Ruminant Stomach and Intestine Flashcards Preview

Erin's Gross Lectures > Ruminant Stomach and Intestine > Flashcards

Flashcards in Ruminant Stomach and Intestine Deck (54):
1

What is a ruminant?

mammals that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through bacterial actions (stomach fermenter)
- also regurgitate food so it can be chewed again

2

Where does fermentation occur in the horse?

cecum and ascending colon

3

What are the four regions of the ruminant stomach?

- Reticulum (stomach with net)
- Rumen (papillary stomach)
- Omasum (stomach with leaves)
- Abomasum (true stomach)

4

What does the orientation and size of the abdominal viscera vary with?

age and pregnancy

5

How are the viscera arranged in a newborn calf?

- liver and abomasum are enlarged compared to a 5 year old cow
- enlarged abomasum displaces the liver to the right of the abdomen

6

How are the viscera arranged in a 5 year old cow?

- the rumen is large and occupies the entire left side of the abdomen
- The liver is pushed cranially by the omasum

7

How are the viscera arranged in a heavily pregnant cow?

- uterus displaces the rumen dorsally and abomasum cranially

8

How does the ruminant stomach sit in the cow?

- laterally compressed with the bulk of it displaced to the left (fills right side of abdomen)
- Extends from the diaphragm to the pelvic inlet
- Sometimes caudoventral part extends well over median plane into the right half of the abdominal cavity

9

What does the parietal surface of the ruminant stomach lay against? Visceral surface?

Parietal surface: is in contact with the left abdominal wall, diaphragm, and floor of the abdomen
Visceral surface: faces the right and is related chiefly to the intestines and the liver

10

Where are the dorsal and ventral curvatures/ where do they lay?

Dorsal curvature: lies against the diaphragm and dorsal aspect of the abdominal cavity
Ventral curvature: follows the contour of the abdominal floor

11

What divides the rumen into various compartments?

external grooves on the surface correlate with internal pillars that divide the rumen into various compartments

12

What are the grooves on the surface of the rumen?

- cranial and caudal grooves
- L/R longitudinal grooves
- Dorsal and ventral coronary grooves
- L/R accessory grooves

13

What separates the ventral ruminal sac from the caudoventral blind sac?

the ventral coronary groove/pillar

14

What separates the dorsal ruminal sac from the caudodorsal blind sac?

the dorsal coronary groove/pillar

15

What is the insula ruminis and where is it found?

A sac located between the right accessory groove and the right longitudinal groove

16

How does a vet obtain access to the rumen in the ox?

through the paralumbar fossa (left)

17

Where does the spleen attach in the ox and where is it located?

attached to the craniodorsal aspect of the atrium of the rumen; located in the left hypochondriac region

18

What is the intraruminal orifice (or intraruminal osteum)

an internal ring that is bound by the right and left longitudinal pillars and the cranial and caudal pillars and is the boundary between the dorsal and ventral ruminal sacs

19

What is the ruminoreticular fold?

separates the reticulum from the atrium in ruminents

20

What is found in the dorsal-most layer and ventral-most layer of the rumen?

dorsal = gas bubble
ventral = liquid zone

21

Where is the reticulum located?

at the cranioventral part of the stomach and lies immediately caudal to the left half of the diaphragm

22

Where does traumatic reticulitis or hardware disease occur? What causes it?

In the reticulum. Occurs when metal objects become lodged within the reticulum

23

What happens to the reticular groove in the unweaned animal and why?

it closes to form a tube-like gastric groove, which conveys milk directly from the esophagus to the abomasum

24

What can happen during traumatic reticulitis or hardware disease?

1. sharp objects can pierce through the cranial aspect of the reticulum and the diaphragm and may puncture the pericardium and/or heart

25

How is traumatic reticulitis or hardware disease treated?

placement of magnets into the reticulum collects metal scraps and prevents them from puncturing through the walls of the reticulum

26

What causes/stimulates the formation of the gastric groove?

- stimulated by ADH
- In adult, use of drugs (eg: copper sulfate) can help crate the tube so that certain products bypass the fore-stomachs and travel directly into the abomasum

27

What is the sequence of flow with an open reticular groove?

cardia -> reticular groove -> reticulum -> ruminoreticular orifice -> rumen -> ruminoreticular orifice -> reticulum -> regurgitation

28

What is the sequence of flow with a closed reticular groove?

cardia -> reticular groove -> reticulo-omasal orifice -> omasal groove -> omasoabomasal orifice -> abomasal groove

29

What is the cavity of the omasum occupied by?

numerous longitudinal folds, or laminae

30

What are the two openings of the omasum?

