Pelvic region Flashcards
What are the wings of the atlas and sacrum modifications of?
transverse process
how does the orientation of the wing of the ilium change as a calf or foal matures
wing of ileum is first vertical and changes to horizontal as the animal matures
what is the functional reason driving the change of the wing of the ileum with age
ileum must widen to support the weight of the GI tract -> calf is originally simple stomached, and as the rumen develops, the ileum must get wider to support the weight
compare fore v. hind limb extrinsic muscles –> why is one group insignificant
- hind limb has more intrinsic muscles for pushing but limited extrinsic muscles
- the forelimb has half as much intrinsic muscles but massive extrinsic muscles
- extrinsic muscles are not as important in the hind limb during force transfer because the sacroiliac joint facilitates much of the force transfer from limbs to axial skeleton
what is the topographic relationship of longitudinal and circular muscle in the gut
-composed of an inner circular layer and an outer longitudinal layer
what are 2 specialized longitudinal muscle structures of the large intestine
-large intestine: bands are longitudinal smooth muscle while sacculations are circular and form when muscles contract
describe 2 smooth muscles attached to bone
- rectococcygeous m: from the longitudinal (outer) muscle of the rectum to ventral part of caudal vertebrae; horizontally directed
- retractor penis/clitoris m: vertically directed and deep to levator ani m.
what species have specialized longitudinal smooth muscle structures in LI
horses, pigs, humans
why is the pelvic diaphragm important in human anatomy
supports the abdominal viscera in standing or sitting persons
what is the structure of the pelvic diaphragm in domestic animals
- coccygeus m. + levator ani m.
- arise from the inside of the pelvis and attach on the terminal parts of the digestive urogenital tracts and the tail
what is the value of the pelvic diaphragm in quadrupeds
main visceral pressure is here due to the abdominal press (the grunt)
what is the perineum
- deep fascia and muscle
- seals the pelvic outlet around the terminal portions of the urogenital and digestive tracts
disorders of the perineum
- dogs: perineal hernias in old males
- mare: perineal lacerations during pregnancy (foal feet tear vestibule/rectum)
- bull: ischiorectal approach to vesicular glands for removal
compare the sacrosciatic ligament of ungulates with the sacrotuberous ligament of the dog and cat
- sacrosciatic ligament is broad, flat, and covers a huge area - caudal edge corresponds to sacrotuberous ligament
- sacrotuberous ligament is cord-like
how are the greater and lesser sciatic foramen formed and what passes through them in the horse and ox
- greater foramen: sciatic nerve and cranial gluteal
- lesser foramen: internal obturator tendon in the horse, caudal gluteal artery in the ruminant