Gastrointestinal Principles Flashcards

1
Q

What are the four generalised components of the digestive tract wall?

A

Mucosa
Submucosa
Muscaularis Externa
Serosa

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2
Q

What is the alimentary canal?

A

The whole passage along which food passes through the body from mouth to anus during digestion

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3
Q

What are the four major functions of the alimentary canal?

A

Motility
Secretion
Digestion
Absorption

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4
Q

What happens to the lumen when circular muscle contracts?

A

It becomes narrower and longer

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5
Q

What happens to the intestine when longitudinal muscle contracts?

A

It becomes shorter and fatter

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6
Q

What happens when the muscularis mucosae contracts?

A

Change in absorptive and secretory area mucosa and mixing activity

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7
Q

What is the function of the Myenteric Plexus?

A

Regulates motility and sphincters

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8
Q

What is the function of the Submucous Plexus?

A

Modulates epithelia and blood vessels

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9
Q

What is glycogenesis?

A

Synthesis of glycogen from glucose

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10
Q

What is glycogenolysis?

A

Breakdown of glycogen to form glucose

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11
Q

What is gluconeogenesis?

A

De novo synthesis of glucose from metabolic precursors

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12
Q

What are the metabolic precursors for the synthesis of glucose?

A

Lactate
Amino Acids
Glycerol

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13
Q

What is the role of Glycogen Synthase?

A

Synthesis of glycogen from UDP-glucose by extending chains of glycogen

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14
Q

What are the three components of the small intestine?

A

Duodenum
Jejunum
Ileum

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15
Q

What are the three components of the large intestine?

A

Caecum
Appendix
Colon

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16
Q

What are the three additional features of the digestive system?

A

Liver and Gallbladder
Pancreas
Salivary Glands

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17
Q

Where is the myenteric plexus located?

A

Muscularis Externa

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18
Q

Where is the submucosal plexus located?

A

Submucosa

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19
Q

What is the name of gastrointestinal pacemaker cells?

A

Interstitial cells of cajal

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20
Q

What type of epithelium is in the oesophagus?

A

Stratified Squamous Epithelium

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21
Q

What type of epithelium is in the stomach?

A

Stratified Columnar Epithelium

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22
Q

What do chief cells in the stomach secrete?

A

Digestive enzymes

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23
Q

What do parietal cells in the stomach secrete?

A

Hydrochloric acid

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24
Q

What is the top portion of the stomach called?

A

Cardia

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25
Q

What is the middle main part of the stomach called?

A

Body/Fundus

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26
Q

What is the bottom portion of the stomach called?

A

Pylorus

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27
Q

How does the Muscularis Externa differ in the stomach?

A

It has an additional oblique muscle layer to aid with the churning of food

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28
Q

Where is the pyloric sphincter?

A

Between the stomach and the duodenum of the small intestine

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29
Q

What are enterocytes?

A

Cells of the digestive system. Tall columnar cells with a brush border and are the principle absorptive cells

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30
Q

What is the role of goblet cells?

A

Produce mucin to protect epithelium and lubricate passage of material

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31
Q

What are Paneth Cells?

A

Found at the base of the crypts of Lieberkuhn and have a defensive function

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32
Q

What is the role of neuroendocrine cells in the small intestine?

A

Produce hormones that contribute to the control of secretion and motility

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33
Q

What is the role of stem cells in the small intestine?

A

Found at the base of the crypts of Lieberkuhn to divide to replenish epithelium

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34
Q

What are Peyer’s Pathches?

A

Aggregation of lymphoid tissue

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35
Q

What is in the portal triad?

A

Hepatic Artery
Portal Vein
Bile Duct

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36
Q

What type of collagen is in reticular fibres?

A

Type III Collagen with some Type I Collagen

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37
Q

What are hepatic stellate cells?

A

Modified fibroblasts that deal with connective tissue and store vitamin A within fat droplets

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38
Q

What are kupffer cells?

A

Resident macrophages within the liver sinusoids that remove particular matter from the blood and help remove worn out blood cells

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39
Q

What is a mesentery?

A

A fold of the peritoneum which attaches the stomach, small intestine, pancreas, spleen, and other organs to the posterior wall of the abdomen

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40
Q

What is the omenta?

A

A fold of peritoneum connecting the stomach with other abdominal organs

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41
Q

What nerves form the parasympathetic innervation of the GI tract?

A

Vagal and Pelvic Nerves

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42
Q

Where do the vagal nerves originate to supply the GI tract?

A

Medulla Oblongata

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43
Q

Where do the pelvic nerves originate to supply the GI tract?

A

Sacral Spinal Cord

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44
Q

What does excitatory parasympathetic innervation of the GI tract cause?

A

Increased gastric, pancreatic and small intestinal secretion
Increased blood flow
Increased smooth muscle contraction

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45
Q

What does inhibitory parasympathetic innervation of the GI tract cause?

A

Relaxation of some sphincters

Receptive relaxation of the stomach

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46
Q

Where do the sympathetic nerves of the GI tract originate from?

A

Thoraco-lumbar region

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47
Q

What does excitatory sympathetic innervation of the GI tract cause?

A

Increased sphincter tone

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48
Q

What does inhibitory sympathetic innervation of the GI tract cause?

A

Decreased motility
Decreased secretion
Decreased blood flow

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49
Q

What is colonic mass movement?

A

A powerful sweeping movement that forces faeces into the rectum

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50
Q

What is the migrating motor complex?

A

A powerful sweeping contraction from the stomach to the terminal ileum

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51
Q

What are tonic contractions?

A

Sustained contractions that can occur at varying pressures at different points in the GI tract

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52
Q

What joint opens the mouth?

A

Temporomandibular joint

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53
Q

What are the three pairs of jaw closing muscles?

A

Masseter
Temporalis
Medial Pterygoid

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54
Q

What muscle is involved in jaw opening?

A

Lateral Pterygoid

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55
Q

What nerve innervates the muscles of the jaw?

A

Mandibular division of the trigeminal nerve - CN V3

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56
Q

What are the three main salivary glands called?

A

Parotid
Submandibular
Sublingual

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57
Q

What are the four extrinsic muscles of the tongue?

A

Palatoglossus
Styloglossus
Hyoglossus
Genioglossus

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58
Q

At what vertebral level does the pharynx become the oesophagus?

A

C6 vertebral level

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59
Q

What are the two neuroendocrine hormones that report fat status to the brain?

A

Leptin

Insulin

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60
Q

What is the major site of amino acid degredation?

A

Liver

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61
Q

What is the function of aminotransferases in transamination?

A

Move the amino group for alpha amino acids to alpha keto acids

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62
Q

What are the major carriers of nitrogen in the blood to the liver?

A

Alanine and Glutamine

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63
Q

What chemicals digest protein?

A

Pepsin and Hydrochloric Acid

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64
Q

What chemicals digest carbohydrates?

A

Salivary Amylase

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65
Q

What do mucous cells in the GI tract secrete?

A

Mucous and Bicarbonate

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66
Q

What do parietal cells in the GI tract secrete?

A

Hydrochloric acid

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67
Q

What do endochromaffin-like cells in the GI tract secrete?

A

Histamine

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68
Q

What do G cells in the GI tract secrete?

