Flashcards in Repro 4- male anatomy Deck (97):
What is the errectile tissue found in the male penis?
In the root-
- 2x crura (right and left crus of the penis)
- 1x bulb of penis
In the shaft
2x corpora cavernosa
1x corpus spongiosum (swells distally to form glans penis)
What are the muscles of the penis? And their functions
2X ischiocavernosa (maintains erection by compression of veins, stopping blood from leaving)
2x bulbospongiosus (expel last drops of urine and maintain erections)
What are the main parts of the male reproductive tract?
testes and scrotum
seminal vesicles and prostate gland
In relation to the testes, where is the epidydimis?
on the posterolateral side.
Where do the testes begin development?
In the posterior abdominal wall.
What connects the testes to the abdomen?
The spermatic cord.
How can the testes be anatomically divided up?
What different areas are there within the testes?
split into lobules (coming from the tunical albuginea)which contain seminiferous tubules.
These drain into the rete testes (grid like)
This drains via the efferent tubules into the epididymis (for storage)
What are the 2 coverrings of the testes?
Where are they derived from?
Tunica vaginalis- covers the testis anteriorly and is derived from the abdominal peritoneum during development.
Tunica albuginea- fibrous capsule enclosing entire testis, and splitting it into lobules.
How can the epididymis be further classified?
What's the innervation of the testes?
Via the testicular plexus
Also autonomic and sensory fibers.
Whats the arterial supply of the testes?
The testicular arteries, which come off the abdominal aorta, just below the renal arteries.
Whats the venous drainage of the testes?
the testicular veins.
The left testicular vein drains into the left renal vein,
The right testicular vein drains into the IVC.
describe the pampiniform plexus and it's function.
It's a meshwork of veins which surround the testicular arteries, and act to cool the blood going to the testes.
The testes lie lower than the core of the body so they are cooler, as this is more optimal for sperm development. Venous blood is cooler because it has been further from the core, so as it returns to the body it cools the warm arterial blood coming from the core.
Where are the testicular veins derived from?
The pampiniform plexus.
What's the lymphatic drainage of the testes?
How does this differ from the drainage of the scrotum?
testes- drain via the para-aortic lymph nodes (think of embryonic origin)
Scrotum- drain to local superficial inguinal nodes.
What could be the cause of an enlarged scrotum?
What is a hydrocoele?
collection of serous fluid within the tunica vaginalis,commonly due to failure of the tunica vaginal to properly close.
(There will always be a small amount of serous fluid because the tunica vaginalis is derived from abdominal coverings, therefore peritoneum)
What is a haematocoele?
Collection of blood in the tunica vaginalis.
How can you tell the difference between a hydrocoele and a haematocoele?
Trans-illumination- shine a light through the testes, hydrocoele you'll pass more light through because serous fluid is transparent compared to blood.
What is a spermatocoele?
A painless fluid filled cyst in the epididymis, which may be due to dead sperm.
What is epididymitis?
Infammation of the epididymis due to infection, usually
viral or bacterial.
Would treat with the appropriate medication.
What is a varicocoele?
dilation of the veins within the testes.
Feel like a bag of worms.
Can be due to impaired drainage of the veins, so more commonly affects the left testicle because this drains into the left renal vein, a smaller vessel.
What is the scrotum?
a fibromuscular cutaneous sac
What are the contents of the scrotum?
What is the dartos muscle?
What's it'f function?
How does it achieve this?
A flat sheet-like muscle found under the skin, which acts to regulate temperature by wrinkling the skin.
Wrinkled skin will have decreased surface area, so lose less heat.
What's the arterial supply of the scrotum?
Anterior scrotal artery (from the external pudendal nerve, which comes from the external iliac artery)
Posterior scrotal artery (from the internal pudendal artery, which comes from the internal iliac artery)
from which main nerves does the scrotum receive it's innervation?
-anterior scrotal nerves (ilioinguinal nerve)
-posterior scrotal nerve (perineal nerve)
-posterior cutaneous nerve of thigh
Where dot he lymphatics of the scrotum drain?
Superficial inguinal nodes.
What's the function of the cremaster muscle?
Acts to raise/lower the testes, in response to temperature changes.
Where does the spermatic cord originate and end?
Begins at the deep inguinal ring (lateral to the inferior epigastric arteries)
travels through inguinal canal and superficial inguinal ring
ends at posterior border of testes.
