Male Perineum Flashcards
what are the components of the ale pelvis?
ureter, bladder, urethra
prostate, ductus deferens, seminal vesicles, bulbourethral glands
rectum
ABDOMINAL GIT splits into the greater pelvis - caecum, appendix, part of the sigmoid colon and ileum
Vessels, nerves, lymphatics and lots of systems and small spaces
what kind of tissue is scrotum?
How is it embryologically formed?
What is in the scrotum?
Fibromuclular cutaneous sac
from two scrotal swellings, fusing to form the SCROTAL RAPHE -> which is biolically resembling the labia major
CONTENT:-
testis - site of sperm production
Epididymis - storage reservoir for sperm
Spermatic cord - a collection of muscle fibres, vessels, nerves and vas def
What muscles form the scrotum?
DARTOS MSUCLE-> smooth muscle. Wrinkles the skin to reduce heat loss
Supplied by the genital branch of the GENITOFEMORAL nerve
CREMASTER MUSCLE -> Inner. elevation of testes. Sensory from ilioguinal n. Motor from genitofemoral n.
Where is the sperm made?
Seminiferous tubules -> drain through RETE TESTIS -> Efferen ductules into the epipdidymis where they’re stored
parts of the epididymis
head, body and tail -> continues to become Vas deferens and leave scrotu
what are the vas deferens?
what is the trajectory of them?
Comminicating tubes // the epi and urethra
Travels in spermatic cord (within the inguinal canal)
Then behind the INERIOR EPI ARTERY. -> Passes infront of th ureter. The continues to become the ampulla of ductus deferens before entering the urethra trough the prosptate.
The vas def, seminal vesicle and prostate empty into the prosthetic urethra to make the semen.
The Seminal vesicles are behind the vas def
what are the arterial contents of the spermatic cord?
testicular artery
deferential artery
cremasteric artery
what nerves are in the spermatic cord?
nerves to cremaster (genital branch of GF n) testicular nerve (symp - motor)
Ilio-inguinal runs alongside the sperm cord but isn’t actually in it (sensory to the cremaster)
apart from nerves and vessels - what are the other contents of spermatic cord?
What abnormalities of the testis can occur to give large dilation?
V deferens
Pampiniform plexus
Lymph vessles
Tunica vaginalis
VARICOCELE
Abnormal enlargement and dilatation of pampiniform plexus -> Varicocele
Caused by defective valves or compression by nearby structure
Painless
Described as feeling like a ‘bag of worms’
what happens in a testicular torsion?
caused by twisted spermatic cord -> ischameia of the testis
surgery required
inflammed testis
what is hydrocele?
accumulation of fluid around the testes
caused by fluid secreted from remnant piece of peritoneum wrapped around the testicle
can resolve on its own
what is the lymphatic drainage from the testis lie?
Follows testicular arteries back to the para-aortic lymph nodes
the para-aortic lymh nodes contineu superiorly to become the mediastinal LN
where does the lymph drainage of the SCROTUM go?
Drains to the superficial inguinal lymph nodes
where are the seminal vesicles located?
How does it correspond with the vas deferens?
laterally to the ampullas of VAS DEFERENS
Excretory ducts from each seminal vesicle and corresponding vas deferens = two EJECTORY DUCTS
EJE DUCTS immediately pass through the prostate gland through the subatnce and into the prostatic urethra
where is the bladder in comparison to the prostate?
where are the bulbourethral glands?
bladder sits on the prosttae. It’s transfixed by the prostatic urethra
bulbourethral glads are just below the prostate
how is the internal urethral sphincter managed during sympathetic?
closed during ejaculation by SYMPATHETIC stimulus
PARASYMO relaxes th sphincter
REMEMBER: EXT SPHINCTER = SKELETAL MUSCLE
which structures in males are felt in diital rectal exams of healthy man?
prostate rectum full badder seminal vesicles bulbi-urethral gland membranous urethra when catheterised
what are the parts of the urethra?
What is often the issue with catheters?
