Brainscape's Knowledge GenomeTM

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


See full index

gastroenterology - RA > Physiology > Flashcards

Physiology Flashcards

1
Q

The large intestine is the principal site of dietary nutrient absorption.
True/ False?

A

False

The small intestine is the principle site of dietary nutrient absorption.

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

Which muscle type is predominant in the motility of the GI tract?

A

Smooth muscle

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

What are the main functions of the large intestine?

A

Reabsorbs fluid + electrolytes

Stores faecal matter

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

The exocrine and endocrine parts of the pancreas are both part of the GI system.
True/ False?

A

False

Only the exocrine pancreas is part of the GI system.

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

Name some accessory structures of the GI tract!

A

Salivary glands
Pancreas
Liver
Gall bladder

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

Which parts of the GI tract are under skeletal muscle control?

A

Mouth + pharynx
Upper oesophagus
External anal sphincter

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

Name two polysaccharides!

A

Starch

Glycogen

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

Name two disaccharides!

A

Sucrose

Lactose

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

Name three monosaccharides!

A

Glucose
Fructose
Galactose

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

What are proteins broken down into?

A

Amino acids
Dipeptides
Tripeptides

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

The apical membrane of an enterocyte faces the lumen.

True/ False?

A

True

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

Which membrane of an enterocyte faces the blood?

A

Basolateral membrane

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

What are the 4 main layers of the GI tract wall, from innermost to outermost?

A

Mucosa
Submucosa
Muscularis externa
Serosa

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

What is the function of epithelial cells in the mucosa?

A

Absorption

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

What is the importance/ function of the muscularis mucosa?

A

Can change the lumen shape/ surface area to facilitate absorption

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

What does contraction of circular muscle do to the lumen of the digestive tract?

A

Makes it narrower and longer

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

What does contraction of longitudinal muscle do to the lumen of the digestive tract?

A

Makes it shorter and fatter

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

What is the function of gap junctions between adjacent smooth muscle cells?

A

Enable slow wave of contraction to spread across smooth muscle sheet

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

Which cells drive slow wave electrical activity?

A

Interstitial cells of Cajal (ICCs)

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

What type of cells are ICCs?

A

Pacemaker cells

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

What must happen for ICCs to produce contraction?

A

Slow wave amplitude must reach threshold to trigger an action potential

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

The upstroke of the AP generated by ICCs is mediated by Na+ influx.
True/ False?

A

False

Mediated by Ca++ influx through Ca++ channels

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

The force of contraction in the GI tract is related to the number of action potentials discharged from ICCs.
True/ False?

A

True

The more APs fired, the greater the force of contraction

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

What determines the basal electrical rhythm of the digestive tract?

A

Slow wave electrical activity

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

All slow waves trigger contraction.

True/ False?

A

False

Threshold must be reached first

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

What is the nervous system of the gut called?

A

Enteric nervous system

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

The parasympathetic system plays a bigger role in the enteric nervous system than the sympathetic system.
True/ False?

A

True

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

The submucous plexus mostly regulates —.

The myenteric plexus mostly regulates —.

A

The submucous plexus mostly regulates epithelia and blood vessels.
The myenteric plexus mostly regulates motility and sphincters.

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

Parasympathetic outflow is thoraco-lumbar.

True/ False?

A

False

Cranio-sacral

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

Which nerve provides parasympathetic cranial outflow?

A

Vagus nerve

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

Which nerve provides parasympathetic sacral outflow?

A

Pelvic nerves

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

Post-ganglionic neurones are essentially intrinsic to the ENS.
True/ False?

A

True

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

Name a local nerve reflex of the GI tract!

A

Peristalsis

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

Name a short nerve reflex of the GI tract!

A

Intestino-intestinal reflex

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

What is the intestino-intestinal reflex?

A

Overdistention in one area of the intestine causes relaxation in the rest of the intestine

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

Name a long nerve reflex of the GI tract!

A

Gastroileal reflex

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

What is the gastroileal reflex?

A

Stomach signals increase motility of the ileum - open the ileocaecal valve to empty chyme to prepare ileum to receive fresh chyme from the stomach

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

What happens to the propulsive (oral) segment in peristalsis?

A

Circular muscle contracts

Longitudinal muscle relaxes

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

What happens to the receiving (aboral) segment in peristalsis?

A

Circular muscle relaxes

Longitudinal muscle contracts

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

Which substances mediate contraction of circular/ longitudinal muscle?

