3 Flashcards
1
Q
Which arteries innervate the foregut, midgut and hindgut?
A
Foregut – celiac artery
Midgut – superior mesenteric artery
Hindgut – inferior mesenteric artery
2
Q
Which direction does the line of attachment of the ventral and dorsal mesogastrium swing to as the foregut develops
A
The line of attached of the ventral mesogastrium swings the R and forms the lesser curve and top of proximal duodenum.
The line of attachment of the dorsal mesogastrium swings to the L and forms the greater curve of the stomach and underside of the proximal duodenum.
3
Q
Where does the ventral mesogastrium line of attachment run along?
A
Lesser curve of the stomach
4
Q
Where does the dorsal mesogastrium line of attachment run along?
A
Greater curve of the stomach
5
Q
Which section is the ascending and descending colon a part of?
A
Ascending colon – midgut
Descending colon – hindgut
2/3 of proximal transverse colon = midgut
1/3 of distal transverse colon = hindgut
6
Q
List the accessory digestive organs
A
Teeth, tongue, salivary glands, liver, gallbladder and pancreas
7
Q
What is the duodenum involved in breaking down mainly?
A
Proteins
8
Q
What are Brunner’s glands and where are they located?
A
Produce mucus-rich alkaline secretion containing bicarbonate to neutralise stomach acid.
Duodenum (above the hepatopancreatic sphincter)
9
Q
What are micelles?
A
Lipid molecules that arrange themselves in a spherical form in aqueous solutions.
10
Q
What does the submucosa consist of?
A
Areolar connective tissue; has many blood and lymph vessels, submucosa plexus, glands
11
Q
What are the 2 main types of nerves that are innervating the GIT?
A
Intrinsic (ENS) and extrinsic (ANS)
12
Q
What does stimulating the parasympathetic system do in the GIT?
A
Increases GI secretions and motility by increasing enteric nervous system activity.
13
Q
What kind of emotions may slow down digestion?
A
Anger, fear, anxiety
14
Q
What lies between the layers of muscularis?
A
Myenteric plexus
15
Q
What does the peritoneum consist of?
A
Simple squamous epithelium layer (mesothelium) with underlying supporting layer of areolar tissue.
16
Q
What makes peritoneum different to pericardium and pleura?
A
Peritoneum is the largest serous membrane of the body.
It has folds that binds organs to each other and to walls of abdominal cavity.
17
Q
What is the purpose of the folds of the peritoneum?
A
Mesentery and mesocolon – hold intestines loosely allowing muscular movements with contractions.
Protection from damage
Attaches organs to abdominal cavity.
18
Q
What is the largest peritoneal fold called?
A
Greater omentum
19
Q
What attaches the liver to the anterior abdominal wall and diaphragm?
A
Falciform ligament
20
Q
What does the mesentery fold do?
A
Binds jejunum and ileum to posterior abdominal wall
21
Q
List the 5 peritoneal folds.
A
Greater omentum, Falciform ligament, Lesser omentum, Mesentery, Mesocolon
22
Q
Which peritoneal fold binds the transverse colon and sigmoid colon to the posterior abdominal wall?
A
Mesocolon
23
Q
Which peritoneal fold attaches the stomach, duodenum and transverse colon?
A
Greater omentum
24
Q
How many layers does the greater omentum have?
A
4 layers because it doubles back onto itself
25
Where does the lesser omentum attach?
Stomach and duodenum to the liver.
26
What do the 4 muscles of the tongue with the prefix ‘–glossus’ do?
They are the extrinsic muscles that manoeuvre food for chewing, shaping into rounded mass and force food to back of mouth for swallowing.
Names:
- Genioglossus
- Hyoglossus
- Styloglossus
- Palatoglossus.
27
Which tongue muscles are used for speaking and swallowing?
Intrinsic
4 paired intrinsic muscles of the tongue originate and insert within the tongue, running along its length.
- Superior longitudinal muscle
- Inferior longitudinal muscle
- Vertical muscle
- Transverse muscle.
28
What type of epithelium does the oral mucosa have?
Thick stratified squamous
Needs to be thick because oral cavity lining is subjected to lots of wear and tear
29
What would happen if the salivary gland is occluded?
Painful enlargement of gland, infection can contract into the gland from oral cavity.
30
What are the vestibule and oral cavity?
Vestibule – space between lips and teeth
Oral cavity proper – behind teeth and gums to fauces (opening between oral cavity and throat)
31
Name the 3 types of salivary glands and say where they are found
Parotid– inferior and anterior to ears.
