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MEDSCI 142 > Section 8: Digestive System > Flashcards

Section 8: Digestive System Flashcards

1
Q

Gut - structure

A

A soft muscular tube

~5m long

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2
Q

Gut - function

A

Where food is stored, broken down and absorbed

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3
Q

Glands associated with gut tube

A

Pancreas

Liver

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4
Q

Tooth: Enamel

A

Crystalline rods/prisms of calcium phosphate and carbonate
No cells –> difficult to replace
No sensation

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5
Q

What is the hardest tissue of the body

A

Enamel of teeth

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6
Q

Tooth: Dentin

A

Similar to bone, but cells (odontoblasts) are localised at junction between dentin and pulp instead of scattered

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7
Q

Tooth: Pulp

A

Core of tooth
Soft tissue
BVs, nerves, lymphatics

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8
Q

Tooth: Cementum

A

Calcified CT surrounding dentin in root region

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9
Q

Tooth: Periodontal ligament

A

Collagen fibres linking alveolar bone to cementum

Rapid turnover

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10
Q

Tooth: Alveolar bone

A

Bone of the socket

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11
Q

Tooth: Enamel - what does it cover

A

Covers dentin in the crown region

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12
Q

Tooth: Periodontal ligament - size

A

Short in terms of distance, but has large X-sectional area

So distance between cementum and alveolar bone is v short

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13
Q

Tooth: Periodontal ligament - mechanoreceptors - functions

A

Protection, e.g. biting a fork

Force transducers, e.g. braces

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14
Q

Tooth: Periodontal ligament - rapid turnover

A

Lots of collagen synthesis

Vit C is crucial for this, so a poor vit C supply –> scurvy –> teeth can fall out

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15
Q

Tooth: Why is it important to remove infections in the pulp

A

Because there’s a blood supply there –> bacteria can travel into blood vessel

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16
Q

How many roots do most teeth have

A

3-4

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17
Q

Tongue has both _____ and ______ muscles

A

Intrinsic

Extrinsic

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18
Q

Tongue: Intrinsic muscles

A

Longitudinal - along length of tongue
Vertical
Horizontal/transverse

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19
Q

Tongue: Intrinsic muscles - contraction

A

Longitudinal - shortens tongue
Vertical - flattens tongue
Horizontal/transverse - narrows tongue

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20
Q

Tongue: Papillae

A

Projections towards surface of tongue

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21
Q

Tongue: Papillae - types

A

Filiform
Fungiform
Vallate

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22
Q

Tongue: Papillae - filiform

A

Sharp-like
No taste buds
Flexible

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23
Q

Tongue: What is the most common form of papillae

A

Filiform

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24
Q

Tongue: Papillae - fungiform

A

Mushroom-like projections

Some have taste buds but not many

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25
Q

Tongue: Papillae - vallate

A

Most important for taste buds

Surrounded by a groove like a moat - protection

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26
Q

Tongue: Papillae - different regions

A

Depending on the region of tongue, have diff frequencies of types of papillae

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27
Q

Salivary glands - major types

A

Parotid - serous only
Sublingual - mixed, mostly mucous
Submandibular - mixed

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28
Q

Salivary glands: Types of cells

A 
Serous cells (watery)
Mucous cells (viscous)
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29
Q

Salivary glands: Serous cells

A

Contribute a watery component towards saliva that is enzyme-rich

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30
Q

Salivary glands: Serous cells - enzymes

A

Amylase

Lysozyme

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31
Q

Salivary glands: Enzymes - amylase

A

Breaks down carbohydrate/starchy debris around teeth
Contained within zymogen granules and released in batches when you chew food to make sure there’s not abundant starch for bacterial growth

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32
Q

Salivary glands: Enzymes - lysozyme

A

Antibacterial properties

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33
Q

Salivary glands: Mucous cells

A

Viscous/sticky
Good for lubricating
Contain mucin granules

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34
Q

Salivary glands: Types of cells - staining

A

Serous cells = quite dark-staining

Mucous cells = quite light-staining

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35
Q

Salivary glands: Parotid glands - location

A

In front of ears

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36
Q

Digestive system - functions

A

Digestion
Absorption
Secretion
Transport

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37
Q

Digestive system: Functions - digestion

A

Chemical breakdown of ingested food into absorbable molecules
Requires secretion

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38
Q

Digestive system: Functions - absorption

A

Movement of nutrients, water and electrolytes through epithelial lining of gut into blood or lymph

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39
Q

Digestive system: Functions - secretion

A

Saliva - enzymes and mucous

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40
Q

Gaining surface area - methods

A

Gross convolutions
Luminal folds/wrinkles
Projections towards lumen = evagination
Projections away from lumen = glands

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41
Q

Gaining surface area: Luminal folds - examples

A

Circular in small intestine = plicae circulares

Longitudinal, e.g. stomach = rugae

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42
Q

Gaining surface area: Evagination - examples

A

Villus/villi, small intestine

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43
Q

Gaining surface area: Glands - examples

A

Stomach and small intestine

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44
Q

Gaining surface area - must take what into account?