A

ACh

Substance P

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

Which substances mediate relaxation of circular/longitudinal muscle?

A

VIP

NO

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

What is the process of segmentation called in the large intestine?

A

Haustration

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

The upper oesophageal sphincter is controlled by smooth muscle.
True/ False?

A

False

Skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

The lower oesophageal sphincter is controlled by smooth muscle.
True/ False?

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Which anal sphincter is controlled by skeletal muscle?

A

External anal sphincter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Which receptors are stimulated when food reaches the pharynx?
What do they do?

A

Pharyngeal pressure receptors send afferent impulses to the swallowing centre in the medulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What happens to the larynx during swallowing?

A

Elevates to prevent food from entering the trachea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What happens if food becomes lodged in the oesophagus?

A

Secondary peristaltic wave, more forceful than the first, is triggered locally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What are the 3 major pairs of salivary glands and their locations?

A

Parotids - over the masseter below ears
Submandibular - lower edge of mandible
Sublingual - under tongue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Sublingual salivary gland contribute towards 70% of saliva.

True/ False?

A

False

Submandibular gland contributes 70% of saliva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

How much saliva is contributed to by the parotid glands?

A

25%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What are the antibacterial components of saliva?

A

Lysozyme
Lactoferrin
Immunoglobulins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What is xerostomia?

A

Dry mouth syndrome due to inadequate production of saliva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Primary saliva secretion occurs from where?

A

Acinus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Secondary saliva secretion occurs from where?

A

Duct cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What does the primary saliva secretion consist of?

A

Na, K, Cl and HCO3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

How is the primary saliva secretion modified by duct cells?

A

Remove Na and Cl
Add some K and HCO3
Diluted as no H2O movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

NaCl content of saliva is lower than that of the plasma.

True/ False?

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Glucose content of saliva is higher than that of the plasma.
True/ False?

A

False

No glucose in saliva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

When flow rate is high, HCO3 content of the saliva increases.
True/ False?

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

How does the simple (unconditioned) reflex stimulate salivary glands to increase saliva production?

A

Pressure receptors in mouth activate in presence of food and sent afferent impulses to salivary centre in the medulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

How does the conditioned reflex stimulate salivary glands to increase saliva production?

A

Think/smell/see food activates cerebral cortex which activates salivary centre in the medulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Which nerves carry parasympathetic innervation of saliva production control?

A

Facial nerve

Glossopharyngeal nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What is the effect of parasympathetic stimulation upon saliva production?

A

Large volume
Watery
Enzyme rich

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What is the effect of sympathetic stimulation upon saliva production?

A

Low volume
Thick
Mucus rich

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What are the 4 main anatomical areas of the stomach?

A

Fundus
Body
Antrum
Pylorus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

Where does most mixing/churning of food take place in the stomach?

A

Antrum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What is the substance produced when food mixes with gastric secretions?

A

Chyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

Name a substance which can be absorbed by the stomach!

A

Ethanol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Thickness of smooth muscle lining decreases distally in the stomach.
True/ False?

A

False

Increasing thickness distally (antrum thickness greater than fundus thickness)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

What occurs in retropulsion?

A

Peristaltic wave forces chyme against closed pyloric sphincter, so chyme bounces back and undergoes more mixing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Name 2 gastric factors promoting gastric emptying

A

Volume of chyme (larger volume increases motility due to distention)
Consistency of chyme (thinner liquid facilitates emptying)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

Which 2 duodenal factors delay gastric emptying?

A

Enterogastric reflex
Release of enterogastrones

*An enterogastrone is any substance in the lower gastrointestinal tract which opposes the forward motion of the contents of chyme when exposed to lipids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What is the enterogastric reflex?

A

Duodenum signals to stomach that it has enough chyme so slow down emptying/ peristaltic contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What is the effect of enterogastrones on gastric emptying?

A

CCK and secretin release from duodenum inhibit stomach contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

Where is the pyloric gland area located?

A

Antrum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

Where is the oxyntic mucosa area located?

A

Fundus and Body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

Which cells are contained in the pyloric gland area?

A

D cells

G cells

79
Q

What do D cells secrete?

A

Somatostatin

80
Q

What do G cells secrete?

A

Gastrin

81
Q

Which cells are contained in the oxyntic mucosa?

A

Parietal cells
Enterochromaffin-like cells
Chief cells

82
Q

What do ECL (Enterochromaffin-like cells) cells secrete?

A

Histamine

83
Q

What do parietal cells secrete?

