Topography of Pelvis Flashcards
3 main body cavities
thoracic, abdominal, and pelvic cavity
Pelvic cavity is …
continuous with abdomen and a tubular passage
Bony pelvis is formed by
Pelvic girdle (2 fused os coxae, also called bony ring)
sacrum
1st and 2nd caudal vertebrae
Boundaries of pelvic outlet
- First ca. vertebra
- Sacrotuberous ligaments (dog only) & muscles
- Ischial arch
- bony ring (surrounding entrance)
- terminal line (sacrum, ilium shaft, pubis)
What is the transverse and conjugate diameter
The transverse diameter: the greatest distance between arcuate lines of ilium.
The conjugate diameter: the distance between the sacral promontory and the pecten pubis.
Terminal parts of 3 systems
- Digestive tract
- Reproductive (male/female)
- Lower urinary tract
Where is the perineal region
extends from anus to scrotum/vulva
perineum: the wall and associated structures closing the pelvic outlet and surrounding the anal and urogenital canals
what muscles anchor the rectum in place (aka pelvic diaphragm)
coccygeus and levator ani
(2 V shaped muscles)
What holds the urogential diaphragm? (anchors repro tract)
mainly fascia
Most dorsal body system in the pelvis
GI system (rectum)
Most middle body system in the pelvis
repro system
Most ventral body system in the pelvis
urinary system
demarcation between descending colon and the rectum
pelvic inlet!
colon shifts from left side to the midline
Urinary bladder position
lies directly on pelvic floor
▪ Empty … thick wall, feels solid
– lies almost within the pelvic cavity
▪ Full … thin wall (may rupture if
blocked)
– Extends cranially into the abdomen
3 parts of urinary bladder
apex, body, and neck (fixed) ( cranial to caudal)
What is the urinary bladder trigone? and what are its boundaries?
smooth triangular region on the dorsal internal wall of the
bladder neck.
▪ Boundaries:
– the 2 openings of ureters
– the internal urethral orifice
ventral to the urinary bladder is the
pubis
dorsal to the urinary bladder is the
repro organs and supporting folds
peritoneal fixation of the bladder
2 lateral ligaments , and median ligament
(round ligament is above lateral ligament)
What is the urachus
embryonic patent urachus (umbilical cord on the inside of the fetus)
should go away after umbilical cord is cut, can leave a bladder diverticulum which can be a site for bacteria
pelvic urethra in male
- extends from bladder to pelvic outlet
- widest diameter of entire urethral length
- urethralis muscle
thick layer of skeletal muscle – “external urethral sphincter
has pelvic and penile urethra in males
dogs lack a ____ urethra
preprostatic
pelvic urethra in females is ____ and opens into the ____
short, vestibule
ductus deferns
continuation of the epididymis duct
terminates in the pelvic urethra
