Intestines- Gross Anatomy

Question 1

describe the canine intestinal flow (9)

Answer 1

1. stomach through pyloric sphincter to cranial duodenum
2. cranial duodenal flexure to descending duodenum
3. caudal duodenal flexure to ascending duodenum
4. ascending duodenum through duodenojejunal flexure into jejunum
5. jejunum to ileum (beginning of ileum outline by ileocecal fold)
6. ileum to cecum/ascending colon at ileocecal orifice
7. asending colon to transverse colon
8. transverse colon to descending colon (longest segment of colon)
9. descending colon to rectum

Question 2

describe the ileocolic and cecocolic orifices in the canine (3)

Answer 2

1. ileum and cecum open to ascending colon via 2 separate orifices, so the ileum and cecum do not directly communicate in the dog because enter through through 2 separate holes
2. there is a sphincter between the ileum and ascending colon
3. there is not a sphincter between the cecum and the ascending colon

Question 3

describe the intestinal flow of the horse (11)

Answer 3

1. stomach through pyloric sphincters to descending duodenum
2. descending duodenum to jejunum
3. jejunum to ileum with ileocecal fold (beginning of ileum is the fold)
4. through ileocecal orifice into cecum
5. through cecocolic orifice to right ventral ascending colon
6. run cranially to sternal flexure
7. sternal flexure to left ventral ascending colon running caudally to pelvic flexure
8. through pelvic flexure to left dorsal ascending running cranially to diaphragmatic flexure (right on top of sternal flexure)
9. through diaphragmatic flexure to right dorsal ascending colon
10. right dorsal ascending colon run under liver to transverse colon
11. transverse colon to descending colon

Question 4

what are the 3 most likely points of impaction in equine intestines?

Answer 4

1. cecocolic orifice (large volume in cecum squeeze through small orifice)
2. pelvic flexure between left ventral ascending and left dorsal ascending colon (very sharp turn)
3. as right dorsal ascending colon narrows to transverse colon)

Question 5

describe the ileocecal and cecocolic orifice of horses (3)

Answer 5

1. ingesta runs through ileocecal into cecum, then through cecocolic to colon
2. ileum and cecum do not directly communicate due to the separate orifices
3. all openings/orifices are in the cecum (were in the colon in the dog)

Question 6

how many taenia are seen in the cecum and ventral colon, in the left dorsal colon, in the right dorsal colon, and in the transverse and descending colon?

Answer 6

1. cecum and ventral colon: 4 bands (4 on the floor)
2. left dorsal colon: 1 band
3. right dorsal colon: 3 bands
4. transverse and descending colon: 2 bands

Question 7

which is more folded: the ascending ventral or the dorsal ventral colon?

Answer 7

ascending ventral colon more folded (more bands) than ascending dorsal colon

Question 8

describe the intestinal flow of the cow

Answer 8

1. from abomasum to cranial duodenum
2. cranial duodenum through cranial duodenal flexure to descending duodenum
3. descending duodenum through caudal duodenal flexure to ascending duodenum
4. through ascending duodenum to jejunum (like dog)
5. jejunum to ileum with ileocecal fold (like dog and horse)
6. through ileocecal orifice to cecum
7. through cecocolic junction (NOT ORIFICE) to proximal loop of ascending colon
8. through proximal loop of ascending/spiral colon spiraling clockwise until central flexure
9. direction change of spiral colon at central flexure to counterclockwise until distal loop of ascending/spiral colon
10. distal loop of ascending/spiral colon to transverse colon
11. transverse colon to descending colon to rectum

Question 9

describe the ileocecal orifice and cecocolic junction in the cow

Answer 9

ileocecal orifice opens into the cecocolic junction, so there is only one opening