Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Gastrointestinal system > Ruminants > Flashcards

Ruminants Flashcards

1
Q

Which compartment of the ruminant stomach is the equivalent to the simple stomach?

A

Abomasum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which part of the stomach has the inner surface raised into ridges?

A

Reticulum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the role of papillae in the rumen?

A

Increase SA for absorption of H2O, VFAs, ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which nerve regulated long reflex arcs in the neural plexus of the rumen?

A

Vagus nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What epithelial lining is present in the fore-stomach wall, why does this need to be protective?

A

Stratified squamous epithelium - keratinised

Roughage is very abrasive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the function of the omasum?

A

Functions as pump regulating outflow from rumen into abomasum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is present in the omasum that helps with its function?

A

Long papillae that increase SA and contain smooth muscle so they can contract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What 3 components are secreted from the columnar epithelium lining the abomasum?

A

HCl
Pepsinogen
Rennin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where do the most dense particles fall to in the stomach?

A

Reticulum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where does gas from fermentation collect?

A

At the top of the dorsal sac

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the 3 types of contraction in the rumino-reticulum?

A

Primary - mixing
Secondary - eructation
Rumination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the order of primary contractions during eating?

A
  1. First reticular contraction
  2. Second reticular contraction
  3. Cranial blind sac contraction
  4. Dorsal sac contraction
  5. Ventral sac contraction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What simulates rumination?

A

When coarse material stimulates oesophageal opening

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How many minutes of rumination are required per Kg of roughage eaten?

A

60 mins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where does newly swallowed material enter during rumination?

A

forced into dorsal sac and replaced by partially fermented material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What generates negative pressure in the oesophagus?

A

Thorax expansion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How do secondary contractions lead to eructation?

A
  • occur every 2-3 primary contractions

- Oesophageal opening usually below level of gas hence gas can’t escape during rumination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What causes bloat?

A

Failure to eructate:

  • oesophageal obstruction
  • increased ruminal pressure
  • stretching of rumen
19
Q

What receptors are located in the sensory cells that regulate fore stomach motility?

A

Tension receptors

Mechano and chemo recpetors

20
Q

Where are tension receptor cells located and how do they affect motility?

A

Concentrated around oesophageal opening, oesophageal groove, reticulum wall, rumen pillars & cranio-dorsal blind sac wall
INCREASE motility

21
Q

Where are mechano- & Chemo-receptor containing cells located and how do they affect motility?

A

Located in basal layer of rumen epithelium

DECREASE motility

22
Q

How does increased VFA concentration / increased osmolarity / consequent decreased pH lead to normal decreased motility?

A

Sensed by chemo-receptor containing cells
Motility & rumination decreased
Food particles broken down more slowly
Decreases rate of passage of food

23
Q

What would be the features of abnormal motility?

A
  • severe distention of fore-stomach
  • very low pH
  • motility decreased
24
Q

What do the 2 sets of nerve clusters in the central control of motility regulate?

A
  • Frequency of ruminal contractions / rumination

- Force of ruminal contractions

25
Q

Describe the anatomy of the stomach at the time of birth

A

Abomasum developed but not fore-stomach

Fore-stomach develops when lamb starts to eat more roughage at about 2-3 weeks old

26
Q

Describe the passage of milk in a young ruminant

A

Milk passes from oesophagus direct to omasum and thence abomasum for digestion hence avoiding fermentation by developing rumen

27
Q

When would the oesophageal groove reflex be retained?

A

Retained if milk continues to be fed

Retained in browsers

28
Q

What are the functions of the rumino-reticulum?

A

Provide environment for microbial population

Delay gut-transit to allow sufficient time for fermentation

29
Q

What is the purpose of an anaerobic environment in the rumino-reticulum?

A

Prevent total degradation resulting in metabolites that host can use for energy

30
Q

How does the microbial population form in the stomach when it it sterile at birth?

A

Microbes have to be ingested

- transferred by licking/grooming

31
Q

In what types of diet do protozoa proliferate?

A

With high starch diets and are reduced with high fibre diets

32
Q

What is the role of fungi in the ruminant stomach?

A
  • small proportion of microbial population

- can break down lignin aerobically (straw)

33
Q

How is homeostasis of the fermentation chamber maintained?

A
  • food fermented into VFAs and ammonium
  • water enters rumen
  • ammonium taken up by microbes
  • VFAs absorbed by host
  • water reabsorbed
34
Q

What causes rumen acidosis?

A

Consumption of increased levels of hCHO

35
Q

What occurs as a result of rumen acidosis?

A
  • VFAs increase
  • low pH injures rumen epithelium
  • water enters rumen by osmosis
  • dehydration/hypovolaemic shock
36
Q

What 3 factors is the rate of fermentation dependent on?

A

Type of feedstuff
Volume of feedstuff
Microbial balance

37
Q

What happens to the monosaccharides that have been broken down by bacterial surface enzymes in the rumen?

A

Dissolved in rumen fluid but not available to host as immediately taken up by microbes and metabolised via glycolysis
VFAs are the waste product of the microbes, they are the main energy source for ruminants

38
Q

What are the two metabolic pathways propionate can be formed by?

A

Via anaerobic glycolysis of pyruvate

From lactate

39
Q

What does methane production represent?

A

10% energy loss from total food energy

40
Q

NPN is essential for a healthy microbial population, what are the 2 main sources of it in a ruminants diet?

A 
Grass = 5-15% NPN
Silage = 70% NPN
41
Q

What can be added to a ruminants diet to increase NPN?

A

Urea

42
Q

What happens to the rumen pH as fermentation proceeds?

A

It decreases

43
Q

What happens to lactic acid in the rumen?

A

Stronger acid therefore more poorly absorbed than VFAs
Tends to remain in rumen lowering pH
When absorbed, converted to glucose by liver

44
Q

What is absorbed in the omasum?

A

10% of VFAs, leaving only 10% to pass into the abomasum
Water
Sodium ions

Gastrointestinal system (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions