Session 4 - Group Work Flashcards
Which structure lies on the posterolateral border of the tests?
Epididymis
What do the seminiferous tubules anastomose to form posteriorly?
Rete testis
A fluid layer in the cavity of the ——— allows the testis to move
freely in the scrotum.
tunica vaginalis
Where is the origin of the testicular arteries?
Aorta, just inferior to the renal vessels
The testicular veins arise from the ______________ plexus and drain into the
_____________ on the right and the ____________ on the left.
pampiniform, IVC, left renal vein
How may the cremasteric reflex be evoked and what does it demonstrate?
Stroking the superior part medial thigh evokes elevation of the testis on that side. This part of
the thigh is innervated by the ilioinguinal nerve (L1); the genital branch of the genitofemoral
nerve (L1, L2) innervates the cremaster muscle. Hence, a spinal reflex arc is demonstrated.
Which smooth muscle layer causes the scrotal skin to wrinkle when exposed to cold temperatures?
Dartos
Discriminate between the lymphatic drainage of the scrotum and that of the testes
The scrotal skin (fascia and tunica vaginalis) drains to the superficial inguinal lymph nodes whereas lymphatic drainage of the testis is via the spermatic cord to the para-aortic glands at the transpyloric plane, L1 (hence, upper abdomen must be palpated). Further spread may be to mediastinal and cervical nodes.
Explain why spread of malignancy from the testis to the cervical nodes of the neck is not uncommon?
Lymphatic drainage to para-aortic nodes, which anastomose with intra-thoracic and in turn cervical lymph nodes
The efferent ductules transmit sperm from the —– to the ——–
Rete testis, head of the epidiymis
Describe the course of the vas deferens
Tail of epididymis, inguinal canal, side wall of pelvis close to ischial spine, then travels
medially and joins with ducts from the seminal vesicle to form ejaculatory duct which joins
the prostatic urethra, inferior to the bladder. (Hence, bladder, urethral and prostate infection
may spread to the vas deferens here.) It is typically 45 cm long
The spermatic cord commences superiorly at the deep inguinal ring lateral to the
___________________ artery. Passing through the inguinal canal it
terminates at the posterior border of the __________________.
inferior epigastric, testis
During vasectomy, the vasa deferentia are sectioned and ligated bilaterally from the
superoanterior scrotal wall. What are the consequences to (a) the sperm and (b) the
composition of the ejaculate (generally) after vasectomy?
(a) Sperm degenerate in the epididymis and proximal ductus deferens, debris is
removed by phagocytosis
(b) The ejaculate is composed of secretions form the prostate, seminal vesicle, and
bulbourethral glands only.
From which layers of the anterior abdominal wall are the fascial coverings of the
spermatic cord derived?
The double layer of the tunica vaginalis is surrounded by
• Internal spermatic fascia (from transversalis fascia)
• Cremasteric fascia (from fascial covering of the internal oblique)
• External spermatic fascia (from the external oblique aponeurosis)
These are followed by a layer of superficial fascia lying directly beneath the scrotal skin
During descent of the testes, at what fetal month do they usually …
…reach the iliac fossa …………………. month
…travel through the inguinal canal … month
…reach the external ring ……………… month
…enter the scrotum …………………….. month
(3, 7, 8, and 9 months respectively
What are the consequences of undescended testis?
infertility and potentially malignancy
What are the contents of the spermatic cord?
Ducts: Vas deferens (and its artery)
Vessels: Testicular artery, cremasteric artery, pampiniform plexus of veins
Nerves: Autonomic nerves, genital branch of the genitofemoral nerve
The smooth muschel of which structures contract in peristaltic waves during emission?
Prostate
Vas deferens
Seminal vesicles
How is the smooth muscle of prostate, vas deferens and seminal vesicles controlled?
