Brainscape's Knowledge GenomeTM

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


See full index

Physiology S2 > Test 1: Small and Large Intestine > Flashcards

Test 1: Small and Large Intestine Flashcards

1
Q

Why are ruminants unable to digest plant material directly?

A

they lack the enzyme to break down cellulose in plant cell walls.

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

In how many chambers does ruminant digestion occur? Name them.

A

4 chambers:
- rumen
- reticulum
- omasum
- abomasum

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

What are the non glandular parts of the ruminant stomach?

A
  • rumen
  • reticulum
  • omasum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the name of the terminal glandular stomach of the ruminant?

A

abomasum

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

What is the first part of the ruminant stomach? What is its function? What is its appearance?

A

RETICULUM:
- HONEYCOMB appearance
- moves food into the rumen and omasum
- causes regurgitation of injesta
- collection compartment for foreign objects

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

What is the largest part of the ruminant stomach? What is its function? What is its appearance? What is produced?

A

RUMEN:
- leaf like PAPILLAE
- storage compartment
- facilitates microbial (bacterial and protozoal) fermentation of injesta
- Volatile fatty acids are biproducts which are absorbed and serve as a direct energy source

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

What is produced in the rumen?

A

volatile fatty acids
- directly accessible energy source

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

What type of material is digested in the rumen? How? What is the purpose of this digestion?

A

carbohydrates
- microbial fermentation
- purpose: produce ATP for bacterial protein synthesis and growth
- Volatile fatty acids are absorbed through the rumen into the portal vein and are carried to the liver

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

What are the different types of microorganisms in the rumen?

A
  • bacteria
  • protozoa
  • fungi
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is needed for the digestion of cellulose?

A

microorganisms such as bacteria, fungi and protozoa.

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

What do rapid changes in feed affect in the ruminant stomach?

A

the microflora of the forestomachs

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

What do rumenal bacteria digest?

A
  • main: cellulose
  • starch
  • sugars
  • other plant material
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the living condition of rumenal bacteria?

A

completely anaerobic (obligate anaerobes)

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

What vitamins do rumenal bacteria synthesize?

A

B vitamins

B for Bacteria

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

Where do large amounts of bacteria end up in?

A

abomasum

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

How are rumenal bacteria classified? Based on what factor?

A

Rumenal bacteria are classified based on what nutrients they metabolize.

  • cellulolytic
  • hemicellulolytic
  • amylolytic
  • proteolytic
  • sugar utilizers
  • ammonia producers
  • vitamin synthesizers
  • methane producers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How do ruminants produce methane? What else comes with the methane?

A

CO2 + H2 + CH4

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

Explain the structure of rumen protozoa.

A
  • large
  • single celled
  • microscopic cillia (help push food towards their mouth)
  • obligatory anaerobes
  • eat large amounts of starch at a time
  • store starch in their bodies
  • 50% of rumen
  • 40x the size of rumenal bacteria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What do rumen protozoa store? What does this help in?

A
  • store starch
  • slows down the production of acids (rumen pH doesn’t get too low)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What do rumen potozoa feed on? What does that help in?

A
  • starch (not as much acid is produced)
  • bacteria (prevents bacterial overgrowth)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What do rumenn protozoa produce?

A

fermentation end products:
- acetate
- butyrate
- hydrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Where do rumen methane bacteria live? Why?

A

on the surface of rumenal protozoa, for immediate access to hydrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Explain the location of rumenal protozoa. Why?

A
  • slower moving fiber mat of the rumen
  • so that they aren’t washed out before they multiply
  • multiplication is very slow (15-24h) in comparison to bacteria (13min)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What may reduce the number of protozoa in the rumen?

A
  • low roughage diets
  • reduce retention of fibers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Explain features of rumen fungi. Conditions? Function? Nutrition?

