Lecture 2: Pelvic and Perineal Myology Flashcards
What is the Perineal Body; what does it contain; attachement for what muscles; sometimes reffered to as?
- Irregular fibromuscular mass in the midline between the Anal Canal and Perineal Membrane
- Contains Collagenous and Elastic Fibers
- Attachment point for the Bulbospongiosus M, External Anal Sphincter M., Superficial Transverse Perineal M, and Deep Transverse Perineal M.
- Sometimes classified as the Central Tendon of the Pelvic and Urogenital Diaphragms
What is the origin, insertion, action, and innervation for the Superficial Transverse Perineal M.?
O: Ischiopubic Ramus and Ischial Tuberosity
I: Perineal Body
A: Support/fix perineal body, Support Abdominopelvic Viscera and resist increases in Intraabdominal Pressure
N: Deep perineal N.
What muscle is indicated by the arrows?
Superficial Transverse Perineal M.
What is the origin, insertion, action, and innervation for the Ischiocavernosus M.?
O: Ischiopubic Ramus and Ischial Tuberosity
I: Medial aspect of the Crus of Penis (males) or Clitoris (females) and perineal membrane medial to the crura (both)
A: Maintain erection of Penis or Clitoris by compressing venous drainage, forcing blood from the Crura into the body of the Penis or Clitoris
N: Deep Perineal N.
What muscle is this?
Ischiocavernosus M.
What muscle and other strucutre is this?
- Ischiocavernosus M.
- Right Crus of the Clitoris
What is the origin, insertion, action, and innervation for the Bulbospongiosus M.?
O: Median Raphe, ventral bulb of penis and perineal body (male), Perineal body (female)
I: Perineal membrane, fascia of bulb of penis and corpus spongiosum and corpora cavernosa of the penis (male), fascia of bulb of the vestibule of vagina, pubic arch and fascia of the corpora cavernosa of the clitoris (females)
A: Support/fix perineal body (both)
- Compress bulb of penis; compressing venous drainage (erection), forces blood from root of penis to the body; expels final drops of urine/semen from the urethra (males).
- Compress vaginal orifice, assists in erection of bulbs of vestibule of vagina and compress the greater vestibular gland (females)
N: Deep perineal N.
What muscle is this?
Bulbospongiosus M.
What muscle is this?
Bulbospongiosus M.
The urogenital diaphragm muscle layer is described as being deep to?
Deep to and separated from the Superficial Perineal muscles by the Perinal Membrane; however, may contain elements of the Superficial Perinal Muscles and Perineal Membrane
What is the origin, insertion, action, and innervation for the External Urethral Sphincter M.?
O: Surrounds the Urethra
I: Surrounds the Urethra
A: Constrict Urethra maintaining urinary continence
N: Dorsal Nerve of the Penis or Clitoris
What is the origin, insertion, action, and innervation for the Compressor Urethrae M.?
O: Ischiopubic Ramus and Ischial Tuberosity
I: Median Raphe and Urethra via External Urethral Sphincter M.
A: Contrict Urethra maintaining urinary continence
N: Dorsal Nerve of the Penis or Clitoris
What is the origin, insertion, action, and innervation for the Urethrovaginal Sphincter M.?
O: Ischiopubic Ramus and Ischial Tuberosity
I: External wall of the Vagina
A: Compress the Vagina
N: Dorsal Nerve of the Citoris
What is the origin, insertion, action, and innervation for the Deep Transverse Perineal M.?
O: Ischiopubic Ramus and Ischial Tuberosity
I: Median Raphe, Perineal Body and External Anal Sphincter
A: Support/Fix Perineal Body, support Abdominalpelvic Viscera and Resists Increases in Intraabdominal Pressure
N: Deep Perineal N.
*SMOOTH MUSCLE in the Female*
What is described as being smooth muscular mass along the posterior edge of the Perineal Membrane in females?
The Deep Transverse Perineal M.
What is the origin, insertion, action, and inervation for the External Anal Sphincter M.?
O: Skin and fascia surrounding Anus and Anococcygeal Body
I: Perineal Body
A: Constricts the Anal Canal during Peristalsis, resists Defecation, support/fix perinal body
N: Inferior Rectal N.
What is the location, type of muscle, and innervation for the Internal Anal Sphincter M.?
- Surrounds superior 2/3 of Anal Canal
- Thickening of Circular muscular layer
- Innervated by: PNS fibers from Pelvic Splanchnic Ns.
What is the origin, insertion, action, and innervation for the Puborectalis M?
O: Posterior aspect of the Pubic Body
I: Externalwall of the Rectum and Anal Canal
A: Maintain Anorectal Flexure, supports Pelvic Viscera, resists increases in Intraabdominal Pressure
N: Nerve to the Levator Ani M. (S4)
What is the origin, insertion, action, and innervation for the Pubococcygeus M.?
O: Posterior aspect of the Pubic Body and anterior most part of the Tendinous Arch of Obturator Fascia
I: Coccyx, Anococcygeal Body, contralateral Pubococcygeys M.
A: Supports Pelvic Viscera, resists increases in Intraabdominal Pressure
N: Nerve to the Levator Ani M. (S4)
What is the origin, insertion, action, and innervation for the Iliococcygeus M.?
O: Posterior part of the Tendinous Arch of Obturator fascia and Ischial Spine
I: Coccyx and Anococcygeal Body
A: Supports Pelvic Viscera, resists increases in Intraabdominal Pressure
N: Nerve to the Levator Ani M. (S4)
What is produced by the Pubococcygeus M.?
Several small slips of muscle (accessory muscles) that extend to nearby structures, all sharing similar action and innervation as the Pubococcygeus M.
- Levator Prostate M. (males)
- Pubovaginalis M. (females)
- Puboperinealis M. and Puboanalis M. (both)
What is the origin, insertion, action, and innervation for the Coccygeus M.?
O: Ischial Spine
I: Inferior Sacrum and Coccyx
A: Support Pelvic Viscera, flexes Coccyx
N: Nerve to the Coccygeus (S4, 5; branches of the Coccygeal Plexus)
Label the arrows on the left from top to bottom?
- Tendionous arch of the levator ani M.
- Iliococcygeus M.
- Pubococcygeus M.
- Puborectalis M.
Label the arrows on the right side from top to bottom?
- Obturator Internus M.
- Piriformis M.
- Coccygeus M.
- Sacrospinous L.
What is the origin, insertion, action, and innervation for the Obturator Internus M.?
O: Pelvic surfaces of the Ilium and Ischium and Obturator Membrane
I: Greater Trochanter of Femur
A: Rotate thigh laterally, stabilize femoral head in acetabulum
N: Nerve to the Obturator Internus M
What is the origin, insertion, action, and innervation for the Piriformis M.?
O: Pelvic surface sacral segments S2-S4, greater sciatic notch, and sacrotuberous L.
I: Greater Tronchanter of Femur
A: Laterally rotate and ABduct thigh, stabilize femoral head in acetabulum
N: Nerve to the piriformis m.