A

Gastrin

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69
Q

What do D cells in the GI tract secrete?

A

Somatostatin

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70
Q

What do chief cells in the GI tract secrete?

A

Pepsinogen

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71
Q

What is glycogenin?

A

An enzyme that acts as a glycogen primer by polymerises the first few molecules of glucose to form the glycogen primer for glycogen synthesis

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72
Q

What is transglycosylase?

A

A branching enzyme that introducglycosidic branches onto glycogened alpha 1-6

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73
Q

What is the role of brunners glands and where are they located?

A

They broduce and alkaline substance to neutralise the chyme and are found in the submucosa of the duodenum

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74
Q

What are the strips of smooth muscle in the large intestine called?

A

There are 3 Teniae Coli

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75
Q

What is billirubin?

A

A normal by-product of the breakdown of red blood cells

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76
Q

What are the four anatomical segments of the liver?

A

Right lobe
Left lobe
Caudate lobe
Quadrate lobe

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77
Q

What artery provides blood supply to the gallbladder?

A

Right hepatic artery

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78
Q

What are the three branches of the celiac trunk?

A

Splenic artery
Hepatic artery
Left gastric artery

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79
Q

What are the branches of the hepatic artery?

A

Gastroduodenal then Superior pancreatico-duodenal

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80
Q

What arteries supply the lesser curvature of the stomach?

A

Right and left gastric arteries

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81
Q

What arteries supply the greater curvature of the stomach?

A

Right and left gastro-omental arteries

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82
Q

What vein drains the organs of the foregut?

A

Splenic vein

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83
Q

What vein drains the organs of the hindgut?

A

Inferior mesenteric vein

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84
Q

What vein drains the organs of the midgut?

A

Superior mesenteric vein

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85
Q

What does the endoderm give rise to in GI embryology?

A

Epithelium of the mucosa

Associated ducts and glands

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86
Q

What does the visceral mesoderm give rise to in GI embryology?

A
Lamina propria
Muscularis Mucosa
Muscularis Externa
Connective tissue of the submucosa
External Connective tissue
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87
Q

What does the neural crest give rise to in GI embryology?

A

Enteric nervous system
Meissners plexus
Auerbachs plexus

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88
Q

What hormone triggers the Migrating Motor Complex?

A

Motilin

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89
Q

What hormones inhibit the Migrating Motor Complex?

A

Gastrin

Cholecystokinin

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90
Q

Where is gastrin released?

A

Released from G cells of gastric antrum and duodenum

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91
Q

What is the action of gastrin?

A

Stimulates proton secretion by gastric parietal cells

Stimulates growth of gastric mucosa

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92
Q

Where is secretin released?

A

Released from S cells of the duodenum in response to protons and fatty acids in the lumen

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93
Q

What is the action of secretin?

A

Promotes secretion of pancreatic and biliary bicarbonate

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94
Q

Where is Cholecystokinin released?

A

Released from I cells of the duodenum and jejunem in response to monoglycerides, free fatty acids, amino acids and small peptides in the lumen

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95
Q

What is the action of Cholecystokinin?

A

Inhibits gastric emptying
Causes secretion of pancreatic enzymes required for digestion
Stimulates relaxation of the sphincter of oddi and contraction of the gall bladder to eject bile into the duodenum
Potentiates the action of secretin

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96
Q

Where is Glucose dependent insulinotropic peptide released?

A

Released from K cells of the duodenum and jejunum in response to glucose, amino acids and fatty acids

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97
Q

What is the action of Glucose dependent insulinotropic peptide?

A

stimulates release of insulin from pancreatic β-cells (incretin action)
inhibits gastric emptying

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98
Q

Where is Glucagon like peptide 1 released?

A

from L cells of the distal ileum, released primarily in response to glucose and fats

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99
Q

What is the action of Glucagon like peptide 1?

A

stimulates insulin secretion (incretin action)
inhibits glucagon secretion from pancreatic α-cells
decreases gastric acid secretion and emptying and also appetite

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100
Q

Where is Motilin released?

A

from M cells of duodenum and jejunum, secreted during fasting state

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101
Q

What is the function of Motilin?

A

initiates the migrating motor complex

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102
Q

Where is Ghrelin released?

A

from Gr cells of the gastric antrum, small intestine and elsewhere (e.g. pancreas)

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103
Q

What is the function of Ghrelin

A

stimulates appetite

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104
Q

What receptor do peptide hormones bind to?

A

G-protein coupled receptors

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105
Q

What is the juice secreted from the small intestine called?

A

Succus Entericus

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106
Q

Where are the digestive enzymes of the pancreas released from?

A

Blind ended ACINAR CELLS

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107
Q

Why is there a high bicarbonate solution released from the pancreas into the duodenum?

A

To neutralise the acidic chyme

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108
Q

What mediates the cephalic phase of pancreatic secretion?

A

Vagus stimulation of mainly acinar cells

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109
Q

What mediates the gastric phase of pancreatic secretion?

A

gastric distension evokes a vagovagal reflex resulting in parasympathetic stimulation of acinar and duct cells

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110
Q

What phase results in the majority of pancreatic secretion?

A

Intestinal phase

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111
Q

What are the two types of digestion in the small intestine?

A

Luminal digestion

Membrane digestion

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112
Q

What mediates luminal digestion?

A

Pancreatic enzymes

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113
Q

What mediates membrane digestion?

A

Enzymes situated at the brush border of epithelial cells

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114
Q

What is absorption?

A

the processes by which the absorbable products of digestion are transferred across both the apical and basolateral membranes of enterocytes (absorptive cells of the intestinal epithelium)

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115
Q

What is the term that encompasses digestion and absorption?

A

Assimilastion

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116
Q

Give examples of polysaccharides…

A

Starch

Glycogen

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117
Q

Give examples of oligosaccharides…

A

Sucrose

Lactose

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118
Q

What are the limits of alpha amylase?

A

Cannot cleave terminal alpha 1,4 links, alpha 1,6 links or alpha 1,4 links next to branch points

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119
Q

What can alpha amylase break amylose into?

A

Maltotriose

Maltose

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120
Q

What can alpha amylase break amylopectin into?

A

Maltotriose
Maltose
Alpha limity dextrins

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121
Q

Why is there a rate limit on assimilation?

A

The rate of digestion is faster than the rate of absorption (except for lactose)

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122
Q

What is the name of the space between the endothelial cells and hepatocytes in the sinusoids of the liver?

A

Space of Disse

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123
Q

What type of collagen supports the parenchyma of the liver?

A

Type III collagen along with some type I collagen in the space of disse.

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124
Q

What are hepatic stellate cells?

A

They are modified fibroblasts involved in connective tissue. They store vitamin A fat droplets in the cytoplasm.

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125
Q

What can happen to hepatic stellate cells in some pathological conditions?

A

They can transform into myofibroblasts and create scar tissue.

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126
Q

What are Kupffer cells?

A

They are resident macrophages in the sinusoids. They remove particulate matter from the blood and remove worn out RBC.

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127
Q

What is bile?

A

Bile is an alkaline solution containing water, ions, phospholipids, bilirubin and bile salts.

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128
Q

What is bilirubin?

A

This is a pigment responsible for the breakdown of haemoglobin. It is excreted in the bile and results in the brown colour of faeces.

