Pelvis and Perineum – osteology and boundaries Flashcards
How many vertebrae is sacrum made up of?
5
How many vertebrae is coccyx made up of?
4
List bones of the pelvis
- Sacrum
- ilium
- coccyx
- coxal bone
- ischium
- pubis
What is the Lumbosacral joint?
joint between lumbar vertebra and the first sacral segment of the vertebral column.
What is Sacroiliac joint?
Joint between ilium and sacrum
What is Pubic symphysis?
cartilaginous joint between R + L pubic bones
What is Sacrococcygeus joint?
Joint between sacrum and coccyx
What is bi-spinous diameter?
- Diameter between ischial spines
- narrowest transverse diameter
– also used to determine birth
What is sig of triradiate cartilage?
Eventually fuses and forms one hip bone in adult – why its div into 3 parts
What is true pelvis?
Space between pelvic inlet and outlet
What is false pelvis?
Inlet to top of iliac crest
Why is there No diaphragm sep true and false pelvis?
allow room for uterus and bladder and rectum to expand
What is function of pelvic diaphragm?
pelvic organs stay in place and don’t collapse when abdom pressure inc
separates pelvis from perineum.
What is diff between male and female pelvis?
- Sub-pubic angle = 80 degrees in males and 120 degrees in females – wider for childbirth
- females have deeper greater sciatic arch
What is Antero-posterior diameter of pelvic inlet?
50-60 degrees
What is diagonal conjugate diameter?
- Should be 10.5-11 cm – narrowest diameter for birth
– 8/9cm or less – can’t deliver vaginally
What is obstetric conjugate diameter?
Diagonal conjugate minus 1.5cm
Antero-posterior diameter of pelvic outlet?
10-15 degrees
Where is the rectovesical/perineal pouch?
in male between rectum and bladder
Where is uterovesical pouch located?
- in female between uterus and bladder
What is function of pelvic floor?
supports the pelvic organs and separates pelvic cavity from perineum
What would happpen if pelvic floor is incompetent?
- Incontinence = can’t control bladder/rectum,
- prolapse = organs leaking out e.g. vaginal walls of women who’ve had more than 1 child = multi-parous women
What are the 2 muscles of pelvic diaphragm?
- Levator ani
- Coccygeous
What are 3 parts of levator ani?
puborectalis, pubococcygeus and iliococcygeous
What is genito-urethral opening?
opening in males – sperm and urine from same opening
What is Perineum divided into?
- Urogenital and Anal triangles
Name 3 points of urogenital triangle
- pubic symphysis
- R + L ischial tuberosities
Name 3 points of anal triangle
- coccyx
- R + L ischial tuberosities
List 4 muscles of the perineum
- Ischiocavernosus
- Bulbospongiosus
- Transverse perineal
- All converge to form perineal boody
What is perineal mem?
- Mem between perineal diaphragm and perineal muscles
- attached to ischial tuberosities and ischiopubic ramus
What is deep perineal pouch?
Between lower pelvic diaphragm/floor and peri mem
What is superficial perineal pouch?
- Everything between skin and perineal mem
– all muscles in triangle contained within it
List features of male perineum
- deep peri pouch
- peri mem
- sup peri pouch
- deep peri fascia
- corpus cavernosum
- urethra
- ext. urethral sphincter
What happens if shatter pubic symphysis?
blood pool in deep pouch and go up as limited by peri mem
What can cause urethral injuries?
- pelvic trauma
- complications of urinary catheterization
What does peri mem cause if damage to urethra?
working as limiting mem – if damage to urethra outside/from the bottom – pooling of blood outside = extraversation injuries
How do ishcial foss comm with each other?
Posteriorly