A

Conditions:
- multiple types of fungi (both anaerobic and aerobic)
- attach to food particles
- reproduce slowly

Function:
- split fibrous material (making it more accessible for bacteria)
- fermentation

Nutrition:
- recieved from bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Explain the function of the omasum. What is its structure?

A
  • contains numerous LAMINAE (tissue leaves)
  • grinds ingesta
  • reduce particle size
  • absorb water
  • absorb VFA
  • prevent abomasum buffering
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Explain the function of the abomasum. What is its structure? What is its function?

A
  • true gastric stomach

Structure:
- 3 regions: cardiac, fundic, pyloric
- pH: 2.6

Function:
- digestive secretions
- proteolytic enzymes
- HCl
- denatures proteins
- kills bacteria and pathogens
- dissolves minerals
- gastric digestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Explain the layering of content in the rumen of cows

A

gas
fiber mat (intense fermentation)
intermediate zone (intense fermentation)
liquid zone (moderate fermentation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What types of contractions occur in the reticulorumen?

A

1) MIXING contractions (primary contractions)
2) contractiosn related to RUMINATION (transport of forestomach content to the oral cavity for chewing)
3) contractions related to ERUCTATION OF GAS (secondary contractions)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is rumination? Purpose? Differences depending of diet?

A

transport of forestomach content to the oral cavity for additional chewing:
- reduces size of feed particles
- expose new surfaces to fermentation
- rich fiber diet=longer fermentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How much gas do ruminants produce in a 24h period?

A

2000-4000L

32
Q

What organs secrete digestive juices into the small intestine?

A

accessory glands:
- pancreas
- liver
- gallbladder

33
Q

How does the small intestine and its nearby organs protect themselves from digestive enzymes?

A

produce inactive forms of enzymes which are only activated in the duodenum.

34
Q

What are the two main functions of the pancreas?

A
  • exocrine function
  • endocrine function
35
Q

What is the exocrine function of the pancreas?

A
  • secretes pancreatic juice into the small intestine
  • produce sodium bicarbonate (neutralizes gastric contents in the duodenum)
  • zymogen granules (in acinar cells) produce digestive enzymes
36
Q

What is the endocrine function of the pancreas?

A
  • secretes insulin and glucagon (regulate blood sugar and carbohydrate metabolism)
37
Q

What are the major pancreatic enzymes? What do they digest? Into what?

A
  • amylase (polysaccharides–>disaccharides)
  • lipase (triglycerides–>fatty acids)
  • nuclease (nucleic acids–>nucleotides)
  • proteinases (peptides–>amino acids) (all secreted in their inactive form)
38
Q

Explain the activation of enzymes in the duodenum.

A

trypsinogen + enterokinase –> trypsin (active)

trypsin + chymotrypsynogen –> chymotripsin (active)
trypsin + proaminopeptidase –> aminopeptidase (active)
trypsin + procarboxypeptidase –> carboxypeptidase (active)

39
Q

What are the two major hormones regulating pancreatic proteases in the small intestine? What is their function?

A

CCK- induces secretion of pancreatic enzymes
Secretin- induces secretion of HCO3-

40
Q

What are the function sof the liver?

A
  • lipid metabolism
  • production of bile (fat emulsification)
  • carbohydrate metabolism (glycogenesis, glycogenolysis)
  • storage of glycogen, iron, and vitamins A, D, B12
  • pcontains phagocytes (destroy damaged erythrocytes and foreign substances)
  • blood reservoir
  • coagulation blood factors
  • cholesterol production
  • converts and inactivated toxic substances
41
Q

What is bile? What is it composed of?

A
  • yellowish-green alkaline solution
  • contains bile salts, bile pigments, cholesterol, neutral fats, phospholipids, and electrolytes
  • chief bile pigment: billirubin (waste product of heme)
42
Q

What is the function of bile?

A
  • emulsify fats
  • facilitate fat and cholesterol absorption
  • help solubilize cholesterol
43
Q

Explain the position of the gall bladder.

A
  • inferior,
  • visceral surface of the liver
43
Q

What is the function of the gall bladder?