Submandibular – medial and inferior to body of mandible
Sublingual – under tongue and mylohyoid muscle
32
Which salivary gland consists of only serous acini?
Parotid
33
Which of the salivary glands are the largest? Where does its duct open into the mouth?
Parotid, parotid duct pierces buccinator muscle to open into vestibule (opposite upper 2nd maxillary molar)
34
Which salivary glands lie between (under) the tongue and mylohyoid muscle?
Sublingual
35
Are the submandibular or sublingual glands most superior and lateral?
Sublingual glands are superior and lateral to submandibular glands
36
What are the boundaries of the mouth? – roof, floor, lateral walls, anterior, posterior
```
Roof – hard and soft palate
Floor – mylohyoid muscle
Lateral walls – cheeks (buccinator muscles, connective tissue, mucous membrane, skin)
Anterior – labia
Posterior – palatoglossal folds
```
37
List the 4 muscles of mastication and their functions.
Temporalis – elevation and retraction of mandible
Masseter – elevation of mandible
Lateral pterygoid – protrusion and side-to-side movements of mandible
Medial pterygoid – elevation and side-to-side movements of mandible
38
What is the 5th muscle that is an accessory muscle of mastication?
Buccinator – accessory mastication muscle
39
What is the function of the motor neurons of the myenteric plexus?
Control gut motility
40
What is the function of the motor neurons of the submucosal plexus?
Control secretion
41
What are the 2 types of sensory neurons of the ENS of the GIT?
Chemoreceptors – responds to chemical changes in food within the lumen
Mechanoreceptors – activated when food distends the walls of GI organs
42
What is the function of the sensory neurons in the GIT?
Detect stimuli in the lumen
43
Where is the submucosal plexus found?
Within the submucosa
44
Where is the myenteric plexus found?
Between the longitudinal and circular smooth muscles of the muscularis layers.
45
What does parietal peritoneum line?
Walls of abdominal cavity
46
What does visceral peritoneum line?
Some of the organs in the cavity
47
Where does the peritoneal cavity lie relative to the parietal and visceral peritoneum?
Between them.
Contains lubricating serous fluid.
48
What are the 2 types of muscles of the tongue?
What is their function?
Extrinsic – move tongue side-to-side, in and out (manoeuvre food)
Intrinsic – alter shape and size (for speaking and swallowing)
49
Which nerve innervates the teeth and gums?
Maxillary nerve
50
Where does the oropharynx lie relative to the oral cavity?
Posterior to the oral cavity
51
What are the folds running off from either side of the uvula?
Anterior fold – palatoglossal fold
Posterior fold – palatopharyngeal fold
52
What is located between anterior (palatoglossal) and posterior (palatopharyngeal) folds?
Tonsillar fossa
53
What is the function of the uvula?
Prevents swallowed food from entering nasal cavity
54
What are the functions of the incisors, canines, premolars and molars?
Incisors – cut food
Canines – tear food
Premolars – crush and grind food
Molars – grind food
55
At which vertebral level does the pharynx end?
C6
56
Where does the oesophagus start and end relative to the vertebral levels?
C6 – start
| T10 – end
57
Where does the oesophagus pierce the diaphragm?
T10
58
What is the narrowing where the pharynx and oesophagus meet called?
Pharyngo-oesophageal narrowing
59
What type of muscle is the upper and lower oesophageal sphincters made from?
Upper – skeletal
| Lower – smooth
60
Which sphincter prevents gastro-oesophageal reflux?
Lower oesophageal sphincter
61
List the 3 anatomic constrictions of the oesophagus.
Pharyngo-oesophageal narrowing
Upper oesophageal sphincter
Lower oesophageal sphincter
62
What is the histological colour change at the gastro-oesophageal junction. And what causes it?
Pink to red
The blood vessels are closer to surface with a simple columnar layer and more further away with the pink stratified squamous epithelium.
63
Name the vertical lines that make up the 9 divisions of the abdominal regions
L and R midclavicular lines
64
Name the horizontal lines that make up the 9 divisions of the abdominal regions
Transpyloric plane
Transtubercular plane
65
The stomach is fixed proximally at the what?
Diaphragm
66
What is the distance from incisors to gastro-oesophagus junction?
40cm
67
What nerve supplies the stomach?
1. Sympathetic fibres via splanchnic nerves and celiac ganglion supply blood vessels and musculature
2. Parasympathetic fibres from the medulla travel in the gastric branches of the vagi
3. Sensory vagal fibres – gastric secretion.
68
What nerve supplies the jejunum and ileum?
Lesser splanchnic nerves
69
What nerve supplies the gallbladder?