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129
Q

What are bile salts?

A

They are used for the emulsification of fats in the digestive tract.

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130
Q

What are bile canaliculi?

A

These are small channels that bile flows through that is formed by tight junctions of adjacent hepatocytes.

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131
Q

What enzyme activates the proenzyme trypsinogen from the exocrine pancreas?

A

Enteropeptidases

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132
Q

What is the role of vomiting?

A

It is a defence mechanism triggered by the emetic centre located in the brainstem

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133
Q

What different systems act on the vomiting centre?

A
Higher cortical centres
Vestibular nuclei
Chemoreceptor trigger zone
Vagal afferents
Enterochromaffin cells
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134
Q

What drugs act on the higher corticol centres?

A

Antihistamines

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135
Q

What drugs act on the vestibular nuceli?

A

Antimuscarinics

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136
Q

What drugs act on the chemoreceptor trigger zone?

A
Phenothiazines
Domperidone
Metoclopramide
Dopamine receptor antagonists
5-HT3 Receptor andagonists
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137
Q

What drugs act on enterochromaffin cells?

A

Nablione
Metoclopramide
5-HT3 Receptor andagonists
Neurokinin-1 receptor antagonists

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138
Q

What are the main neurotransmitter systems involved in nausea and vomiting?

A

5-HT, dopamine and ACh

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139
Q

Examples of antihistamines…

A

Cyclizine
Promethazine
Diphenydramine

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140
Q

Examples of antimuscarinics…

A

Scopolamine (hyoscine)

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141
Q

Examples of 5-HT3 receptor antagonists…

A

Ondasetron
Granisetron
Palonosetron

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142
Q

Examples of dopamine receptor antagonists…

A
Chlorpromazine
Droperidol
Haloperidol
Prochlorperazine
Metoclopramide
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143
Q

Examples of neurokinin-1 receptor antagonists…

A

Fosaprepitant

Aprepitant

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144
Q

What is the action of antihistamines?

A

Antagonist at histamine H1 receptors in the brain

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145
Q

What is the action of antimuscarinics?

A

Antagonist at muscarinic acetylcholine M1 receptors in the brain

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146
Q

What is the action of 5-HT3 receptor antagonists?

A

Act primarily as antagonists at 5-HT3 receptors in the chemoreceptor trigger zone of the medulla in the hindbrain.
Also act on 5-HT3 receptors in the GI tract

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147
Q

What is the action of dopamine receptor antagonists?

A

Act primarily as antagonists at D2 receptors in the chemoreceptor trigger zone in the medulla.
Also act on D2 receptors in the GI tract

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148
Q

What is the action of neurokinin-1 receptor antagonists?

A

Act primarily as NK1 receptors in the GI tract and the chemoreceptor trigger zone of the medulla, blocking the effects of substance P which evokes vomiting

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149
Q

Examples of antidiarrhoeal drugs…

A

Loperamide, diphenoxylate

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150
Q

Examples of laxatives…

A

Ispaghula husk, senna, lactulose

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151
Q

What is the action of loperamide and diphenoxylate?

A

Opiates that bind to nano-opiate receptors.

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152
Q

What is the peritoneum?

A

A thin, transparent, semi-permeable serous membrane that lines the abdominal cavity.

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153
Q

What is an intraperitoneal organ?

A

An organ that is covered on both the anterior and posterior side by the visceral peritoneum

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154
Q

What is a retroperotineal organ?

A

An organ that is covered only on the anterior surface by the visceral perotineum

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155
Q

What is a mesentery?

A

A double layer of visceral perotineum that suspends the organ from the posterior abdominal wall

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156
Q

How do the greater and lesser peritoneal sacs communicate?

A

Through the omental foramen

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157
Q

What organs are retroperitoneal?

A

SAD PUCKER
S- Supraadrenal glands
A- Aorta
D- Duodenum

P- Pancreas
U-Ureters
C- Colon
K- Kidneys
E- (O)esophagus
R- Rectum
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158
Q

Describe the greater omenta…

A

It consists of four layers pf visceral peritoneum. It descends from the greater curvature of the stomach and proximal part of the duodenum and doubles back up to attach to the anterior portion of the transverse colon.

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159
Q

What type of nerves supply the abdominal organs?

A

Sensory- Visceral Afferent
Motor- Autonimic Motor Nerves
The Enteric Nervous System

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160
Q

Derscribe the route of visceral afferent nerves from the abdomen…

A

They typically run alongside sympathetic fibres back to the spinal cord.

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161
Q

At which spinal cord level do foregut visceral afferents enter?

A

T6-T9

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162
Q

At which spinal cord level do midgut visceral afferents enter?

A

T8-T12

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163
Q

At which spinal cord level do hindgut visceral afferents enter?

A

T10-L2

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164
Q

At what level do the sympathetic fibres leave the spinal cord to reach abdominal organs?

A

T5-L2

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165
Q

Describe the route of sympathetic nerves to the abdominal organs…

A
  1. They leave the spinal cord between T5-L2
  2. They move into the sympathetic truck but don’t synapse
  3. The move out of the sympathetic trunk through abdominopelvic splanchnic nerves and synapse at the prevertebral ganglia
  4. They then move alongside the branches of the aorta and other nerves as part of a periatrerial plexus
  5. They then reach the smooth muscle and glands of the organs
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166
Q

Name the nerves that supply the abdominal body wall…

A

Thoracoabdominal nerves
Subcostal Nerve
Iliohypogastirc Nerve
Ilioinguninal Nerve

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167
Q

Name the three branches of the coeliac artery…

A

Common hepatic artery
Splenic artery
Left gastric artery

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168
Q

Name some branches of common hepatic artery…

A

Gastroduodenal artery

Superior pancreatic duodennal artery

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169
Q

What vessels are the main blood supply of the stomach?

A

Right and left gastric arteries- lesser curvature

Right and left gastro-omental arteries - greater curvature

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170
Q

What vessels supplies blood to the gall bladder?

A

Cystic artery

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171
Q

What muscles facilitate the closure of the jaw?

A

Masseter
Medial Pterygoid
Temporalis

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172
Q

What muscle facilitates the opening of the jaw?

A

Lateral Pterygoid

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173
Q

What cranial nerve supplies the muscles of mastication?

A

The mandibular division of the trigeminal nerve (CN V3)

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174
Q

What is the name of the upper dental arch?

A

Maxillary

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175
Q

What is the name of the lower dental arch?

A

Mandibular

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176
Q

What is the course of CN V3?

A
  1. Pons
  2. Foramen Ovale
  3. Muscles of mastication and general sensory area
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177
Q

What is the course of CN V2?

A
  1. Pons
  2. Foramen Rotunda
  3. Sensory Area
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178
Q

Which nerves supply sensation to the anterior 2/3rds of the tongue?

A
General sensory (touch) - CN V3
Special Sensory (taste) - CN VII
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179
Q

Which nerve supplies the posterior 1/3rd of the tongue?

A

General and special sensory - CN IX

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180
Q

What is the course of CN VII?

A
  1. Pontomedullary Junction
  2. Internal Acoustic Meatus
  3. Stylomastoid Foramen
  4. Sensory and Motor Area
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181
Q

What is the chorda tympani?

