Pelvic Diaphragm :Pelvic Diaphragm :

N.supply :perineal branch of S4 N. and perineal branch of pudendal N.

It is formed of levator ani Ms.+ small coccygeus Ms. + their covering fascia.

It is incomplete anteriorly to allow passage of urethra in males /and urethra & vagina in female.

The pelvic diaphragm : divides the cavity of pelvis into main pelvic cavity above & perineum below.

The perineum is diamond shaped ,bounded anteriorly by symphysis pubis …posteriorly by coccyx … laterally by ischial tuberosities.

Anal triangle : it is the posterior division of perineum /bounded posteriorly by tip of coccyx… and on each side by ischial tuberosity & sacrotuberous lig. overlapped by lower border of gluteus maximus.

Contents of Anal triangle Contents of Anal triangle ::

Anus.Anus. Lower part of Anal canalLower part of Anal canal.(.(upper part lies in upper part lies in

pelvis)pelvis) Ano-coccygeal body (or raphe)Ano-coccygeal body (or raphe) : :a a

fibrofatty mass that extends from fibrofatty mass that extends from anusanus to to tip tip of coccyx.of coccyx.

Ischio-rectal fossaIschio-rectal fossa on each side. on each side.

Anus :Anus :lies in midline.

The skin around anus and over ischio-rectal fossa on each side is supplied by inferior rectal N. (somatic).

Lymph vessles of the skin of anus drain into medial group of superficial inguinal L.N.

Anal CanalAnal CanalIt is about 1,5 in. long, descending from rectal ampulla to anus.

Posteriorly : anococcygeal body, which is a mass of fibrous tissue lying between anal canal & coccyx.

Laterally : fat-filled ischiorectal fossae.

Anteriorly : -In male : perineal body, urogenital diaphragm, membranous part of urethra, and bulb of penis. -In female : perineal body, urogenital diaphragm, and lower part of vagina.

Structure of anal Structure of anal canalcanal

Mucous membrane of upper ½ is derived from hindgut entoderm.

It is lined by columnar epithelium.

It is thrown into vertical folds-anal columns, which are joined together at their lower end by semilunar folds called anal valves.

Nerve supply : autonomic hypo-gastric plexus (as rectal mucosa), sensitive only to stretch.

Arterial supply : superior rectal artery –of inferior mesenteric/ sup.rectal v., a tributary of inf. Mesenteric and portal v.

Lymphatic drainage : along sup. Rectal artery to pararectal nodes, then to inferior mesenteric nodes.

Structure of anal Structure of anal canalcanal

Mucous membrane of lower ½ is derived from ectoderm of proctodeum.

It is lined by stratified squamous epithelium, which gradually merges at anus with perianal epidermis.

No anal columns.

Nerve supply : somatic inferior rectal N., sensitive to pain, temperature, touch and pressure.

Arterial supply : inferior rectal artery –of internal pudendal /inf.rectal v., a tributary of int. pudendal v. and drains to internal iliac v. (systemic venous drainage)

Lymphatic drainage : to medial group of superficial inguinal ligament.

Structure of anal Structure of anal

canalcanal

Pectinate line: it is the line of joining between upper & lower halves of anal canal/ at the level of anal valves..

Muscle coat : as rectum- consists of outer longitudinal & inner circular layer of smooth muscle. The longitudinal muscle descends between the internal & external anal sphincters.

Anal sphincters :

1-Involuntary internal sphincter: is formed by thickening of smooth circular L.of muscular coat at upper end of anal canal. 2-Voluntary external sphincter: a-Subcutaneous part : surrounds the lower end of anal and has No bony attachment. b-superficial part : attached to coccyx behind and the perineal body in front. c-deep part : encircle upper end of anal canal and has no bony attachments.

Puborectalis musclePuborectalis muscleIt is fibres of the two levator

ani muscles, forming a sling around the junction of rectum & anal canal.

It is attached in front to pubic bones.

At the junction of rectum & anal canal, the internal sphincter, deep part of external sphincter & puborectalis muscles form a ring called anorectal ring which can be felt on rectal examination.

Involuntary internal sphincter supplied by …by symp. Fs. .from inferior hypogastric plexus.Voluntary external sphincter… by inferior rectal N. + perineal branch of S4 N.

Ischiorectal Fossa :Ischiorectal Fossa :Its base is the skin of perineum.

