3.6 - Ruminant stomach and equine cecum

Roughage with a high content of indigestible carbohydrates

What is the primary herbivore diet of ruminants

Takes up the majority of the abdomen and sits mainly on the left side but extends to the right

Describe the location of the ruminant stomach within the abdominal cavity

Left

Within the abdominal cavity, is the right or left the parietal side of the ruminant stomach

right

Within the abdominal cavity, is the right or left the visceral side of the ruminant stomach

Intestines, abdominal wall, and liver

What organs does the visceral side of the ruminant stomach have a relationship with?

Diaphragm, spleen, and abdominal wall

What organs does the visceral side of the ruminant stomach have a relationship with?

Rumen, reticulum, omasum, and abomasum

What are the four compartments of the ruminant stomach, list them in the order that food goes through them

Rumen

1

Reticulum

2

Omasum

3

abomasum

4

Rumen

1

Reticulum

2

Abomasum

3

Left longitudinal groove

1

Ruminoreticular groove

2

Cranial groove

3

Caudal groove

4

Dorsal coronary groove

5

Ventral coronary groove

6

Atrium

7

Dorsal sac

8

Ventral sac

9

Caudodorsal blind sac

10

Caudoventral blind sac

11

Right longitudinal groove

1

Caudal groove

2

Cranial groove

3

Dorsal coronary groove

4

Ventral coronary groove

5

Dorsal sac

6

Ventral sac

7

Caudodorsal blind sac

8

caudaoventral blind sac

9

Papillae

The rumen's internal lining is full of these projections, what are they called

Pillar

The grooves on the outside of the rumen project inwards, what are they called

Smooth muscle

The inward pillar projections of the rumen are made of ___________

Keratinized stratified squamous epithelium with abundant papilla

Describe the epithelium of the rumen

True

T/F - the epithelium of the rumen has the same layers as skin

Fundus

2

Lesser curvature

3

Ruminoreticular groove

1

Greater curvature

2

Reticular/esophageal groove

1

Cardias

2

Reticulo-omasal surface

3

Left lip of esophageal groove

4

Right lip of esophageal groove

5

Keratinized stratified squamous epithelium with long and short papilla

Describe the reticulum epithelium

Reticulum

Which internal surface of the ruminant stomach has the "honey comb" appearance

Primary laminae

1

Secondary laminae

2

Tertiary laminae

3

Neck with reticulo-omasal orafice

4

Omasal groove

5

Omasal-abomasal groove

6

Keratinized stratified squamous with laminae

Describe the epithelium of the omasum

Body

1

Pyloric part

2

Pylorus

3

Torus pylorus

4

Duodenum

5

Simple columnar epithelium

Describe the epithelium of the abomasum

Rumen

The first compartment of the ruminant stomach and the site of fermentation

Bacteria, protozoa and yeast

microbes of the rumen

Carbohydrates and proteins from the animal's diet

What is the substrate that the rumen microbiome uses

breaks it down into smaller molecules and then uses them to create their own proteins necessary for growth

How do the microbes of the rumen use the proteins from the animal's diet

true

T/F - in ruminants, the microbes follow the pathway of food throughout the entire stomach

Volatile fatty acids

What are carbohydrates converted into in the rumen

Energy

What are the volatile fatty acids used for after being absorbed by the ruminal wall

Reticulum

A pouch like structure cranial to the rumen that captures small particles that don't need additional mechanical breakdown

Larger

The reticulum is the smallest compartment in cattle, but how what is it like in sheep and goats

omasum

Functions to absorb fluid and concentrate food

So the fluid doesn't dilute the acid and enzymes in the abomasum

Why is it important for the omasum to remove fluid from the food

Abomasum

The true stomach of the ruminant that functions in the glandular digestion of food and breakdown of proteins

Abomasum

What part of the ruminant stomach do the microbes die and break down as a source of protein

Brings microbes in contact with new food and moves materials out of the rumen

2 main functions of the reticuloruminal cycle

Larger food particles get pushed back into the esophagus while smaller particles that don't need extra mechanical action move to the reticulum

Where does food go during the reticuloruminal cycle

Gas, today's food, yesterday's food

What are the 3 layers found in the rumen/reticulum from top to bottom

You can tell the number of cycles from pressure against the fist

What is the purpose of a rectal palpation of the rumen/reticulum in regards to the reticuloruminal cycle

Reticular artery

1

Celiac artery

2

Omasal-abomasal artery

3

Left ruminal artery

4

Right ruminal artery

5

Dorsal branch of omasal-abomasal artery

6

Ventral branch of omasal-abomasal artery

7

Reticular artery

1

Left ruminal artery

2

Right ruminal artery

3

Dorsal vagal trunk

Innervation of the entire rumen and parts of the abomasum and omasum

Ventral vagal trunk

Innervation of the reticulum and parts of the omasum, abomasum, and pylorus

Progressive indigestion and chronic abdominal distension

What are 2 clinical signs that a ruminant has lesions to their vagal trunk

Abomasum

During the preruminal phase in the first 2-3 weeks after birth when the calf is only drinking milk, what portion of the ruminant stomach is the most prominant

Reticulo-rumen and omasum take up larger protions and rumen takes up the majority

During the transitional phase up until total weaning, what are the proportions of the devleoping ruminant stomach

12 weeks

At what point in ruminant development is the rumen fully developed

Mouth - esophagus - reticular groove - omasal groove - abomasum

What is the passageway of milk in calves

allows milk to bypass the rumen and reticulum

What is the main purpose of the reticular groove

Right of the medial place and has a comma shape

Describe the location and shape of the equine cecum

Simple columnar epithelium, similar to that of the colon

Describe the epithelium of the equine cecum