Sympathetic - Hypogastric nerve )L1, L2)
Seminal vesicles - identifying the substances
they secrete, the functions of such and the percentage volume of secretion the
glands contribute to the semen (seminal fluid)
Seminal vesicles
- Fructose (Used in ATP production)
- Prostaglandins (facilitate sperm motility and smooth muscle contraction in the female tract)
- Clotting factors (particularly semenogelin (proteins which help temporarily to coagulate semen after ejaculation)
Alkalinity - Helps to neutralize the acid in the male urethra and female reproductive tract
- 60% volume
Prostate - identify the substances
they secrete, the functions of such and the percentage volume of secretion the
glands contribute to the semen (seminal fluid)
Prostate
- Proteolytic enzymes (PSA) which breakdown clotting proteins frpom the seminal vesicles, re-liquefying semen 10-20 minutes after ejaculatiion
- Citric acid
- Acid phosphotase
- 25% volume
Bulbourethral glands - identify the substances
they secrete, the functions of such and the percentage volume of secretion the
glands contribute to the semen (seminal fluid)
Alkaline fluid neutralizes acid of vagina and a mucous that lubricates the end of the penis and urethral lining
A prostate can grow to the size of an orange when enlarged but what is its usual
size?
Chestnut or golf ball (3 cm round)
Which part of the prostate gland is felt on rectal examination?
Posterior (median groove)
Enlargement of which lobe of the prostate causes urethral obstruction?
Median (This may not be detected on rectal examination; the lateral lobes, however, are
readily detected on rectal examination).
The arterial supply to the prostate, the inferior vesical artery, is a branch of the
________________________________.
Internal iliac artery
Why is it that cancer of the prostate often presents later than benign prostatic
hyperplasia (BPH)?
The cells that enlarge in BPH are close to the urethra, therefore causing a blockage of the
urethra. Cancerous cells are more peripheral and therefore only occlude the urethra at a
later, more advanced stage.
How do levels of PSA vary in BPH and carcinoma of the prostate?
BPH PSA normal/ slightly raised, carcinoma PSA markedly raised
Explain why carcinomas of the prostate spread readily to the pelvis and vertebrae.
(Hint : consider venous drainage)
Veins from prostatic venous plexus with dorsal vein of penis into internal iliac vein. Some of the veins pass verterbrae and are valveless, hence spread of malignancy
List the three parts of the urethra
Prostatic
Membranous
Spongy
Which part of the urethra is lead distensible
Membranous, due to the surrounding sphincter urethrae muscle and perineal membrane
Name the erectile tissue in the penis
Corpus cavernosa
Corpus spongiosum
Describe the arterial supply of the penis
Branches of the internal pudendal artery form
1) Deep arteries
2) Dorsal arteries
3) Arteries of the bulb
1) and 2) supply the crura and corpus cavernosa. 2) and 3) supply the bulb and the corpus spongiosum
Which fibrous capsule surrounds the corpora cavernosa?
Tunica albuginea
During erection of the penis, venous engorgement occurs through vasodilation of the
coiled (helicine) arterioles to the corpora cavernosa, hence increasing blood flow.
What is the effect of the tunica albuginea and fascial sheaths?
These resist expansion, such that internal pressure rises and occludes venous
drainage. Blood from the cavernous spaces drains into a venous plexus (which
are compressed during erection), then into the deep dorsal vein. This, along with
increased arterial flow, maintains rigidity of the penis for intercourse.
(Venous return is also restricted by contraction of the bulbospongiosus and
ischiocavernsosus muscles.)
Whist the corpus spongiosum swells with blood, it does not become rigid. Why not?
Whilst the tunica albuginea does surround the corpus spongiosum it is not as
fibrous or restrictive as that which surrounds the corpora cavernosa. High
pressure in the corpus spongiosum would occlude the urethra and hence prevent
ejaculation of the semen.
Predict what may happen, if the neck of the bladder (vesical sphincter) does not
close during ejaculation?
Retrograde ejaculation into the bladder
The pudendal nerves carry afferent, sensory information from the glans to the CNS
but which efferent outflow is involved in erection?
Pelvic nerve, parasympathetic (S2 - S4) , via inferior hypogastic plexuses promotes erection
in erectile tissue, through relaxation of smooth muscle in the fibrous trabeculae and
cooled arteries
Emission is sympathetically controlled. Ejaculation occurs via sympathetic outflow (L1 – L2)
Hypogastric, sympathetic, involved mostly in depression of erection, by increasing myogenic
tone in arterial smooth muscle.