Its medial wall is levator ani & anal canal.

Its lateral wall is obturator internus, covered with pelvic fascia.

Contents :dense fat , pudendal nerve & int.pudendal vessels inside the pudendal canal on the lat.wall of the fossa , inf. Rectal N.& vessels cross fossa to reach anal canal.

Pudendal Nerve :Pudendal Nerve :Branch of sacral plexus.

It leaves pelvis through greater sciatic foramen , crossing back of sacrospinous ligament, and passes through lesser sciatic foramen to enter perinum.

It passes in the pudendal canal in ischiorectal fossa.

Branches of Pudendal Branches of Pudendal Nerve :Nerve :

Inf. rectal N… supplies ext.anal sph., m.m.of lower ½ of anal canal & perianal skin.

Perineal N… supplies muscles of urogenital triangle ,and skin of scrotum (or labia majora).

Dorsal N. of penis… to penis (or clitoris).

Internal Pudendal Internal Pudendal Vessels :Vessels : Internal pud.arteryInternal pud.artery … branch of … branch of

internal iliac artery ,passes from gluteal internal iliac artery ,passes from gluteal region to pelvis through G.S.foramen region to pelvis through G.S.foramen and enters perineum through lesser and enters perineum through lesser sciatic foramen.sciatic foramen.

Branches of int. pud.arteryBranches of int. pud.artery :1-inf. :1-inf. Rectal artery supplies… lower ½ of anal Rectal artery supplies… lower ½ of anal canal. 2-branches to penis (or labia canal. 2-branches to penis (or labia majora & clitoris).majora & clitoris).

Int. pud. VeinInt. pud. Vein : drains into int. iliac : drains into int. iliac vein.vein.

Internal Hemorroids (piles) Internal Hemorroids (piles) ::

Are due to varicosities of tributareis of superior rectal vein.

Hemorrhoid is a fold of m.m. & submucosa containing a varicosed tributary of sup. Rectal vein. (B)

It occurs in upper ½ of anal canal where m.m. innervated by autonomic N.S., so they are painless and sensitive only to strech.

Position of varicosed tributaries of the vein lie in anal columns at 3-,7-,and 11-o’clock positions. (C)

A, normal tributary of superior rectal vein within the anal column. B, varicosed tributary of superior rectal vein forming internal homorroids. C, positions of varicosed tributaries of the vein.

External Hemorroids :External Hemorroids :Are varicosities of tributaries of inf. Rectal vein.

They are covered by m.m of lower ½ of anal canal or skin & commonly associated with internal hemorrhoids.

Innervated by inf. Rectal nerves, so they are painful & sensitive to pain,temp, touch & pressure.

It is recognized as a small acute tender swelling at the anal margin.

Perianal Abscesses :Perianal Abscesses :Produced by fecal trauma to anal mucosa , or infection of anal fissure (due to tearing of anal valve), or infection of anal mucosal gland.

Types : 1-Submucous abscess. 2-Subcutaneous(beneath perianal skin) 3-Ischiorectal abscess. 4-pelvirectal abscess (bet.ampulla of rectum & upper surface of levator ani.

Ischiorectal abscess may involve the opposite fossa by spread of infection across midline behind anal canal.

Anal Fissure :Anal Fissure :In chronic constipation … the anal valves may be torn down to the anus forming the fissure.

It is elongated linear ulcer which lies most commonly in midline posteriorly.

It is a very painful condition specially during defecation because the fissure extends to the lower ectodermal part of anal canal which is supplied by somatic nerve (inf.rectal nerve).

Anal fissre is examined under local anesthesia.

Anal Fistula :Anal Fistula :Due to inadequate treatment of anal abscesses ,leading to fistula.

It opens between the anal canal lumen., and skin close to anus.

If the abcess opens onto only one surface, it is known as a sinus.

The most important part of sphincteric mechanism of anal canal is the anorectal ring ,it consists of : 1-int. sphincter. 2-puborectalis part of levator ani. 3-deep part of ext.sph.

Damage to ano-rectal ring will produce fecal incontinence.

Cancer and lymph drainage of Cancer and lymph drainage of lower Anal Canal :lower Anal Canal :

Lower ½ of m.m.of anal canalLower ½ of m.m.of anal canal is is drained to drained to superficial inguinal superficial inguinal L.N.L.N.

