Pelvis And Perineum 1 Flashcards
Contrast true and false pelvis
- The iliac blades contribute to the abdominal cavity = “false pelvis”
- Below the pelvic inlet is the pelvic cavity =“true pelvis”
Contrast pelvic inlet and pelvic outlet
• Pelvic inlet - sacral promontory, sacral ala, arcuate line, pectineal line,
pubic crest
• Pelvic outlet - Anterior: pubic symphyses, ischiopubic ramus; Posterior: ischial tuberosities, sacrotuberous ligaments and sacrum
What does the pelvis consist of?
Funnel shaped muscle that reinforces the pelvic organs Anterior defect = urogenital hiatus Consists of : levator ani muscle • Iliococcygeus • Pubococcygeus \: Coccygeus (ischiococcygeus)
What the peritoneum and its pouches?
- Where the peritoneum folds over the organs it creates pouches where fluid may collect
- The rectouterine pouch (of Douglas) is the lowest point in the abdominopelvic cavity in the upright position
What is Culdoscopy/Culdoscentesis?
Culdoscope is an endoscopic instrument that can be inserted through the posterior part of the vaginal fornix to examine the ovaries or uterine tubes
Culdoscentesis: checks for abnormal fluid in the abdominal cavity behind the uterus
What are the make internal organs?
The testes are considered part of the internal organs
Their development, blood supply, innervation and lymphatic drainage is all connected to the lumbar region
What are the important ideas of the vascular supply?
Pelvic arteries are very variable, especially in regards to their origin. Name arteries for what they supply!
With the exception of the ovaries, all pelvic viscera are supplied by branches of the internal iliac arteries
Venous drainage follows the arteries and there is great difference between male and female
What are the veinous interconnections of the inner pelvis ?
The prostatic venous plexus drains into the Inferior vesicle veins and subsequently into the internal iliac vein The plexus may also drain into the sacral veins and into the internal vertebral plexus of Batson
What are the lymphatic drainage of the pelvic organs?
Male
• Testes drain to lumbar nodes
• Prostate, seminal vesicles, ductus deferens drain into internal iliac nodes
Female Uterine fundus (with ovaries and uterine tubes) drains to lumbar nodes
Body of uterus, cervix and upper vagina drain to external & internal iliac nodes
Lower vagina drain into superficial inguinal
What is the pelvic plane line?
Pelvic pain line (PPL)
imaginary line corresponds to the lower limit of the peritoneum
What happens above the pelvic pain line?
Above PPL - the visceral afferents (body of uterus, uterine tubes, peritoneal portion of bladder) for pain travel via the sympathetics
They travel in the inferior hypogastric plexus
Pain is referred to the T10-L2 areas
What happens below the pelvic pain line?
Below PPL - the visceral afferents (the cervix, the upper portion of vagina and majority of the urinary bladder) for pain travel via the parasympathetics
They travel in the inferior hypogastric plexus
Pain is referred to the S2-S4 areas
Note: the pelvic pain line in the GI tract is located at the midpoint of the sigmoid colon
Explain what is the perineum
- Area of the groin between the upper thighs, external to the pelvic diaphragm
- Perineal organs (external genitalia) are below the pelvic outlet
- Divided into two unequal triangles (approx. 45° to each other) • Urogenital anteriorly
- Anal posteriorly
- Their bases are formed by same line, midpoint = perineal body
What is the fascia of the urogenital triangle?
The membranous layer (Colle’s) of fascia is continuous with the fascia of the anterior abdominal wall
Fused to the inguinal ligament
Fused to the perineal membrane posteriorly
Fused to the ischiop
What are the perineal pouches?
The fascia of the inferior limits of the pelvic diaphragm, perineal membrane and superficial perineal fascia create 2 spaces where fluid may accumulate
• Deep perineal pouch; deep to the perineal membrane
• The superficial perineal pouch; superficial (external) to the perineal
membrane
What muscles are Innervated by the somatic motor of the pudendal(S2-4) innervation?
SOMATIC Motor Innervation: • external anal sphincter
• ischiocavernosus
• bulbospongiosus
• muscles of the perineal pouches
What is Innervated by the somatic sensory innervation of the pudendal nerve (S2-4)?
- anus
- scrotum/labia
- penis/clitoris
- lower 1⁄4 of vagina
What is Innervated by the sympathetic innervation of pudendal nerve (S2-S4)?
SYMPATHETIC Innervation: Sweat glands and smooth muscle in skin and vessels of: • scrotum/labia • penis • anal region
What are the branches of the pudendal nerve?
Inferior rectal nerve
Perineal nerve
Dorsal nerve of the penis/clitoris
What is the function of the inferior rectal nerve?
Inferior rectal nerve – crosses the ischioanal fossa
Motor: external anal sphincter
Sensory: anal canal below the pectinate line
What is the function of the perineal nerve?
Perineal nerve
Motor: bulbospongiosus and transverse perineal muscles
Sensory: posterior scrotal / labial
What is the function of dorsal nerve of the penis/clitoris?
Dorsal nerve of the penis / clitoris runs on the dorsum of penis ends in the glans (sensory supply for body and glans)
What is the significance of pudendal canal-Alcocks canal?
Passage within the obturator fascia (lateral wall of ischioanal fossa) – internal pudendal vessels & pudendal nerve run from the lesser sciatic notch to the perineum
Pudendal nerve and internal pudendal artery pass out the greater and in the lesser sciatic notch
Explain the veinous drainage of the perineum
Venous drainage of the penis (and clitoris) is via the deep dorsal vein These drain into the prostatic plexus ♂ vesicular plexus ♀ The posterior scrotal ♂, posterior labial ♀, become the internal pudendal vein receive branches from the external anal sphincter Branches from the anterior scrotum ♂, labia majora ♀ drain into external pudendal vein
What is the lymphatic drainage of the perineum?
The erectile tissues of the penis and clitoris and the labia minora drain into the deep inguinal nodes
Lymphatics from the perineal skin drain into the superficial inguinal lymph nodes (horizontal group)
What is pudendal canal syndrome?
Compression of the pudendal nerve typically in the pudendal canal leads to;
• Burning sensation/numbness to the perineum region;
• particularly the posterior aspect of the scrotum and labia majora
• Skin of the penis, labia minora and inferior aspect of the vagina and anal canal
• Dorsal nerve of the penis - loss of sensation to the head of the penis and clitoris
• Rectal incontinence
• Sexual impotence (failure to ejaculate) - bulbospongiosus muscle
