15. Male reproductive system Flashcards
male genital organs
testes epididymis vas deferens ejaculatory duct seminal vesicles prostate
testis is surrounded by this fibrous capsule
tunica albuginea
this testis lies lower than the other side
left testis
posterior to the testis is this structure, vas deferens on its medial side
epiidymis
epididymis ave legnth
6 m long
storage and maturation of sperm cells
epididymis
blood supply/ venous drainage of epididymis
testicular a./v.
cremasteric artery (from inferior epigastric artery)
artery from vas deferens (from inferior vesical artery)
lymphatic drainage of epididymis
lumbar
testes near the deep inguinal ring
4th fetal month
testes within the deep inguinal ring
7th fetal month
descent into the scrotum from the deep inguinal ring
next few days to weeks after 7th fetal month
cotro
crytotorchid testis most likely location
inguinal canal
cryptorchidism occurs in __% o premature males
30%
thick walled muscular tube that transports spematozoa from epididymis to urethra
vas deferens
approx. length of vas deferens
45 cm long
path of vas deferens
from lower end of the epididymis–> inguinal canal –> crosses ureter to reach posterior bladder –> expands forming ampulla –> joins seminal vesicle –> ejaculatory duct
union of ampulla of vas deferens and duct of seminal vesices
ejaculatory duct
length of ejaculatory duct
<1 in
pierce the posterior surface of the prostate and opens into prostatic urethra
ejaculatory duct
alkaline phosphatase of semen is from
prostatic gland
testes are suspendedfrom the abdomen by the
spermatic cord
The testes have an ellipsoid shape. They consist of a series of lobules, each containing
seminiferos tubules
The seminiferous tubules are lined by
sertoli cells
fx of sertoli cells
aid the maturation process of the spermatozoa
In the interstitial tissue lie _____the that are responsible for testosterone production.
Leydig cells
Spermatozoa are produced in the
seminiferous tubules
The developing sperm travels through the tubules, collecting in the
rete testes
transport the sperm from the rete testes to the epididymis for storage and maturation.
efferent tubules
closed sac of parietal peritoneal origin that contains a small amount of viscous fluid
covering the testes
tunica vaginalis
penetrates into the parenchyma of each testicle with diaphragms, dividing it into lobules.
tunica albuginea
The most proximal part of the epididymis. It is formed by the efferent tubules of the testes, which transport sperm from the testes to the epididymis.
head
Formed by the heavily coiled duct of the epididymis.
body
The most distal part of the epididymis. It marks the origin of the vas deferens, which transports sperm to the prostatic portion of the urethra for ejaculation.
tail
give anastomoses to the main testicular artery.
cremasteric artery (from inferior epigastric artery)
artery from vas deferens (from inferior vesical artery)
Venous drainage is achieved via the paired testicular veins. They are formed from the
pampiniform plexus in the scrotum
left testicular vein drains into the
left renal vein
right testicular vein
drains
IVC
Since the testes are originally retroperitoneal organs, the lymphatic drainage is to the
lumbar and para-aortic nodes, along the lumbar vertebrae.
scrotum- lymph drains into the nearby
superficial inguinal nodes.
causes of scrotal swelling
- inguinal hernia
- hydrocele
- hematocele
- varicocele
- epididymitis
a collection of serous fluid within the tunica vaginalis.
hydrocele
congenital form of hydrocele is most commonly due to
failure of the processus vaginalis to close
adult hydrocele is often associated with
inflammation or trauma and rarely, testicular tumors.
a collection of blood in the tunica vaginalis.
hematocele
hematocele is distinguished from hydrocele by
transillumination (where a light is applied to the testicular swelling). Due to the dense nature of blood, light is unable to pass through.
gross dilation of the veins draining the testes.
varicocele
which testes is more commonly affected by varicocele
The left testicle is more commonly affected, as the left testicular vein is longer and drains into the left renal vein at a perpendicular angle.
can look and feel like a “bag of worms” within the scrotum
large varicocele
Varicocoele is quite common in the general population; its prevalence is estimated at
15-25%
inflammation of the epididymis, usually caused by bacterial or viral infection
epididymitis
fibromuscular cutaneous sac, located between the penis and anus. It is dual-chambered, forming an expansion of the perineum.
scrotum
Embryologically, the scrotum is derived from the paired genital swellings. During development, the genital swellings fuse in the midline – in the adult this fusion is marked by the
scrotal raphe
scrotum is biologically homologous to the
labia majora
is a sheet of smooth muscle, situated immediately underneath the skin of the scrotum
dartos muscle
scrotum receives arterial supply from
anterior and posterior scrotal arteries
anterior scrotal artery arises from the external pudendal artery, while the posterior is derived from the internal pudendal artery.
nerves supplying the scrotum
Anterior and anterolateral aspect – Anterior scrotal nerves derived from the genital branch of genitofemoral nerve and ilioinguinal nerve
Posterior aspect – Posterior scrotal nerves derived from the perineal branches of the pudendal nerve and posterior femoral cutaneous nerve.
