Anatomy of the Ruminant Gastrointestinal System - Dr. Masty

The ruminant has _____ ribs

13 pairs (26 total)

The last rib is rib number...

rib 13

Dorsal boundary of the paralumbar fossa

transverse processes of lumbar vertebrae

Cranial boundary of the paralumbar fossa

last rib (rib 13)

Caudal boundary of the paralumbar fossa

tuber coxae

Ventral boundary of the paralumbar fossa

line of tension generated by the internal abdominal oblique

A surgical site at the paralumbar fossa is used to access the...

rumen

Cranial boundary of the paralumbar fossa: surgical site

rib 13

Caudal boundary of the paralumbar fossa: surgical site

tuber coxae

Location of the incision of the surgical site for paralumbar fossa:

half way between rib 13 and the tuber coxae

Four compartments of the ruminant stomach:

1.) rumen

2.) reticiculum

3.) omasum

4.) abomasum

Which compartments of the ruminant stomach are on the left side?

rumen and reticulum

The rumen is separated into compartments by a series of __________

grooves

The grooves onthe surface of the ruemn will contain...

nerves and arteries

Five types of grooves on the rumen surface:

1.) cranial and caudal grooves

2.) longitudinal groove

3.) coronary groove

4.) ruminoreticular groove

5.) accessory groove

cranial and caudal grooves of the rumen

run from one side of the rumen to the other

longitudinal groove of the rumen

separates the dorsal sac and ventral sac of the rumen

coronary grooves of the rumen

dorsal and ventral grooves that help separate where the blind sacs are

ruminoreticular groove

groove between the reticulum and rumen

accessory groove

small groove coming dorsally off the longitundial groove

Three compartments of the rumen

1.) dorsal sac

2.) ventral sac

3.) caudal blind sacs

dorsal sac

the dorsal/upper portion of the rumen

the cranial end of the dorsal sac is called the...

cranial sac

ventral sac

the ventral/lower portion of the rumen

the cranial end of the ventral sac is called the...

recess

caudal blind sacs

blind sacs located dorsally and ventrally

Two caudal blind sacs

1.) caudodorsal blind sac

2.) caudoventral blind sac

reticulum

1

ruminoreticular groove

2

esophagus

3

cranial sac

4

cranial groove

5

dorsal sac

6

left longitudinal groove

7

left accessory groove

8

left dorsal coronary groove

9

caudodorsal blind sac

10

caudal groove

11

left ventral coronary groove

12

caudoventral blind sac

13

ventral sac

14

abomasum

15

ruminal recess

16

Which compartments of the ruminant stomach are on the right side?

omasum and abomasum (and some parts of the rumen and reticulum)

The right side of the rumen is also divided into...

compartments separated by the same grooves as the left side

ventral sac

1

right ventral coronary groove

2

caudoventral blind sac

3

caudal groove

4

caudodorsal blind sac

5

right dorsal coronary groove

6

dorsal sac

7

right longitudinal groove

8

right accessory groove

9

insula

10

esophagus

11

omasum

12

reticulum

13

abomasum

14

pylorus

15

The rumen has grooves on the _________ of its surface as well

inside

grooves on the inside of the rumen are called...

pillars

pillars of the rumen

muscular ridges on the inside of the rumen that correspond to the grooves on the outside of the rumen

Three pillars on the inside of the rumen:

1.) cranial and caudal

2.) longitudinal

cranial and caudal pillars

travel from one side of the rumen to the other

longitudinal pillars

separate the dorsal and ventral sac on the inside of the rumen

coronary pillars

dorsal and ventral grooves that help separate where the blind sacs are on the inside of the rumen

Instead of a ruminoretricular pillar on the inside of the rumen, it is called...

ruminoretricular fold

Four compartments on the inside of the rumen:

1.) dorsal and ventral sacs

2.) caudal blind sacs

dorsal and ventral sacs on the inside of the rumen

the dorsal/uppper and ventral/lower portions of the rumen on the inside

Two caudal blind sacs on the inside of the rumen

1.) caudodorsal blind sac

2.) caudoventral blind sac

Gastric groove

groove on the inside of the rumen that goes from the esophagus into the amobasum

the gastric groove is only present in...

young animals

Why is the gastric groove present in young animals?

the three forestomach chambers are not fully developed, so milk bypasses them and heads straight to the abomasum for digestion instead

The gastric groove is broken up into three parts:

1.) reticular groove

2.) omasal groove

3.) abomasal groove

Which part of the gastric groove closes to allow the milk to be shunted to the omasum?

reticular groove

What does the mucosal surface of the rumen look like?

shag carpet due to presence of many small papillae

What does the mucosal surface of the reticulum look like?

honey-comb pattern

What does the mucosal surface of the omasum look like?

sheets of paper "many plies", due to ridges of tissue called laminae

What does the mucosal surface of the abomasum look like?

series of folds and ridges

esophagus

1

cardia

2

dorsal sac

3

right accessory pillar

4

insula

5

right longitudinal pillar

6

right dorsal coronary pillar

7

caudodorsal blind sac

8

right ventral coronary pillar

9

caudal pillar

10

caudoventral blind sac

11

ventral sac

12

ruminal recess

13

cranial pillar

14

cranial sac

15

reticulum

16

ruminoreticular fold

17

reticular groove

18

The blood supply to the rumen arises from the __________ artery

celiac

Three branches of the celiac artery

1.) left gastric

2.) hepatic

3.) splenic