A

Time

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45
Q

Tunics of gut tube - what are they

A

Mucosa (mucous membrane)
Submucosa
Muscularis externa (external smooth muscle)
Serosa

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46
Q

Tunics of gut tube: Mucosa - components

A

Epithelium
Lamina propria
Muscularis mucosae

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47
Q

Tunics of gut tube: Mucosa - epithelium

A

Specialised for protection, absorption, secretion, or combination of all 3
Physical barrier between outside world and internal systems

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48
Q

What happens if there’s a breach of the epithelium

A

Results in ulceration

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49
Q

Tunics of gut tube: Mucosa - lamina propria

A

Soft fibrous bed of loose CT where the epithelium rests
Carries nerves and blood capillaries
Populated with defense cells and collagen
Support

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50
Q

Tunics of gut tube: Mucosa - lamina propria - lymphocytes

A

Scattered throughout gut to control pathogens / harmful agents coming through

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51
Q

Tunics of gut tube: Mucosa - muscularis mucosae

A

2 thin layers of smooth muscle; inner circular and outer longitudinal
Provides mucosa with some movement independent of external muscle coat

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52
Q

Tunics of gut tube: Submucosa

A

Thick bed of loose CT carrying larger BVs, lymphatic vessels and nerves (submucosal plexus)
Connects mucosa to external muscle coat, but allows some movement between them

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53
Q

Tunics of gut tube: Muscularis externa

A

2 layers to produce peristalsis (transport)

Inner circular layer and outer longitudinal layer

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54
Q

Tunics of gut tube: Muscularis externa - myenteric nerve plexus

A

Occurs between the two layers of the muscularis externa

Responsible for coordinating the 2 layers

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55
Q

Enteric nervous system is made up of…

A

Submucosal nerve plexus + myenteric nerve plexus

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56
Q

Enteric nervous system: SNS and PNS

A

PNS excites/stimulates enteric NS

SNS inhibits function of enteric NS

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57
Q

Enteric nervous system and ANS

A

Enteric NS is thought of as a separate entity, but has many interactions with ANS

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58
Q

Tunics of gut tube: Serosa

A

A slippery outer covering for gut tube (except oesophagus)

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59
Q

Tunics of gut tube: Serosa - layers

A

Two layered;
Outer mesothelial boundary
CT layer

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60
Q

Tunics of gut tube: Serosa - AKA…

A

Visceral peritoneum

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61
Q

Tunics of gut tube: Serosa - adventia

A

Where a structure is not in contact with the body cavity, the outermost CT layer is referred to as the adventitia

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62
Q

Mesothelial cells secrete…

A

Serous fluid

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63
Q

Oesophagus - structure

A

Muscular tube
Extends from pharynx to stomach
Normally empty with lumen collapsed, and expands to accommodate food/water

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64
Q

Oesophagus - functions

A

Transport (fast travel time, due to peristalsis)
Protection
No absorption or digestion, little secretion

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65
Q

Oesophagus: Epithelium

A

Thick, stratified squamous, with sacrificial outer layers for protection against abrasive fragments of food
Protects against friction and abrasion

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66
Q

Oesophagus: Epithelium - how are cells replaced

A

By division in basal layers at BM, then slow migration outwards

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67
Q

Oesophagus: The entire epithelium is renewed every ______

A

7 days

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68
Q

What is the most variable throughout the gut tube

A

Epithelium

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69
Q

Serosa vs adventitia

A

Serosa: when an organ is not in contact with a neighbouring organ, and instead is in contact with a body cavity
Adventitia: glues one organ to its adjacent organs

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70
Q

Omentum

A

A fatty apron-like structure that hangs off the transverse colon
Must cut this away to expose underlying organs