The lymphatic fluid from the scrotum drains to the nearby
superficial inguinal nodes.
refers to a collection of vessels, nerves and ducts that run to and from the testes. They are surrounded by fascia, forming a cord-like structure.
spermatic cord
The spermatic cord is formed at the opening of the inguinal canal, known as
deep inguinal ring
deep inguinal ring is located laterally to these vessels
inferior epigastric vessels
The cord passes through the inguinal canal, entering the scrotum via the
superficial inguinal ring
The contents of the spermatic cord are mainly bound together by three fascial layers and their derivations from the anterior abdominal wall:
External spermatic fascia – derived from deep subcutaneous fascia (fascia innominata).
Cremaster muscle and fascia – derived from the internal oblique muscle and its fascial coverings.
Internal spermatic fascia – derived from the transversalis fascia
The three fascial layers themselves are covered by a layer of
superficial fascia
forms the middle layer of the spermatic cord fascia. It is a discontinuous layer of striated muscle that is orientated longitudinally.
cremaster muscle
The cremasteric reflex can be stimulated by stroking the
superior and medial part of the thigh.
This produces an immediate contraction of the cremaster muscle, elevating the testis on the side that has been stimulated.
cremasteric reflex
nerve that supplies the cremaster muscle.
Genital branch of the genitofemoral nerve
network of veins, responsible for the venous drainage of the testes. It has a unique configuration, wrapping itself around the testicular artery
pampiniform plexus
acts as a heat exchanger, cooling the arterial blood before it reaches the testes.
pampiniform plexus
The wall of the vas deferens consists largely of smooth muscle, arranged in three muscle layers:
inner layer : longitudinal smooth muscle
intermediate layer - circular smooth m.
outer- longitudinal s.m.
movement is also facilitated by the inner mucosal layer of the vas deferens – which is lined by cells that possess
microvilli
anatomical course of the vas deferens is as follows:
It is continuous with the tail of the epididymis.
Travels through the inguinal canal, as part of the spermatic cord.
Moves down the lateral pelvic wall close to the ischial spine.
Turns medially to pass between the bladder and the ureter and then travels downward on the posterior surface of the bladder.
The inferior narrow part of the ampulla joins the duct from the seminal vesicle to form the ejaculatory duct
is a surgical emergency, where the spermatic cord twists upon itself. This can lead to strangulation of the testicular artery, resulting in necrosis of the testes.
testicular torsion
A common cause of testicular torsion is spasm of the
cremasteric muscle fibers
diagnosis of testicular torsion can be confirmed
ultrasound and colour doppler scanning.
The main clinical feature of testicular torsion
severe, sudden pain in the affected testis which usually lies higher (due to the torsion of the cord) in the scrotum.
bulbourethral glands also known as
Cowper’s glands
are a pair of pea shaped exocrine glands located posterolateral to the membranous urethra.
Cowper’s glands
contribute to the final volume of semen by producing a lubricating mucus secretion.
Cowper’s glands
the largest accessory gland in the male reproductive system.
prostate
act to break down clotting factors in the ejaculate.
proteolytic enzymes
This allows the semen to remain in a fluid state, moving throughout the female reproductive tract for potential fertilisation.
proteolytic enzymes
prostate is positioned inferiorly to the neck of the bladder and superiorly to this structure
external urethral sphincter
Most importantly, posteriorly to the prostate lies the
ampulla of the rectum
The proteolytic enzymes leave the prostate via the
prostatic ducts
prostatic ducts - open into the prostatic portion of the urethra, through 10-12 openings at each side of the
seminal colliculus (or verumontanum)
three zones of the prostate
central zone
transitional zone
peripheral zone
surrounds the ejaculatory ducts, comprising approximately 25% of normal prostate volume.
central zone
The ducts of the glands from the ____ zone are obliquely emptying in the prostatic urethra, thus being rather immune to urine reflux.
central
located centrally and surrounds the urethra, comprising approximately 5-10% of normal prostate volume.
transitional zone
The glands of the _____ are those that typically undergo benign hyperplasia (BPH)
transitional zone
makes up the main body of the gland (approximately 65%) and is located posteriorly.
peripheral zone
The ducts of the glands from the peripheral zone are ____ emptying in the prostatic urethra; that may explain the tendency of these glands to permit urine reflux.
vertically
high incidence of acute and chronic inflammation found in these compartment of the prostate
peripheral zone
high incidence of prostate carcinoma at this zone.
peripheral zone
the fourth zone of the prostate
fibromuscular stroma
arterial supply to the prostate comes from
prostatic arteries, which are mainly derived from the internal iliac arteries
Venous drainage of the prostate is via the
prostatic venous plexus (draining into the internal iliac veins)
prostatic venous plexus also connects posteriorly by networks of veins, including the
Batson venous plexus, to the internal vertebral venous plexus.
prostate receives sympathetic, parasympathetic and sensory innervation from the
inferior hypogastric plexus
The smooth muscle of the prostate gland is innervated by sympathetic fibres, which activate during
ejaculation
represents the most commonly diagnosed cancer in men, especially in countries with high sociodemographic index.