A

Branch of the facial nerve (CN VII) that connects to the lingual branch of CN V3

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182
Q

What are the exrinsic muscle of the tongue?

A

Palatoglossus
Hyoglossus
Styloglossus
Genioglossus

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183
Q

What nerve supplies the muscles of the tongue?

A

Hypoglossal (CN XII)

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184
Q

What nerves supplied the longitudinal muscles of the pharynx?

A

CN X and CN IX

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185
Q

What nerve supplies the circular muscles of the pharynx?

A

CN X

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186
Q

Where does the oesophagus begin?

A

The inferior edge of the cricopharyngeus muscle ( @ vertebral level C6)

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187
Q

Where are peptic ulcers most commonly located?

A

Duodenal bulb or the antrum of the stomach

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188
Q

What is the cause of peptic ulcers?

A

Acid pepsin results in mucosal damage and gastric ulcers

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189
Q

What are the two kinds if peptic ulcers?

A

Gastric and duodenal ulcers

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190
Q

What is the most common cause of peptic ulcers?

A

H. Pylori

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191
Q

What are some other causes of peptic ulcers?

A

Long term use of NSAIDs

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192
Q

How can we differentiate between gastric and duodenal ulcers?

A

Gastric - worsened by eating

Duodenal - improved by eating

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193
Q

What are the investigations for H. Pylori Infection?

A

Urea breath test or stool antigen test

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194
Q

Eating what food can lead to Bacillus Cereus?

A

Reheated rice

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195
Q

What is the role of chief cells?

A

Release pepsinogen which is changed to pepsin in the presence of HCL

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196
Q

ECL cells

A

Release histamine which is used to help with acid secretion

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197
Q

Parietal cells

A

Macin acid secreting cells, also secreted intrinsic factor which absorbs B12

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198
Q

What are the three phases of digestion?

A
  1. Cephalic phase
  2. Gastric Phase
  3. Intestinal Phase
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199
Q

What are the triggers of the cephalic phase?

A

Psychological triggers

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200
Q

What mediates the cephalic phase?

A

Vagus nerve and ACh mediates response

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201
Q

What is the role of ACh in the cephalic phase?

A

Stimulates acid and histamine release directly

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202
Q

What is the role of the Vagus Nerve in the cephalic phase?

A

Stimulates gastrin releasing peptide for gastrin secretion

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203
Q

What triggers the gastric phase?

A

Distention of the gastric wall

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204
Q

What mediates the gastric phase?

A

Distention detected by vagal afferent and increases vagal efferent activity for acid secretion.
Local plexuses activated

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205
Q

In which digestive phase is the highest amount of acid secreted?

A

Gastric phase

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206
Q

What triggers the intestinal phase?

A

Triggered when food enters the duodenum

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207
Q

What mediates the intestinal phase?

A

CCk released from I cells and GIP released fromK cells due to the presence of lipids and carbohydrates

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208
Q

What is the role of secretin and CCK in the intestinal phase?

A

Secretin and CCK stimulates pancreatic and biliary stimulation

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209
Q

What activates the parietal cells?

A

ACh
Vagus Nerve
Gastrin - directly and indirectly via ECL and histamine route

210
Q

What inhibits the parietal cells?

A

Somatastatin - Directly and indirectly by inhibiting gastirn release

211
Q

What is the relevence of the proton pump in the partieal cells?

A

This pumps out H+ which combines with Cl- to produce acid.

212
Q

What is the action of H. Pylori?

A

Damage gut epithelium and increase acid. This can lead to peptic ulcers.

213
Q

What is the proton pump?

A

H+/K+ ATPase

214
Q

What supplies blood to the foregut?

A

Coeliac Trunk (T12)

215
Q

What supplies blood to the midgut?

A

Superior mesenteric artery (L1)

216
Q

What supplies blood to the hindgut?

A

Inferior mesenteric artery (L3)

217
Q

What does the Left gastric artery supply?

A

Lower oesophagus, lesser curvature of the stomach

218
Q

Midgut

A

Superior Mesenteric Vein

219
Q

What drains the Foregut?

A

Splenic Vein

220
Q

What drains the Midgut?

A

Superior Mesenteric Vein

221
Q

What drains the Hindgut?

A

Inferior mesenteric Vein

222
Q

What is the Portosystemic anastamoses?

A

Communitcation between veins in the hepatic system and vena cavae system

223
Q

Where is referred pain from the hindgut?

A

Hypogastrium

224
Q

Where is referred pain for appendicitis?

A

Periumbilical region T8-T10

225
Q

What is the cisterna chyli?

A

Major lymph duct in the abdomen, next to the crus of the diaphragm and becomes that thoracic duct after passing up through the diaphragm

226
Q

Transcellular

A

Transport mechanisms through the cell then pumped out through the basolateral membrane

227
Q

What is reponsible for secretion in the gut?

A

Crypts of Lieberkuhn

228
Q

What cells are in the crypts

A

Stem cells, proliferating cells and differentiating cells

229
Q

What factors affect absorption and secretion?

A
Nutrient intake
Gastric motility
Intestinal motility
Number and state of enterocytes
Blood and lymph supply
Luminal factors, irritants, bile and bacterial toxins
230
Q

Water absorbed

A

Jejunum

231
Q

What is responsible for absorption in the gut?

A

Villi

232
Q

Where is the majority of the water absorbed?

A

Jejunum

233
Q

What is the action of the SGLT1?

A

Pumps sodium ions with glucose into the enterocytes, setting up an electrochemical gradient for water to follow via the paracellular route

234
Q

What are the nerves that signal between the ENS and the CNS?

A

Vagal and spinal afferents signal from gut to CNS

Vagal and splanchnic efferents signal from CNS to gut

235
Q

What is the role of the plexuses of the ENS?

A

Senses Luminal contents

Controls muscles and glands, blood flow, motility, secretion, mucosal growth

236
Q

What are the 5 parts of the pancreas?

A
Head
Uncincate pancreas
Neck
Body
Tail
237
Q

What is the uncicate pancreas?

A

A projection that arises from the lower part of the has and extends medially to lie beneath the body of the pancreas.

238
Q

What is the role of acinar cells in the pancreas?

A

Synthesise, store and secrete enzymes

239
Q

What does the sphincter of oddi do?

A

Controls the opening and closing of the major duodenal papilla.

240
Q

Examples of proteases…

A

Chymotrypsin and Trypsin

241
Q

What is the role of lipase?

A

Break down triglycerides

242
Q

What is the role of amylase?

A

Break down starch into sugars

243
Q

How is trypsinogen activated?

A

Enterokinases activate trypsinogen into trypsin

244
Q

What vein drains blood from the foregut to the liver?

A

Splenic Vein

245
Q

What vein drains blood from the midgut to the liver?

A

Superior Mesenteric Vein

246
Q

What vein drains blood from the hindgut to the liver?

A

Inferior Mesenteric Vein

247
Q

What vein drains cleaned blood away from the liver?

A

The hepatic veins draining into the inferior vena cave

248
Q

What are the two reccesses in the peritoneal cavity in relation to the liver?

A

Subphrenic recess

Hepatorenal recess

249
Q

What are the three layers of the mucosa?

A

Epithelium
Lamina Propria
Muscularis Mucosa

250
Q

Where are peyers patches located?