Cancer of lower ½ of anal canalCancer of lower ½ of anal canal leads to leads to secondary deposits in secondary deposits in inguinal L.N.inguinal L.N.

It is bounded Anteriorly… by pubic arch.

Laterally … by ischial tuberosities.

Posteriorly : transverse line passing through the 2 ischial tuberosities.

It lies in diamond -shaped perineum.

Urogenital Triangle

Fascia of Urogenital Fascia of Urogenital Triangle :Triangle :

Superficial fascia : 1- fatty layer (fascia of camper) : it is continuous with fat of ischiorectal fossa + superficial fascia of thigh. In scrotum, the fat is replaced by smooth muscle – dartos muscle. 2- membranous layer (colles’fascia) : it is attached posteriorly to posterior end of urogenital diaphragm/laterally to pubic arch/anteriorly, it is continuous with : the fascia of scrotum (or labia majora) , fascia of penis, membranous layer of superficial fascia of abdomen (Scapa’s fascia).

Urogenital DiaphragmUrogenital Diaphragm It is a musculofascial It is a musculofascial diaphragm ,lies in anterior part of diaphragm ,lies in anterior part of perineum (in urogenital triangle) perineum (in urogenital triangle) , filling in the gap of pubic arch., filling in the gap of pubic arch.

It is formed byIt is formed by sphincter sphincter urethrae & deep transverseurethrae & deep transverse perineal Msperineal Ms ,which are ,which are enclosed enclosed between the between the superior fascial superior fascial layerlayer & & inferior fascial layerinferior fascial layer (or perineal membrane).(or perineal membrane).

The closed space between The closed space between superficial & deep layers of fascia superficial & deep layers of fascia is known as is known as DeepDeep perineal perineal pouch.pouch.

The opened space between the The opened space between the urogenital diaphragm urogenital diaphragm aboveabove/ and / and membranous layer of superficial membranous layer of superficial fascia fascia belowbelow is called – is called – superficial perineal pouch,superficial perineal pouch, which is which is anteriorly anteriorly communicates communicates with the space between with the space between superficial fascia of abdomen & superficial fascia of abdomen & anterior abdominal Ms. anterior abdominal Ms. Laterally,Laterally, it is closed by its attachment to it is closed by its attachment to pubic arch. pubic arch.

Contents of Male & Female Contents of Male & Female Urogenital triangleUrogenital triangle

In Male :In Male : 1-Penis. 1-Penis. 2-Scrotum. 2-Scrotum.

In Female :In Female : 1-External 1-External genitalia (Clitoris). genitalia (Clitoris). 2-Orificies of 2-Orificies of Urethra and /Vagina.Urethra and /Vagina.

The root of penis is formed of 3 masses of erectile tissue : the bulb and right +left crura of penis.

The bulb lies in midline and is attached to undersurface of urogenital diaphragm. It is covered by bulbospongiosus muscle. It is continued forward into body of penis forming the corpus spongiosum. It is traversed by the urethra.

Each crus is attached to side of pubic arch and covered by ischiocavernosus muscle. The 2 curura converge anteriorly into the body of penis forming corpora cavernosa.

The body of penis, +glans penis, containing the external urethral meatus.

Contents of Contents of Male Male Urogenital Urogenital Triangle Triangle

Male urethra :Male urethra :Prostatic urethra : it is 1 ½ inch-widest & it is the most dilatable part.

Membranous urethra : ½ inch long, lies within the urogenital diaphragm ,surrounded by sphincter urethrae muscle ,it is least dilatable part of urethra

Penile urethra :6 inch long, enclosed in the bulb, corpus spongiosum and glans of penis.

-The part of urethra that lies in glans penis is dilated to form fossa terminalis.

-The bulbourethral glands open into penile urethra below urogenital diaphragm.

-The external meatus is the narrowest part of entire urethra.

Blood supply/ Lymph drainage Blood supply/ Lymph drainage /innervation of penis :/innervation of penis :

Arteries : 1-Corpora Arteries : 1-Corpora cavernosa :cavernosa : by by deep artery of deep artery of penis. penis. 2-2-Corpus spongiosum :Corpus spongiosum : by by artery of bulbartery of bulb + + dorsal artery of dorsal artery of penis…..all of these arteries are penis…..all of these arteries are branches of internalbranches of internal pudendal pudendal arteries.arteries.