Preprostatic part (1.5cm) Prostatic (2.5cm) Membranous (2cm) - first bend happens after this (near where the external urethral is) Spongy (15cm)
External urethral orifices is the narrowest part of it
They can often get caught int the NAVICULAR FOSSA
- catheter must be able to navigate 90degree bend as it passes from the perineum into the pelvis
Describe the structure of the penis
Root - most proximal part. in the suferficial perineal pouch of pelvic floor.
Contains three erectile tissues (two crura and bulb of penis) - these then go on to become the corpus cavernosa and corpus spongiosum respectively
AND
two muscles (ischiocavernosus and bulbospongiosus)
Body - free part of the penis - located // the root and the glans. suspended from the pubic symp. - made of 3 cylinders of erectile tissues - two corpora cavernosa and corpus spongiosum (contains the spongy urethra)
Glans - most distal. expansion of the corpus spongiosum
what fasica does the penis have?
there is the deep fascia and the superficial
what is the arterial supply to the penis?
Dorsal arteries of th penos
Deep arteries of the penis
Bulbourethral artery - supplying to the bulb corpus spongiosum and glans
- Then there are branchs that supply to the cavernosus spaces which are usually helical
These arteries are all branches of the internal pudendal artery
This vessel arises from the anterior division of the internal iliac artery.
REMEMBER: BLOOD TO THE TESTES = TESTICULAR ARTERY
Blood supply of the rectal canal
Superior rectal artery - inferior mesenteric a
Middle rectal artery - internal iliac a
Inferior rectal artery - from internal pudendal a
what is the venous drainage of the rectum?
Above pectineal line = superior rectal vein -> Inf mesenteric vein
BELOW - Inferior rectal vein -> which empties into the internal pudendal vein
what is the frunulum of prepuce?
The prepuce (foreskin) is connected to the surface of the glans by the frenulum
which arteries supply the cavernosus spae?
the helicine arteries that can relax via PSNS allowing blood blow
what are haemorrhoids/piles?
Normallt the anus has vascular cushions to help stool store.
these can become inflamed and swollen and cause haemorrhoids.
skin covering the blood vessels become inflamed.
Can be internal or externa. diff marked by pectinate line on anus
What nerves supply the penis?
Somatic: PUDENDL S2-S4
- sensory = dorsal nerve of penis
- motor = to perineal muscles; bulbospongisum and ischiocavernosus (causing ejectuation) and external sphincter
PARASYMP S2-4
- vasodilation of arterioles in erectile tissue
- secretio in prosate, bulbourethral gland
SYMP - L1-L2
- contraction of smooth muscle of epididymis, vas deferens, seminal vesicles and prostate causing emission
- contraction of the internal sphincter urethral sphincter during ejac to prevent the reflux f spern.
SO
PSNS - erectile tissue/secretion
SNS - Emission/ejaculation
Describe the neurovascular mechanism of ejaculation
1) ERECTION
2) SECRETION
3) EMISSION
4) EJACULATION
5) DETUMESCENCE
decsirb the erection aspect of ejaculation
Psych stimulation -> central PSNS pathway -> pudendal artery/arteriole relax allowing blood flow into cavernous spaces of erectile tissue
describe the secretion aspect of ejac
PSNS ganglia stimulation -> protate, seminal vesicles (+ other glands in females)
describe the emission aspect of ejac
central SNS pathway stimulation -> muscles contaction of vas def, prostate, sem vesi,
symp inhibition action -> bladder muscle contrcation prevented (cntraction of int sphincter)
decssirb ethe ejacylation process
entry of semen into urethra -> somatoc reflex triggered via pudendal nerve -> contrcation of bulbospongiosum
describe the detumescence aspect of ejac
activation of selected sympathteic nerve supplying pudundal arterioles -> arteriole constriction to restrict blood supply to cavernosus spaces -> inhbition of erection
Outline the pelvic lymph drainage
Most organs are drained to the common iliac nodes via internal or external lyph ndes
External iliac LNs Inguinal nodes External genitalia Vagina Cervix Bladder
Internal iliac (& sacral) LNs Cervix Prostate Rectum Perineum Buttock Thigh
Testes & Ovaries -> lumbar group of aortic nodes
