Alimentary - Ruminant

Question 1

How many stomachs are there in the rumen?

Answer 1

1 stomach - 4 chambers

Question 2

What is the vasculature of the rumen stomach?

Answer 2

Coeliac artery

Question 3

What can you feel on the left hand side of a rumen?

Answer 3

Rumen, reticulum and ventrally is the abomasum

Question 4

What can you feel on the right hand side of the rumen?

Answer 4

Intestines, omasum and ventrally is the abomasum

Question 5

What is the anatomy of the rumen?

Answer 5

Covered in papillae.

4 layers - stratified squamous epithelium, lamina propria and submucosa, muscularis interna.

Grooves run externally with pillars to make papillae muscular.

Question 6

What is the chemistry of the rumen?

Answer 6

Near neutral pH (6.8) supporting a microbiome of bacteria.

VFA are produced and and needs saliva to buffer it

Question 7

How much saliva is produced by a cow?

Answer 7

200L

Question 8

What are the VFAs produced?

Answer 8

Propionate
Butyrate
Acetate

Question 9

What does the animal eructate?

Answer 9

Methane
CO2
Ingesta

Question 10

What type of cells line the rumen ?

Answer 10

Stratified squamous epithelium to protect against abrasive diet

Absorbs the VFAs but not water

Question 11

How long do animals ruminate for?

Answer 11

20 hours in a day

Question 12

How do cows regurgitate?

Answer 12

Contraction of reticulum floods cardia with food
This is drawn into the oesophagus and up to the mouth via anti-perisaltic contraction.

Question 13

How are ruminations regulated?

Answer 13

CNX to dorsal vagal nucleus of the brain stem

Question 14

What monitors the afferents?

Answer 14

Afferents on the ruminoreticulum monitor distension, ingesta consistency, pH and VFAs conc

Question 15

What kind of movements of the rumen are there?

Answer 15

Primary and secondary

Question 16

What are the primary movements of the rumen?

Answer 16

Ruminoreticular mixing cycle starting in reticulum. Follows a figure of 8 formation and happens every 60s

This is to allow microbes to circulate around the food

Question 17

What are the secondary movements of the rumen?

Answer 17

A caudal to cranial wave to lead to eructation and rumination

Occurs every 20s and can be heard at paralumbar fossa

Question 18

What is the anatomy of the reticulum?

Answer 18

Honeycomb structure with layers of stratified squamous epithelium, lamina propria and lamina muscularis mucosae

Question 19

What happens in the reticulum?

Answer 19

Fermentation and if there are heavier materials they will sit here for a while like hardware disease

Question 20

What is the anatomy of the omasum?

Answer 20

Between ribs 8-11 on right hand side

Comrprised of keratinised stratified squamous epithelium, with muscles, looks like leaves

Question 21

What does the omasum do?

Answer 21

Contracts to absorb fluid and then moves solids onto the abomasum

Question 22

What is the abomasum?

Answer 22

Most like a simple stomach

Question 23

What is the oesophageal groove?

Answer 23

Abdomen of the calf isn’t using rumen so when it head is tilted the milk misses the rumen and reticulum it goes straight through.

Question 24

What happens in milk gets into the calfs rumen?

Answer 24

It will undergo bacterial breakdown and produce lactic acid leading to acidosis and clotting

Question 25

That is the muscle responsible for flicking off flies?

Answer 25

Cutaneous trunk line