arterial supplies to testes
Testicular aa
Cremasteric aa
Aa to vas deferens
Origin testicular aa
Abdominal aorta
Origin cremasteric aa
Inferior epigastric aa
Origin aa to vas deferens
Inf vesical aa
VV drainage testes
Testicular vv from pampiniform pelxus
VV drainage testes
Testicular vv from pampiniform plexus
Drainage left testicular vv vs right testicular vv
Left –> L renal vv –> IVC
Right –> IVC
Lymphatic drainage testes
Lumbar + para-aortic nodes
Lymphatic drainage scrotum
Superficial inguinal nodes
Embryological origin scrotum
genital swellings
Which muscle in the scrotum causes it to wrinkle?
Dartos muscle
Why is it important for the dartos muscle to wrinkle the scrotum?
Decreases surface area –> reduces heat loss
arterial supply to scrotum
Anterior and posterior scrotal aa
Origin anterior scrotal atery
External pudenal artery
Origin posterior scrotal artery
Internal pudendal artery
Nerve supply anterolateral scrotum
Anterior scrotal nerve
what is the anterior scrotal nerve a branch of?
ilioinguinal
Nerve supply posterior scrotum
Posterior scrotal nerve
what is the posterior scrotal nerve a branch of?
Perineal branch of pudendal nerve
Lymphatic drainage scrotum
Superficial inguinal nodes
3 fascial coverings spermatic cord
External spermatic fascia
Cremasteric fascia
Internal spermatic fascia
What is the external spermatic fascia derived from?
deep subcutaneous fascia
What is the cremasteric fascia dervied from?
Internal oblique mm
What is the internal spermatic fascia derived from?
transverse fascalis fascia
afferent/sensory limb cremasteric reflex
Ilioinguinal nn
efferent/motor limb cremasteric reflex
genital branch GF nn
Contents spermatic cord (9)
3 aa - testicular, cremasteric, aa to vas deferens
pampiniform plexus
2 nn
genital branch GF
Autonomic
3 other
vas deferens
processus vaginalis
lymph vessels
journey of spermatozoa to the prostatic urethra
testes –>semineferous tubules –> rete testes –> efferent tubules –>epididymis –> vas deferens –> ampulla –> ejaculatory duct –> prostatic urethra
How many muscle layers in vas deferens
3
What are the 3 layers of muscle in the vas deferens
inner - longitudinal SM
intermediate - circular SM
outer - longitudinal SM
what is the inner muscle layer of the vas deferens lined with? (and their role)
microvilli
help sperm advance
Course of vas deferens
continuous w/ epididymis
through inguinal canal as part of cord
moved down lateral pelvic wall close to ischial spine
turns medially between bladder + ureter –> posterior surface bladder
Ampulla + duct from semial vesicle –> ejaculatory duct
Role of prostate gland
Secretes proteolytic enzymes into semen which break down clotting factors when ejaculating
What is superior and inferior to the prostate gland?
Superior = external urethral sphincter
Inferior = bladder neck
What is inferolateral to the prostate gland
Levator ani muscles
What proportion of the prostate gland is gladular tissue?
⅔
What proportion of the prostate gland is fibromuscular
1/3
What are the 3 main zones of the prostate gland
Central zone
Transition zone
Peripheral zone
how do central zone prostatic ducts differ from peripheral zone prostatic ducts?
Central are oblique - less reflux
Peripheral are vertical - more reflux
What zone of the prostate do you feel on DRE
peripheral zone
Which zone of the prostate surrounds the urethra?
transitional
Which zone of the prostate typically undergoes BPH?
transitional
Which zone of the prostate is most at risk of malignant change?
peripheral
What is the 4th ‘zone’ of the prostae gland
Fibromuscular stroma
What does the fibromuscular stroma of the prostate gland merge with?
Urogenital diaphragm
arterial supply prostate
prostatic artery
what is the prostatic artery a branch of?
Internal iliac
venous supply prostate
prostatic venous plexus
prostatic venous plexus drains into…
internal iliac vv
nerve supply prostate
inferior hypogastric plexus
Shape of bulbourethral glands
pea shaped
where do the bulbourethral glands open into
spongy urethra
Embryological origin bulbourethral glands
urogenital sinus
function bulbourethral glands
produce mucus secretions containing glycoproteins aka pre cum
LUBRICATION + CLEAR OUT URETHRA + NEUTRALISE
arterial supply bulbourethral glands
artery to bulb of penis
nerve supply bulbourethral glands
hypogastric nn
pelvic nn (from pudendal nn)
lymphatic drainage bulbourethral glands
internal/external iliac nodes
shape seminal vesicles
5cm long, tubular
function seminal vesicles
produce many of constituents semen
where are the seminal vesicles
between bladder fundus and rectum
what 2 structures separate the seminal vesicles from the rectum?
retrovesicle pouch
periprostatic fascia
what is the mucosa of the seminal vesicles lined with?
pseudostratified columnar epithelium
effect of testosterone on epithelium of seminal vesicles
makes taller
which structures are derived embryologically from the mesonephric ducts (SEED)
S - Seminal glands
E - ejacualtory ducts
E - epididymis
D- ductos vas deferens
What % of semen volume is from the seminal vesicles
70%
constituents seminal fluid from vesicles (4)
alkaline fluid to neutralise
fructose for sperm energy
prostaglandins to suppress female immune response to sperm
clotting factors
internal iliac artery branches (8)
obturator artery
superior vesical
inferior vesical
middle rectal
internal pudendal
lateral sacral
superior gluteal
inferior gluteal
Draw internal iliac artery branches
DO IT!!!