A

Lamina propria

251
Q

What is the Auerbach’s Plexus?

A

Mesenteric Plexus

252
Q

What is the Meissners Plexus?

A

Submucosal Plexus

253
Q

What is the role of the serosa?

A

Prevents friction with other abdominal organs

254
Q

What are exocrine secretions?

A

Enzymes and digestive juices

255
Q

What are endocrine secretions?

A

Hormones

256
Q

What are the constituents of the saliva

A
Water - 99.5%
Amylase
Mucus
Lysozyme
Lactoferin
257
Q

What innervates the sublingual and submandibular glands?

A

Branch of the facial nerve

258
Q

What innervates the parotid gland?

A

Branch of the glossopharyngeal duct

259
Q

What is the function of the saliva?

A

Digestion and antimicrobial properties

260
Q

What is xerostomia?

A

Dryness in the mouth often caused by salivary gland hypofunction

261
Q

What is an other name for swallowing?

A

Deglutination

262
Q

What are the two phases of swallowing?

A

Oropharangeal - voluntary

Oesophageal - involuntary

263
Q

What contains the major blood vessels supplying the mucosa of the GI tract?

A

Submucosa

264
Q

What is the function of enterochromaffin-like cells?

A

Secrete histamin whcih stimulates G cells to produce gastrin

265
Q

How many litre of human saliva is produced a day?

A

1-2 litres

266
Q

Where is cholecystokinin released from?

A

Enteroendocrine cells of the duodenum and jejunum due to lipids and protein.

267
Q

What is the action of cholecystokinin?

A

Signals via sensory nerves to the hindbrain and stimulates it

268
Q

Where is Peptide YY released from?

A

From Endocrine mucosal L-cells after a meal

269
Q

What is the action of peptide YY?

A

Inhibits gastric motility, slows gastric emptying and reduces food intake

270
Q

Where is glucagon-like peptide 1 released from?

A

Product of the pro-glucagon gene. it is also released from L-cells in response to food indigestion

271
Q

What is the action of glucagon like peptide 1?

A

Inhibits gastric emptying and reduces food intake

272
Q

Where is oxyntomodulin released from?

A

Product of the pro-glucagon gene and is released from oxyntic cells and L-cells of the small intestine after a meal

273
Q

What is the role of oxyntomodulin?

A

Acts to suppress appetite however the mechanisms by which it does this are unclear

274
Q

Where is obestatin released from?

A

Produced from the gene that encodes ghrelin and is released from cells lining the stomach and small intestine.

275
Q

What is the action of obestatin?

A

I tis thought to reduce food intake and may antagonise the actions fo ghrelin, but the mechanism by which it does this is unknown

276
Q

What are satiation signals?

A

These are signals that are given off during a meal to help limit the meal size?

277
Q

What are the gut peptide satiation signals?

A
Cholecystokinin
Peptide YY
Glucagon like peptide 1
Oxyntomodulin
Obestatin
278
Q

What is ghrelin?

A

The hunger signal

279
Q

Where is ghrelin released from?

A

Oxcyntic cells in the stomach

280
Q

When are ghrelin levels high?

A

Before a meal, during periods of fasting and hypoglycaemia

281
Q

What is the action of ghrelin?

A

Stimulates food intake, decreases energy expenditure, decreases fat utilazation

282
Q

What is the name of the strands of smooth muscle in the large intestine?

A

Taeniae Coli

283
Q

What is the name of the bulges on the large intestine?

A

Haustra

284
Q

What mediates ileocaecal sphincter tone?

A

Enteric neurones, the vagus nerve, sympathetic nerves and hormonal signals

285
Q

What occurs in the gastroileal reflex?

A

Relaxation of the ileocaecal valve
Increased contractions of the ileum
Delivery of chyme from the ileum to the caecum

286
Q

What are the triggers of the gastroileal reflex?

A

GI hormones - Gastrin and CCK

Extrinsic autonomic hormones

287
Q

Where does the appendix emerge from the posteriomedial caecal wall?

A

Appendiceal orriface

288
Q

What does the colon absorb?

A

Na+, Cl-, H2O

Short chain fatty acids

289
Q

What does the colon secrete?

A

K+, HCO3-, mucus

290
Q

What are the primary functions of the colon?

A

Absorption
Secretion
Resevoir
Periodic elimination of faeces

291
Q

What is the content of faeces?

A

H2O

Solids - cellulose, bacteria, bilirubin, small amount of salt

292
Q

What is the function of colonocytes?

A

Mediate electrolyte absorption, driving H2O absorption

293
Q

What is the function of crypt cells in the colon?

A

Mediate ion secretion

294
Q

What do goblet cells secrete?

A

Mucous containing glycoaminoglycans

Trefoil proteins for host defence

295
Q

What enhances Na+ and K+ absorption?

A

Aldosterone

296
Q

What is the role of gut commensal bacteria?

A

Compete with pathogenic microbes
Promote motility and maintain mucosal integrity
Synthesise vitamin K2 and free fatty acids that are absorbed
Activate some drugs

297
Q

What does the common hepatic duct join with to form the common bile duct?

A

Cystic duct from the gall bladder

298
Q

What is the ampulla of vater?

A

Join of the bile duct and pancreatic duct

299
Q

Where does the ampulla of vater drain into?

A

2nd part of the duodenum through the major duodenal papilla

300
Q

What are the three sphincters of the bile duct?

A

Sphincter of oddi
Bile duct sphincter
Pancreatic duct sphincter

301
Q

What are the main causes of jaundice?

A

Gallstones

Carcinoma of the head of the pancreas

302
Q

What are the exocrine cells of the pancreas?

A

Acinar Cells

303
Q

What are the endocrine cells of the pancreas?

A

Islets of Langerhans

304
Q

What is produced by the endocrine portion of the pancreas?

A

Insulin and Glucagon

305
Q

What nerves innervate the pancreas?

A

Vagus

Abdomino pelvic splanchnic nerves

306
Q

What mediates pancreatic secretion?

A

Hormones

307
Q

Describe the blood supply to the pancreas?

A

Mainly splenic artery
also
Superior pancreaticoduodenal arteries
Inferior pancreaticoduodenal arteries

308
Q

Where does the superior pancreaticoduodenal arteries come from?

A

Gastroduodenal artery

309
Q

What are the 4 parts of the duodenum?

A

Superior
Descending
Horizontal
Ascending

310
Q

Where does the jejunum begin?

A

Duodenaljejunal flexure

311
Q

Where does the ileum end?

A

Ileocaecal junction

312
Q

What are the differences between the jejunum and ileum?

A

Jejunum mucosa - plicae circulares (highly folded)

Ileum mucosa - much smoother

313
Q

What is the blood supply to the jejunum and ileum?

A

Superior mesenteric artery via the jejunal and ileal arteries

314
Q

What is the venous drainage from the jejunum and ileum?

A

Jejunal and ileal veins to superior mesenteric veins to hepatic portal vein

315
Q

What is the role of bile?

A

It helps for the absorption of fats from the GI tract lumen into the intestinal cells

316
Q

What are lacteals?

A

Specialied lymphatic vessels of the small intestine

317
Q

What lymph nodes drain foregut organs?

A

Celiac nodes

318
Q

What lymph nodes drain midgut organs?

