Repro 4 Flashcards
4 component parts of male reproductive system?
paired testes- site of spermatozoa production, and sex hormone secretion
duct system- transports spermatozoa to urethra
accessory sex glands- supply fluid components to semen: prostate, seminal vesicles, bulbourethral glands
penis
type of gland the testis is?
compound tubular gland
What does the tunica albuginea form posteriorly that contains many interconnected channels which provide passageways for sperm to enter duct system?
mediastinum testis
muscle contained within superficial fascia of the scrotum?
dartos muscle
what are the testes contained within?
the scrotal sac
the 2 types of cells found within the seminiferous epithelium?
sertoli cells (supporting cells) spermatogenic cells (germ cells)
most primitive spermatogenic cells?
spermatogonia-rest on BM
distinguishing between spermatids and spermatozoa on microscopy?
spermatids- lightly stained round nucleus
spermatozoa- deeply staining heads, which appear to be embedded in sertoli cells, their tails hanging into lumen of seminiferous tubule
approximate length of spermatogenesis?
70 days
what is oligozoospermia?
clinical condition where abnormally low number of spermatozoa in semen.
what is azoospermia?
no sperms appear in ejaculate
what is cryptorchid (maldescended) testis, and what problems can it create?
spermatogenesis impaired as elevated temperature. Germs cells absent, while Sertoli and Leydig cells secrete male sex hormones.
Associated with increased incidence of malignant testicular tumours
what is orchitis?
inflammation of testes- occurs in some people who suffer mumps after puberty, causing impaired spermatogenesis, occasionally leading to seminiferous tubule degeneration, or at times, infertility.
what happens to sperm in the epididymis?
transport, mature, stored
stored in tail segment until ejaculation
name of terminal portion of vas deferens?
ampulla
how is the ejaculatory duct formed?
ampulla of vas deferens joins with duct of seminal vesicle
ejaculatory duct then opens into prostatic urethra
epithelial lining of ductus epididymis- duct of the epididymis?
pseudostratified columnar with stereocilia
discontinuous layer of longitudinally-oriented strands of striated muscle enclosing spermatic cord?
cremaster muscle
collection of small veins surrounding vas deferens, and forming most bulk part of spermatic cord?
pampiniform plexus
which bacteria may cause epididymitis?
N gonorroheae, E coli, Chlamydia trachomatis
sequence of secretions that forms ejaculate?
bulbourethral glands
prostate
spermatozoa
seminal vesicles
where do the seminal vesicles lie?
posterior to prostate
where are the bulbourethral glands located?
within the urogenital diaphragm
3 cylindrical bodies of erectile tissue forming the penis?
2 corpora cavernosa penis
single corpus cavernosum urethrae (corpus spongiosum)
importance for testes to be contained within scrotum?
keeps them at the low temperature necessary for spermatogenesis by allowing the testis to sit outside of the body
what remnant of peritoneum forms a fluid filled structure around testes?*
tunica vaginalis
why is the spermatic cord important to the testes?
it contains the testicular blood vessels- testicular artery and pampiniform venous plexus, and the ductus deferens
function of the small amount of fluid in the cavity of the tunica vaginalis?
to allow testes to move freely in scrotum
origin of testicular arteries?
abdominal aorta, just inferior to renal arteries- IV disc between L1 and L2 vertebrae
origin of testicular veins?
pampiniform venous plexus, which lies anterior to the vas deferens and surrounds the testicular artery in the spermatic cord
drainage of testicular veins?
R: IVC
L: left renal vein
drainage of testicular veins?
R: IVC
L: left renal vein
how may the cremasteric reflex be evoked and what does it demonstrate?
by lightly stroking medial aspect of superior part of the thigh, which causes the cremaster muscle to contract and result in rapid elevation of the testis on the same side. Area of skin supplied by ilioinguinal nerve which synapses in the SC and activates the motor fibres of the genital branch of the genitofemoral nerve causing cremaster muscle contraction
problem of hyperactive cremasteric reflex in children?
may be mis-diagnosed as cryptorchidism
hyperactive reflex can be aboloished by getting children to sit cross-legged in a squatting position as if the testes are descended, they can then be palpated in the scrotum
problem of hyperactive cremasteric reflex in children?
may be mis-diagnosed as cryptorchidism
hyperactive reflex can be aboloished by getting children to sit cross-legged in a squatting position as if the testes are descended, they can then be palpated in the scrotum
where is the internal spermatic fascia derived from?
transversalis fascia
where is the cremasteric spermatic fascia derived from?