What are the coverrings of the spermatic cord and from where do they originate?
-external spermatic fascia (from the aponeurosis of the external oblique)
-cremasteric muscle and it's fascia (from the internal obliqe and it's fascia)
-internal spermatic fascia (From the tranversalis fascia)
What are the features of the cremasteric muscle?
What is the cremasteric reflex?
By stroking the superior-medial aspect of the thigh, there will be an instant lifting of the corresponding testis, due to contraction of the cremasteric muscle
What are the limbs of the cremasteric reflex?
afferent- illioinguinal nerve
Efferent- gential branch of genitofemoral nerve.
What are the contents of the spermatic cord?
-artery to the vas deferens (from inferior vesicle artery)
-genital branch of the genitofemoral nerve
What is the vas deferens?
A stright thick muscular tube that carries sperm from the epididymis to the seminal vesicle, where they combine to from the ejaculatory duct.
What are the wall layers of the vas deferens?
3 muscular layers
Why is a rich autonomic innervation required in the vas deferens?
to permit fast movement of the sperm towards ejaculatory duct.
What is the route of the vas deferens?
-continuous with the tail of the epididymis
-travels through the inguinal canal
-runs along lateral pelvic wall (close to ischial spines)
-turns medially between urethra and bladder
-combines with seminal vesicle to from ejaculatory duct.
What is it called when there is twisting of the spermatic cord upon itself?
/Why is testicular torsion a medical emergency
It can block blood supply of the testicular artery, leading to necrosis of the testes.
When does testicular torsion normally occur?
During physical activity/ exercise.
How do you identify a testicular torsion?
ultrasound and colour doppler scanning.
What is doppler scanning?
The use of high frequency sound waves that bounce of blood flowing through vessels to give you an idea of the blood flow.
What is the function of the prostate?
To secrete proteolytic enzymes which break down clotting factors, keeping the semen in a fluid state during ejaculation and within the female.
What is the size of the prostate?
What proportion of this is glandular/fibromuscular?
the size of a walnut.
What is the prodtate gland surrounded by?
The fibrous capsule of the prostate.
What are some important anatomical relations of the prostate?
-surrounds the urethra
-lies between the neck of the bladder and EUS
-close proximity tot he rectum posteriorly, (DRE)
How and when are the proteolytic enzymes secreted?
Via proteolytic ducts, into the prostatic part of the urethra, just before ejaculation.
Which 2 ways can you divide the prostate gland up?
-zones (more commonly used)
What are the zones of the prostate gland?
-central zone surrounds the ejaculatory ducts, (comes from wollfian duct embryologically)
-transitional zone- surrounds urethra, (embryologically from urogenital sinus)
- peripheral zone- makes up the bulk, found posteriorly, (originates from urogenital sinus)
Which zone of the prostate would you feel best via a DRE?
What is BPH?
Benign prostatic hyperplasia, benign growth of the prostate gland, mainly the transitional zone.
Leads to difficulty initiating urination, frequency and urgency.
Common in older males.
What happens in prostatic carcinoma?
This is cancer of the prostate which affects the peripheral zone mainly, so will be easily felt via a DRE, which will feel hard and irregular.
Symptoms will not present till late, when the carcinoma is of sufficient size to affect the urethra.
What is the arterial supply of the prostate?
prostatic arteries, derived from the internal iliac arteries.
What is the venous return of the prostate?
prostatic venous plexus, which drains into the internal iliac veins.
What is the innervation of the prostate?
inferior hypogastric plexus
provides sympathetic, paraympathetic and sensory innervation.
What is the function of the bulbourethral glands?
And alkaline in nature so help to neutralise any acidic urine left in the distal urethra.
Where do you find bulbourethral glands?
Postero-lateral to the membranous urethra, within the fibers of the external urethral sphincter.
Where do the bulbourethral glands open their secretions into?
The proximal spongey urethra.
Where are the bulbourethral glands derived from embryologically?
the urogenital sinus
What is the arterial supply to the bulbourethral glands?
arteries to the bulb of the penis.
What is the innervation of the bulbourethral glands?
autonomic innervation from the prostatic plexus?
What does Point and Shoot mean?
parasympathetic innervation goes into maintaining the erection before ejaculation, and sympathetic innervation is involved in the ejaculation.
Where do the bulbourethral glands lymphatics drain to?
internal and external iliac lymph nodes.
