Brainscape's Knowledge GenomeTM

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


See full index

Year 1 Animal Physiology > 1. Digestive System > Flashcards

1. Digestive System Flashcards

Structure and Function of the System Control of GI Motility and Secretion

1
Q

Name the 7 main parts that make up the digestive system

A

Mouth, Pharynx, Oesophagus, Stomach, Small intestine, Large Intestine and Rectum

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

Name the 4 accessory organs of the digestive system

A

Salivary Gland, Liver, Gall Bladder and Pancreas

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

Why digest?

A

Fuel cells, break down large molecules to smaller ones which can then diffuse into cells and bloodstream for usage

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

What are the 4 main phases of gastrointestinal system?

A

Motility, Secretion, Digestion and Absorption

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

Which of the 4 phases are not controlled?

A

Absorption

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

What can be secreted into the lumen?

A

Enzymes (for digestion), salt, water, Mucus, HCl, HCO3

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

What is the inner-most layer of the lumen wall?

A

Mucosa

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

What is the function of the mucosa?

A

Increase surface area due to folded membrane, protective surface, secretes enzymes, defence against bacteria.

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

Name the three layers of the mucosa and their function

A

Mucous Membrane (protect surface, contains exocrine and endocrine gland cells), Lamina Propria (lyphoid tissue - important for defence) and Muscularis Mucosa (smooth muscle)

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

What is the function of the submucosa?

A

Thick layer of connective tissue for distensibility and elasticity. Contains larger blood and lymph vessls and contains nerve network which stimulates contraction and hormonal release.

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

Name the nerve network of the submucosa and muscularis externa

A

Submucosal plexus and myentric plexus

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

Name the muscle that makes up the muscularis externa

A

Smooth muscle

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

What affect do each layer in the muscularis externa have on the lumen when contracted?

A

Circular layer (contraction decreases diameter of lumen) and longitudinal layer (contraction shortens tube).

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

What does contraction of muscularis externa result in?

A

Produces mixing and propulsive movement

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

What is the function of the serosa?

A

Secrete serous fluid for lubrication - prevents friction

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

What is the function of mesentry?

A

Holds lumen to body wall - fIxation in the body and allows movement for mixing.

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

What does enteric innervation mean?

A

Within tract (involves myentric and submucosal plexus) and is interconnected (motor, secretory and sensory neurones)

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

What does extrinsic innervation mean?

A

Brain innervation - further away.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What effect does parasympathetic innervation have on the activity of the gut

A

Increases activity - rest and digest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the function of villi?

A

Increases surface area due to folded epithelial layer (e.g. Small intestine: 300m2) - shedding (whole new lining every 5 days) - absorption via capillaries (except for fats (lacteal))

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is secreted by the salivary gland and why?

A

Salt, water, mucus, amylase - lubraication and polysaccharide (starch) digestion

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

Which part of the digstive system secretes lingual lipase?

A

Tongue for lipid digestion

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

Why is mucus secreted by the oesophagus?

A

Lubrication - prevents friction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Why is HCl secreted by the stomach?

A

Activates Pepsin to pepsinogen which digests proteins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the function of HCO3?

A

Bicarbonate neutralises chyme and adjusts pH after stomach.

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

Where is bile salts stores?

A

Gall Bladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is secreted by the liver?

A

Bile slats, HCO3 and waste

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

Where is most of digestion taken place?

A

Small Intestine

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

Where is water reabsorpted to prevent loss?

A

Large Intestine

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

Is mucus secreted in the large Intestine?

A

Yes for lubrication

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

What is the function of the rectum?

A

Defecation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What makes up carboydrates?

A

Monosaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Fatty Acids and Glycerol form what?

A

Lipids (fats)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Name a polysaccharide?

A

Glycogen, Cellulos, Amylopectin, amylose (strach)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What does amylase do and where is it secreted?

A

Amylase breaks down strach in the mouth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How is glucose transported into epithelial cells?

A

Via cotransport with Na+ ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

How is fructose transported into epithelial cells?

A

Via protein channel straight into cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How does pepsinogen digest proteins?

A

Breaks bonds between amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is the difference between endopeptidases and exopeptidases?

A

Endopeptidases break bonds between AAs, Exopeptidases act on the ends of chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What type of molecule is moved into epithelial cells via endocytosis

A

Small peptides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

How is amino acids transported into epithelial cells?

A

Via co-transport with Na+ ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Name the 3 lipases and what do they act on?

A

Lingual, gastric and pancreatic lipases and they act on lipids (fats)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Where is most lipids digested?

A

Small intestine

44
Q

What is the problem with large lipid droplets?

A

Small surface area: volume ratio - not many enzymes can act on the lipids at once.

45
Q

What do bile salts do?

A

Increase SA:V ratio by creating several small droplets from one big one creating more sites for enzymes to act upon. They also prevent reaggregation of droplets together.

46
Q

What are micelles?

A

Small droplets which act as reservoir to store FAs and glycerol

47
Q

How are FAs and glycerol secreted out of epithelial cells and where to?

A

Exocytosis (vesicles) into lacteal.

48
Q

How is water absorbed?

A

Osmosis via channel transporters down osmotic graident.

49
Q

How are fat soluble vitamins absorbed?

A

Follow fat absorption

50
Q

How is vitamin B12 absorbed?

A

Bind to intrinsic factor.

51
Q

What does the control of the GI respond to?

A

Distension, osmolarity and acidity and concentration of molecules

52
Q

Name the 3 types of control systems

A

Neural, Hormonal and Local muscle response

53
Q

what does submucosal plexus control?

