Hello everyone,how are you all doing? I am doing well and i hope you to too.we learned about uoperlimb and lowerlimb and now we are entering into Pelvis and Perineal region.so lets learn about it.

PELVIS

Pelvis has 3 bones called Pubic,ilium and ischium.

pelvis has many vital visceral organs like uterus,urinarybladder,rectum and anus etc.so to avoid prolapse of thse vital organs downwards there are two diaphragm which gives support to these pelvis organs.they are Pelvic diaphragm and Urogenital diaphragm.lets learn where they are present and how they support.

PELVIC DIAPHRAGM

It extends from pubic symphysis anteriorly to coccyx posterioly and gives support and prevents prolapse of pelvis visceral organs.

It is made up if 2 muscles -

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• Levator ani muscle(pubococcygeus&iliococcygeus muscles)
• Coccygeus/Ischiococcygeus

It is a vestigial muscle in humans and it is present in animals which has tail.as we don't have tail because we don't have coccygeus muscle.

Modifications of pubococcygeus muscle -

• Pubourethralis
• Pubovaginalis
• Puborectalis

CLINICAL ASPECT OF PUBORECTALIS MUSCLE

Puborectalis forms the Ano-rectal angle and it helps in maintaining continence.

When we use western toilets we sit in the position shown in the below image.but there ia disadvantage with it.the puborectalis muscle gets contracted when we sit in that position and angle is decreased less than 90⁰.feces cannot pass through and defecation becomes uneasy.

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but when we use Indian toilets we sit in squatting postion the puborectalis muscle gets relaxed and the ano-rectal angle is increased and the rectum and anus lie in the same plane and the anal sphincters also becomes relaxed.so defecation becomes easy.

In squatting position

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So atry to sit in squatting position when you go to toilet.

UROGENITAL DIAPHRAGM

It is present beneath the pelvic diaphragm but it is not as lengthy as pelvic diaphragm.

Two orifices opens through this diaphram.uro(urethra) and genital(vagina) so it is called as Urogenital diaphragm

It is made up of two muscles -

• External urethral sphincter muscle
• Deep transverse perineal muscle

These two muscles are present in Deep perineal pouch and above these two muscles there is a fascia called Superior fascia of urogenital diaphragm and Inferior fascia of urogenital diaphragm/Perineal membrane.

PERINEAL BODY

It is dense fibrous one which is present in pelvis and 10 muscles are attached to this body.if it gets damaged the pelvis organs prolapse.so this is so strong.what are muscles that it get attached to it.you can aee in below pic

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4 paired muscles -

1. Bulbospongiosus
2. Superficial transverse perineal muscle
3. Deep transverse perineal muscle
4. Levator ani

2 unpaired muscles

• External anal sphincter muscle
• Longitudinal muscles of anal canal

PERINEUM

In lithotomy position the region which we see is perineum and you can see perineum is divided into Urogenital traingle and Anal triangle

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When we go from superficial to deeply these are the structure we are going to see.

From Superfical to Deep -

• Superfical fascia/Colle's fascia
• Inferior fascia/Perineal membrane
• Superior fascia of urogenital diaphragm

Two pouches between these fascias are Deep perineal pouch and Superficial perineal pouch

DEEP PERINEAL POUCH

Boundaries -

Boundaries	Structures
Superiorly	Superior fascia of urogenital diaphragm(UGD)
Inferiorly	Inferior fascia of UGD/Perineal membrane
Laterally	Ischiopubic ramus

Contents of Deep perineal pouch -

• External urethral sphincter muscle
• Deep transverse perineal muscle
• Membranous urethra in male
• Bulbourethral gland of cowper in male

You can see below diagram of deep perineal pouch to understand easily

SUPERFICIAL PERINEAL POUCH

Boundaries -

Boundaries	Structures
Superiorly	Inferior fascia of urogenital diaphragm(UGD)/Perineal membrane
Inferiorly	Superior fascia of fascia of perineum/Colle's fascia
Laterally	Ischiopubic ramus

Contents of Superficial perineal pouch -

• Superficial transverse perineal muscle
• Bulbspongiousus muscle
• Crus/Ischiocavernous muscle
• Greater vestibular gland/Bartholin's gland in female

CLINICAL ASPECTS

After learning about pelvis and perineum the we need to put more focus on pouches.

1. What if Membranous urethra which is present in Deep perineal pouch gets ruptured?

Then the urine is going to leak out from urethra into deep perineal pouch.

1. What if Bulbar urethra gets ruptured?

Then the urine gets leak out from bulbar urethra and gets collected in the Superficial perineal pouch, Scrotum, Thighs and Anterior abdominal wall upto axilla Because the anterior superfical abdominal fascia extended downwards and continues as scrotal fascia and then to superfical fascia/Colle's fascia.

Thanks for reading.there is something left in the perineum region to learn stay tuned for next post.

With regards,