A

HCl

Intrinsic factor

84
Q

What do chief cells secrete?

A

Pepsinogen

85
Q

What does autocatalytic mean with regards to pepsinogen and pepsin?

A

Pepsin formation triggers further pepsin formation from pepsinogen

86
Q

What is the role of intrinsic factor in the oxyntic mucosa?

A

Binds vitamin B12

87
Q

What is the role of histamine in the oxyntic mucosa?

A

Stimulates HCl secretion

88
Q

What is the role of gastrin in the pyloric gland area?

A

Stimulates HCl secretion

89
Q

What is the role of somatostatin in the pyloric gland area?

A

Inhibits HCl secretion

90
Q

Describe how parietal cells produce HCl!

A

In parietal cells carbonic anhydrase combines CO2 and H2O to form H+ and HCO3.
HCO3 is transported out of the cell in exchange for Cl via an antiporter.
H+ is secreted via a proton pump.
H+ and Cl combine to form HCl.

91
Q

What are secretagogues?

A

Substances promoting secretion of HCl (gastrin, ACh, histamine)

92
Q

In response to secretagogues, where do proton pumps move from and to in the parietal cell?

A

Move from inactive tubulovesicles in the cytoplasm to being active in the apical membrane

93
Q

What are the 3 phases of gastric secretion?

A

Cephalic - chewing and swallowing - gastric secretion
Gastric - distension - gastric secretion
Intestinal - stomach empties - gastric secretion inhibited

94
Q

What is involved in the cephalic phase?

A

Stomach is prepared to receive food by conditioned reflex, chewing or swallowing, leading to gastric secretion through ACh and GRP (gastrin releasing peptide)

95
Q

What is involved in the gastric phase?

A

Distention due to food causes mechanoreceptors to augment secretion

96
Q

What is involved in the intestinal phase?

A

Gastric secretion is halted through secretin, CCK and somatostatin as the stomach empties

97
Q

What is the importance of the mucus gel layer on the surface of mucous secreting cells?

A

Prevents pepsin/ HCl reaching the apical surface of the cells and damaging the cells

98
Q

What are the two forms of starch?

A

Amylose

Amylopectin

99
Q

Amylose and amylopectin are branched chain molecules.

True/ False?

A

False

Amylose isn’t but amylopectin is branched

100
Q

Which type of bond links glucose monomers in amylose?

A

alpha-1,4

101
Q

Which type of bonds link glucose monomers in amylopectin?

A

alpha-1,4

alpha-1,6 for branched chain

102
Q

Glycogen is a branched chain polysaccharide.

True/ False?

A

True

103
Q

Which type of bond links glucose monomers in glycogen?

A

alpha-1,4

alpha-1,6

104
Q

Name two oligosaccharides (disaccharides)!

A

Lactose

Sucrose

105
Q

Which monomers make up sucrose?

A

Glucose and fructose

106
Q

Which monomers make up lactose?

A

Glucose and galactose

107
Q

Which enzyme carries out luminal digestion of starch?

A

Alpha-amylase

108
Q

What is starch broken down into in luminal digestion?

A

Oligosaccharides - e.g. maltose, lactose sucrose

109
Q

Which enzymes carry out brush border digestion of maltose, lactose and sucrose?

A

Maltase
Lactase
Sucrase-isomaltase

110
Q

What are oligosaccharides such as lactose, maltose and sucrose broken down into in brush border digestion?

A

Monosaccharides - e.g. glucose, fructose, galactose

111
Q

Alpha-amylase breaks down all alpha-1,4 glucose linkages.

True/ False?

A

False

Only breaks down linear internal links - not terminal links, hence no production of glucose

112
Q

Lactase can only break down lactose.

True/ False?

A

True

113
Q

How is isomaltase unique?

A

It is the only enzyme that can split the branching of alpha-1,6 linkages

114
Q

What is lactose intolerance?

A

Inability to digest lactose, caused by lactase insufficiency

115
Q

Absorption of monosaccharides involves entry via the basolateral membrane and exit via the apical membrane.
True/ False?

A

False

Other way around!

116
Q

What is meant by secondary active transport?

A

Transport either via cotransport or antiport

117
Q

What are oligopeptides?

A

Dipeptides
Tripeptides
Some tetrapeptides
[products of protein digestion]

118
Q

What denatures proteins in the stomach?

A

HCl

119
Q

Which enzyme cleaves protein into peptides in the stomach?

A

Pepsin

120
Q

Is pepsin essential for protein digestion?