Prostatic carcinoma
The malignant prostatic cells commonly originate from this zone
peripheral zone
Prostate carcinoma also commonly spreads via the ____to the vertebral bodies and cause skeletal metastases.
Batson venous plexus
However, due to the peripherally-advancing tumor, symptoms may be
minimal
is an enzyme (serine protease) secreted by the prostatic epithelium that aids the liquification of the ejaculate by lysing seminal vesicle proteins.
Prostate Specific Antigen (PSA)
the main clinical use of PSA
tumor marker specific for prostate carcinoma.
these may also increase the PSA levels in the serum:
inflammation, severe constipation, extended sexual intercourse or catheterisation
inverted pyramid the size of a walnut
prostate
Base of prostate located
inferior to the neck of bladder
apex of the prostate lies
on the sphincter urethra
BPH commonly occurs at this site
periurethral zone of the prostate
adenocarcinoma of prostate
lab results
elevated
prostatic acid phosphatase
prostate specific antigen
They contribute to the final volume of semen by producing a lubricating mucus secretion.
bulbourethral glands (also known as Cowper’s glands)
bulbourethral glands can be found in this layer
deep perineal pouch
Cowper’s glands themselves can be described as compound tubulo-alveolar glands lined by
columnar epithelium
Embryologically the bulbourethral glands are derived from the
urogenital sinus
•along with the bladder, prostate and urethra
cowper’s glands , bladder, prostate and urethra
development are greatly influenced by
DHT (dihydrotestosterone)
During sexual arousal, the bulbourethral glands produce a mucus secretion containing
glycoproteins
three purposes of glycoproteins secreted by bulbourethral glands
Serves as lubrication medium for the urethra and the tip of the penis.
Expels any residue of urine, dead cells or mucous through the urethral meatus, preparing a clean and lubricated pathway for ejaculation.
Helps to neutralise residual acidity in the male urethra (secretions are alkaline).
spermatozoa in body temperature survive for more than
48 hours
The arterial supply of the bulbourethral glands is derived from the
arteries to the bulb of the penis
innervation of bulbourethral glands
pelvic ganglia (PG), sympathetic chain ganglia (L2–S3), the caudal mesenteric ganglion and dorsal root ganglia (L1–L3, S1–S3); via hypogastric nerve and the pelvic nerve or pelvic branch of the pudendal nerve.
Like the seminal vesicles the bulbourethral glands drain into the
internal and external iliac lymph nodes
ultimately provide around 70% of the total volume of semen.
seminal vesicles
glands located between the bladder fundus and the rectum (separated from the latter by the rectovesicle pouch and the rectoprostatic fascia).
seminal glands
seminal gland - has a honeycombed, lobulated structure with a mucosa lined by
pseudostratified columnar epithelium
seminal glands lined by pseudostratified columnar epithelium
These columnar cells are influenced by
testosterone
Seminal glands, along with the Ejaculatory ducts, Epididymis and Ductus (vas) deferens, are derived from the
mesonephric ducts
the fluids from the _____are included in the late ejaculate fractions.
seminal vesicles
neutralises the acidity of the male urethra and vagina in order to facilitate the survival of spermatozoa.
Alkaline fluid
have a role in suppressing the female immune response to foreign semen.
Prostaglandins
designed to keep semen in the female reproductive tract post-ejaculation.
Clotting factors
arteries to the seminal gland are derived from
inferior vesicle, internal pudendal and middle rectal arteries, all of which stem from the internal iliac artery.
The innervation of the seminal gland, like much of the male internal genitalia, is mainly
sympathetic
Point and Shoot
lymphatic drainage of the seminal gland is the
external and internal iliac lymph nodes.
Inflammation of the seminal vesicles
vesiculitis or spermatocystitis
vague perineal or penile pain, discomfort during ejaculation and haemospermia (blood in the ejaculate) are suggestive of
vesiculitis or spermatocystitis
In rare cases, obstruction of the seminal vesicle duct may lead to abscess formation.
tx
paracentesis
which may be facilitated by transrectal ultrasound (TRUS) guided aspiration.
A laboratory investigation of ____ in a sperm specimen may provide indirect evidence of seminal vesicle dysfunction, obstruction or congenital absence
fructose levels
