Pelvis Flashcards
Name the components of the Ilium.
- Iliac fossa
- Iliac crest
- Anterior superior iliac spine
- Posterior superior iliac spine
- Anterior inferior iliac spine
- Posterior inferior iliac spine
Name the components of the Ischium.
- Ischial tuberosity
- Lesser sciatic notch
- Ischiadic (Ischial) Spine
- Greater Sciatic notch
Name the components of the Pubis.
- Superior ramus
- Inferior ramus
- Body
- Pubic Crest
- Pubic tubercle
- Pectineal line
- Obturator foramen and membrane
“False Pelvis”
Pelvis Major
Lowermost part of the abdominal cavity lying between the iliac fossae.
“True Pelvis”
Pelvis Minor
Inferior to the superior pelvic aperture. Contains pelvic viscera.
Main contents of the Pelvis
(1) Rectum
(2) Bladder
(3) Uterus/vagina in females; prostate gland in males
Ligaments of the Pelvis
PUBIC SYMPHYSIS: Joins the two pubic bones
SACROILIAC LIGAMENTS: From iliac to sacral tuberosities
ILIOLUMBAR LIGAMENTS: L5 transverse process to iliac crest
SACROTUBEROUS LIGAMENT: From lateral sacrum and coccyx to the medial side of the ischial tuberosity
SACROSPINOUS LIGAMENT: From lateral sacrum and coccyx to ischial spine
Muscles of the Pelvis
(1) Obturator Internus
(2) Piriformis M.
(3) Pelvic Diaphragm
(4) Urogenital Diaphragm
Obturator Internus and Externus Muscles
INTERNUS:
- Laterally rotates and stabilizes hip
- Innervation: Nerve to obturator internus
- Inserts into Greater Trochanter
OBTURATOR EXTERNUS has same insertion except outside of obturator membrane. It serves to rotate and adduct the hip.
Pectinate line
Pain sensory above the line
None below
Anal blood supply
Superior Rectal Br. of Mesenteric A. (Upper 2/3rds)
Middle Rectal A [from internal iliac A.] (lower 1/3rd muscular layer)
Inferior Rectal A. [from internal pudendal A.] (anastomoses with superior rectal in anal columns)
How is the Trigone of bladder different from the rest of the bladder?
Of mesodermal origin, whereas everything else is endodermal.
Pirformis Fossa Muscle
- Inserts into greater trochanter
- Laterally rotates and abducts thigh
- Innervation: Anterior primary rami S1, S2
What structures forms the pelvic diaphragm?
- Levator Ani Muscles
- Coccygeus Muscle
- Fascia
Muscles of Levator Ani
- Iliococcygeus
- Pubococcygeus
- Puborectalis
- Pubovaginalis/puboprostaticus
Coccygeus Innervation
Anterior Primary Rami
Arcus Tendinous
Whitish tendonous band that is part of the pelvic fascia and marks the line of attachment of the special fascia associated with the pelvic viscera.
External iliac artery later become the…
Femoral artery
Main divisions of the Internal Iliac
The Anterior and Posterior divisions of the Internal Iliac
The branches off external iliac artery
- Inferior epigastric
- Deep circumflex iliac
All of the posterior division arteries of the internal iliac artery go to…
Muscles
Branches of Posterior Division of Internal Iliac
(a) Ilioblumbar
(b) Lateral Sacral
(c) Superior gluteal
Branches of Anterior Division of Internal Iliac
(a) umbilical
(b) superior vesical
(c) obturator
(d) inferior vesical
(e) middle rectal
(f) inferior gluteal
(g) internal pudendal
Main important vein in pelvis
Uterine/Vaginal (ut/iv)
Where does the sacral plexus rest?
On the piriformis muscle, where it gives branches to the pelvis and the perineum and then splits to give anterior and posterior divisions
Sacral Plexus branches to the Pelvis/Perineum
(1) N. to piriforis
(2) perforating cutaneous
(3) pelvic splanchnics (autonomics)
(4) PUDENDAL N.
(5) Perineal branch of S4
Anterior Division Nerves of Sacral Plexus
- tibeal art of sciatic
- nerve to quadratus femoris and inferior gemellus
- nerve to obturator internus and to superior gemellus
- medial part of posterior femoral cutaneous n.
- PUDENDAL N.
Posterior Division Nerves of Sacral Plexus
- superior gluteal n.
- inferior gluteal n.
- common peroneal part of sciatic (fibial)
- lateral part of posterior femoral cutaneous n.
- n. to piriformis
- perforating cutaneous n’s
Ganglion Impar
Small ganglion at the front of the coccyx where the sympathetic trunks converge after descending from the abdomen along the sacrum.
What notable muscle does the obturator nerve NOT innovate?
Obturator internus. This is innervated by the nerve to the Obturator internus. The obturator nerve DOES HOWEVER, innervate the external obturator, among other muscles.
Functional of Pudendal nerve
- Main nerve of the perineum.
- Carries sensation from the external genitalia of both sexes and the skin around the anus/perineum
- Motor supply to various pelvic muscles including external urethral sphincter and external anal sphincter
DAMAGE TO THIS NERVE (often during childbirth) MAY CAUSE SENSORY LOSS OR FETAL INCONTINENCE
Sympathetic innervation of the pelvis
SUPERIOR HYPOGASTRIC PLEXUS. Receives contributions from the lumbar splancnics n’s. The branches of the SHP spill into the pelvis as the R and L HYPOGASTRIC N’s.
-They mix with the pelvic splanchnics to form the INFERIOR HYPOGASTRIC PLEXUS
Parasympathetics of the Pelvis
PELVIC SPLANCHNICS (S2-4)
Combine with the sympathetic branches to form the INFERIOR HYPOGASTRIC PLEXUS on the walls of the pelvis
What defines the rectum?
It is continuous structurally with the colon but is called the rectum once the mesentery is lost
When you here this word, think “bladder”
Vesical
Muscular component of bladder walls
Detrusor Muscle
The prostate is perforated (pierced) by the…
Urethra
Large ligament surrounding uterus
Broad ligament
What holds up the ovaries?
Sensory ligaments
Relationship between uterine artery and ureter.
“Water under the bridge”
The ureter crosses UNDER the uterine aretery
Blood supply of Ovaries
Ovarian Artery