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71
Q

Fatty tissue - function

A

Protection

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72
Q

Omentum - lymphatic tissue

A

Helps control localised infection by migrating to quarantine the infection

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73
Q

Swallowing food - pathway

A

Food is pushed backwards by tongue –> oropharynx –> laryngopharynx –> oesophagus

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74
Q

Swallowing food - epiglottis

A

Bolus comes in contact with epiglottis, pushing it backward to seal off the glottis (opening to trachea)

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75
Q

Adventitia between trachea and cartilage

A

Loose because it needs to move/expand

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76
Q

Oesophagus - luminal surface

A

Many layers of stratified squamous epithelium

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77
Q

Tunics of gut tube: Mucosa - lamina propria - blood vessels

A

Supply epithelium with nutrients and O2, and take waste away from epithelium

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78
Q

Oesophagus: External muscle (Muscularis externa)

A

Contains additional skeletal muscle in upper third of oesophagus to allow rapid contraction and voluntary control of swallowing

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79
Q

Oesophagus: Serosa

A

Majority of oesophagus doesn’t lie in a body cavity so lacks a serosa
Instead is mostly covered with a fibrous adventitia

Only when it passes the diaphragm into abdominal cavity where it starts to have serosa

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80
Q

Bolus of food travels down the oesophagus by _____

A

Peristalsis

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81
Q

Oesophagus: Peristalsis

A

Involves coordinated contraction of inner circular and outer longitudinal muscle layers (muscularis externa)
Inner = narrows tube
Outer = shortens tube –> squeezing motion

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82
Q

Stomach - structure

A

J-shaped bag on left side

Enlargement of gut tube

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83
Q

Stomach - capacity

A

~1.5L

84
Q

Stomach - primary function

A

Storage, since food is eaten quicker than its digested and absorbed

85
Q

Stomach - regions

A

Cardia
Fundus
Body
Pylorus

86
Q

Stomach - rugae

A

Transient structures - only when empty, it’s lined with longitudinal folds called rugae
When stomach is full, wrinkles flatten
Increases SA

87
Q

Stomach: Pyloric sphincter

A

Well-developed muscular sphincter at outlet

Controls rate of chyme flow into duodenum

88
Q

Stomach: Pyloric sphincter is a thickening of…

A

Inner circular layer of muscles

89
Q

Stomach: Sphincter at inlet

A

Less developed

If not well-developed enough, can result in gastric reflux

90
Q

Stomach: Epithelium

A

Forms many pits lined with mucus-secreting cells

Gastric glands open into pits

91
Q

Stomach: External muscle / Muscularis externa

A

Additional layer (3 in total) with addition of innermost oblique layer - gives churning motion –> mixing waves

92
Q

Stomach: Functions

A 
Storage
Secretion of acids, enzymes, mucous
Digestion of proteins by pepsin
Absorption of water, ions, some drugs
Protection
Transport (mixing waves)
93
Q

Chyme = ?

A

Food + gastric juice

94
Q

Mucosa of stomach: Gastric pits

A

Pores

95
Q

Mucosa of stomach: Gastric glands

A

Increase SA

96
Q

Mucosa of stomach: Parietal cells

A

Pumps out H+ and Cl- separately, which recombine in lumen instead of killing the cell - kills microbes and living cells
Secretes intrinsic factor

97
Q

Autodigestion

A

When a cell makes pure HCl - we don’t want this!

98
Q

Mucosa of stomach: Parietal cells - what is HCl important for

A

Sterilisation of food

Acidifying environment –> indirectly helps with digestion

99
Q

Mucosa of stomach: Parietal cells - intrinsic factor

A

Important for B12 absorption, which is critical for haematopoiesis / RBC formation

100
Q

Lack of RBCs leads to…

A

Anaemia

101
Q

Mucosa of stomach: Chief cells

A

Secrete pepsinogen into lumen –> travels up past the acidic environment by parietal cells and become activated into pepsin –> digests luminal contents

102
Q

Mucosa of stomach: Chief cells - structure

A

Have apical granules in their cytoplasm which contain pepsinogen

103
Q

Mucosa of stomach: Chief cells - what is pepsin

A

A protein-splitting enzyme

104
Q

Mucosa of stomach: Surface mucous cells

A

Secrete insoluble alkaline mucus which protects the mucosa from acid and pepsin, i.e. protects stomach from digesting itself
But some cells will still die

