GI Part 11

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Rumens are able to get glucose from their diet.

False

What do ruminants depend on in order to meet their glucose needs?

They depend on proprionate and VFA to meet their glucose needs

How many contractions does the rumen undergo?

1

2 (correct)

3

4

What is the purpose of the first primary (aka mixing) contraction?

To reduce the particle size of forage Signup and view all the answers

How many ruminal contractions occur per minute on average?

1-3 Signup and view all the answers

The rate and strength of contractions depends on ________

The rate and strength of contractions depends on the structure of the diet. Signup and view all the answers

The secondary contraction is referred to as _______

Secondary contraction is referred to as eructation Signup and view all the answers

Secondary contractions (aka eructation) is a caudal moving contraction

False Signup and view all the answers

Course, fibrous feeds stimulate the most frequent and strongest contractions

True Signup and view all the answers

What is the function of secondary contractions?

It’s function is to force gas toward the cranial portion of the rumen Signup and view all the answers

The regurgitation reflex is a secondary contraction

False Signup and view all the answers

What is the function of the regurgitation reflex?

It’s function is to bring large particles from the rumen back to the mouth so that it can be chewed to reduce particle size Signup and view all the answers

What initiates the regurgitation reflex in ruminants?

Contraction at the mid-dorsal rumen Signup and view all the answers

How often does typical regurgitation occur in ruminants?

Every 2-3 minutes Signup and view all the answers

What role does antiperistalsis play during regurgitation?

It moves the bolus to the mouth Signup and view all the answers

Which of the following correctly describes the role of the lower esophageal sphincter during regurgitation?

It relaxes to allow the bolus entry Signup and view all the answers

What percentage of cows in a herd should ideally be actively chewing cud at any given time?

60% Signup and view all the answers

The gases produced during rumination are mainly …

Carbon dioxide Signup and view all the answers

The eructation center is localized in the ____ and receives _ fibers from mechanoreceptors placed in the ___ sac of the rumen.

The eructation center is localized in the medulla and receives afferent fibers from mechanoreceptors placed in the dorsal sac of the rumen Signup and view all the answers

What is another word to describe bloating?

Tympanism Signup and view all the answers

What mechanism fails in cattle leading to tympanism or bloating?

The eructation mechanism Signup and view all the answers

Which of the following is a typical cause of legume bloat in cattle?

Rapidly growing alfalfa or clover pastures Signup and view all the answers

What is the result of gas becoming trapped in tiny bubbles during bloating?

Inability to form a normal free gas bubble in the rumen Signup and view all the answers

Which of the following is NOT a common cause of impaired eructation in cattle?

Absence of dietary sugars Signup and view all the answers

What is not detected by the mechanoreceptors of the rumen's dorsal sac?

Presence of gas Signup and view all the answers

The stretch receptors and chemo receptors monitor distention and consistency of the __, _, and

ingests, pH, VFA concentration and ions Signup and view all the answers

What initiates the closure of the esophageal groove in ruminants?

Anticipation of suckling and pharyngeal stimulation Signup and view all the answers

What function does the esophageal groove serve in young ruminants?

To divert milk to the abomasum, bypassing the rumen Signup and view all the answers

What physiological mechanism causes the muscles of the groove to contract?

Reflex action from brainstem impulses via the vagus nerve Signup and view all the answers

What happens to the esophageal groove when it is stimulated?

It twists and its lips close to form a tube Signup and view all the answers

What type of reflex primarily mediates the closure of the reticular groove?

Cephalic phase reflex stimulated by anticipation of feeding Signup and view all the answers

Which of the following are ketones that are produced during ruminant ketosis?

Acetone Signup and view all the answers

Which conditions primarily lead to the occurrence of ruminant ketosis in dairy cows?

High milk production shortly after calving Signup and view all the answers

What is the consequence of an inadequate supply of oxaloacetate during the degradation of acetyl CoA?

Accumulation of acetoacetyl CoA Signup and view all the answers

Which sequence correctly describes the metabolic pathway of acetate and butyrate entering the Krebs cycle?

Acetate, butyrate -----> acetyl CoA -----> citrate Signup and view all the answers

Which of the following statements is true about the degradation of acetoacetyl CoA?

It leads to the production of three ketone bodies. Signup and view all the answers

What is the primary motility pattern in the cecum?

Mixing with low-amplitude contractions Signup and view all the answers

In the ventral colon, which of the following are the predominant motility pattern(s)?

Haustral segmentations Signup and view all the answers

How do small and big particles behave in the ventral colon?

Small particles flow distally while big particles are retained. Signup and view all the answers

Which statement correctly describes haustral segmentations in the ventral colon?

They mix the ingesta without transporting it forward. Signup and view all the answers

What is the predominant effect of motility patterns in the cecum on ingesta?

Movement and mixing of ingesta within haustra. Signup and view all the answers

All the glucose available to ruminants originates from gluconeogenesis. The most important precursor of glucose in ruminants is proprionate

True Signup and view all the answers

Proprionate enters the Kreb cycle at the level of ______

Proprionate enters the Kreb cycle at the level of succinate. Signup and view all the answers

What is the primary purpose of gluconeogenesis in ruminants?

To produce glucose during periods of potential deficiency Signup and view all the answers

Which of the following statements about propionate in ruminants is accurate?

Almost all absorbed propionate is utilized by the liver before it can enter the bloodstream. Signup and view all the answers

In the context of glucose synthesis in high-producing dairy cows, what is the predominant destination for the glucose produced?

Lactose synthesis for milk. Signup and view all the answers

What role does acetate play in ruminant metabolism?

It is a precursor for fatty acid synthesis in adipose tissues. Signup and view all the answers

What percentage of glucose needs in ruminants does gluconeogenesis typically satisfy?

85 - 100% Signup and view all the answers