SUGER 1 - Inguinal Canal & External Genitalia Flashcards
Where and what is the inguinal canal?
- located above the inguinal ligament
- oblique passage through the muscles of the anterior abdominal wall
Where does the inguinal canal start and end?
START: deep inguinal ring (hole in tranversalis fascia)
END: superficial inguinal ring (hole in external oblique aponeurosis)
Where is the superficial ring in relation to the pubic tubercle?
above and medial to pubic tubercle
What does the inguinal canal contain in males? In females?
M: spermatic cord and ilioinguinal nerve
F: round ligament of uterus and ilioinguinal nerve
What is an aponeurosis?
white fibrous tissue - thin sheet-like tendon
- can bind muscles together
- can connect bone to muscle
The aponeurosis of the internal oblique and the transversus abdominis form what?
the conjoint tendon
Where is the conjoint tendon and where does it insert into?
- found behind superficial inguinal ring
- insets into pubic crest
What forms the roof and the floor of the inguinal canal?
ROOF: internal oblique, transversalis fascia
FLOOR: inguinal ligament
Clinical significance of inguinal canal?
common site for HERNIAS as it is a potential site of weakness
What lies over the spermatic cord?
Ex. ob aponeurosis and in. ob fibres
Where do the ilioinguinal and iliohypogastric nerves arise from?
L1
What does the ilioinguinal nerve innervate?
MALE: skin of root of penis and scrotum
FEMALE: mons pubis and labia majora
Sensory and motor innervation of iliohypogastric nerve
S: skin over lateral gluteal region and above pubis
M: internal and transverse abdominal muscles
Lumbar plexus arises from…
T12-L5
Origin, insertion and action of the cremaster muscle?
O: inguinal ligament
I: tunica vaginalis
A: raise and lower the scrotum
What is the inferior epigastric artery a branch of? What does it anastomose with and where?
Branch of external iliac artery
- anastomoses with superior epigastric artery at umbilicus
Superior epigastric artery
supplies anterior abdominal wall and some of diaphragm
- cremasteric branch - supplies coverings of spermatic cord
- pubic branch
What is a hernia?
intestine/peritoneum pushes through the inguinal canal
Explain the 2 types of hernia
INDIRECT: comes through deep inguinal ring - right through the inguinal canal
DIRECT: invaginates posterior wall of inguinal canal - medial to inferior epigastric
Why does a direct inguinal hernia not descend into the scrotum?
conjoint tendon wont allow it to
Where can a direct hernia be found?
medial to the inferior epigastric artery
What are the 3 coverings of the spermatic cord?
- external spermatic fascia (from apo of ex. ob)
- cremaster muscle and fascia (from int. ob)
- internal spermatic fascia (from transversalis fascia)
Structures making up the spermatic cord run from..
- deep inguinal ring
- inguinal canal
- superficial inguinal ring
- into scrotum
Spermatic cord contents (3,3,3,3)
3 ARTERIES - testicular artery, artery to vas def, cremaster artery
3 VEINS - pampiniform plexus of veins, vein of vas def, cremasteric vein
3 NERVES - ilioinguinal, genitofemoral, sympathetic
3 OTHER - vas def, lymphatics, tunica vaginalis
Skin sensation to the anterior 1/3 external genitalia is supplied by:
ilioinguinal nerve
What is the pampiniform plexus?
- network of veins
- venous drainage of the testes
- wraps around testicular artery
Apart from venous drainage, what does the pampiniform plexus do?
acts as a heat exchanger - cooling arterial blood before it reaches the testes
Where does the right and left testicular vein drain into?
R: IVC
L: left renal vein
Where does the testicular artery come from?
branches of the abdomina aorta, below renal arteries
What do the testes do?
- produce spermatozoa aka. sperm
- secrete testosterone
What is the testes covered by?
the same three layers that cover the spermatic cord
- external spermatic fascia
- cremaster muscle and fascia
- internal spermatic fascia
What is the tunica vaginalis?
serous covering surrounding testes
- has parietal and visceral layer
What is the fibrous capsule encasing the testes?
tunica albuginea - (inner layer after tunica vag)
How many seminiferous tubules found in a single lobule in the testes?
1-3 mil
What are the network of tubules in the hilum of the testes? What does it do?
- rete testis
- transports sperm from seminiferous tubules to efferent ducts
Where do the sperm mature?
in the epididymis - connected to rete testes by efferent ducts
What structure transports sperm to the urethra?
vas deferens
What opens up into the vas deferens?
the seminal vesicles - secrete some of the components of the semen
vas deferens + seminal vesicles = ?
EJACULATORY DUCT
What is the scrotum?
pouch of skin containing the testes, epididymis and lower spermatic cord
- skin = thick, dark, wrinkly
The scrotum is made up of..
- skin
- dartos (involuntary/smooth muscle)
- fascia
What does the dartos muscle do?
- works with cremasteric muscle to elevate testes
- regulates temperature of the testicles in scrotum
- high mobility for penile skin
Contraction and expansion of the dartos muscle does what?
CONTRACTION: less heat loss . warms testicles
EXPANSION: cools testicles
3 parts of the penis
- root
- body
- glans
What is the glans of the penis formed by? What does it contain?
- corpus spongiosum
- opening of urethra
What is the external urethral meatus?
slit-like opening where urine exits urethra
The small dilation of the end of the glans is the..
navicular fossa
3 cylinders of erectile tissue
2 x corpus cavernosa
corpus spongiosum
What contains most of the blood in the penis during an erection?
corpus cavernousua
Which fibrous layer surrounds each cavernous body to maintain an erection?
tunica albuginea
What does the bulb of the penis become? What does this structure then become?
- bulb becomes corpus spongiosum
- cs then becomes glans penis
Where does the penile urethra enter, run and open?
enters bulb, runs through the corpus spongiosum, then opens at external urethral meatus
How many muscles of the root of the penis? What do they do?
2 x bulbospongiousus - contracts to empty urethra of urine and semen
2 x ischiocavernosus - (surround crura) - contracts to maintain erection
How does the ischiocavernous muscle contract to maintain an erection?
contraction forces blood from cavernous crura into the corpus cavernosa - maintaining erection
Arterial supply of the penis?
They are branches of the internal pudenal artery that arises from the internal iliac artery
- deep arteries
- dorsal arteries
- bulbourethral arteries
Venous drainage of the penis?
- deep dorsal veins (drains cavernous spaces)
2. superficial dorsal veins (drains skin and cutaneous tissue)
Innervation of the penis
S2-S4
sensory & sympathetic innervation to glans: DORSAL NERVE OF PENIS
What causes and erection? (POINT AND SHOOT)
PARASYMP: inc blood flow
SYMP: initiates ejaculation
Fluid in the tunica vaginalis is known as..
hydrocele
Varicocele refers to..
dilated veins in the pampiniform plexus