Veins :Veins : drain into drain into internal internal pudendalpudendal veins.veins.

Lymph drainage :Lymph drainage : skin :skin : into into superficial inguinal L.Ns. / superficial inguinal L.Ns. / Deep structures :Deep structures : into internal into internal iliac L.Ns.iliac L.Ns.

Nerve supply :Nerve supply : pudendal N. + pudendal N. + pelvic plexus.pelvic plexus.

Contents of Contents of Male Male Urogenital Urogenital Triangle Triangle

Scrotum & its wall : 1-skin. 2-superficial fascia : smooth dartos muscle (replace fatty layer of abdominal wall) + Colles’s fascia (membranous layer of superficial fascia). 3-External spermatic fascia from external oblique. 4-Cremasteric fascia from internal oblique. 5-Internal spermatic fascia from fascia transversalis. 6-Tunica vaginalis : is a closed sac that covers anterior, lateral, and medial surfaces of testis.

Blood supply/ Lymph drainage Blood supply/ Lymph drainage /innervation of Scrotum/innervation of Scrotum

Arteries : 1- Arteries : 1- external pudendal of external pudendal of femoral artery.femoral artery. 2- 2- scrotal branches of scrotal branches of internal internal pudendal arteries.pudendal arteries.

Veins :Veins : as the arteries. drain into as the arteries. drain into femoralfemoral or or internal internal pudendal vein.pudendal vein.

Lymph drainage :Lymph drainage : skin :skin : into medial group of into medial group of superficial inguinal L.Ns. / superficial inguinal L.Ns. / Testis & epididymisTestis & epididymis :into :into Lumbar (para-aortic) L.Ns. Lumbar (para-aortic) L.Ns.

Nerve supply :Nerve supply : 1-Anterior surface :1-Anterior surface : by ilio-inguinal by ilio-inguinal Ns.+ genital branch of genitofemoral N. Ns.+ genital branch of genitofemoral N. 2-Posterior surface :2-Posterior surface : by scrotal by scrotal branches from perineal N. + perineal branch branches from perineal N. + perineal branch posterior cutaneous N. of the thigh. posterior cutaneous N. of the thigh.

Contents of female Contents of female Urogenital TriangleUrogenital Triangle

External genitalia.External genitalia. Orifices of Orifices of urethra urethra & & vagina.vagina. The vaginaThe vagina is directed is directed

upward & backward.upward & backward. The cervix pierces its anterior The cervix pierces its anterior

wall.wall. Its upper ½Its upper ½ lies above pelvic lies above pelvic

floor floor within the main pelviswithin the main pelvis between U.B. anteriorly & between U.B. anteriorly & rectum posteriorly.rectum posteriorly.

Its lower ½Its lower ½ lies lies in perineumin perineum between urethra between urethra anteriorly anteriorly & & anal canal anal canal posteriorly.posteriorly.

Supports of vaginaSupports of vagina : : 1-upper 1/31-upper 1/3 …levator …levator ani, transverse ani, transverse cervical ,pubocervical, and cervical ,pubocervical, and sacrocervical lig. sacrocervical lig. 2-middlle 1/32-middlle 1/3 ……urogenital diaphragm.urogenital diaphragm. 3-lower 3-lower 1/31/3 …perineal body.…perineal body.

Contents of Superficial Contents of Superficial Perineal Pouch In Perineal Pouch In malemale : :Root of penis + its

covering Ms. As bulbospongiosus (covers bulb of penis on each side) & ischiocavernosus muscles (cover crus penis on each side).

Superficial transvrse perineal Ms

arise from ischial ramus and inserted into perineal body… it fix perineal body in the center of perineum.

All Ms. of pouch+ skin are Supplied by perineal branch of pudendal N.

Perineal body : a small fibrous mass lies at the center of posterior margin of

Urogenital diaphragm/. it gives attachment to : 1-ext.anal sphincter. 2-bulbospongiosus muscle. 3-superficial transverse perineal Ms.

Contents of Superficial Contents of Superficial Perineal Pouch in Perineal Pouch in Female :Female :Bulbospongiosus

muscle, surrounds orifice of vagina and covers vestibular bulbs.

Ischiocavernosus muscle, covers crus of clitoris on each side.