A

No

121
Q

What are the active enzymes that digest protein in the duodenum?

A 
Trypsin
Chymotrypsin
Elastase
Procaroxypeptidase A
Procaroxypeptidase B
122
Q

Where does most fat digestion take place?

A

Small intestine

123
Q

Which enzyme cleaves off fatty acids from triglycerides in the stomach?

A

Gastric lipase

124
Q

What is the main lipid digesting enzyme in the duodenum?

A

Pancreatic lipase

125
Q

What do bile salts do to large lipid droplets?

A

Emulsify them into smaller droplets

126
Q

Which enzyme acts as a cofactor for lipase to help it gain access to the triglyceride chain?

A

Colipase

127
Q

What is a mixed micelle?

A

Emulsified fat globule containing monoglyceride, fatty acids, phospholipid, bile salt and cholesterol

128
Q

How are short and medium -chain fatty acids absorbed into capillaries?

A

Exit basolateral membrane via diffusion

129
Q

What happens to long-chain fatty acids and monoglycerides once in the enterocyte?

A

Resynthesised to triglyceride in the ER and incorporated into chylomicrons

130
Q

What coats the cholesterol ester-triglyceride complex to form a chylomicron?

A

Apolipoprotein (apo-B48)

131
Q

How does the chylomicron exit the enterocyte?

Where does it go?

A

Exocytosis into the lymphatic system

132
Q

Chylomicrons are cleaved by — in muscle and adipose tissue.

A

Lipoprotein lipase

133
Q

What carries the free fatty acids and glycerol released by chylomicron degradation?

A

Albumin

134
Q

What does a chylomicron remnant consist of?

A

Cholesterol and phospholipid

135
Q

Which protein allows cholesterol absorption?

A

NPC1L1 protein

136
Q

How does the scaffold containing cholesterol bound to NPC1L1 move around the cell?

A

Via myosin runners

137
Q

When calcium concentration is low, it is absorbed via Ca channels.
Which vitamin increases expression for these channels?

A

Vitamin D

138
Q

Ferric iron can be absorbed by the enterocyte.

True/ False?

A

False

Must be converted to ferrous iron (Fe2)

139
Q

What is the other mechanism (other than receptor transport) by which iron can be absorbed by the enterocyte?

A

Haem is taken up and degraded by haem oxidase

140
Q

What is the storage form of iron called?

A

Ferratin

141
Q

What are the ranges for normal BMI?

A

18.5-25

142
Q

What are the ranges for BMI classed as overweight?

A

25-29

143
Q

What are the ranges for BMI classed as obese?

A

30-39

144
Q

What are the ranges for BMI classed as morbidly obese?

A

Greater than 40

145
Q

How is obesity “a disease of the brain”?

A

The brain sees new fat/ weight as normal, and attempts to lose weight are seen as a threat to survival, so the new weight is defended

146
Q

Lesioning ventromedial hypothalamus causes leanness.

True/ False?

A

False

Lesioning ventromedial hypothalamus causes obesity

147
Q

Which lesioning part of the hypothalamus causes leanness?

A

Lateral part

148
Q

Define satiation!

A

Feeling of fullness during/ following a meal

149
Q

Define satiety!

A

Period from end of one meal to beginning of next

150
Q

What effects do satiation signals have during a meal?

A

Increased signals limit meal size

151
Q

What is ghrelin?

A

A hunger signal - levels increase before a meal and decrease after a meal

152
Q

Which 2 hormones report the “fat status” of fat stores to the brain?

A

Leptin

Insulin

153
Q

Levels of leptin and insulin increase in the blood as more fat is stored.
True/ False?

A

True

154
Q

Reduced leptin mimics starvation.

True/ False?

A

True

155
Q

Name a drug that can be prescribed to tackle obesity!

A

Orlistat

156
Q

How does Orlistat work?

A

Inhibits pancreatic lipase to decrease triglyceride absorption

157
Q

Vomiting is due to stomach contraction.

True/ False?

A

False

Stomach, oesophagus + sphincters are relaxed

158
Q

Which centre coordinates vomiting in the brainstem?

A

Vomiting centre (VC) in the medulla oblongata

159
Q

Does nausea always cause vomiting?

A

No

160
Q

Toxic materials stimulate enterochromaffin cells to release which mediator of vomiting?

A

5-HT (serotonin)

161
Q

Which 3 stimulants stimulate the brainstem to act on the vomiting centre to initiate vomiting?