105
Q

Mucosa of stomach: Undifferentiated cells

A

Stem cells dividing to generate new epithelium

Migrate upwards to replace superficial cells which died

106
Q

Mucosa of stomach: Mucous neck cells

A

Secrete soluble acid mucus at mealtimes

107
Q

Mucosa of stomach: Enteroendocrine cells

A

Secretes gastrin (hormone) into bloodstream

108
Q

Mucosa of stomach: Enteroendocrine cells - stimuli

A

When you eat food:

  • stomach becomes distended/stretched
  • pH of stomach changes
109
Q

Mucosa of stomach: Enteroendocrine cells - what does gastrin stimulate

A

Secretion of acid and pepsinogen
Muscular contractions of stomach
Relaxes pyloric sphincter

110
Q

Mucosa of stomach: Enteroendocrine cells - structure

A

Granules are basolaterally located

111
Q

Liver is made of…

A

Epithelial cells called hepatocytes

112
Q

Liver - hepatocytes

A

Multi-talented cells, performing many metabolic functions

113
Q

Liver: Every hepatocyte requires…

A

Access to:

  • nutrient-laden blood drained from intestinal wall
  • oxygenated blood from systemic circuit
  • ducts which drain bile to gall bladder
114
Q

Liver: Hepatocytes - structure

A

Stacked up like a wall with canals passing through them

115
Q

Liver: Hepatocytes - Bile canaliculus

A

Little canals that carry bile

116
Q

Liver: Hepatocytes - capillaries

A

Hepatocytes are flat either side by capillaries, which are v leaky
Thick enough to let through lymph, but exclude RBCs

117
Q

Liver: Hepatocytes - microvilli

A

Increases SA available for transport proteins to be embedded in membrane to allow substrate to be absorbed into mepatocyte

118
Q

Liver: Hepatocytes - sinusoid

A

Can accommodate more than 1 RBC

Wide and leaky (fenestrated)

119
Q

Liver: Hepatocytes - sinusoid fenestration

A

Allow passage of lymph but exclude RBCs

120
Q

Lymph

A

Watery part of blood

121
Q

Liver lobules

A

Formed by plates of hepatocytes stacked tgt

Hexagonal in X-section

122
Q

Liver lobules: Portal triads

A

Found at the edges of each lobule

123
Q

Liver lobules: Hepatic portal vein

A

Carries nutrient-rich but oxygen-poor blood to feed into lobule

124
Q

Liver lobules: Hepatic artery

A

Carries systemic oxygen-rich blood to supply hepatocytes

125
Q

Liver lobules: Blood in sinusoids

A

Mixed; both nutrient and O2 rich, which is consumed by hepatocytes until eventually drained by central vein away from liver –> IVC –> heart

126
Q

Liver lobules: Where is bile carried

A

In canaliculi between adjacent hepatocytes

Transported through ductules that connect canaliculi and feed into bile duct

127
Q

Liver lobules: Triad - components

A

Hepatic portal vein
Hepatic artery
A branch of the bile duct

128
Q

Liver lobules: Bile - direction

A

Opposite direction to blood

129
Q

Sinusoids - leakiness

A

More leaky than typical capillary because have fenestrations - allows more watery components of blood to pass through to hepatocytes

130
Q

Bile ductules

A

Combine into a bile duct which converge and feed into gallbladder

131
Q

Bile - functions

A

Helps emulsify fats –> increases SA for things to act on them, e.g. pancreatic enzymes
Once pancreatic enzymes have digested smaller fat globules, bile helps absorb the fats

132
Q

Emulsification

A

Breaking down large fat globules into smaller ones

133
Q

Where is bile released and stored

A

Released from liver and transported and stored in gallbladder

134
Q

When/where is bile released during a meal

A

Into duodenum (small intestine)

135
Q

Pancreas

A

Dual-function organ

Both endocrine and exocrine

136
Q

Pancreas: Exocrine gland

A

Manufactures precursors of digestive enzymes and secrete them as alkaline ‘pancreatic juice’ via duct system leading to duodenum

137
Q

Pancreas: Exocrine - why are enzymes released as precursors

A

To prevent autodigestion

138
Q

Pancreas: Exocrine gland - when are precursors converted to their active form

A

Once they arrive in duodenum

139
Q

Most food substances are digested by…

A

Pancreatic enzymes

140
Q

Pancreas - tree

A

Leaf = acinus
Twigs and branches = duct system
Trunk = main pancreatic duct

141
Q

What organ makes bile and what happens to the bile

A

Liver makes bile, can either be stored in gallbladder or ejected directly through common bile duct into duodenum