A

stores and concentrates bile secreted by the liver

43
Q

Explain the species differences related to the gall bladder.

A

dogs, cats, humans:
- fat digestion is intermitent
- unnecesary continuous bile presence
- gall bladder facilitates the transfer of large quantities of bile salts to the small intestine during digestion + continuous transport of waste products from the hepatocytes to the bile

horses, ruminanats:
- continuous digestion- flow of bile does not fluctuate
- horses lack a gallbladder
- ruminants have a gall blader with a short retention time and poorly concentrating mechanism

44
Q

Explain the regulation of bile release.

A
  1. chyme enters duodenum
  2. CCK and secretin released (bloodstream)
  3. production of bile stimulated in liver
  4. weak contractions of gall bladder (caused by vagal stimulation)
  5. CCK’s cause gallbladder contraction + hepatopancreatic relaxation
  6. bile enters duodenum
45
Q

Explain the adaptations of the small intestine depending on species differences.

A

carnivores: shorter
herbivores: longer

46
Q

Explain the adaptations of the large intestine depending on species differences.

A

hind hut fermantation depending on structure and size

47
Q

Where is the small intestine located? What are its parts? What is its function?

A

Location:
- from pyloric sphincter
- to ileocecal valve

Division:
- duodenum
- jejunum
- ileum

Functions:
- digestion (intestinal glands)

48
Q

What are the different intestinal enzymes? What do they digest? Into what?

A
  • maltase: maltose–>glucose
  • sucrase: sucrose–>glucose + fructose
  • lactase: lactose–>glucose+galactose
  • peptidase: peptides–>amino acids
  • lipase: triglycerides–>fatty acids+glycerol
  • nuclease: nucleotides–>nitrogenous bases
  • enterokinase: trypsinogen–>trypsin
49
Q

How are intestinal secretions stimulated?

A
  • gastrc juice
  • chyma
  • distension of the small intestine
50
Q

Explain the structure of villi. What does it absorb?

A

blood capillaries:
- absorb water (osmosis)
- glucose (active transport)
- amino acids (active transport)
- vitamins & minerals (active transport)
- short chain fatty-acids (passive diffusion)

lymphatic capillaries:
- long chain fatty-acids (passive diffusion)

51
Q

Explain the differences in absorption depending on the location in the small intestine.

A

duodenum:
- amino acids,
- vitamins,
- lipids
- glucose and other sugars

jejunum:
- carbohydrates
- proteins

ileum:
- vitamin B12
- bile salts
- remaining nutrients

52
Q

What are the types of contractions in the small intestine? What are their functions?

A

types:
- segmentation (mixes intestinal content)
- peristalsis (moves intestinal content)

function:
- mix content
- ensures lumenal content comes in contact with epithelial cells
- transports chyme along the digestive tract

53
Q

Explain the process of segmentation. What is segmentation? What it its function?

A
  • most common type of contraction in the small intestine
  • ring-like contractions occuring simultaneously at regular intervals

Function:
- divides intestinal content into many small segemnts
- mixing of injesta with digestive juices
- bring new content into contact with absorptive surfaces

54
Q

Explain the process of peristalsis. What is peristalsis? When is it initiated? How? What it its function?

A
  • waves of contractions (moving from one part of the GI tract to the next)
  • initiated when a segment of the intestine recieves chyma

expansion stimulates:
- contraction of circular muscle (proximal to stimulated part)
- receptive relaxation (distal to stimulated part)

function:
- displacement of chyme

55
Q

How is the small intestine regulated?

A

1) Neural Regulation:
- parasympathetic nerve activity: increases contraction strength
- sympathetic nerve activity: weakens contraction strength
- peristalsis
- segmentation

2) Reflex Regulation:
- feed composition
- emotions

3) Humoral Regulation:
- gastrin, motilin, CCK, seratonin, histamin, bradicinin, VIP, NT

56
Q

What is peristalsis and segmentation regulated by?

