Repro 4- male anatomy Flashcards
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
spermatic cord
seminal vesicles and prostate gland
penis
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?
head
body
tail
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?
- Hydrocoele
- haematocoeal
- varicocoeal
- spermatocoeal
- inguinal hernia
- epididymitis
- trauma
- tumour?
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?
- testes
- spermatic cord
- epididymis
- Dartos muscle
- cremaste muscle
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?
- genitofemoral nerve,
- 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?
It’s discontinous,
striated
orientated longitudinally
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?
- testicular artery
- pampiniform plexus
- cremasteric artery
- artery to the vas deferens (from inferior vesicle artery)
- vas deferens
- lymph nodes
- genital branch of the genitofemoral nerve
- processus vaginalis
- autonomic nerves
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
- inner longitudinal
- middle circular
- outer longitudinal
Why is a rich autonomic innervation required in the vas deferens?
to permit fast movement of the sperm towards ejaculatory duct.