Identify some common causes of erectile dysfunction.
- psychological problems
- tears in fibrous capsule of corpora cavernosa
- obstruction of blood flow to corpora cavernosa
- pharmacologica
Which part of the penis is removed in circumcision?
prepuce (foreskin)
Discriminate between the obstetric conjugate and the diagonal conjugate, which are
assessments of the female bony pelvis made during pregnancy prior to labour. (see
pages 7 - 9 Symonds and Symonds).
The OBSTETRIC conjugate is measured from the midpoint (i.e. thickest ) part of the pubis
(posterior surface) to sacral promontory. This is obstetrically the most important AP diameter
(as it is the narrowest AP diameter that the fetus passes through) and is usually about 10cm.
This diameter can only be assessed with imaging therefore clinicians use the DIAGONAL
CONJUGATE measured from inferior border of pubis to sacral promontory as an
assessment tool. This is measured by introducing two fingers into the vagina and palpating
the sacral promontory and noting where on one’s hand the under edge of pubis is. Most
clinicians do this so often that they immediately know by how far in the fingers go whether
this measurement is adequate. It usually needs to be about 11.5 cm.
A 22-year old male has a scrotal swelling.
4.40. List the causes of scrotal swelling?
hernia, hydrocoele, epididymal cyst, epididymitis, orchitis, spermatocoele, varicocoele, a
testicular mass and a cyst of the cord. A testicular mass is the most important diagnosis.
Why does a lump in the testis of a 22 year old need follow up?
Any lump in the testis must be a suspected tumour. Testicular cancer is the commonest
cancer that affects young men between the ages of 19 to 44 years old. Almost half of all
testicular cancers occur in men under 35 years old
In very general terms, how might you discriminate between a hernia and a swelling
associated with the testis?
A hernia can be reduced then feel for normal scrotal contents.
Which veins are dilated in a varicocœle? What does it feel like upon palpation?
The veins of the pampiniform plexus become dilated in the standing position. For reasons
that are postulated rather than known; it occurs, almost invariably, on the left side and a
right-sided varicocœle should always suggest malignant obstruction of the right testicular
vein. On palpation it feels like a bag of worms.
Predict why is a varicoceole almost always on the left? Why is a right sided
varicocoele potentially worrying? Hint think about the venous drainage.
The left testicular vein empties vertically into the renal vein. much higher than the right
drainage. The varicosities form when the valve system between these two veins fails and
blood falls backwards under the pull of gravity. The right testicular vein drains directly into
the inferior vena cava at an oblique angle, further down. Its valves do not have to support the
same weight of blood as those in the left testicular vein and are therefore much less likely to
fail. A right sided varicocoele is very uncommon and is suggestive of other, potentially more
serious problems such raised IVC pressure - e.g. due to obstruction.
What is a hydrocœle? Explain why hydrocœles in young boys often get bigger when they cough (or cry)”
A hydrocœles is usually a painless enlargement of the testis caused by accumulation of
watery fluid, in a persistent processus vaginalis (tunica vaginalis) surrounding the testis. It
can grow as large as a grapefruit!
Hydrocœles at this age are usually still connected to the peritoneal cavity by some persisting
patency of the processus. The patency is limited so raised intra-abdominal pressure is
required to send i.p. fluid through into the hydrocœle.
Explain why trans-illumination with a small bright torch can distinguish an epididymal
cyst from a spermatocœle.
An epididymal cyst contains clear fluid and transilluminates ‘brilliantly’, while a spermatocœle
contains turbid fluid that inhibits transillumination. Epididymal cysts arise from unconnected
segments of the efferent tubules that sprouted from the mesonephric duct hence the clear
fluid content. Spermatocœles arise similarly, but the segment is marginally connected to the rete testis and contains degenerate products of spermatogenesis. There is no important
clinical difference between them, other than embryological origin.
What is a haematoceole of the testis?
An accumulation of the blood in the tunica vaginalis (e.g., traumatic rupture of the testicular
artery). If therefore does not transilluminate.
Why is a NMR very good and palpation very poor at assessing lymphatic spread from
a testicular tumour?
Para-aortic nodes only become palpabl when they are massive