A

the enteric nervous system

57
Q

What sphincter is present at the transition between the small intestine and the colon? What else do some species have to prevent the retrograde flow of the colonic content?

A

ileocecal sphincter
(one way gate)

some species: mucosa in the sphincter forms a flap

58
Q

Explain the large intestine. Where is it located? What are its species differences? What does it consist of?

A
  • tube between the terminal ileum and anus

species differences:
- horse, ruminant, pig: ileocecal valve
- dogs: ileocolic valve

Structure:
- cecum
- colon
- rectum

dog- collie

59
Q

What are the functions of the large intestine?

A
  • absorption of water and ions
  • microbial digestion
  • absorption of carbohydrates and proteins
  • digestion (microbial enzymes)
  • produce HCO3 and mucin

HCO3- neutralization of organic acids (formed by fermentation)

60
Q

Explain the digestion occuring in the large intestine depending on diet differences.

A

Carnivores:
- large intestine is of small significance
- digestion completed in the small intestine

Herbivores and Omnivores:
- microbial degredation processes are very important
- rabbit: fermentation in the cecum (COPROPHAGY)
- horses: fermentation in colon

rabbit- ceCUM ; horse-COLon

61
Q

What types of contractions occur in the large intestine?

A
  • segmentation (haustrastion contractions)
  • peristalsis
  • antiperistalsis (retard movement of injesta- absorption of water and electrolytes)
  • mass movements (intensive and prolongued peristaltic movements- strips area clear of contents)
62
Q

Explain the rectum. Where is it located? What glands does it have? What stimulates its contractions?

A
  • terminal portion of the colon
  • mucous-secreting glands
  • sensory receptors detect stretching/distension and trigger defacation

carnivore and omnivore rectum- empty most of the time

63
Q

Explain the anus. What controls the passage of feces? Voluntary? Involuntary? What stimulates contractions?

A
  • internal and external sphincters control the passage of feces
  • dogs&cats- voluntary control (early life)
  • ruminants, horses, birds- involuntary
  • parasympathetic signals stimulate contractions (colon and rectum)
  • smooth muscle cells in the internal sphincter relax
  • defecation occurs
64
Q

What are the parts of the bird digestive system?

A

1) beak, mouth, pharynx
2) esophagus, crop
3) proventriculus, gizzard
4) small intestine
5) cecum
6) colon & cloaca
7) pancrease
8) liver

65
Q

Where does the fiber microbial degredation occur in birds?

A

ceca

66
Q

What do birds have which have fiber-rich diets?

A

large ceca

67
Q

What birds have specifically good fiber digestibility?

A

ostriches, geese, and ducks

68
Q

Explain the crop. What is it? Where is it located? What is its function?

A
  • pouch-like enlargement of the esophagus
  • food is temporarily stored (later passed onto stomach in small, regulated portions)
  • neutral pH
  • allows the degradation of starch (with salivary amylase and bacterial fermentation)
69
Q

What is the proventriculus?

A

the ‘true stomach’
- glandular stomach
- place where digestion occurs

70
Q

In birds, what marks the end of the jejunum and the start of the ileum?

A

Merkel’s diverticulum

71
Q

Explain the ceca in birds. What is it? What is its function?

A

ceca=plural of cecum
- blind pouches at the junction of the small and large intestines

function:
- reabsorption of water
- fermentation
- production of B-vitamins
- minimal absorption and nutrient release

72
Q

What occurs in the large intestines of the birds?

A

large intestine is short!
- empties into cloaca
- fecal material is voided by the vent

  • water reabsorption
  • fiber fermentation (bacteria)
  • H2O soluble vitamin synthesis (bacteria)
73
Q

What happens in the rectum and cloaca?

A

absorption of water and ions

74
Q

What do bird feces contain? What is it transported in?

A
  • white crystals of uric acid
  • transported with the urine
  • colloidal suspension

Physiology S2 (17 decks)

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