Gross 2 Pelvic Region and Perineum Flashcards
What is the Pelvic Inlet?
This divides the abdominal and pelvic cavities .
- Has an oblique plane that runs along the pelvic brim, and divides the pelvis into greater and lesser pelves
What is the Greater Pelvis? What is the Lesser Pelvis? What is Pelvic Outlet?
Greater Pelvis: The area of the pelvis NOT enclosed by bones
Lesser Pelvis: The area of the pelvis enclosed by bones
Pelvis Outlet: Inferior aperture of the pelvis; plane at the level of the pubic arch and coccyx
What contents are in the Pelvic Cavity? (Greater and Lesser Pelvis)
The Greater Pelvis contains some parts of small and large intestine
The Lesser Pelvis contains:
- Terminal parts of ureters
- Urinary bladder
- Rectum
- Genital organs
- Blood vessels } Supplies Pelvis and LE
- Lymphatics } Supplies Pelvis and LE
- Nerves } Supplies Pelvis and LE
What are the Muscular Walls of the Pelvic Cavity, what muscles accompany the walls?
Lateral wall: Obturator Internus
Posterosuperior: Piriformis
Floor: - Coccygeus (Ischiococcygeus)
- Levator Ani (Puborectalis, Pubococcygeus, and
Iliococcygeus)
What are the Fascial and Ligamentous structures of the Pelvic Walls? (5)
- Obturator Internus fascia
- Obturator Membrane
- Anterior SI joint ligament
- Sacral-Tuberous Ligament
- Sacral-Spinous Ligament
Where is the Perineum/Perineal Compartment?
The area below the pelvic diaphragm and deep to external region of skin including genitals to gluteal folds, and area between thighs
How is the Perineum/Perineal Compartment divided?
Its divided into two regions by a transverse line joining the anterior ends of the ischial tuberosities; then two oblique plane intersect at the transverse line creating:
- Urogenital Triangle
- Anal Triangle
What contents are in the Anal Triangle?
Contains the Ischioanal fossa and a Median part.
Median Part contains:
- Anal canal: Rectum to Anus
- Internal Anal Sphincter: Within anal canal; smooth muscle innervated by parasym. (Pelvic splanchnic)
- External Anal Sphincter: Skeletal muscle innervated by inferior rectal nerve (Pudendal)
- Perineal Body: Fibrous mass anterior to anus, attachment site for superficial transverse perineal muscle, bulbospongiosum, and outer layer of the external anal sphincter
- Anococcygeal ligament: From posterior aspect of anal canal to coccyx; attachment site for pubococcygeus and iliococcygeus and external anal sphincter
What is the Neurovasculature in the Ischioanal Fossa?
The main structures are in the Pudendal Canal:
Pudendal Nerve:
- Gives a branch of inferior rectal nerve (Motor to external anal sphincter;Sensory to skin around anus)
- Gives off sensory branches to external genitalia
Internal Pudendal Artery:
- Gives off an Inferior Rectal artery; supplies blood to the rectum and anus
-Gives off arteries to external genitalia
Internal Pudendal Vein
- Gives off an inferior rectal vein; drains blood form the rectum and anus
- Branches drain blood from external genitalia
Where is the Urogenital Triangle?
Its bordered by the pubic symphysis, inferior pubic ramus and ischium, posteriorly by the anal triangle and superiorly by levator ani muscle
- Divided into a superficial and deep space by the perineal membrane
What is in the Superficial Space of the Urogenital Triangle?
- Superficial Transverse Perineal Muscle
- Bulbospongiosum Muscle
- Ischiocavenosus Muscle
All innervates by pudendal
What is in the Deep Space of the Urogenital Triangle?
Known as the Urogenital Diaphragm
- External Sphincter Urethra muscle
- Compressor Urethra Muscle
- Deep Transverse Perineal Muscle
- Urethrovaginal Sphincter Muscle (Females)
All innervated by pudendal
What is the the function of the Urogenital Triangle and what nerve innervates this area?
Function:
- Expulse urine after bladder empties
- Expulse semen
- Maintain erection by compressing veins into the bulb of the penis
Innervation:
- Pudendal N.
What structures of the pelvic floor and perineum may be torn or stretched during childbirth?
- Muscles of perineum, levator ani, and ligaments of the pelvic fascia and the nerves supplying these structures
What happens if the structures of the pelvic floor are torn or stretched during childbirth?
- Urinary incontinence
- Fecal Incontinence
What are the arteries in the Internal Iliac-Anterior Division for males?
- Umbilical (With a Superior Vesical B.)
- Obturator
- Inferior Vesicle
- Inferior Gluteal
- Middle Rectal
- Internal Pudendal (With Dorsal A. to Penis, and Inferior Rectal A. branches)
What are the arteries in the Internal Iliac-Anterior Division for females?
- Umbilical (With a Superior Vesical B.)
- Obturator
- Uterine (With Vaginal A.)
- Inferior Gluteal
- Middle Rectal
- Internal Pudendal (With Dorsal A. to Clitoris, and Inferior Rectal A. branches)
What pelvic arteries arise from the Aorta?
- Superior Rectal: comes off inferior mesenteric
- Testicular/Ovarian: Off aorta
- Medial Sacral: Off posterior aspect of abdominal aorta
What is the function of the Umbilical Artery?
Before birth, the umbilical arteries are the main continuation of the internal iliac arteries, through the umbilical ring into the umbilical cord
What is the function of the Obturator Artery?
Arises close to the origin of the umbilical A., to the obturator muscles
(supplies obturator Internus/Externus)
What is the function of the Inferior Vesical Artery?
Occurs consistently only in males. In females it may occur as a branch of internal iliac or as a branch of the uterine artery. Supplies the prostate, seminal vesicle, bladder and Vas Deferens
What is the function of the Vaginal A.?
Supplies numerous branches to the anterior and posterior surfaces of the vagina
What is the function of the Middle Rectal Artery?
Supplies the rectum
What is the function of the Inferior Gluteal Artery?
Supplies the muscles and skin of the gluteal area and the posterior surface of the thigh
What is the function of the Iliolumbar Artery?
The iliolumbar A. has two branches: Iliac branch and Lumbar branch.
- The Iliac branch supplies the iliacus and ilium
- The lumbar branch supplies the psoas major and quadratus lumborum
What is the function of the Lateral Sacral Artery?
- Supplies the Erector Spinae muscles of the back and the skin overlying the sacrum