A

Superior mesenteric nodes

319
Q

What lymph nodes drain hindgut organs?

A

Inferior mesenteric nodes

320
Q

What lymph nodes drain the kidneys, posterior abdominal wall, pelvis and lower limbs?

A

Lumbar nodes

321
Q

What are the adiposity signals?

A

Insulin and Leptin

322
Q

How do the adiposity signals work?

A

They inform the hypothalamus to alter the energy balance, hence to eat less and increase energy burn. This can malfunction in obesity

323
Q

Where is leptin released?

A

It is made and released from fat cells

324
Q

Where is insulin released?

A

It is made and released from pancreatic beta cells

325
Q

What are the two main causes of leptin resistance?

A

Defective leptin transport into the brain

Altered signal transduction following leptin

326
Q

What are thermogenic adipocytes?

A

They increase energy expenditure uncoupling of oxidative metabolism from ATP production

327
Q

What is the process of digestion?

A
  1. Protein digestion by pepsin and HCl

2. Carbohydrate digestion by salivary amylase

328
Q

Where are gastric juices produced?

A

Gastric glands in the gastric mucosa

329
Q

What is the orad stomach?

A

Fundus and Proximal Body

330
Q

What is the caudad stomach?

A

Distal body and antrum

331
Q

What are the gastric factors that allow stomach emptying?

A

Fluidity of the Chyme

Volume of the Chyme

332
Q

What is the enterogastric reflex?

A

This decreases antral activity by signals from intrinsic nerve plexuses and the ANS

333
Q

What are the two gland areas in the stomach?

A

Oxcyntic gland area

Pyloric gland area

334
Q

What are the gastric secretions for the oxyntic cells of the stomach?

A
HCl
Pepsinogen
Intrinsic Factor
Gastroferrin
Mucous
Histamine
335
Q

What is the function of HCl in gastric secretion?

A

activates pepsinogen to pepsin, denatures proteins and kills most of the micro-organisms ingested with food

336
Q

What is the function of pepsinogen?

A

The inactive form of pepsin

337
Q

What is the function of intrinsic factor?

A

Binds to vitamin B12 and facilitates subsequent absorption

338
Q

What is the function of Gastroferrin?

A

Binds to Fe2+ and facilitates subsequent absorption

339
Q

What is the function of histamine?

A

Stimulates HCl secretion from parietal cells

340
Q

What is the function of mucous in the stomach?

A

To protect the stomach

341
Q

What secretions are produced from the pyloric glands?

A

Gastrin
Somatostatin
Mucous

342
Q

What is the function of gastrin?

A

Stimulates HCl secretion and motility

343
Q

What is the function of somatostatin?

A

Stimulates HCl secretion and motility

344
Q

What is H. Pylori?

A

Gram -ve curvilinear rod

345
Q

Where are the three main anastomoses in the GI tract?

A

Oesophageal, anterior abdominal wall, rectum

346
Q

What are the sites of water absorption in the GI tract?

A

Small (majority in the jejunum) and Large intestion

347
Q

Where is the main site for cobalamin (vitamin B12) absorption?

A

Terminal Ileum

348
Q

How much water do we excrete each day?

A

100ml

349
Q

Where is the main site of paracellular transport?

A

Small Intestine

350
Q

Where is the main site of transcellular transport?

A

Large intestine

351
Q

What is the barrier in the stomach to protect it from acid?

A

Mucus-bicarbonate barrier

352
Q

What are the hormones involved in gut repair?

A

Gastrin

353
Q

Where is the main site of peyer’s patches?

A

Ileum and colon

354
Q

What are the antigen presenting cells in peyer’s patches?

A

M cells

355
Q

What is the main antibody involved in gut immunity?

A

IgA

356
Q

What is secreted locally to cause vasodilation in the case of acid penetration in the stomach?

A

CGRP and NO

357
Q

What binds to crypt cells to stimulate intestinal secretion?

A

ACH and VIP

358
Q

What are chylomicrons made of?

A

Triglycerides, phospholipis and cholesterol

359
Q

What are firmicutes bacteria?

A

Microbacteria that ferment dietary fibre to short chain fatty acids

360
Q

What are the main types of firmicutes bacteria?

A

Buterate

361
Q

Where is intrinsic factor released?

A

Parietal Cells

362
Q

Where does peristalsis occur?

A

Oesophagus and intestines

363
Q

Which two muscles are used to close the mouth?

A

Temporalis and masseter

364
Q

What are the three phases of swallowing?

A
  1. Oral
  2. Pharyngeal
  3. Oesophageal
365
Q

What regulates the flow of bile and pancreatic juice?

A

Sphincter of oddi

366
Q

What hormone relaxes the sphincter of oddi?

A

CCK

367
Q

What does the sphincter of oddi surround?

A

Ampulla of vater

368
Q

Where is CCK produced?

A

I cells

369
Q

What connects the gallbladder to the common bile duct?

A

Cystic duct

370
Q

What is bilirubin excreted as in faeces?

A

Stercobiligen

371
Q

What is a carrier protein produced by the liver?

A

Albumin

372
Q

What is dysbiosis?

A

An alteration in the microbiome caused by a change in the microbiomes composition

373
Q

What cells produce saliva?

A

Acinus cells

374
Q

What innervates the submandibular and sublingual glands?

A

Facial nerve

375
Q

What innervates the parotid gland?

A

Glossopharyngeal nerve

376
Q

Where is iron absorbed in the body?

A

Duodenum and upper jejunum

377
Q

What is carcinoid of the appendix?

A

Cancer of the crypts of lieberkuhn in the appendix

378
Q

What are adhesions?

A

Areas of scar tissue that can cause organs or tissues in the abdomen to stick together

379
Q

What increases the surface area of the small intestine?

A

Villi- finger like projections created by folds in the mucosa
Microvilli - brush border on the luminal surface of the enterocytes

380
Q

What is the glycolax layer?

A

This is a gelatinous layer that coats the brush border microvilli

381
Q

What blood vessel supplies the small intestine?

A

Superior mesenteric artery

382
Q

What are the different types of ingested lipids?

A

Triacylglycerols
Phospholipids
Cholesterol
Fatty Acids

383
Q

What are the main types of phospholipids?

A

Glycerophospholipids

384
Q

How does emulsification occur in the GI tract?

A

Chewing in the mouth
Gastric churning in the stomach - mixed with digestive enzymes
Segmentation and peristalsis in the small intestine - pancreatic and biliary secretion

385
Q

What are lamellae?

A

A coat of amphiphillic moclecules that form a surface layer on the emulsion droplets

386
Q

What are contained within laemellae?

A

Products of lipid digestion
Biliary phospholipids
Cholesterol
Bile Salts

387
Q

When are bile salts added to the lamellae?

A

As the droplets become from multilamellar to unimellar, further bile salts are added

388
Q

What are the uses of bile salts in emulsification?

A

Act as detergents to help emulsify large lipid droplets to small droplets

389
Q

How is gastric lipase secreted?

A

From chief cells in response to gastrin

390
Q

Why is gastric lipase inactivated when it leaves the stomach?

A

Unfavourable pH

Broken down by pancreatic proteases

391
Q

What is the main enzyme involved in lipid digestion?

A

Pancreatic Lipase

392
Q

Where is pancreatic lipase secreted?