Celiac plexus supplies sympathetic innervation, the vagus nerve supplies parasympathetic innervation, and the right phrenic nerve conveys sensory information.
70
List the 4 functions of the stomach
Mixes saliva, food, gastric juice to form chyme
Secretes gastrin into blood
Secretes gastric juice which contains HCl, pepsin, intrinsic factor
71
List 3 functions of the stomach
Mixes saliva, food, gastric juice to form chyme
Secretes gastrin into blood
Secretes gastric juice which contains HCl, pepsin, intrinsic factor
72
What is the function of the ligament of Treitz?
Attaches the duodenojejunal flexure to the anterior wall
73
What is gastrin secreted by?
What is gastrin?
What function does it have?
Secreted by: G cells in the pyloric antrum (stomach), duodenum, pancreas
A peptide hormone that stimulates secretion of gastric acid (HCl) by the parietal cells of the stomach and aids in gastric motility.
74
Where does the pancreatic duct and common bile duct meet?
Hepatopancreatic ampulla
75
What does secretions from the pancreas and bile duct enter through into the duodenum?
Major duodenal papilla
76
What does secretions from the pancreas and bile duct enter through into the duodenum?
Major duodenal papilla
77
What is the uncinated process?
Hook-shaped projection/protuberance from a bone/organ.
78
What chemical gives pancreatic juice a slightly alkaline pH?
Sodium bicarbonate
79
How is white adipose tissue used for energy?
It’s moved to the liver, muscle and kidney.
The fat is turned into a ketone body which can be used by body cells and brain (only in starvation state).
80
Name the enzymes in pancreatic juice.
Pancreatic amylase, trypsin, chymotrypsin, caryboxypeptidase, andelastase, pancreatic lipase, ribonuclease, deoxyribonuclease
81
What does the Ventral Mesogastrium run along?
The lesser curve of the stomach
82
What is neovascularisation?
Formation of new blood vessels between adjacent blood vessels
83
What type of an ulcer causes pain to start about 2-3 hours after eating?
Duodenal ulcer
84
List the 4 muscles making up the abdominal wall.
Rectus abdominus, transverse abdominus, internal oblique, external oblique
85
What is the aponeurosis?
Layers of flat broad tendons with wide attachment area
86
What forms the inguinal ligament?
A band running from the pubic tubercle to the anterior superior iliac spine.
Inferior border by the external abdominal oblique aponeurosis and is continuous with the fascia lata of the thigh.
87
Which 2 muscles that make up the abdominal wall are at right angles to one another?
Internal and external oblique.
External (hands in pocket direction).
Internal (hips to medial linea alba)
88
Which 2 abdominal muscles are at right angles to one another?
Internal and external oblique.
External (hands in pocket direction).
Internal (hips to medial linea alba)
89
Which 4 abdominal muscles form the anterolateral abdominal wall?
External oblique, internal oblique, transverse abdominus, rectus abdominis, pyramidalis
90
Which abdominal muscle originates from the crest of pubis and pubic symphysis?
Transverse abdominus
91
Which abdominal muscle inserts are the costal cartilages 5-9 and xiphisternum?
Rectus abdominus
92
Is the rectus abdominus or the transverse abdominus most deep?
Transverse abdominus
93
Which abdominal muscle originates from the lumbar fascia, iliac crest, costal cartilages 7-12?
Transverse abdominus
94
What is the linea alba?
A fibrous structure that runs down the midline of the abdomen
95
At the level of the umbilicus how does the aponeurosis cover the rectus abdominus?
External oblique and ½ internal oblique pass anteriorly to the rectus abdominus and the other ½ f internal oblique and transverse abdominus passes posteriorly.
96
At the level of the umbilicus how does the aponeurosis cover the rectus abdominus?
External oblique and ½ internal oblique pass anteriorly to the rectus abdominus and the other ½ of internal oblique and transverse abdominus passes posteriorly.
97
Which arteries supply the rectus abdominus and what is their function?
Inferior and superior epigastric arteries; to increase the intra-abdominal pressure --> .allows defecation, depress ribs, supports intestines.
98
What double fold of the peritoneum attaches transverse and sigmoid colon to the posterior abdominal wall?
Mesocolon
99
What is the purpose of the hole in the anterolateral abdominal wall?
Allows the spermatic cords in men and round ligament in women to reach the testes/uterus by passing through the inguinal canal.
100
What passes through the deep inguinal ring, through the canal, out the superficial inguinal ring?
Spermatic cords – men
Round ligament of uterus- women
101
Why is the inguinal canal a point of weakness?
