Anatomy_of_the_Perineum_Broken_Down_11Sep24.pdf

Anatomy of the Perineum Broken Down Structure Overview (from most cranial -> caudal) 1. Pelvic Diaphragm 2. Deep Perineal Pouch 3. Perineal Membrane 4. Superficial Perineal Pouch NOTE: Pelvic Diaphragm and Pelvic Floor are sometimes used interchangeably, they are NOT the same....

Anatomy of the Perineum Broken Down Structure Overview (from most cranial -> caudal) 1. Pelvic Diaphragm 2. Deep Perineal Pouch 3. Perineal Membrane 4. Superficial Perineal Pouch NOTE: Pelvic Diaphragm and Pelvic Floor are sometimes used interchangeably, they are NOT the same. Pelvic Floor includes all the structures of the Pelvic Diaphragm, Deep Perineal Pouch, Perineal Membrane (3). 1. Pelvic Diaphragm (Muscles most Lateral -> Medial) a. Muscles: i. Coccygeus Muscle ii. Levator Ani (most Lateral -> Medial) 1. Iliococcygeus 2. Pubococcygeus 3. Puborectalis b. Innervation: i. Sacral Nerve Roots (S2, S3, S4) ii. Pudendal nerve c. Blood Supply i. Inferior Gluteal Artery ii. Inferior Vesical Artery iii. Pudendal Artery d. Action/Purpose: i. This is the foundational/main support of the pelvic region, without the pelvic diaphragm muscles and individual will be incontinent for PEE and POO (puborectalis) -> the fibers relax so bathroom activities can happen. It also helps resist changes in inter-pelvic pressure. e. Honorable mentions: i. The Sacrospinous ligament, which creates the lesser/greater sciatic foramen adds more stability to the pelvic girdle (from outside of it) bg limiting movement. 2. Deep Perineal Pouch  a. Muscles of Deep Perineal Pouch i. Muscles in MEN AND WOMAN: 1. Deep Transverse Perineal Muscle 2. External Urethral ii. Muscles ONLY in Woman: 1. Compressor Urethrae Muscle 2. Sphincter Urethrovaginalis Muscle b. Blood Supply: 1. Perineal Artery c. Nerve Supply: 1. Perineal Nerve (S2,S3,S4) d. Action/Purpose: i. This layer is involved with supporting the diaphragm and preventing urinary incontinence (PEEPEE ONLY) 3. Perineal Membrane a. Blood Supply: Internal Pudendal Artery b. Nerve Supply: Perineal Nerve (S2,S3,S4) c. Action/Purpose: More support (can’t get enough support..) and separate the DEEP Perineal Pouch from the SUPERFICIAL Perineal Pouch 4. Superficial Perineal Pouch a. Muscles (Lateral -> Medial) i. Ischiocavernosus Muscle ii. Transverse Perineal Muscle (attached to PERINEAL BODY across) iii. Bulbocavernosus Muscle (also called Bulbospongiosus Muscle in men) b. Ligaments: i. Perineal Body c. Blood Supply: Internal Pudendal Artery (Ischiocavernosus), Perineal Artery d. Nerve Supply: Pudendal Artery (S2,S3,S4) “S2-3-4 keep your penis/poo/peee off the floor) e. Action/Purpose: Since these are SUPERFICIAL they don’t over much support, they are more for SUPERFICIAL things like SEX -> flexing muscle to hold up penis/clitoris or to help express the glands in/around vagina for lubrication during sex.. You get the picture f. Honorable Mentions: i. Great Vestibular Gland (Bartholin Gland) ii. Colles' fascia -> it is in the superficial layer but ABOVE the muscles 5. Pelvic Conditions/Honorable Mentions: a. A weakened pelvic floor will lead to stress urinary incontinence from -> hypermobility of bladder neck +urethra b. Internal Anal sphincter is part of the RECTUM therefore if you see that answer it is a trick answer -> not part of pelvic floor c. Although I didn’t review the Broad Ligament above just remember the Broad Ligament INDIRECTLY attaches to the ovaries therefore one can conclude that the Broad Ligament does include the ovaries -> Broad Ligament doesn't comprise the vagina d. The Perineal Nerve Branches from the Pudendal Nerve