A

Acinar cells of the pancreas in response to CCK

393
Q

What TAGs does gastric lipase hydrolyse?

A

Position 3

394
Q

What TAGs does pancreatic lipase hydrolyse?

A

Position 1 and 3

395
Q

Where are bile salts released?

A

Hepatocytes of the liver

396
Q

What can a failure to secrete bile salts result in?

A

Lipid malabsorption

Secondary vitamin deficiency due to a failure to absrod fat soluble vitamins A, D, E, K

397
Q

What is colipase?

A

An amphipathic polypepetide that binds to bile salta and lipase allowing access of the lipase to tri- and di-acylglycerols

398
Q

How is colipase secreted?

A

It is secreted as procolipase which is activated by trypsin

399
Q

What protein is used in the transport by endocytosis of chylomicrons?

A

Niemann-Pick C1-like 1 protein

400
Q

How is calcium absorbed when there is a high lumenal concentration of calcium?

A

Passive paracellular diffusion

401
Q

How is calcium absorbed when there is a low lumenal concentration of calcium?

A

Calcium channels via active absorption

402
Q

Where is iron absorbed?

A

Duodenal Enterocytes

403
Q

What form of iron can be absrobed?

A

Fe2+ ferrous ion

Haem

404
Q

What promotes reduction of Fe3+ to Fe2+?

A

[HCl] in stomach
Vitamin C
Duodenal Cytochrome B

405
Q

What prevents Fe2+ forming insoluble anion salts?

A

Binding of Fe2+ to gastroferrin

406
Q

What transports Fe2+ to the basolateral membrane?

A

Mobilferrin

407
Q

What transports Fe2+ across the basolateral membrane?

A

Ferroportin 1

408
Q

What does Haem oxidase convert haem into?

A

Fe2+ and biliverdin

409
Q

What does vitamin B12 bind to in the stomach?

A

Haptocorin

410
Q

What does vitamin B12 bind to in the small intestine?

A

Intrinsic factor

411
Q

How is vitamin B12 absorbed in the terminal ileum?

A

Vitamin B12-intrinsic factor complex is absorbed by endocytosis

412
Q

What are the major mechanisms for the absorption of Na+ from the jejunum?

A

Na+/glucose and Na+/amino acid co transport
Na+/H+ exchange
Na+/H+ and Cl-/HCO3- exchange in parallel
Epithelial Na+ channels (ENAC)

413
Q

What is the pH of the lumen of the jejunum?

A

Alkaline due to the presence of bicarbonate from the pancreas

414
Q

What is the overall charge of Na+ and Cl- absorption?

A

Electroneutral

415
Q

What chemicals reduce sodium chloride absorption?

A

Intracellular cAMP, CGMP, Ca2+

416
Q

What condition causes reduction in NaCl absorption?

A

Diarrhoea

417
Q

What increases the work of the ENAC channel?

A

Aldosterone

418
Q

How does Cl- absorption occur?

A

Passively via transcellular or paracellular routes, however there are additional mechanisms

419
Q

What drives passive Cl- absorption in the intestines?

A

Negative potential due to electrogenic transport and movement of Na+

420
Q

Where does Cl- secretion occur from?

A

Cells of the crypts of Liberkuhns

421
Q

What channel on the apical membrane allows for the transport of Cl- in to the lumen?

A

CFTR

422
Q

What can cause the CFTR channel to be indirectly activated?

A

Bacterial Enterotoxins
Several hormones and neurotransmitters
Immune cell products
Some laxatives

423
Q

What agents cause the direct activation of the CFTR channel?

A

cAMP, cGMP, Ca2+

424
Q

What are the paracolic gutters?

A

Potential space between the lateral edge of the ascending and descending colon and the abdominal wall.

425
Q

What is the name of the segmented pouches of the large intestine?

A

Haustra - formed by the tonic contraction of the teniae coli

426
Q

What is the most common location of the appendix?

A

Retrocaecal

427
Q

Why is the sigmoid colon very mobile?

A

It has its own mesentery.

428
Q

Where is the connection between the small and large intestine?

A

Ileocaecal valve

429
Q

What does the abdominal aorta bifurcate to?

A

Common Iliacs

430
Q

What do the lateral branches of the abdominal aorta supply?

A

Kidneys
Adrenal Glands
Gonads
Body wall

431
Q

What are the branches of the superior mesenteric artery?

A
Inferior Pancreaticoduodenal
Middle Colic
Right Colic
Ileocolic
Jejunal and Ileal Branches
Appendicular
432
Q

What are the branches of the inferior mesenteric artery?

A

Left colic
Sigmoid colic
Superior rectal

433
Q

What is the marginal artery of drummond?

A

An anastomosis between the branches of the SMA and IMA around the large intestine

434
Q

Where dos the hindgut extend to?

A

Pectinate line

435
Q

What supplies the remainder of the GI tract beyond the pectinate line?

A

Internal Iliac Artery

436
Q

What drains the foregut organs?

A

Splenic Vein

437
Q

What are the locations of the three anastomoses of the two venous systems?

A

Distal end of the oesophagus
Skin around the umbilicus
Rectum and the anal canal

438
Q

What is diffuse type gastric cancer?

A

This is seen in younger patients and has worse prognosis. Can spread in all layers in the gastric wall

439
Q

What is intestinal type gastric adenocarcinoma?

A

H. PYLORI. This is more common in the elderly and in Eastern Asia. It is a progression from normal mucosa to chronic gastritis to atrophic gastritis and can lead to intestinal metaplasia and dysplasia that can lead to cancer.

440
Q

What are the three acinar zones of the liver?

A
  1. Periportal zone
  2. Mid acinar zone
  3. Pericentral zone
441
Q

What is the progression of liver disease?

A

Insult
Inglammation
Fibrosis
Cirrhosis

442
Q

What are the three types of jaundice?

A

Pre-Hepatic Jaundice
Hepatic Jaundice
Post-Hepatic Jaundice

443
Q

What is Pre-Hepatic Jaundice?

A

This is where there is too much haem to break down due to conditions that heighten the bloods rate of haemolysis

444
Q

What is hepatic jaundice?

A

Liver cells are injured of dead due to diseases of the liver

445
Q

What is post-hepatic jaundice?

A

Bile cannot escape into the bowel due to an obstructed biliary system

446
Q

What is cirrhosis?

A

This is when there are bands of fibrosis separating degenerative nodules of hepatocytes

447
Q

What is the viral pathogen of hepatitis A?

A

Ebstein-Barr Virus

448
Q

What is the viral pathogen of Hepatitis B?

A

Yellow fever virus

449
Q

What is the viral pathogen of Hepatitis C?

A

Herpes Simplex Virus

450
Q

What is the viral pathogen of Hepatitis E?

A

Cytomeglovirus

451
Q

What is the viral pathogen of Hepatitis D?

A

Delta Agent

452
Q

How is Hepatitis A spread?

A

Faecal oral route

453
Q

How is Hepatitis B and C spread?

A

Sexually . by blood products (Hep B also spread vertically)

454
Q

What is haemochromoatosis?

A

The presence of excess iron in the liver

455
Q

What is the cause of primary haemochromatosis?

A

Genetic condition causing excess iron absorption

456
Q

What is the cause of secondary haemochromatosis?