fascia of both superficial and deep surfaces of internal oblique muscle, and transversalis fascia
where is the external spermatic fascia derived from?
external oblique aponeurosis and its investing fascia
describe the course of the spermatic cord
begins at deep inguinal ring, lateral to the inferior epigastric vessels, passes through inguinal canal, exits at superficial inguinal ring, and ends in the scrotum at the posterior border of the testis
why is a L sided varciocele more common than a R sided one?
because the acute angle of entry of the R testicular vein into the IVC is more favourable to flow than the nearly 90 degree angle at which the L testicular vein enters the L renal vein, making it more susceptible to obstruction or flow reversal
contents of the scrotum?
testis
first part of spermatic cord
epididymis
optimum temp for enzymes responsible for spermatogenesis?
2 degrees below normal body temp
what is the septum of the scrotum?
continuation of dartos fascia separating scrotum into R and L compartments internally, 1 for each testis
how is septum of scrotum marked externally?
by scrotal raphe- cutaneous ridge marking line of fusion of labioscrotal swellings
what is the internal spermatic fascia lined by internally?
the parietal layer of the tunica vaginalis
what is the sinus of the epididymis?
slit-like recess of tunica vaginalis, between body of the epididymis and PL surface of testis
where does an undescended testis commonly lie?
in the inguinal canal
why is increased risk of testicular malignancy in undescended testis in cryptorchidism part. problematic?
not palpable and not usually detected until cancer has progressed
what structures enable an adequate temp in testes for spermatogenesis to occur?
dartos muscle
cremaster muscle
pampiniform venous plexus
location of scrotum in relation to penis and pubic symphysis?
PI to penis, and inferior to PS
where is the surface of the testis not covered by the visceral layer of the tunica vaginalis?
where testis attaches to epididymis and spermatic cord
what is the processus vaginalis and how is it formed formed?
peritoneal invagination which made pathway for descent of testes into scrotum
musculo-fascial layer evaginates into scrotum as it develops, together with peritoneal membrane
describe course of testicular arteries?
pass retroperitoneally in oblique direction, crossing over ureters and inferior parts of external iliac arteries to reach deep inguinal rings where enter inguinal canal, exit through superficial inguinal rings, enter spermatic cords to supply testes
artery or 1 of its branches anastomoses with artery of vas deferens
how is pampiniform venous plexus formed?
by veins emerging from testis and epididymis
importance of configuration of pampiniform venous plexus?
veins wrapped around testicular artery in a meshwork that enables cooler venous blood to pass next to warmer arterial blood, that can then be cooled via a heat-exchange mechanism to ensure testes are kept in cool environ. necessary for spermatogenesis
components of spermatic cord?
testicular artery cremasteric artery artery to vas deferens vas deferens pampiniform venous plexus genital branch of genitofemoral nerve vestige of processus vaginalis lymphatic vessels
why is testicular torsion a surgical emergency?
necrosis of testis may occur: twisting of spermatic cord obstructs venous drainage, with resultant oedema and haemorrhage, and subsequent obstruction of the testicular artery. Twisting just above upper pole of testis.
how can recurrence/occurrence of torsion of spermatic cord on contralateral side be prevented?
both testes surgically fixed to scrotal septum- continuation of dartos fascia
lymphatic drainage of testes?
paraaortic lymph nodes- not palpable, would only be seen by imaging
lymphatic drainage of scrotum?
superficial inguinal lymph nodes- palpable
innervation of testes and scrotum?
lumbar plexus- anterior surface
sacral plexus- posterior and inferior surfaces
what is a hydrocele of testis?
serous fluid in tunica vaginalis so layers opened up. Confined to scrotum, tunica vaginalis distended.
why might haematocoele of testis occur?
collection of blood in tunica vaginalis may result from rupture of branches of testicular artery by trauma to testis
how could a hydrocele of testis be differentiated from a haematocele?
transillumination- blood does not transilluminate as denser so doesn’t let light pass through
what is a varicocele?
varicosities of pampiniform venous plexus
why is a varicocele typically not visible when patient supine?
veins able to drain, especially if scrotum elevated as gravity allowed to empty the veins
how may varicoceles be caused?
defective valves in testicular vein, or kidney or renal vein problems e.g. traction on SMA causing compression of L renal veins
what is a spermatocele?
epididymal cyst containing spermatogonia
developmental basis of indirect inguinal hernia?
reopening of processus vaginalis
potential continuity between peritoneal cavity and tunica vaginalis- so between abdomen and scrotum
what does seminal vesicle develop from?