- reticulo-omasal orifice
- omasoabomasal orifice

31

What is the inner appearance of the omasum?

has many parallel folds of varying sizes (omasal laminae) with interlaminar recesses between them
- laminae are studded with papillae

32

What is the inner appearance of the abomasum?

Has spiral folds that are permanent (do not dissapear with distention as is the case with rugae)

33

What does the torus pyloricus do and where is it?

A round protuberance on the internal aspect of the pylorus on the side of the lesser curvature that enhances the pyloric sphincter

34

Where are the majority of stomach compartments located?

deep to the ribs

35

Where is the border of the base of the paralumbar fossa? What is the cranioventral and caudoventral border?

Base: along the tips of the lumbar transverse processes
Cranioventral: last rib
Caudoventral: ridge formed by the part of the internal abdominal oblique muscle that extends from the tuber coxae to the ventral end of the last rib of the ox

36

What are the attachments of the greater omentum?

- abomasum (greater curvature)
- reticulum
- Left longitudinal groove (superficial leaf)
- Right longitudinal groove (deep leaf)
- Also mesoduodenum (of descending duodenum, from cranial to caudal duodenal flexure), left lobe of pancreas, spleen

37

What are the attachments of the lesser omentum?

- abomasum (lesser curvature)
- Omasum (base)

38

What is formed by the superficial and deep leaves of the greater omentum?

Form a sling within which the bulk of the intestines reside
- Also forms a bursa within which the ventral ruminal sac resides

39

What is the main blood supply of the rumen and where is it found?

- right ruminal artery ( a branch of the splenic a.) which courses in the right accessory groove, through the caudal groove. (gives off R/L dorsal and ventral coronary aa. within corresponding coronary grooves)
- Left ruminal a. which passes through the cranial groove from right to left and extends into the left accessory groove.

40

What is the main blood supply to the omasum?

left gastric artery (branch of the celiac artery)

41

What supplies the reticulum with blood?

- reticular artery of the left ruminal artery
- Accessory reticular artery (may branch from left gastric a.) (gives rise to left gastroepiploric a.)

42

What supplies the greater and lesser curvatures of the abomasum with blood?

greater curvature: left and right gastroepiploric aa.
lesser curvature: left and right gastric aa.

43

What is the major innervation of the rumen, omasum and reticulum?

dorsal vagal trunk
- the atrium of the rumen, omasum, reticulum, and abomasum are innervated by branches from both the dorsal an ventral vagal trunks

44

What is the supraomental recess bound by?

bound by the rumen on the left and the greater omentum on the right

45

True or false? During pregnancy, the Gravid uterus may extend into the supraomental recess.

True

46

True or false? The major duodenal papilla of large ruminants drains both the pancreatic duct and bile duct.

False. only the bile duct in large ruminents. The pancreatic duct travels to the minor duodenal papilla instead

47

True or false? The major duodenal papilla of small ruminants drains both the pancreatic duct and bile duct.

True

48

What are the parts of the spiral loop?

- centripetal gyri
- Central flexure
- Centrifugal gyri

49

Which gyri is always on the outer-most surface of the spiral?

Centrifugal gyri

50

Which gyri carries ingesta into the loop?

centripetal gyri

51

What supplies the jejunum with blood?

- jejunal aa. of the cranial mesenteric artery
- Collateral branch (only in ruminants)

52

What supplies the ileum with blood?

- ileal aa. of jejunal a. and collateral branch
- Mesenteric ileal branch of ileocolic a.
- Antimesenteric ileal branch of cecal a. of ileocolic a.

53

What part of the ascending colon is supplied by the colic branch of ileocolic a.? Right colic a.?

Colic branch: supplies first half of ascending colon: proximal loop, centripetal portion of spiral loop
Right colic a: supplies second half of ascending colon: centrifugal portion of spiral loop, distal loop

54

What does the collateral branch of the cranial mesenteric a. supply?

contributes to blood supply of the last centrifugal loop of the ascending colon and distal jejunum