GI physiology Flashcards

1
Q

besides mechanical ingestion, what systems are necessary to acquire and ingest food?

A

sensory

  • tactile
  • visual
  • olfactory
    • memory
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

prehension

A

seizing food and conveying it into the mouth

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

Mastication

A

mechanical breakdown of food in the mouth

chewing

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

deglutition

A

swallowing

3 stages:

  • through the mouth (voluntary)
  • through the pharynx (reflex)
    • through esophagus (reflex)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

segmentation

A

back and forth mixing due to intermittent contraction of circular smooth muscle

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

peristalsis

A

unidirectional (usually aboral) waves of contraction

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

propulsive motility

A

moving bolus aborally

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

retentive motility

A

material is retained longer

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

mixing motility

A

material in lumen is churned

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

digestive transit time

A

timing of getting material from one area to another

short in birds (less digestion of high energy berries)

long in ruminants (30+ hours)

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

digestion vs absorption

A

digestion is a reduction in size using physical, chemical, and enzymatic breakdown. Aim is to make molecules small enough to be absorbed.

Absorption: transport of nutrient particles into vascular system

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

mechanical digestion

A

simple decrease in size

mastication

gastric digestion through contractions, mixing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

enzymatic digestion

A

hydrolysis of chemical bonds via enzymes produced by alimentary tract or bacteria

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

chemical digestion

A

hydrolysis of chemical bonds via HCl

mostly in stomach

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

ruminant saliva

A

buffered solution required to help support rumen microbes buffer acid produced in fermentation

antifoaming characteristics

flow is continuous but varies with activity

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

major digestive enzyme in saliva

A

salivary amylase

17
Q

maldigestion and malabsorption diseases

A

share clinical signs but etiologies are different and are treated differently

18
Q

elimination

A

Production, temporary storage, expulsion of fecal mass

19
Q

detoxification

A

liver is integral

20
Q

GI bacteria management

all species must:

A
  • prevent bacteria from leaving gut
  • maintain correct types of bacteria
  • keep colonic bacteria out of small intestine
    • provide a good environment for fermentation bacteria
21
Q

GI intrinsic neuronal control

A

enteric nervous system

component of ANS

controls majority of GI functions independent of CNS

22
Q

intrinsic GI hormones

A

regulate secretions, not released into lumen

made by alimentary tract

have local and systemic functions (secreted into circulation)

23
Q

extrinsic neuronal control of GI system

A

parasympathetic: vagus, pelvic n
sympathetic: splanchnic, and hypogastric nerves

only extrinsic gut hormone is aldosterone (water absorption)

24
Q

aldosterone

A

extrinsic GI hormone that regulates water absorption

25
Q

immune function of the GI system

A

pathogens can enter GI since its exposed to environment

26
Q

peyer’s patches

A

immune surveillance of intestinal lumen

facilitate immune response in gut

especially in ileum

27
Q

paneth cells

A

secrete antimicrobial peptides and proteins in gut

28
Q

luminal phase of digestion

A

within the lumen of the GI tract

varies in region of GI tract (chemical, physical, and chemical)

mouth through at least small intestine

enzymes produced by the organ itself, accessory organs, and/or hosted microbes

29
Q

luminal digestion produces:

A

short chain polymers that are still to big to be absorbed

in ruminant and equine symbiotic bacteria can produce some absorbable products

30
Q

mucosal phase of digestion

A

only in small intestine

enteric enzymes further digest end products of luminal digestion

absorbable products

31
Q

intracellular phase of digestion

A

only in small intestine

important only for protein

32
Q

short GI reflexes

A

from gut directly back to gut

named from origin to destination (ex gastrocolic)

usually affect motility or secretion

33
Q

long GI reflexes

A

from gut to spinal cord or brainstem the back to gut

ex: defecation, vomiting

34
Q

starch

A

repeting units of glucose

highly digestible

35
Q

cellulose

A

repeating units of glucose

not digestible without microbial flora

36
Q

hindgut fermenters

A

horse

large intestine is modified to host microbes and support fermentation

microbial mass passed out in feces

37
Q

foregut fermenters

A

ruminants

stomach modified to host fermentative microbes