SM_201b: Anatomy of the Pelvis and Perineum I Flashcards
Pelvis is composed of the ____ and ____
Pelvis is composed of the left and right innominate bone and sacrum
Each innominate bone (hip bone = os coxae) consists of three fused bones: ____, ____, and ____
Each innominate bone (hip bone = os coxae) consists of three fused bones: ischium, ilium, and pubis
Ilium articulates with ___
Ilium articulates with sacrum
Ischium articules with the ____ and ____ in the ____
Ischium articules with the pubis and ilium in the acetabulum
Pubis articulates with the ____
Pubis articulates with the opposite pubis
Describe the right innominate bone and sacrum
Right innominate bone and sacrum
____ separates the greater and lesser sciatic nothces
Ischial spine separates the greater and lesser sciatic nothces
____ and ____ ligaments are important in the pelvis
Sacrotuberous and sacrospinous ligaments are important in the pelvis
Pelvic brim (inlet of birth canal) consists of ____, ____, ____, ____, and ____
Pelvic brim (inlet of birth canal) consists of pubic tubercles and crest, pecten pubis, arcuate line of ilium, ala (wing) of sacrum, and sacral promontory
- Pelvis is adapted for visceral support and has lateral muscles for trunk support
Female birth canal has a ____, ____, ____, and ____
Female birth canal has a relatively long pubis, wider subpubic angle, relatively long sacral alae, and wider greater sciatic notch
- Relatively large
- Widest dimension: between arcuate lines of ilia
- Smallest: between ischial spines
Describe the process of birth
Birth
- Baby’s head enters the wide pelvic inlet turned sideways
- As the head encounters the narrow outlet between the ischial spines, it rotates
- The head and neck extend anteriorly under the pubic symphysis to avoid the coccyx
Weight of the trunk tends to rotate the ____, and the ligaments are arranged to resist this force
Weight of the trunk tends to rotate the sacrum anteriorly, and the ligaments are arranged to resist this force
Pelvic diaphragm is a ____ that supports the ____ and helps ____
Pelvic diaphragm is a skeletal muscle cone closing off the pelvic outlet that supports the pelvic viscera and helps raise intra-abdominal pressure
Pelvic diaphragm muscles include ____ and ____
Pelvic diaphragm muscles include levator ani and ischiococcygeus
- Levator ani: puborectalis + pubococcygeus + iliococcygeus
Levator ani consists of ____, ____, and ____
Levator ani consists of puborectalis, pubococcygeus, and iliococcygeus
____ is the central tendon of the perineum
Perineal body is the central tendon of the perineum
Pubo-rectal sling (puborectalis) is the ____
Pubo-rectal sling (puborectalis) is the most medial part of the pubococcygeus muscle
Pubo-rectal sling (puborectalis) functions to ____ and ____
Pubo-rectal sling (puborectalis) functions to maintain constant muscle tone to bend the rectum and relaxes during defecation when the rectum straightens
Uterus prolapses due to a weak ____
Uterus prolapses due to a weak pubococcygeus
(drops into the vagina)
Although the diaphragm is bowl-shaped, the fibers sweep posteriorly to the ____ and around the anus to the coccyx and ____
Although the diaphragm is bowl-shaped, the fibers sweep posteriorly to the perineal body and around the anus to the coccyx and anococcygeal ligament
____ runs from the ischial spines to the coccyx
Ischiococcygeus runs from the ischial spines to the coccyx
(bone to bone: cannot elevate anus)
Levator ani ____ attach to the pelvic brim and has a low origin on the ____
Levator ani does NOT attach to the pelvic brim and has a low origin on the pelvic wall
- Attachment from middle of pubis to ischial spines
- Obturator internus and its fascia above it
- Obturator nerve crossing pelvic brim to its canal
Describe the pelvic diaphragm
Pelvic diaphragm
____, ____, and ____ are primarily retroperitoneal
Bladder, vagina, and rectum are primarily retroperitoneal
Uterus and sigmoid are ____ because they have mesenteries
Uterus and sigmoid are NOT primarily retroperitoneal because they have mesenteries
Females have only a _____ urethra
Females have only a short membranous urethra
Membranous urethra in female is ____ and passes through the ____
Membranous urethra in female is short and passes through the urogenital diaphragm
Parasympathetics cause ____ of the bladder, while sympathetics supply the ____
Parasympathetics cause contraction of the bladder, while sympathetics supply the trigone
___ connects ureter orifices and urethral exit surrounded by the ___
Trigone connects ureter orifices and urethral exit surrounded by the internal urethral sphincter
Duct of each seminal vesicle joins the ____ to form an ____
Duct of each seminal vesicle joins the ampulla of each ductus deferns to form an ejaculatory duct
- Ductus (vas) deferns passes over ureters
Kidney has ____ segments defined by the ____
Kidney has five segments defined by the five segmental arteries
Minor and major calyces open into the ____ anterior nad posterior to a midline section of the kidney
Minor and major calyces open into the renal pelvis anterior nad posterior to a midline section of the kidney
____, ____, and ____ are common sites for kidney stones to lodge
Renal pelvis, common iliac vessels, and entrance to the bladder are common sites for kidney stones to lodge
True anal canal is below the valves at the ___
True anal canal is below the valves at the pectinate line
Pectinate line is at the bottom of the columns, which is the site of the ____
Pectinate line is at the bottom of the columns, which is the site of the cloacal membrane
Anal canal includes portions from the ____ and ____
Anal canal includes portions from the hindgut and body wall
(join at the pectinate line)
Nerves, muscles, venous drainage, and lymphatics are all different above and below the ___ where the ___
Nerves, muscles, venous drainage, and lymphatics are all different above and below the pectinate line where the endoderm joined the ectoderm
- Smooth vs skeletal muscle
- Visceral vs general sensory
- Parasympathetics vs somatomotor
Venous drainage above the pectinate line is into the ____
Venous drainage above the pectinate line is into the portal system
Venous drainage below the pectinate line is into the ____
Venous drainage below the pectinate line is into the internal iliac / caval system
Para-umbilical veins anastamose with the ____
Para-umbilical veins anastamose with the superficial gastric veins
Left gastric and lower esophageal veins anastamose with the ____
Left gastric and lower esophageal veins anastamose with the azygous system
Superior rectal vein travels into the ___
Superior rectal vein travels into the portal system
Internal hemorrhoids get ____ innervation so there is ____
Internal hemorrhoids get visceral sensory innervation so there is no pain
External hemorrhoids get ____ innervation so there is ____
External hemorrhoids get general sensory innervation so there is intense pain and itching
Hemorrhoids are ____
Hemorrhoids are dilated rectal / anal veins
Pectinate line divides lymph flow between the ____ and ____
Pectinate line divides lymph flow between the gut (above) and body wall (below)
Lumbar splanchnics supply ____ and ____ to ____
Lumbar splanchnics supply sympathetics and visceral sensory to superior hypogastric plexus (and on to pelvic plexus)
Pelvic splanchnic nerves are ____ and ____
Pelvic splanchnic nerves are parasympathetic and visceral sensory
