SUGER anatomy: male genitalia Flashcards
how many erectile tissues are there in the BODY of the penis?
- there are 3 cylinders of erectile tissue
what are the 3 layers of erectile tissue in the BODY of the penis?
2x corpora cavernosa
1x corpus spongiosum
which erectile tissue is on the dorsal surface/top of the penis?
the 2 corpora cavernosa tissues
which erectile tissue is on the ventral surface/bottom of the penis?
the corpus spongiosum
what is the glans and what erectile tissue is it made from?
- end of the penis
- corpus spongiosum
what structure does the penile urethra form when it reaches the glans?
- it dilates and forms the navicular fossa
- this opens at end (urethral meatus)
through what tissue does the penile urethra travel through?
corpus spongiosum
what is the main artery of the perineum (in both sexes)?
the internal pudendal artery
what is the internal pudendal artery a terminal branch of?
the internal iliac artery
what are the 3 branches of the internal pudendal artery that supply the penis?
- the dorsal arteries (runs along top)
- the deep arteries
- the Bulbourethral artery
describe the venous drainage of the penis
by paired veins
- superficial dorsal
- deep dorsal
what are the 3 parts of the penis?
root
body
glans
what and where is the root of the penis?
- most proximal
- fixed
- not visible externally
- within superficial perineal pouch
how many erectile tissues are there in the ROOT of the penis?
3
- L&R crura (laterally)
- the bulb of the penis (in midline)
what do the L&R crura become once they enter the body of the penis?
- continue anteriorly into dorsal body
- form the 2 corpora cavernosa
- separated by septum
what does the bulb of the penis become once it enters the body of the penis?
- travels ventrally
- becomes the corpus spongiosum
what spinal cord segments and spinal ganglia innervate the penis?
S2-S4
what nerve supplies general sensation and sympathetic innervation to the penis?
pudendal nerve
what do the parasympathetic nerve fibres innervate within the penis?
- dilate the arteries of the corpus cavernosa
- causes erection (engorged with blood)
what are the 4 stages of sexual intercourse the penis goes through?
- erection
- emission (mixing of components of semen in the prostatic urethra)
- ejaculation
- remission (returns to flaccid state)
what are the 4 muscles in the root of the penis?
Bulbospongiosus(x2)
Ischiocavernosus(x2)
with which erectile tissue are the Bulbospongiosus muscles associated with?
- the bulb of the penis
- in the root
what action happens when the Bulbospongiosus muscle contracts?
- the spongy urethra is emptied of any residual semen and urine
- there is a pressure increase in the bulb of the penis, which helps to maintain an erection
with which erectile tissue are the Ischiocavernosus muscles associated with?
the left and right crura
in the root of the penis
what action happens when the Ischiocavernosus muscle contracts?
blood is forced from crura to corpora cavernosa
helps to maintain an erection
what are the 3 facia layers of the penis?
- external fascia of colles
- deep/bucks fascia
- tunica albuginea
which fascia layer is the most superficial? which is the deepest?
superficial - external fascia of colles
deepest - tunica albuginea
which fascia layer holds all 3 erectile tissues together.
bucks fascia (deep fascia)
which fascia layer forms an individual capsule around each corpus cavernousum, and is fused in the midline? .
tunica albuginea
name the 2 ligaments that support the root of the penis by attaching it to the pubic symphysis
- suspensory ligament
2. fundiform ligament
what is the term for foreskin? what is it made of?
Theprepuce
= double layer of skin and fascia
where is the prepuce found?
at the neck of the glans (covering it to a variable extent)
what medial skin fold on the ventral surface of the penis connects the prepuce to the surface of the glans?
the frenulum
what is the thepreputial sac?
potential space between the glans and prepuce
which erectile tissue gets the least engorged with blood during an erection? why?
The corpora spongiosum
so not to compress the urethra (which would prevent ejaculation)
what are the male gonads?
the testes (2 testicles)
what is the role of the testes?
to produce sperm and secrete testosterone
what are the 3 fascia layers of the testes?
SAME AS SPERMATIC CORD
- External spermatic fascia
- Cremasteric muscle and fascia
- Internal spermatic fascia
name the sac derived from peritoneum, inside the scrotum, that surrounds the testes
the tunica vaginalis (allowing for friction-free movement.)
which arteries supply the testes?
the 3 arteries in the spermatic cord
- testicular
- cremasteric
- Artery to the vas deferens
what is the venous drainage of the testes?
- the pampiniform venous plexus (the testicular veins, wrapped around testicular artery)
- drains directly into IVC on right, via renal vein on left
describe the testes anatomical relation to:
- the scrotum
- epididymis
- spermatic cord
- lie within the scrotum
- epididymis is on posterolateral aspect of each testicle
- suspended from the abdomen by the spermatic cord
describe the internal features of a testicle (3)
- contains series of lobules
- lobules contain seminiferous tubules
- supported by interstitial tissue
where are the spermatozoa produced within the testes?
in the seminiferous tubules
what cells aid spermatozoa maturation? where are these cells found?
- Sertoli cells
- that line the seminiferous tubules of the testes
what cells are responsible for testosterone production? where are these cells found?
the Leydig cells
found in interstitial tissue of testes
what are the rete testes?
an anastomosing network of delicate tubules located in the hilum of the testicle (mediastinum testis)
what is the role of the rete testes?
carries sperm from where they have been produced in the seminiferous tubules to the efferent ducts.
where do the efferent tubules transport the sperm ? (from the rete testes)
to the epididymis for storage and maturation
form the head pf the epididymis
what is the tunica albuginea?
a fibrous capsule that encloses the testes
also the deepest fascia layer of the penis
innervation of the testes?
from the testicular plexus
describe scrotal skin
thin, wrinkled and more darkly pigmented.
where are the epididymis?