Superficial transverse perineal muscles.

Perineal body …. Lies between vagina & anal canal.

Perineal branch of pudendal N… suppling muscles & skin (as in male).

Contents of Deep perineal Contents of Deep perineal Pouch in Pouch in male :male : Membranous urethra …

lies in urogenital diaphragm.

Sphincter urethrae muscle circular & transverse Fs.,/supplied by perineal branch of pudendal N.

Bulbourethral glands …ducts pierce perineal membrane to enter penile urethra.

Deep transverse perineal Ms. One on each side, small muscle Lie posterior to sphincter urethrae muscle., inserted into perineal body. It help fixation of perineal body.

Internal pudendal vessels.

Dorsal N. of penis.

Coronal section of pelvis

Contents of Deep Perineal Contents of Deep Perineal Pouch In Pouch In Female :Female :

Part of urethra .

Part of vagina.

Sphincter urethrae ,which is pierced by urethra & vagina.

Deep transverse perineal Ms., as in male.

Internal pudendal vessels.

Dosal N.of clitoris.

Coronal section of pelvis

Pudendal Nerve BlockPudendal Nerve BlockIndication : during second stage of difficult labor, using forceps delivery and episiotomt.

Area of anesthesia: is the skin of perineum.

Transvaginal procedure : -The bony landmark used is ischial spine by passing the neddle through vaginal mucous m. -On passing sacrospinous ligament, injection of solution is performed around pudendal N.

Perineal procedure : -The bony landmark is ischial tuberosity, by palpating it subcutaneously at the buttock.. -The neddle is introduced into pudendal canal -1 in. deep to ischial tuberosity, so local anesthetic drug infiltrates around pudendal N.

Injury of perineum during Injury of perineum during childbirthchildbirth

The perineal body :The perineal body : is a fibromuscular mass is a fibromuscular mass

lyinglying between bulb of penis & anal canal between bulb of penis & anal canal in malein male /and /and between lower part of vagina & anal canal between lower part of vagina & anal canal in female,in female, supporting supporting post. Vaginal wall.post. Vaginal wall. It is fixed in positionIt is fixed in position by by insetion of perineal Ms.insetion of perineal Ms. + + levator ani (anterior levator ani (anterior Fs.Fs.)./it is )./it is much larger in femalmuch larger in femal than in male. than in male.

In most cases during childbirthIn most cases during childbirth , there is , there is abrasion abrasion ofof post. Vaginal wallpost. Vaginal wall / /In spontaneous delivary of In spontaneous delivary of child,child, it results in a it results in a severe tear of lower 1/3 of post. severe tear of lower 1/3 of post. Vaginal wall,Vaginal wall, perineal body, and overlying skin,perineal body, and overlying skin, so so lacerations maylacerations may extend into extend into anal canalanal canal and damage and damage the the external sphincter.external sphincter.

Breech deliveries + forceps diliveriesBreech deliveries + forceps diliveries are usually are usually preceded by an preceded by an episiotomy,episiotomy, through through surgical surgical incision inincision in perineal skinperineal skin in a in a posterolateral directionposterolateral direction to avoid the anal sphinctersto avoid the anal sphincters

Perineal membrane (inferior fascia of urogenital diaphragm) in male is piersed by : 1-urethra.

2-internal pudendal artery. 3-dorsal N.of penis.

Perineal membrane in female is pierced by : 1-urethra. 2- vagina. 3-internal pudendal artery. 4-dorsal N. of clitoris.

Clinical Notes :Clinical Notes : Injury to pelvic floorInjury to pelvic floor :during childbirth :during childbirth

can result in loss of support of pelvic can result in loss of support of pelvic viscera leading to viscera leading to uterine & vaginal uterine & vaginal prolapseprolapse ,and alteration in position of ,and alteration in position of bladder neck & urethra leading to bladder neck & urethra leading to stressstress incontinence.incontinence.

Visceral pelvic fascia and infection :Visceral pelvic fascia and infection : the pelvic fascia the pelvic fascia in the region of uterine in the region of uterine cervixcervix is referred to as is referred to as parametrium.parametrium.it is it is a a common sitecommon site for spread of acute for spread of acute infections from uterus & vagina ,so the infections from uterus & vagina ,so the infection becomes chronic pelvic infection becomes chronic pelvic inflammatory disease.inflammatory disease.