diverticulum of vas deferens
what is a hydrocele of the spermatic cord?
presence of excess fluid in a persistent processus vaginalis as result of secretion of abnormal amount of serous fluid from visceral layer of tunica vaginalis
where do the seminal vesicle lie anatomically?
between the bladder and the rectum
where does duct of seminal vesicle join vas deferens?
within body of prostate gland
describe the composition of the seminal vesicle secretion
thick, alkaline fluid with fructose- energy source for sperms, PGs, aa and proteins, so male gamete receives nutrition and is buffered
how are superior ends of seminal vesicles separated from rectum?
by peritoneum of rectovesical pouch
inferior ends separated by rectovesical septum
important anatomical relationships of prostate?
base- neck of bladder
apex- urethral sphincter and deep perineal muscles
muscular anterior surface- urethral sphincter
posterior- ampulla of rectum
infero-lateral- levator ani
why do prostatic malignancies tend to present late?
affect peripheral zone of prostate, so don’t produce urinary symptoms e.g. nocturia and urgency, until later on
how can prostatic malignancies spread via lymphatics?
via internal iliac and sacral LNs
why does the prostate give rise to bony metastases, commonly in the back?
as venous drainage via internal vertebral plexus to vertebrae and brain
why can a DRE be used to look for prostatic malignancy?
as prostate lies anterior to the rectum
3 parts to penis?
root, body and glans
internal structure of penis?
pair of corpora cavernosa dorsally
single corpus spongiosum ventrally which is continuous with glans distally
blood supply of penis?
branches of internal pudendal arteries- branches of anterior division of internal iliac artery
penis innervation?
pelvic splanchnic and pudendal nerves
importance of corpus spongiosum remaining soft during erection?
contains spongy penile urethra so ensures that urethra isn’t obstructed which would prevent release of ejaculate
what covers each cavernous body of penis?
the tunica albuginea
how are the corpora cavernosa and corpus spongiosum bound together?
the deep fascia of the penis- superficial to tunica albuginea and is a continuation of deep perineal fascia
what is the venous drainage of the penis?
blood from cavernous spaces drained by venous plexus of penis, that joins deep dorsal vein of penis, then prostatic venous plexus, internal iliac vein, and IVC
function of bulbospongiosus?
a superficial muscle of perineum, responsible for helping to expel last drops of urine as forms a constrictor that compresses bulb of penis and corpus spongiosum, also assist in keeping an erection by increasing pressure on erectile tissue in root of penis
function of ischiocavernosus?
superficial perineal muscle, surrounds crura in root of penis, compresses veins, restricting venous outflow and so help maintain erection
least distensible part of male urethra?
membranous part
when can suprapubic catheterisation be used?*
bladder very enlarged and risen above pubic bone
how is the posterior rim of the pelvic outlet defined?
by ligaments- sacrotuberous ligament
boundaries of pelvic outlet (inferior pelvic aperture)?
pubic arch anteriorly
ischial tuberosities laterally
inferior margin of sacrotuberous ligament posterolaterally
tip of coccyx posteriorly
features of gynecoid pelvis making it suitable for childbirth?
wide, oval and rounded pelvic inlet
pelvic outlet comparatively large
sacral promontory only makes small indentation into pelvic cavity
wide subpubic angle (>80o)
straight side walls of mid-pelvis
greater sciatic notch almost 90o, well-rounded
ischial spines not too prominent
thin and light shallow false pelvis wide and shallow, cylindrical true pelvis oval obturator foramen small acetabulum
features of male (android) pelvis?
thick and heavy prominent ischial spines prominent projecting promontory of sacrum heart-shaped, narrow pelvic inlet narrow subpubic angle <70o comparatively small pelvic outlet funnel shaped pelvic cavity round obturator foramen large acetabulum deep false pelvis narrow and deep, tapering true pelvis
what is the pelvic inlet (entrance into lesser pelvis)- superior pelvic aperture, formed by?
promontory and ala of sacrum posteriorly
right and left linea terminalis anteriorly: arcuate line, pectineal line and pubic crest
what is the pelvic inlet defined by?
the pelvic brim
* ureter crosses pelvic brim at bifurcation of common iliac artery, and this is a point of ureteric constriction
how is the pelvic inlet assessed clinically?