142
Q

Stomach: Chyme - where does it go

A

Travels through lumen of duodenum

143
Q

Pancreas - inputs

A

3 inputs;
Liver - bile
Stomach - chyme
Pancreas - pancreatic juice / enzyme precursors

144
Q

Pancreas - secretory unit

A

Acinus

145
Q

Pancreas: What does the secretory cell contain

A

Lots of mitochondria and organelles - helps with production

146
Q

Pancreas: What type of cell is the secretory cell

A

Serous type

147
Q

Pancreas: Secretory cell - cytoplasm

A

Has secretory granules / acinar cells containing enzyme precursors, which travel through out of acinus –> ducts –> converge and feed into bigger ducts

148
Q

Small intestine - parts

A

Duodenum (shortest)
Jejunum
Ileum

149
Q

Small intestine - size

A

3cm diameter

3m long

150
Q

Where does most digestion and absorption occur

A

Small intestine

151
Q

What does the small intestine receive exocrine secretions from

A

Liver (bile) and pancreas (pancreatic juice)

152
Q

Small intestine: Duodenum

A 
Shortest part of SI
C-shaped
Not suspended by mesentery
Receives biliary and pancreatic ducts
Close to gallbladder, stomach, pancreas
153
Q

Small intestine: Jejunum

A

Longer ~1m long

Coiled

154
Q

Small intestine: Ileum

A

Longer ~2m long

Coiled

155
Q

Small intestine: Mucosa

A

Specialised to increase SA available for secretion and absorption

156
Q

Small intestine: Submucosa

A

Just downstream of pyloric sphincter contains mucous glands / Brunner glands

157
Q

Small intestine: Submucosa - Brunner/mucous glands

A

Acidic chyme from stomach (mixed with HCl, so pH 1-2)
Secretes HCO3- rich mucous that helps buffer against acidic content coming in
Simultaneously changes pH to optimise environment in duodenum for pancreatic enzymes

158
Q

Small intestine: Increasing SA - methods

A

Gross convolutions (coiled)
Plicae circularis
Villi
Microvilli

159
Q

Small intestine: Increasing SA - Plicae circularis

A

Circular folds
Each is covered with mucosa and has a core of submucosa
Permanent structures

160
Q

Small intestine: Increasing SA - villi

A

Mini finger-like projections / evaginations

Covering is epithelium, core is lamina propria

161
Q

Small intestine: Increasing SA - microvilli

A

Microscopic projections
Form a brush border on surface of individual absorptive cells
Each is covered with cell membrane and filled with cytoplasm

162
Q

Small intestine: Increasing SA - size

A

Gross convolutions = largest, visible with naked eye
Plicae = visible for naked eye
Villi = much smaller, visible with naked eye
Microvilli = microscopic, can’t see with naked eye

163
Q

Small intestine: Nutrient-laden blood in veins goes back to…

A

The liver

164
Q

Small intestine: Lacteals

A

Lymph vessel within each villus

165
Q

Small intestine: Lacteals - function

A

Absorb broken-down products from lumen of SI
Lymph is ‘milked’ along lacteal by contraction of smooth muscle fibres in lamina propria which shorten the villus
Products transported in blood system back to CVS
Fibres arise from muscularis mucosae

166
Q

Small intestine: Lacteals - passive

A

No smooth muscles, so depend on external source of squeezing - muscularis mucosae

167
Q

Small intestine: Muscularis mucosae - smooth muscle fibres

A

Some extend into lamina propria core of villus

When contract –> squeezing motion –> milk lacteals

168
Q

Small intestine: Mucosa - columnar absorptive cells (enterocytes)

A

Absorb small molecules resulting from digestion

169
Q

Small intestine: Mucosa - Where are the microvillus projections located

A

Columnar absorptive cells (enterocytes)

170
Q

Small intestine: Mucosa - goblet cells

A

Embedded among enterocytes
Secrete mucus - provides lubrication to help with movement of substances, absorption and to mix things
Eventually die so need to be replaced

171
Q

Small intestine: Mucosa - undifferentiated cells

A

Stem cells dividing to generate new epithelium / diff cells to replace dying cells

172
Q

Small intestine: Mucosa - paneth cells

A

Secrete bactericidal enzyme lysozyme - localised immune control
Phagocytic
Apical zymogen granules

173
Q

Small intestine: Mucosa - Enteroendocrine cells - stimuli

A

Stimulated by acid from chyme and amino acid fragments (since pepsin has initiated breakdown of proteins)

