pelvis Flashcards
Pelvis region
- area of transition between trunk and lower limbs
2. enclosed by bones, ligaments, muscles
sexual differences in pelves (4)
- xy- pelvic inlet xx- oval (not heart shaped)
- pelvic outlet; larger pelvic outlet; everted ischial spines
- pelvic cavity; shallower greater & lesser pelves
- pubic arch; rounded & wider subpubic angle
pelvic cavity
- funnel shaped space bound by bones of the pelvis
- greater pelvis: btw ala of ilium & p. inlet
- lesser p: btw p. inlet & p. outlet
- continuous with abdominal cavity
- contains urinary bladder, terminal parts of ureters, pelvic genital organs, rectum
perineum
two parts
male/XX
- triangular area of trunk btw thighs and buttocks extending from pubis to coccyx
- seen best in lithotomy position-diamond shape
- separated from pelvic cavity by the pelvic diaphragm (pelvic floor)
- 2 parts: urogenital triangle, anal triangle
- males: penis, scrotum, anus
- females: vulva, clitoris, vagina, anus
OIAN Obturator internus
O: ilium, superior pubic ramus & ischium (anterolateral wall of oelvis minor)
I: greater trochanter of femur
A: none
N: nerve to obturator internus
Piriformis OIAN
O: 2-4th sacral segments
I: greater trochanter of femur
A: none
N: S1-2
Muscles making up pelvic diaphragm function of pelvic diaphragm
- levator ani muscle + coccygeus muscle
- form floor of pelvis, suporting abdominopelvic organs
- aids in urinary and fecal continence
- raises pelvic floor during urination, vomiting, coughing, weight lift
- during parturition, supports the fetal head while the cervix dilates for delivering the baby
Three names that make up the levator ani
- puborectalis
- pubococcygeus
- Iliococcygeus
Tendinous arch of levator ani
- thickened fascia of obturator internus muscle
- attachment for levator ani muscle
Iliococcygeus (one of three muscle making up the levator ani OIAN
O-tendinous arch of obturator fascia
I-perineal body, coccyx
A-support pelvic viscera
N-S4, inferior rectal nerve, cocygeal plexus
OIAN of puborectalis (levator ani)
O-inferior ramus of pubis
I-rectum, prostate in males, vagina in female
A-support pelvic viscera
N-S4-5
OIAN of pubococcygeus
O-inferior ramus of pubis tendinous arch of obturator internus
I-coccyx
A-support pelvic viscera
N-S4-5
involve in episiotomy. Injury may lead to stress incontinence.
OIAN coccygeus
O-ischial spine
I-inferior end of sacrum, coccyx
A-supports pelvic viscera and flexes coccyx
N-S4-5
Pudendal nerve
-supplies sensory innervation to perineum
walls of pelvic cavity posterior- anterior- lateral- inferior- superior-
posterior-sacrum, piriformis m. anterior- pubic rami, pubic symphysis lateral- obturator internus inferior- levator ani m. (iliococcygeus, pubococcygeus, puborectalis) superior-open to abdominal cavity
Arteries in pelvis
- aorta
- common iliac a- external iliac a–>femoral a
- internal iliac a
- iliolumbar a
- lateral sacral a
- superior gluteal a
- inferior gluteal a
- internal pudendal a
- middle rectal a
- superior vesical a
- inferior vesical a
- umbilical a
male/female peritoneal recesses
Male: rectovesical pouch
Female: rectouterine pouch (of Douglas)
vesicouterine pouch
Urinary components (3)
- ureters carry urine from kidney
- urinary bladder temporarily stores urine
- urethra conducts urine from urinary bladder to exterior
Adult: urinary bladder in retropubic space within lesser pelvis.
Children: bladder is in abdomen
enters greater pelvis at 6 yo, lesser pelvis at 16
- What is the muscle that makes the bladder?
- What does the urethral sphincters do?
- Symp innervation
- para innervation
- detrusor m.- internal (involuntary), external (voluntary)
- help maintain urinary continence, internal sphincter prevent semen from entering bladder during ejaculation
- T11-L2, maintain continence by contraction of internal sphincter
- S2-4, allows urination by relaxing internal sphincter and contracting detrusor m.
Four parts of male urethra
- intramural part
- prostatic urethra
- intermediate part
- spongy urethra
Male pelvic viscera (8 structures)
- ductus deferens-takes pathway superior then posterior to bladder transmit sperm from epididymis of testis to prostatic urethra. Toward the end, ductus joins duct of seminal gland to form ejaculatory duct
- urianry bladder
- ureter
- seminal gland (vesicle)
- rectum
- prostate gland
- epididymis
- testis
- seminal glands
- prostate gland
- ejaculatory duct
- bulbourethral glands
- 50-70% semen made of fluid secreted by seminal gland
- 20% semen made of secretion from prostate gland
- ejaculatory duct bring seminal fluid & sperm through prostate into prostatic urethra
- bulbourethral glands secrete a lubricating fluid during sexual arousal
Penis structures
- corpus cavernosum outside
- corpus spongiosum
- erectile tissues fill with blood to become turgid
- spongy urethra runs through corpus spongiosum
- at base of penus corpus cavernosum is called crus of the penis
- corpus of spongiosum is call bulb of the penis
- at the tip of penis corpus spongiosum expands into glans of the penis
What are the two muscles at the base of penis? and the nerve
- ischiovavernosus muscle covers crus of penis
- bulbospongiosus muscle covers bulb of penis
- innervated by pudendal nerve
- erectile tissues covered by thin muscles that help maintain erection
Female pelvic viscera
- short urethra
- vaginal canal lies btw urethra and bladder anteriorly and anal canal and rectum posteriorly
- vaginal canal ends in an expanded fornix that surrounds the cervix of the uterus
female pelvic structures:
-ureter ovarian a and v. uterine tube ovary proper ligament of ovary uterus urinary bladder urethra clitoris labia minora/majora cervix rectum vagina levator ani m. anus vaginal orifice
What is the function of broad ligament and what suspend there?
what does the uterine tube do?
what causes prolapsed uterus?
- secure everything to the lateral pelvic walls
- uterus, uterine tubes, ovaries in the double layer of peritoneum
- uterine tube receives and conveys the ovum from the ovary to the uterine cavity
- prolapsed uterus results when the uterus descends abnormally into the vagina
Erectile tissue homology
penis=clitoris
crus of clitoris/glands of clitoris=crus of penis, glands of penis
bulbs of vestibule=bulb of penis
Structure in female genitalia
- ischocavernous m. covers crus of clitoris
- bulbospongiosus m. covers bulbs of vestibule (the vestibule is the region btw the labia minora)
innervation of pelvis and perineum (symp/para)
- sexual function
- defecation and urination
- para- spinal cord S2-4
-erection relaxation of smooth muscles in walls of arteries, allowing blood to fill erectile tissue
2..symp L1-2
-ejaculation in males contraction of smooth muscles in walls of the ductus deferens, seminal vesicles, prostate and urethra
-orgasm in females rhythmic contractions of smooth muscles in walls of vagina - para S2-4
-relaxation smooth muscle internal sphincters of bladder and rectum, contraction smooth muscle in walls of these organs
-symp L1-2
-contraction of smooth muscle internal sphincters to maintain continence
-voluntary somatic control S2-4
contraction of striated muscle external sphincters to maintain continence.
