Ruminant GIT Part 1

Question 1

Herbivores have digestive apparatus that is able to digest high-fiber plant material such as

Answer 1

Cellulose and hemicellulose

Question 2

Fermentation

Answer 2

• complex carbs get broken down by microorganisms into simple molecules
• prod. Methane (end product)

Question 3

Glandular part of stomach

Answer 3

Abomasum

Question 4

Ileocolic orifice lacks

Answer 4

A sphincter

Question 5

Pillars are

Answer 5

Grooves on inside of stomach

Question 6

Grooves

Answer 6

Depressions on outside of stomach

Question 7

Cow’s main prehension organ

Answer 7

Tongue

Question 8

Small ruminant main prehension organ

Answer 8

Lips

Question 9

Transverse ridge of tongue

Answer 9

• prone to injury
• prone to bacterial infections

Question 10

Papillae

Answer 10

• filiform and conical: mechanical
• fungiform and vallate: taste

Question 11

Esophagus

Answer 11

• striated skeletal m.
• stratified squamous epithelium
• peristaltic/antiperistaltic movement

Question 12

Stomach development

Answer 12

• developed from embryonic gastric spindle
• @ birth, abomasum= 60% stomach (b/c no need for fermentation since calves consume milk)
• @ 2 months rumen and reticulum= 80% stomach

Question 13

Total capacity of ruminant stomach

Answer 13

60L

Question 14

Rumen

Answer 14

• 7th/8th ICS to pelvic inlet
• from abd roof to abdominal floor
• dorsal sac in paralumbar fossa
• ventral sac covered by superior wall of great omentum

Question 15

Reticulum location

Answer 15

• cranial to rumen
• left of midline
• under 6th-8th ribs
• above xiphoid process?

Question 16

Reticulum openings

Answer 16

• cardia
• reticulomasal

Question 17

Ruminoreticular fold

Answer 17

• incompletely divides reticulum and rumen

Question 18

Parts of gastric groove (3)

Answer 18

• reticular groove
• omasal groove
• abomasal groove

Question 19

Gastric groove

Answer 19

• bypass tube for milk when calf is suckling
• closure of muscular lips w/ relaxation of reticulo-omasal orifice and omaso-abomasal orifice covert groove into closed tube
• chemical receptors from mouth sensitive to milk salts and stimulate vagal reflex that closes groove
• copper and nicotine sulfate used for abomasal de-worming meds

Question 20

Ruminal contraction controls

Answer 20

• regulated by vagus n. (Clin sig: vagal indigestion)
• controlled by gastric center in Medulla Oblongata
• usually seen on L side paralumbar fossa

Question 21

3 phases of ruminal contraction

Answer 21

1) biphasic reticular contraction

2) contraction of dorsal ruminal sac

3) contraction of ventral ruminal sac

Question 22

Primary contraction of rumen

Answer 22

• mixing and circulation of digesta
• 3 phases

Question 23

Secondary ruminal contraction

Answer 23

• ingesta flows from ventral blind sac to dorsal blind sac; then dorsal blind sac to ventral blind sac; eructation;

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Question 24

One ruminal contraction cycle is how long

Answer 24

1 minute

Question 25

Movement of ingesta

Answer 25

• ventral sac, cranial sac, reticulum, reticulo-omasal orifice, omasum, omaso-abomasal orifice, abomasum

Question 26

Grain and remasticated roughages fall into

Answer 26

Ventral sac of rumen

Question 27

Organs on left side

Answer 27

• rumen
• spleen, cranial sac, and reticulum