A

Toxins
Mechanical activity/ disease
Motion sickness

162
Q

What effects do vagal efferents have on the oesophagus, stomach and small intestine in the vomiting reflex?

A

Oesophagus shortens
Stomach relaxes
Small intestine retrograde contraction

163
Q

Place the parts of the small intestine in order from shortest to longest

A

Duodenum (0.25m)
Jejunum (2.5m)
Ileum (3m)

164
Q

Which 3 components increase the surface area of the small intestine?

A

Circular folds
Villi
Microvilli

165
Q

Where is gastrin secreted from?

A

G cells of stomach + duodenum

166
Q

Where is CCK secreted from?

A

I cells of duodenum + jejunum

167
Q

Where is secretin secreted from?

A

S cells of duodenum

168
Q

Where is motilin secreted from?

A

M cells of duodenum + jejunum

169
Q

Where is ghrelin secreted from?

A

Gr cells of stomach, small intestine + pancreas

170
Q

Distention, gastrin, CCK, secretin + parasympathetic activity all enhance the secretion of intestinal juice.
True/ False?

A

True

171
Q

What is the migrating motor complex in the small intestine?

A

Strong peristaltic contraction spanning from stomach to end of ileum which clears debris and mucus between meals

172
Q

Gastrin and CCK trigger the migrating motor complex.

True/ False?

A

False

Motilin triggers it; CCK and gastrin inhibit it

173
Q

What does the aqueous salt solution released from pancreatic duct cells do?

A

Neutralises acidic chyme in the duodenum

174
Q

Acid and chyme in duodenum stimulates/ inhibits the release of secretin.
This stimulates/ inhibits release of intestinal juice from pancreas.

A

Acid and chyme in duodenum stimulates the release of secretin.
This stimulates release of intestinal juice from pancreas.

175
Q

Fat and protein in the duodenum stimulates/ inhibits the release of CCK, which stimulates/inhibits release of intestinal juice from pancreas,

A

Fat and protein in the duodenum stimulates the release of CCK, which stimulates release of intestinal juice from pancreas

176
Q

Describe haustration!

A

Intermittent contraction of circular muscle in proximal colon at slow rate to allow contents to move but leave enough opportunity for reabsorption

177
Q

Which nerve conveys efferents to cause either relaxation or contraction of the external anal sphincter?

A

Pudendal nerve

178
Q

Reabsorption of water is largely driven by the reabsorption of which ion?

A

Sodium

179
Q

Which mechanism is the most major in Na reabsorption in the post-prandial period in the jejunum?

A

Na-glucose and Na-amino acid cotransport

180
Q

What is the effect of cAMP, cGMP and Ca2+ on NaCl absorption?

A

Reduce NaCl absorption

181
Q

Where do epithelial Na channels (ENaC) mediate Na absorption?

A

Distal colon

182
Q

Where does blood from the hepatic artery and hepatic portal vein meet and mix in the liver?

A

Sinusoids (fenestrated capillaries that enable blood to leak out into space of Disse)

183
Q

The liver is made up of hexagonal lobules.

List the vessels and ducts contained in each lobule!

A 
Central vein (branch of hepatic vein)
Portal triad (hepatic portal branch + hepatic artery branch + bile duct)
184
Q

What is the direction of blood flow in a liver lobule?

A

Inwardly through sinusoids towards the central vein

185
Q

What is the direction of bile flow in a liver lobule?

A

Outwardly through canaliculi towards the bile duct

186
Q

Canaliculi are formed by the basolateral membrane.

True/ False?

A

False

Canaliculi are formed by the apical membrane

187
Q

Which membrane faces the space of Disse?

A

Basolateral membrane

188
Q

Which 3 types of cell are located in the sinusoidal spaces?

A

Endothelial cells
Kuppfer cells
Stellate (Ito) cells

189
Q

What is the function of endothelial cells in the sinusoidal space?

A

Fenestrated structure allows passage of solute, but not cells

190
Q

What is the function of Kuppfer cells in the sinusoidal space?

A

Macrophages that remove bacterial matter and dead RBCs

191
Q

What is the function of stellate (Ito) cells in the sinusoidal space?

A

Store vitamin A within the space of Disse

May deposit collagen, beginning liver cirrhosis

192
Q

Most bile is secreted by bile duct cells.

True/ False?

A

False

Most is secreted by the liver

193
Q

Most of the bile entering the duodenum is reabsorbed in the terminal ileum.
True/ False?

A

True

gastroenterology - RA (23 decks)

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