1 on each tesitcle (within scrotum)
postolateral side
what its the epididymis?
a heavily coiled duct that stores and transports sperm
what are the 3 parts to the epididymis?
- head - most proximal
- body - heavy coiled duct of the epididymis
- tail - most distal, transports sperm into vas deferens
what are the smooth muscular layers of the vas deferens?
- inner longtiduital
- intermediate circular
- outer longitudinal
how are the vas deferentia adapted to allow sperm to travel through quickly?
- rich innervation
- smooth muscle layers
- has a inner mucosal laye with microvilli that help spermatozoa through
what structure does the vas deferens travel within?
the spermatic cord, inguinal canal
at what point does the vas deferens exit the inguinal canal?
leaves via the DEEP inguinal ring
where is the ampulla of vas deferens?
- after leaves canal, vas deferens goes into side/lateral wall of pelvis
- turns medially onto the back of the bladder
- then becomes the ampulla, just medial to the seminal vesicle
what is the ampulla of vas deferens?
dilated area of vas deferens tube
where does the vas deferens terminate?
it joins the seminal vesicle
after this point it becomes the ejaculatory duct
where does the vas deferens transport sperm to and from?
from tail of epididymis
to ejaculatory duct
what are the seminal vesicles?
2 lobulated sacs (L&R)
what is the role of the seminal vesicles?
to produce semen ingredients
thick alkaline fluid that forms bulk of seminal fluid
describe the epithelium of the seminal vesicles?
has a secretory mucosa lined by pseudostratified columnar epithelium
what is the arterial supply to the seminal vesicles?
arteries stemming from the internal iliac artery
how are the seminal vesicles involved in ejaculation?
their smooth muscles contract via sympathetic innervation
what 2 substances does the ejaculatory duct collect and where form?
- spermatozoa from testes
- semen from seminal vesicles
to what structure does the ejaculatory duct pass on its contents ?
to prostatic urethra
what are the 3 sections of the urethra?
prostatic urethra → membranous urethra → penile urethra
where does sperm leave the body?
out of penile urethra
what is the innervation to the ejaculatory duct?
Testicular plexus
what are the arteries supplying the ejaculatory duct?
the arteries of the spermatic cord
- paired testicular
- creamsteric arteries,
- arteries of the vas deferens
venous drainage of ejaculatory duct?
paired testicular veins from papiniform plexus in scrotum (wrapped around testicular artery)
which structures of the male genitalia are supplied by branches of the internal iliac artery?
- penis (internal pedendal)
- seminal vesicles
- prostate (prostatic arteries)
which structures of the male genitalia are supplied by branches from the spermatic cord?
- testes
- scrotum
- epididymis
- ejaculatory duct
testicular, cremasteric, vas defers artery
which structures of the male genitalia are drained by the paminiform venous plexus?
- testes
- scrotum
- epididymis
- ejaculatory duct
which structures of the male genitalia are innervated by the testicular nervous plexus?
- testes
- scrotum
- epididymis
- ejaculatory duct
what is the prostate?
- aspherical fibromuscular gland
- about the size of a walnut
what structures have openings into the prostate gland?
pierced by urethra and ejaculatory ducts
what is the role of the prostate?
ensure semen is in a fluid state
what enzymes does the prostate glands secrete and what is their action?
- secretesproteolytic enzymes into the semen
- these break down clotting factors in the ejaculate
- makes it more fluid
where is the prostate gland located?
- inferior to neck of bladder
- superior to external urethral sphincter
- anterior to rectum (ampulla)
where is the prostate gland in relation to the levator ani muscle?
- levator ani muscle is inferolateral to prostate gland
through what structures do the proteolytic enzymes leave the prostate into the urethra?
prostatic ducts
what are the 4 zones of the prostate? which are glandular which are fibromuscular?
- central zone - glandular
- transitional zone - glandular
- peripheral zone - glandular
- stroma zone - fibromuscluar
which zone of the prostate surrounds the ejaculatory ducts?
the central zone
which zone of the prostate surrounds the prostatic urethra?
the transitional zone
which zone of the prostate has the highest incidence of inflammation?
the peripheral zone
most posterior
which zone of the prostate is involved in the urine reflex?
the peripheral zone
- because this glandular zone empties into the prostatic urethra VERTICALLY
which zone of the prostate is most anterior?
the fibromuscular stroma zone
what arteries supply the prostate?
prostatic arteries ( from internal iliac)
what veins drain the prostate?
the prostatic venous plexus
what plexus supplies the prostate gland with sympathetic, parasympathetic and sensory innervation ?
the inferior hypogastric plexus
what is the innervation of the smooth muscle of the prostate gland? what is the role of this muscle?
- sympathetic fibres
- for ejaculation
what 2 structures flank the prostate? what happens if they are damaged in surgery?
neurovascular bundles
erectile dysfunction
is the innervation of an erection parasympathetic or sympathetic?
Pointing = Parasympathetic
is the innervation of ejaculation parasympathetic or sympathetic?
Shooting = Sympathetic
how is temperature regulated in the testes for optimum sperm production?
pampiform plexus acts as cooling system via heat exchange
why is the fluid in the seminal vesicles need to be alkaline?
vaginal secretions are acidic so acts as buffer for sperm