A

Exocrine and endocrine secretions

54
Q

What does the myenteric plexus control?

A

Control of peristaltic secretions

55
Q

What is the effect of thinking about food?

A

Causes changes in CNS and affect enteric NS so you start to produce hormones and saliva.

56
Q

Do short reflexes involves the brain?

A

No but long reflexes do

57
Q

What stimulates hormonal release?

A

Receptors in contact with the luminal contents detect extremes in distension, osmolarity and acidity etc…

58
Q

How is hormones secreted into blood?

A

Endocrine gland secretion

59
Q

What are the two families of hormones?

A

Gastrin and Secretin

60
Q

Name the 3 phases of GI control

A

Cephalic, Gastric and Intestinal.

61
Q

Which part of the body is the site of cephalic phase

A

Head

62
Q

Name the two phases of GI control which affected by hormonal control

A

Gastric and Intestinal

63
Q

Control of gastric phase happens in response to what?

A

Distension, Acidity and Peptides

64
Q

What influences cephalic phase?

A

Touch, sight, taste, thought

65
Q

What is mastication?

A

Chewing phase

66
Q

Is mastication voluntary?

A

Yes but eventually you swallow due to excess saliva

67
Q

Which parts of the mouth contain receptors that produce a reflex

A

Gums and Hard Palate

68
Q

Saliva in mouth is secreted in response to what?

A

Presence of food in mouth

69
Q

How is food prevented from entering the lungs

A

Glottis closes to prevent food going down trachea, aryno-oesophageal opens to allows food into oeophagus to stomach

70
Q

What is peristalsis?

A

Constriction and shortening of tube, which moves contents though intestinal tract, mixing an propelling food though.

71
Q

What is secondary peristalsis?

A

Oesophageal distension and it occurs when indigested food has been left behind after primary peristalsis.

72
Q

What causes mixing?

A

Reduction in lumen diameter moves some parts forward and other parts in reverse.

73
Q

Name the 3 parts of stomach

A

Fundus, Body and Antrum

74
Q

What is the function of stomach?

A

Acts as a store for food, mixing, breaks down big molecules into smaller ones, more manageable liquid (chyme)

75
Q

What does the pyloric sphincter do?

A

Prevents food coming back from small intestine.

76
Q

What prevents food re-entering oesophagus?

A

Oesphageal sphincter

77
Q

Name the 3 cells in stomach and what do they secrete?

A

Mucous (mucus), parietal (HCl) and chief (pepsinogen)

78
Q

What is receptive relaxation?

A

Take extra volume of food with little rise in stomach pressure stimulated by eating

79
Q

What is the function of the body in the stomach?

A

Storage

80
Q

Where does mixing take place in the stomach?

A

Antrum

81
Q

What controls emptying in the stomach?

A

Factors in the duodenum

82
Q

Why does excess fat slow emptying of stomach?

A

Fat digestion is slow and so to reduce build up of fats in small intestine and less waste emptying is reduced

83
Q

Name two factors that affect gastric emptying.

A

Amount of chyme, Fat, Acid, Hypertonicity and distension.

84
Q

Does intense pain inhibit motility?

A

Yes

85
Q

What membrane potential change causes contraction?

A

Parasympathetic depolarisation.

86
Q

What secretes gastric juice

A

Oxyntic mucosa and pyloric gland areas.

87
Q

What stimulates chief cells?

A

ACh, Gastrin

88
Q

What is the postprandial alkaline tide?

A

They secrete bicarbonate ions into blood causing temporary increase in pH - maintain plasma’s electrical balance. Back optimal pH.

89
Q

Which of the 3 phases causes a decrease in HCl

A

Intestinal Phase

90
Q

How is pepsinogen converted to pepsin

A

Pepsinogen released by chief cells, mixes with HCl, causing pepsinogen activation to become pepsin (change conformation)

91
Q

What is secreted from pancreas?

A

HCO3 and enzymes

92
Q

Where does most digestion take place?

A

Small intestine

93
Q

What is secreted when pH lowers in the small intestine

A

Plasma secretin levels increases, and pancreas increases bicarb concentration and that neutralises acid in small intestine.

94
Q

What does CCK do?

A

Increased levels increases enzymes released by pancreas which increases rate of digestion of fats and proteins.

95
Q

What stimulates the release of HCO3 from epithelial cells of bile duct?

A

Secretin.

96
Q

What is the sphincter of Oddi

A

Smooth muscle which relaxes when we eat to allow bile and pacreatic juice to flow into small intestine.

97
Q

Does contraction of gall bladder release or inhibit the release of bile salts

A

Releases.

98
Q

Does peristalsis occur in the small intestine?

A

Yes

99
Q

What does Gastro-ileal reflex do?

A

Increases segmentation which stimulates colonic peristalsis and provides an urge to defecate.

100
Q

What is the migrating mobility complex?

A

Short peristaltic waves which pushes indigestible foods through the small intestine. (2hrs)

101
Q

What does motilin do?

A

Increase peristaltic mobility.

102
Q

What does relaxation of ileocecal sphincter result in?

A

Chyme moving into large intestine.

103
Q

What is intestinal segmentation?

A

Causes mass movement through large intestine

104
Q

Which part of the anus is voluntarily controlled?

A

External Anal sphincter.

105
Q

Describe renal distension.

A

Internal sphincter relaxes, external contracts, increased peristalsis in sigmoid colon and increases rectal pressure.

Year 1 Animal Physiology (9 decks)

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