174
Q

Small intestine: Mucosa - Enteroendocrine cells - where is secretin secreted

A

Secreted into capillaries of lamina propria

175
Q

Small intestine: Mucosa - Enteroendocrine cells - what does secretin stimulate

A

Release of pancreatic juice and bile

176
Q

Small intestine: Mucosa - epithelium

A

Short-lived
Cell division occurs deep in glands and migrates
Entire journey lasts ~5 days

177
Q

Large intestine - functions

A

Absorption of salts and water
Conversion of chyme into feces; bacteria ferment remaining carbohydrates
Bacteria produce vitamins (B and K) which are absorbed
Secretion of mucus to lubricate feces
Defecation

178
Q

Large intestine - main function

A

Absorption of water

179
Q

Large intestine: Parts

A

Caecum –> asc colon –> transverse colon –> desc colon –> sigmoidal colon –> rectum –> anus

180
Q

Large intestine: Mucous secretion

A

As colon is reabsorbing water, contents of lumen become more compact/dehydrated
Mucous is secreted to provide lubrication to make sure there’s enough flow

181
Q

Large intestine: Appendix

A

Not a vital organ
Enriched with lymphatic tissue - monitors activity in LI
Vermiform - worm-shaped

182
Q

Large intestine: Appendix - inflammation

A

Appendicitis - acute condition

Could eventually burst –> content would go into peritoneum and infect surrounding organs in abdominal cavity

183
Q

Large intestine: Ileocecal valve

A

Controls intermittent flow of chyme from ileum into caecum

184
Q

Large intestine: Caecum

A

A dilated pouch

Bacteria (not enzymes) are responsible for digestion

185
Q

Large intestine: What do faeces contain

A

Bacteria 30%
Undigested dietary fibre 30%
Cells shed from intestinal lining
Mucous

186
Q

Large intestine: External muscle

A

Outer longitudinal muscle is thickened in three strips = teniae coli, which contract to pull intestinal tube into sac-like pockets (haustra coli)

187
Q

Large intestine: External muscle - Haustra coli

A

Changes shape and position

Allows diff segments of colon to process things at diff rates

188
Q

Large intestine: Mucosa - villi

A

No villi, but many intestinal glands

189
Q

Large intestine: Mucosa - no of goblet cells

A

From asc –> transverse –> desc colon, have an increasing no of goblet cells because content becomes more dehydrated so need more lubrication

190
Q

Large intestine: Mucosa - goblet cells

A

Secrete mucus for lubrication

Die so need to be replaced by undifferentiated cells

191
Q

Large intestine: Mucosa - does it contain paneth cells

A

No, have WBCs instead

192
Q

Large intestine: Mucosa - WBCs

A

Help control environment since lots of bacteria in large intestine

193
Q

Large intestine: Mucosa - Entire epithelium is replaced every…

A

4-5 days

194
Q

Large intestine: Mucosa - lymphocytes (WBCs)

A

Mostly lymphocytes

Lots in lamina propria - large bacterial content of colon

195
Q

Large intestine: Mucosa - columnar absorptive cells (enterocytes)

A

Similar to those in small intestine

Absorb mostly water

196
Q

Rectum: Anal canal

A

Last 2cm of rectum = anal canal

197
Q

Rectum: Anal canal - sphincters

A

Closed by 2 sphincters;
Inner = involuntary smooth-muscle sphincter
Outer = partial-voluntary skeletal-muscle sphincter

198
Q

Rectum: Urge to defecate

A

Felt when rectum fills ~25% of capacity
Stretching of rectal wall initiates reflex contraction of teniae coli –> increases pressure in rectum –> internal anal sphincter relaxes/opens (reflex)

199
Q

Rectum: External sphincter

A

If time is convenient, it relaxes voluntarily

If not, it’s maintained in contracted state and defecation reflex subsides

200
Q

Rectum: Children

A

Takes some time to learn how to control external sphincter

201
Q

Rectum - epithelium

A

At anal region (rectum and anus), epithelium changes from glandular secretory epithelium to stratified squamous to protect from friction

202
Q

Small intestine: Venules in submucosa are tributaries of…

A

Hepatic portal vein

203
Q

Stomach - villi

A

No villi

204
Q

Stomach - goblet cells

A

No goblet cells

205
Q

Gastric juice - pH

A

Very low pH

206
Q

Simple columnar epithelium

A

Specialised for absorption

207
Q

Tooth is fixed in socket by the…

A

Periodontal membrane

MEDSCI 142 (9 decks)

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