A

Ion overload from the diet, transfusions and iron therapy

457
Q

What is Wilson’s Disease?

A

An inherited autosomal recessive disorder of copper metabolism

458
Q

What are the effects of somatostatin?

A
DECREASE
Inhibits pancreatic enzyme secretion
Decreases gastric acid secretion
Decreases gastrin release
Decreases pepsin release
Decreases glucagon release
459
Q

During which digestion phase is the most gastric acid secreted?

A

Gastric Phase

460
Q

What is diverticulosis?

A

This is mucosal herniation through the mucus coat in the colon

461
Q

What is diverticulitis?

A

Inflammation due to known diverticulosis

462
Q

What is a true diverticula?

A

The diverticula includes all layers of the bowel wall

463
Q

What is a false diverticula?

A

The diverticula includes only the serosa and mucosal layer

464
Q

What is the most common complication of diverticular disease?

A

Pericolic Abscess

465
Q

What is a fistula?

A

A communication between two epithelialised organs

466
Q

What are the common types of colitis?

A
Infective
Ulcerative
Crohn's
Ischaemic
Radiation
467
Q

What is colonic angiodysplasia?

A

Submucosal lakes of blood, usually on the riht side of the colon

468
Q

What are the commonest causes of large bowel obstruction?

A

Colorectal cancer
Benign Stricture
Volvulus

469
Q

What is a volvulus?

A

Bowel twists on the mesentery. This may become gangrenous

470
Q

What is a pseudo-obstruction of the bowel?

A

This is where the patient acts as though they have an obstruction but have no real mechanical obstruction

471
Q

What is gastroenteritis?

A

Inflammation of the lining of the stomach, small intestine and large intestine

472
Q

What are the viral causes of gastroenteritis?

A

Rotovirus
Norovirus
Adenovirus

473
Q

What pathogen causes gastroenteritis after eating reheated rice?

A

Bacillus Cerus

474
Q

What are the main causes of bowel obstuction?

A

Adhesions
Hernias
Malignancy

475
Q

What is ‘third-spacing’?

A

Fluid loss into an area where fluid is not normally lost

476
Q

What are adhesions?

A

Scar tissue that binds the abdominal contents together causing a kinking or squeezing of the bowel.

477
Q

What is coeliac disease?

A

A systemic autoimmune condition triggered by dietary gluten peptides.

478
Q

What causes coeliac diseae?

A

Intolerance to protein called prolamins

479
Q

What antibodies are involved in coeliac disease?

A

Anti-TTG antibodies

Anti-endomysical antibodies

480
Q

What is faecal calprotein?

A

A sensitive marker for intestinal inflammation. This is released following the degranulation of neutrophils

481
Q

What is the most common family of pathogens in the GI tract?

A

Enterobacteriaceae

482
Q

What type of bacteria is the enterobacteriaceae?

A

Gram negative rods

483
Q

What is the normal bowel flora in the mouth?

A
Strep. Viridans
Neisseria sp.
Anaerobes
Candida sp.
Staphylococci
484
Q

What is normal bowel flora in the stomach and duodenum?

A

Usually sterile
Few candida sp.
Staphylococci

485
Q

What is the normal bowel flora of the jejunume?

A

Coliforms

Anaerobes

486
Q

What is the normal bowel flora of the colon?

A

Coliforms
Anaerobes
Enterococcus faecalis

487
Q

What is the normal bowel flora of the bile ducts?

A

Usually sterile

488
Q

What are the three levator ani muscles of the pelvic floor?

A

Iliococcygeus
Pubococcygeus
Puborectalis

489
Q

What are the dual nerve supply to the levator ani muscles?

A

‘Nerve to levator ani’
Pudendal Nerve
Both of the sacral plexus

490
Q

Whereabouts in the rectum are faecal masses held?

A

Rectal Ampulla

491
Q

Where is the pouch of douglas?

A

Rectouterine Pouch

492
Q

Where is the anorectal junction?

A

Tip of the coccyx

Anorectal angle

493
Q

Where do the visceral afferents to the rectum enter the spinal cord?

A

Run with parasympathetics to S2-4

494
Q

Where do the sympathetic fibres to the rectum originate?

A

T12-L2 - Then travel via periarterial plexuses around branches of IMA

495
Q

Where do the parasympathetic fibres to the rectum originate?

A

S2-4 - Then travel via pelvic splanchnic nerves and synapse in the walls of the rectum

496
Q

Where does the somatic motor innervation to the rectum originate?

A

S2-4 - Pudendal Nerves

S3-4 - Nerves to the levator ani

497
Q

What is the pectinate line?

A

This marks the junction between part of the embryo which forms the GI tracy and part of that formed by the skin

498
Q

What is the blood supply above the pectinate line?

A

Arterial - Inferior mesenteric artery

Venous - portal venous system - IMV

499
Q

What is the blood supply below the pectinate line?

A

Arterial - Internal Iliac Artery

Venous - Systemic venous system - Internal Iliac

500
Q

What are haemorrhoids?

A

Prolapses of the rectal venous plexuses

501
Q

What are rectal varices?

A

They form in relation to portal hypertension

502
Q

What are the four common areas of hernia in the GI tract?

A

Umbilical
Epigastric
Inguinal
Femoral

503
Q

What are the two factors required for a hernia?

A

Structural weakness

Increased pressure

504
Q

What is a direct inguinal hernia?

A

Caused by a weakness in the posterior wall of the inguinal canal

505
Q

What is an indirect inguinal hernia?

A

The abdominal contents pass through the deep inguinal ring to pass through the inguinal canal.

506
Q

How does bilirubin move to the liver?

A

It binds to albumin. This forms delta bilirubin.

507
Q

How is bilirubin secreted into the biliary system?

A

It is conjugated with glucouronic acid

508
Q

What is the difference between conjugated and unconjugated bilirubin?

A

Conjugated - bound with glucouronic acid

Unconjugate - not bound with glucouronic acid

509
Q

What is direct bilirubin?

A

Conjugated and delta bilirubin

510
Q

What is indirect bilirubin?

A

Unconjugated bilirubin

511
Q

What is urobilinogen?

A

In the colon, the glucouronic acid is removed by bacteria from the conjugated bilirubin. This forms urobilinogen

512
Q

What is stercobilin?

A

Metabolised urobilinogen. This gives faeces their brown colour

513
Q

What do beta islet cells produce?

A

Insulin

514
Q

What do alpha islet cells produce?

A

Glucagon

515
Q

What do delta islet cells secrete?

A

Somatostatin

516
Q

What do f islet cells secrete?

A

Pancreatic polypeptide

517
Q

What are secretions from pancreatic acinar cells?

A

Protease
Pancreatic lipase
Pancreatic amylase

518
Q

What do the epithelial cells lining the duct release?

A

Bicarbonate

Water

519
Q

What type of epithelium lines the gallbladder?

A

Simple columnar epithelium

520
Q

What are Brunner’s Glands?

A

They are glands in the duodenum that secrete mucus that is rich in bicarbonate ions

521
Q

What is the action of prostaglandins in the stomach and duodenum?

A

Stimulate mucus and bicarbonate secretion and vasodilation of nearby blood vessels.

522
Q

Which muscle makes up the pelvic floor?

A

Leviator Ani