Which arteries supply the seminal vesicles? (2)
Inferior vesical aa
Middle rectal aa
FROM INTERNAL ILIAC AA
Innervation seminal vesicles + how to remember
point and shoot
parasymp - erection (point)
symp - ejaculation - (shoot)
LN drainage seminal vesicles
external and internal iliac LN
urethra - lining
stratified columnar epithelium
length male urethra
15-20cm
What are the 3 parts of the male urethra
prostatic urethra
membranous urethra
penile/bulbous urethra
Which part of the male urethra is the widest?
prostatic
which part of the male urethra is the narrowest
membranous
which ducts does the prostatic urethra receive? (2)
ejaculatory ducts
prostatic ducts
aa supply prostatic urethra
inferior vesical aa
LN drainage prostatic urethra
obturator + internal iliac LN
what structure surrounds membranous urethra
external urethral sphincter
aa supply membranous urethra
bulbourethral aa
LN drainage membranous urethra
obturator + internal iliac LN
which ducts are received in the bulbous urethra
bulbourethral glands
what happens to the bulbar urethra in the glans and what does it become
dilates –> navicular fossa
aa supply bulbar urethra
internal pudendal aa
LN drainage bulbar urethra
superficial + deep inguinal LN
nn supply urethra male
prostatic plexus
length of female urethra
4cm
route female urethra
neck of bladder –> through perineal membrane –> vesibule –> urethral orifice
What 2 mucous glands sit either side of the urethral orifice in females + what are the homogenous with in men
Skene’s glands
homogenous with prostate
aa/vv supply female urethra (3)
internal pudendal aa/vv
vaginal aa /vv
inferior vesical branch of vaginal aa/vv
nn supply female urethra (3)
vesical plexus
pudendal nn
pelvic splanchnic (visceral afferents)
proximal female urethra LN drainage
internal iliac
distal female urethra LN drainage
superficial inguinal LN
Role of bladder (2)
Temporary storage of urine
Assists in expulsion of urine
typical maximum volume of bladder in a healthy adult
400-600mls
Name of superior aspect of bladder
apex
what connects the apex of the bladder to the umbilicus? what is the significance?
Median umbilical ligament
remnant of urachus
shape of fundus of bladder and position
posterior
triangular shaped
which part of the bladder is continous with the urethra?
neck
trigone wall vs rest of bladder wall + why?
smooth walled
as developed from mesonephric ducts
muscle of the bladder
destrusor muscle
How does the detrusor muscle of the bladder maintain structural integrity when stretched?
its fibres are orientated in multiple directions
what happens to the fibres of the detrusor muscle in outflow obstruction?
become hypertrophic
what are the 2 sphincters in the urethra?
internal urethral sphincter
external urethral sphincter
difference in males vs females internal urethral sphincter
males - circular smooth fibres - under autonomic control - prevent regurg
females - no muscle present
internal vs external urethral sphincter - which is under voluntary control
external urethral sphincter
aa supply bladder MALES
superior vesical aa
inferior vesical aa
(obturator + inf gluteal also supplement)
aa supply bladder FEMALES
superior vesical aa
vaginal aa
(obturator + inf gluteal also supplement)
vv drainage bladder
vesical venous plexus
where does the vesical venous plexus drain into?
internal iliac veins
lymphatic drainage superolateral bladder
external iliac LN
lymphatic drainage neck + fundus bladder (3)
internal iliac
sacral
common iliac LN
sympathetic nn for bladder + nn root
hypogastric nn T12-L2 - relaxes mm –> retention
parasympathetic nn bladder + nn root
pelvic nn S2-4
somatic nn bladder + nn root
pudendal nn S2-3
inn ext sphincter (voluntary control)
How does bladder communicate with brain
sensory - afferent nn in bladder wall
signal need to urinate when bladder is full
what is the bladder stretch reflex
primitive spinal reflex
micturition = response to stretch of bladder wall
when do you lose bladder stretch reflex?
toilet training
reflex arc of bladder stretch reflex
bladder fills –> stretch –> sensory nn transmit to SC –> parasymp nn (pelvic) –> contraction detrusor mm
reflex bladder - SC transection level
Above T12
Sx reflex bladder
bladder not aware of filling
constantly relaxed
spinal reflex present - empties as it fills
flaccid bladder - SC transection level
Below T12
Sx flaccid bladder
detrusor mm paralysed
no spinal reflex
bladder becomes abnormally distended –> overflow incontinence
length of ureters
25cm
embryological origin ureters
uteric bud from mesonephric duct
course of ureters in abdomen
renal pelvis @ uteropelvic junction –> along ant psoas major –> cross bifurcation of common iliac aa at sacroiliac joint
ureters in abdomen - peritoneal or retroperitoneal?
retroperitoneal
course of ureters in pelvis
down lateral pelvic wall –> turn anteromedially at ischial spine –> pierce bladder obliquely
aa supply - ureters in abdomen (3)
renal aa
testicular/ovarian aa
uteral branch of abdomen aorta
aa supply - ureters in pelvis (2)
superior + inferior vesical aa
aa to watch out for in terms of relation to ureters (3)
ovarian aa
uterine aa (water under the bridge) - vas deferens in males
superior vesical aa
nn supply ureters (3)
renal plexus
testicular/ovarian plexus
hypogastric plexus
which dermatome does referred pain from the ureters present at?
T11/12
Another name for Pelvic Splanchnic Nerves?
nervi erigentes
neumonic to remember layers of the scrotum
Some Damn Examiner Called It The Testes
Skin
Dartos mm
External Spermatic Fascia
Cremasteric fascia
Internal Spermatic Fascia
Tunica
Testes