What is the main function of the seminal vesicles?
Provide the majority of the volume (70%) of semen.
Where are the seminal vesicles?
between the bladder fundus and the rectum.
They are around 5cm long.
They combine with the vas deferens to form the ejaculatory duct.
What are the derivatives of the mesonephric ducts?
Ductus deferens (Vas deferens)
What are the constituents of the fluid released from the seminal vesicles, and what are the functions of each?
-alkaline fluid- neutralise female vagina and distal urethra of urine.
-fructose- nutrition for the spermatozoa, allows them to keep mobile
-prostaglandins- suppress female immune system from responding to the semen as forreign.
-clotting factors- keep semen in female tract post ejaculation.
What is the arterial supply to the seminal vesicles?
branches of the internal iliac artery (inferior vesicle, inferior pudendal, middle rectal)
What is the innervation of the seminal vesicles?
sympathetic (to do with ejaculation, so point and SHOOT)
What is the lymphatic drainage of the seminal vesicles?
To the external and internal illiac nodes.
What is a seminal gland abscess and what's the risk?
the formation of an abscess on the seminal vesicle.
They can rupture and lead to pus being deposited in the peritoneal cavity.
Examined via DRE.
How can examine the seminal vesicles?
via a DRE when the bladder is full.
By palpating them you can stimulate their secretions to be released, which can be sent off and investigated to look for STI's etc.
What are the 2 main functions of the penis?
What 3 structures can the penis be divided into?
What is contained within the root of the penis?
1x bulb of penis,
2x bulbospongiosus muscles
2x ischiocavernus muscles
Where is the root of the penis found?
Stationary, not visible externally.
Within the superficial perineal pouch.
What is found within the body of the penis?
3 cylinders of erectyl tissue:
-2 x corpora cavernosa
-1 x corpus spongiosum
What is the glans penis?
An expansion of the distal corpus spongiosum.
It contains the external urethral oriface.
Where is the urethra found within the penis?
In the root, it is found within the bulb of the penis.
In the body, it is found wihtin the corpus spongiosum.
What is the problem with the urethra being the delivery vessel for semen and how is this prevented?
In order to deliver the sperm, you need erection. Erection could cause occlusion of the urethra, meaning semen can not be ejaculated.
The bulb of the penis and corpus spongiosum fill to a lesser pressure than the other erectile tissue, to prevent this from happening.
What are the 2 types of muscles found within the penis?
Where are they found?
Found within the root of the penis
What is the function of the bulbospongiosus?
it is in close connection to the bulb of the penis, and contracts around the spongey urethra to make sure all the semen is ejaculated.
Also aids in maintaining erection.
What is the function of ischiocavernosus?
surrounds the crura of the penis, and contracts, forcing blood from the cavernous spaces of the crura (the holes in the root of the penis) into the corpora cavernosa (within the body), thus helps to maintain erection.
What are the ligaments of the penis and what does each do?
Suspensory ligament- connects the erectile bodies to the pubic symphesis.
fundiform ligament- connects the linea alba to the penis, and to the pubic symphesis, suspending the penis.
What is the medical name for foreskin?
How is prepuce connected to the skin of the glans?
Via the frenulum, on the ventral side.
What is the preputial sac?
The potential space between the prepuce and the glans.
What is the arterial supply of the penis?
dorsal arteries of the penis,
deep arteries of the penis
(all branches of the internal pudendal artery (which is a branch of the internal iliac artery)
By what 2 veins can blood drain from the penis?
deep dorsal vein of penis
superficial dorsal veins of penis
Whats the innervation of the penis?
sensory and sympathetic is by the dorsal nerves, which are branches of the pudendal nerves.
Parasympathetic innervation is by the cavernous nerves from the prostatic nerve plexus.
What is hypospadias?
when the urethra opens onto the ventral aspect of the penis.
Needs correction with surgery.
What is phimosis?
When the prepuce fits tightly over the glans penis, and you get a build up of smegma (oily secretions) within the preputial sac.
What is paraphimosis?
A more extreme version of phimosis, where the prepuce is tight over the neck of the glans, to the point where there may be interferance with the venous/lymphatic drainage.
There may be enlargement of the glans meaning the prepuce cannot be drawn over it.
What is peyronie's disease?
An abnormal curving of the penis due to accumulation of scar tissue, which can cause pain on erection.
May need surgical correction.