Thorax: Pelvis and perineum Flashcards
pelvis: name parts
- greater pelvis
- lesser pelvis
pelvis: greater pelvis
- false pelvis
- ilium and pubis above linea terminalis
- part of abdominal cavity
pelvis: lesser pelvis
- true pelvis
- sacrum and coccyx
- where pelvic floor exists
pelvis: structure which separates greater and lesser pelvis
pelvic inlet
pelvis: pelvic inlet and list borders
- superior pelvic aperture
- post/ lateral/ ant borders
pelvic inlet: post border
- pelvic brim
- sacral promontory
pelvic inlet: lateral border
- iliopectineal line
pelvic inlet: anterior border
- pubic symphysis
pelvic outlet: list borders
- inferior pelvic aperture
- post/ lateral/ ant borders
pelvic outlet: post border
- coccyx
- sacrum
pelvic outlet: lateral border
- ischial tuberosities and sciatic notch
pelvic outlet: anterior border
- pelvic arch btw converging pubic rami
orientation of pelvis tilt:
- coronal plane
- ASIS and pubic tubercle in same plane
obturator foramen: male
round
obturator foramen: female
oval
pelvic inlet: female
oval
pelvic inlet: male
heart shaped
pelvic outlet: which larger?
female
ischial spine projection: female
does not project far medially unlike males
lumbosacral joints: types
- zygapophyseal
- intervertebral discs
lumbosacral joints: classify IVD
- secondary cartilaginous (symphysis)
lumbosacral joints: ligaments associated
- iliolumbar
- ant longitudinal lig
- lumbosacral lig
sacroiliac joint: classification
synovial plane
sacroiliac joint: articulating surfaces
auricular surface of ilium + sacrum
sacroiliac joint: ligaments (5)
- interosseous lig
- ant sacroiliac
- post sacroiliac
- sacrotuberous lig
- sacrospinous
sacroiliac joint: movements
- gliding, slight rotation
- may ossify with aging
sacrococcygeal joint: classification
- IV disc
- 2ndary cartilaginous joint
pubic symphysis: classification
cartilaginous (symphysis)
pubic symphysis: articulating surfaces
- pubic bones (hyaline cartilage)
- symphyseal surfaces (fibrocartilage disc)
pubic symphysis: ligaments
- superior/ inferior pubic
pelvic ligaments during pregnancy: features
- pelvic joints/ ligs relax
- pelvic movement increase
- coccyx moves post during childbirth (accomodate for movement of foetus -> travel down birth canal)
- all these changes occur as result of increase in sex hormones and hormone relaxin
ligaments associated with pregnancy:
- round lig
- broad lig
- uterosacral lig
pelvic wall: bones
- sacrum
- coccyx
- ilium
- pubis
- ischium
pelvic wall: ligaments
- sacrotuberous
- sacrospinous
- obturator membrane
pelvic wall: muscles
- obturator internus
- piriformis
- pelvic floor muscles (levator ani, coccygeus)
piriformis: forms
- forms posterolateral wall
piriformis: attached to
anterior sacrum near PIIS of ilium, capsule of sacroiliac joint
piriformis: passes through and inserts
greater sciatic foramen and attaches to greater trochanter
obturator internus: forms
anterolateral wall
obturator internus: attaches to
obturator foramen
obturator internus: passes through and inserts
lesser sciatic foramen and attaches to greater trochanter
pelvic floor: formed by
- pelvic diaphragm
- thin musculofascial sheet covering levator ani mm
pelvic diaphragm significance:
- separates pelvic cavity from perineum
perineum: general features
- diamond shaped region below pelvic floor
perineum: made up of
- urogenital triangle
- anal triangle
perineum: contents
- genitalia
- urinary openings
- anus
levator ani: name all muscles
- ischiococcygeus (aka coccygeus)
- iliococcygeus
- pubococcygeus (puborectalis, pubovaginalis, puboanalis, pubourethralis)
pelvic cavity: contents (7)
- urinary bladder
- terminal parts of ureters
- pelvic genital organs
- rectum
- blood vessels
- lymphatics
- nerves
perineum: contents (5)
- penis
- scrotum
- vagina
- vulva (outer component - labia majora/minor)
- anus
pelvic nerves: main trunk
- lumbosacral nerve trunk
pelvic nerves: main plexuses
- sacral and coccygeal plexus
pelvic nerves: supply
both somatic and autonomic supply
pelvic nerves: what nerves form plexuses
- ventral rami of sacral and coccygeal spinal nerves
pelvic nerves: sympathetic ganglion provide
grey rami
pelvic nerves: parasympathetic fibres form
- pelvic splanchnic nerves that enter tiny ganglia near organ of innervation
- S2-4
pelvic nerves: sacral sympathetic trunk provides fibres to
- provides postsynaptic fibres to:
- inf hypogastric plexuses
- sacral plexus for innervation of lower limb
pelvic nerves: sacral parasympathetic plexuses- what originates from S2-4 spinal segments
- pelvic splanchnic nerves
pelvic nerves: pelvic splanchnic + sympathetic fibres =
inferior hypogastric plexuses
pelvic nerves: name inferior hypogastric plexuses
- rectal
- vesical
- uterovaginal
innervation: pudendal nerve sensory
- S3-4
- sensory from external genitalia and anus -> afferent component of erection
innervation: pudendal nerve motor to
- external urethral sphincter and external anal sphincter, levator ani, bulbospongiosus, ischiocavernous mm
innervation: coccygeal plexus
- S4/5 and Coccyx 1
- anococcygeal n.
coccygeal plexus: supplies
skin of coccyx
superior gluteal nerve:
- L4/5 and S1
- innervates gluteus medius, minimus, TFL
inferior gluteal nerve:
- L5 and S1/2
- innervates gluteus maximus
pelvic arteries: abdominal aorta splits into
- R common iliac
- L common iliac
pelvic arteries: R common iliac splits into
- external iliac
- internal iliac
pelvic arteries: external iliac
- deep circumflex
- inferior epigastric aa
pelvic arteries: internal iliac
- posterior trunk
- anterior trunk
pelvic arteries: posterior trunk
- iliolumbar
- lateral sacral
- superior gluteal
pelvic arteries: anterior trunk (8)
- superior vesical
- inferior vesical
- middle rectal
- vaginal
- obturator
- uterine
- internal pudendal
- inferior gluteal
arteries which enter true pelvis: (4)
- gonadal
- median sacral
- internal iliac
- superior rectal
arise from: gonadal artery
- abdominal aorta at level/ below renal arteries
arise from: median sacral artery
- midline from bifurcation of abdominal aorta
arise from: internal iliac artery
- branch of common iliac artery
arise from: superior rectal artery
- branch of inferior mesenteric artery
pelvic veins: which drain into common iliac vein
- internal pudendal
- median sacral
pelvic veins: which drain into internal iliac vein
- superior and inferior gluteal v
- obturator v
- middle rectal v
- lateral sacral v
pelvic veins: which drain into external iliac vein
- inferior epigastric
- deep circumflex
- pubic v