pelvis and perineum

Question 1

what is the function of the pelvis

Answer 1

lower limbs to spine and supports the visceral organs of the pelvis

Question 2

bones of the pelvis

Answer 2

-2 hip bones (os coxae): fusion of the ilium, ischium, and pubis
-sacrum
-coccyx: tail bone, stabilize, can flex

Question 3

divisions of the pelvis

Answer 3

-greater (false) pelvis: houses certain abdominal viscera
-lesser (true) pelvis: accommodates pelvic viscera, bladder, and reproductive organs
-separated by a pelvic brim

Question 4

anatomical features of the pelvis:

Answer 4

-acetabulum: junction of the ilium, pubis, receives the femoral head
-ischial tuberosity
-obturator foramen: almost completely closed off, except for a small passage for vessels and nerves

Question 5

what are differences between the male and female pelvis

Answer 5

-female pelvis: adapted for childbearing, lighter and shallow, wider, and provides more room in the true pelvis. sacrum is oriented posteriorly.
-male: sacrum is oriented anteriorly

Question 6

ligaments of the pelvis function

Answer 6

hold sacrum to oxosca, prevent pelvic tilt
-weight of the trunk tends to rotate the sacrum anteriorly, resists force

Question 7

what are the two ligaments of the pelvis

Answer 7

-sacrospinous ligament: runs horizontal
-sacrotuberous ligament: superior/inferior direction

Question 8

what happens to the pelvic ligaments during pregancy

Answer 8

the hormone relaxin relaxes ligaments and pelvic joints, causes pelvic movement to increase
-cause: increase in pelvic rotation, transverse diameter widens allowing the passage of fetus
-problem: relaxes all ligaments and weakens the joints

Question 9

pelvic diaphragm

Answer 9

-funnel of skeletal muscles closing the pelvic outlet
function: form a floor that supports pelvic viscera inferiorly and helps raise intraabdominal pressure, voluntary control of urination, fecal continence, and uterus support
-constantly contracts

Question 10

pelvic diaphragm: muscle composition

Answer 10

-levator ani
-coccygeus muscles and fascia
-blood supply
-obturator internus: extra

Question 11

origin of pelvic floor muscles

Answer 11

pelvic walls, ring

Question 12

insertion of pelvic floor msucles

Answer 12

coccyx

Question 13

female urogenital hiatus

Answer 13

permits passage of the urethra, vagina, and rectum

Question 14

male urogenital hiatus

Answer 14

pelvic diaphragm permits passage of the urethra and rectum

Question 15

puberectalis muscle

Answer 15

fecal continence: fecal continence
origin: pubis
insert: forms in and attaches to other side of pubis
innerv: ANS

Question 16

pelvis blood supply:
arterial supply

Answer 16

-paired internal iliac arteries and branches: deliver most blood to the lesser pelvis and bifurcate into an anterior and posterior division
-pairs ovarian arteries: from aorta, not iliac
-superior rectal arteries

Question 17

venous drainage of the pelvis

Answer 17

-drain into the internal iliac veins
-mostly internal iliac veins and their branches
-superior rectal veins (portal venous system)
-gonadal veins

Question 18

innervation of the pelvis

Answer 18

-sacral (S1-S4) and coccygeal spinal nerves and pelvic part of the ANS
-lumbosacral trunk: sciatic nerve
-pudendal nerve: main nerve of the perineum and chief accessory nerve of the external genitalia. S2-S4
-superior and inferior gluteal nerves: branches from lumbar and sacral plexus, go backwards
-coccygeal plexus: small network of nerve fibers formed by the ventral rami of S4 and S5

Question 19

pudendal canal

Answer 19

horizontal passageway within the obturator fascia which covers the medial aspect of obturator internus; transmits the internal pudendal vessels and pudendal nerve supply the perineum

Question 20

pudendal nerve

Answer 20

somatic innervation S2-S4 to perineal body wall, muscles, genitalia, external anal sphincter and skin of perineum; also carries sympathetic
-runs through the pelvis-sacrospinous ligament-out and under-along ischium-external genitalia

Question 21

perineum

Answer 21

diamond shaped pelvic outlet that lies inferior to the pelvic aperture

Question 22

what is the perineum bounded by

Answer 22

by the pubic symphysis anteriorly, ischial tuberosities laterally, and coccyx posteriorly.

Question 23

what is the perineum subdivided

Answer 23

-urogenital (UG) triangle: root of scrotum, penis, and vulva
-anal triangle anal canal and anus

Question 24

what muscles is the perineum bounded by

Answer 24

superiorly by levator ani and laterally by obturator internus

Question 25

superficial pouch of the perineum

Answer 25

potential space between the membranous layer of subcutaneous tissue and the perineal membrane; skin, fascia, tissue

Question 26

deep pouch

Answer 26

bounded inferiorly by the perineal membrane and superiorly and laterally by the fascias to the pelvic diaphragm and obturator internus muscles

Question 27

contents of superficial pouch in males

Answer 27

-root (crura and bulb of the penis) and associated muscles (ischiocavernosus and bulbospongiosus) maintain erection
-proximal part of spongy urethra
-superficial transverse perineal muscles
-deep perineal branches of internal pudendal vessels and pudendal nerves

Question 28

contents of superficial pouch in females

Answer 28

-clitoris and associated muscles
-bulb of the vestibule and surrounding muscles (ischocavernosus)
-greater vestibular gland-mucous
-deep perineal branches on internal pudendal vessels and nerves
-superficial transverse perineal muscles

Question 29

contents of deep pouch both sexes share

Answer 29

-contain part of the urethra centrally
-inferior part of the internal sphincter muscle
-anterior extension of the ischioanal fat pads

Question 30

contents of deep pouch in males

Answer 30

-intermediate part of the urethra
-deep transverse perineal muscle
-bulbourethral glands
dorsal neurovasculature of the penis

Question 31

contends of deep pouch in females

Answer 31

-proximal part of the urethra
-mass of smooth muscle that corresponds to the deep transverse perineal muscle
-dorsal neurovascular of the clitoris

Question 32

ischioanal fascia in the anal canal

Answer 32

fat filled, wedge shaped region surrounding the rectum and anus
-location: anal triangle between the skin of anal region and pelvic floor
-neurovascular contents: inferior anal/rectal vessels and nerves and cutaneous branches of the sacral plexus

Question 33

disruption of the perineal body

Answer 33

stretching or tearing of muscles from the perineal body can occur during childbirth which removes support
causes: prolapse of pelvic viscera can occur through the urethra or vaginal orifice and incontinence