AP diameter:
- anatomic conjugate: Measured from the sacral promontory to the superior border of the pubic symphysis
- obstetric conjugate: from sacral promontory to midpoint of pubic symphysis, midpoint of PS can’t be palpated, but this is minimum diameter of pelvic canal as is where pubic bone is thickest
- diagonal conjugate: from sacral promontory to inferior border of pubic symphysis, gives reasonable approx of min AP diameter
how can size of pelvic outlet be increased during pregnancy?
progesterone makes ligaments- sacrotuberous, softer and more capable of stretch, so more give in pelvic outlet
what is the greater pelvis?
(false pelvis) part of pelvis:
superior to pelvic inlet
bounded by iliac alae posterolaterally and antero-superior aspect of S1 vertebra post
occupied by abdom viscera e.g. ileum and sigmoid colon
no obstetric relevance, lies above linea terminalis
what is the lesser pelvis?
(true pelvis) part of pelvis:
between pelvic inlet and outlet
bounded by pelvic surfaces of hip bones, sacrum and coccyx
includes true pelvic cavity and deep parts of perineum, specif ischioanal fossae
bony canal- solid and immobile, so limiting, obstetric relevance
importance of testosterone in spermatogenesis?
necessary for proliferation and differentiation of spermatogenic cells
how is testosterone maintained at a relatively high conc in testes?
due to high concentration of androgen binding protein
how are efferent ductules specialised for sperm transport?
ciliary action- pseudostratified cililiated columnar cells, and myoid contraction- cells beneath BM
which zone of prostate does BPH commonly affect?
transition zone
which zone of prostate does prostatic carcinoma commonly affect?
peripheral zone
most common type of prostatic cancer?
adenocarcinoma
which cells are involved in most ovarian cancers?
epithelial- simple cuboidal
as continuous rupture and repair of epithelium with ova release
name given to site of transition between vaginal and cervical epithelium, which is most common site of neoplasms?
transformation zone
describe the course of the vas deferens
begins in tail of epididymis, at inferior pole of testis
ascends posterior to testis, medial to epididymis
forms main component of spermatic cord
penetrates A abdom wall via inguinal canal
crosses over external iliac vessels and enters pelvis
passes along lateral wall of pelvis, where it lies external to parietal peritoneum
ends by joining duct of seminal vesicle to form ejaculatory duct in body of prostate
nerve roots of ilioinguinal and genital branch of genitofemoral nerves, and hence what is demonstrated by the cremasteric reflex?
ilioinguinal- L1
genitofemoral- L1, L2
spinal reflex arc
which smooth muscle layer causes scrotal skin to wrinkle on cold exposure?
dartos muscle
where are the paraaortic LNs located anatomically?
transpyloric plane*, L1
why can a malignancy in the testis spread to cervical LNs?
testes originate on post abdom wall, relocate to scrotum, taking their lymphatic drainage with them, so drain into para-aortic LNs were metastasis can spread, and these LNs anastomose with intra-thoracic and in turn, cervical LNs
where can bladder, prostate and urethral infections spread to vas deferens?
where it joins the duct of the seminal vesicle to form the ejaculatory duct within the body of the prostate gland, which joins prostatic urethra, inferior to bladder
describe layers surrounding testes, from superficial to deep
scrotal skin superficial fascia (dartos fascia) spermatic fascia: external spermatic cremasteric internal spermatic tunica vaginalis tunica albuginea
at what fetal mnth do testes reach iliac fossa?
3
at what fetal mnth do testes travel through inguinal canal?
7
at what fetal mnth do testes reach external ring?
8
at what fetal mnth do testes enter scrotum?
9
how are peristaltic waves during emission controlled?
Sympathetic nervous system- hypogastric nerve (L1, L2)
function of PGs in secretion by seminal vesicles?
facilitate sperm motility and may promote smooth muscle contraction in female tract
characteristics and components of prostate secretion
thin, milky, slightly acidic
proteolytic enzymes e.g. PSA, pepsinogen
citric acid
acid phosphotase
function of proteolytic enzymes in prostate secretion?
bdown clotting proteins from SV secretion so semen re-liquefied 10-20 mins after ejaculation
function of citric acid in prostate secretion?
used by sperm in TCA cycle for ATP production
why is the membranous part of the urethra the least distensible part?
surrounded by sphincter urethrae muscle and perineal membrane
describe arterial supply of penis
branches of internal pudendal artery which form deep arteries, dorsal arteries and arteries of the bulb
deep arteries and dorsal supply crura and corpora cavernosa
dorsal arteries and arteries of bulb supply bulb and corpus spongiosum
how is corpus spongiosum stopped from becoming rigid in male?
tunica albuginea that surrounds it is not as fibrous or restrictive as that surround the corpora cavernosa
problem of undescended testes?
infertility
increased risk of testicular malignancy