Pressure on this area of weakness can lead to a direct or indirect hernia. Indirect more common
102
What is fascia?
A band or sheet of connective tissue, beneath the skin that attaches, stabilises, encloses, and separates muscles and other internal organs.
103
What forms the deep inguinal ring?
Transverse abdominal muscle and fascia
104
What forms the superficial inguinal ring?
External oblique muscle
105
What forms the spermatic cord?
Ductus deferens, nerves, lymph and blood vessels
106
What double fold of the peritoneum attaches jejunum and ileum to the posterior abdominal wall?
Mesentery
107
Through which inguinal ring does the ductus deferens enter the inguinal canal?
Deep inguinal ring
108
What does the duodenum receive and where from?
Gastric chyme (stomach), pancreatic juice (pancreas), bile (liver)
109
Where does bile emulsify fats into micelles?
Duodenum
110
Where is iron absorbed?
Duodenum
111
Where are most nutrient absorbed?
Jejunum
112
How long is the large intestine?
5ft
113
How long is the large intestine?
5ft
152.4cm
114
Name the parts that makeup the LI in order.
Duodenum, jejunum, ileum
115
What is the ileocecal junction?
Where the ileum (SI) meets the caecum (LI).
116
What causes ulcer formation? – tongue, peptic, duodenal
Tongue – biting the tongue disrupts the lining which allows bacteria to get in and cause disruption of the underlying tissue.
Peptic – disruption of stomach lining allows bacteria to enter and disrupt underlying tissues
Duodenal – digestive tract
117
List the main regions of the stomach.
Cardia, fundus, body, antrum, pylorus
118
Which type of cells can be found in the cardia, pylorus and fundus?
Neck cells – mucus secretion
119
Which type of cells can be found in the fundus?
Parietal/oxyntic – produces HCL (activating pepsinogen) and IF
Chief cells – secretes proteolytic enzymes e.g. pepsinogen (precursor of pepsin)
Neck cells – mucus
120
Chief cells of the stomach produce pepsinogen and chymosin. What is chymosin also known as?
What is its role?
Chymosin, known also as rennin, is a proteolytic (protease) enzyme related to pepsin.
Its role in digestion is to curdle or coagulate milk in the stomach, a process of considerable importance in the very young animal.
121
Which type of cells in the stomach produces HCl?
Parietal cells
122
What do chief cells secrete?
Proteolytic enzymes
Pepsinogen + Chymosin
Pepsinogen is activated into pepsin when it comes in contact with HCl produced by gastric parietal cells.
123
What activates pepsinogen in the stomach?
HCl
124
What causes bleeding around a stomach ulcer?
Blood vessels around the ulcer base if degraded
125
What is immediately inferior to the fundus?
Body of the stomach
Makes up the bulk of stomach
126
What is the pyloric part of the stomach made up of?
Pyloric atrium – wider, more lateral part
Pyloric canal – narrow part
Pylorus and sphincter – distal sphincteric region, has thicker circular layer of smooth muscle that controls the discharge of contents through the pyloric orifice.
127
Which type of histamine receptors increases acid secretion and cardiac stimulation?
H2
128
Where can H3 receptors be found?
Myenteric plexus, presynaptic sites in the brain
129
What do H2 receptor antagonists do?
Block histamine receptors in the gastric mucosa, cardiac muscle, brain and mast cells.
130
What class are the following drugs: cimetidine, ranitidine, famotidine?
H2 receptor antagonist
131
Which type of histamine receptors are found in gastric mucosa, cardiac muscle, brain, smooth muscle, immune cells, myenteric plexus, endothelium of brain, and mast cells?
```
Gastric mucosa – H2
Cardiac muscle – H2
Brain – H2
Smooth muscle – H1, H2
Immune cells – H4
Myenteric plexus in GIT– H3
Endothelium brain – H1
Mast cells – H2
```
132
Which anti-nausea medication has no effect on motion sickness?
5HT3 receptor antagonist
133
What is the action of PPIs?
Reduce H+ secretion from the parietal cells.
134
Which class of drug acts on parietal cells to reduce acid secretion?
PPIs
E.g. omeprazole, esomeprazole, pantoprazole
Indication: Acid reflux, stomach and duodenal ulcers
135
Is omeprazole reversible or irreversible?
Irreversible
136
What are canaliculi?
Microscopic canals
137
How can NSAIDs cause ulcer formation?
They inhibit prostaglandins which maintains the stomach lining by reducing gastric acid secretion and increasing mucus and HCO3- secretion
138
What is given with NSAIDs to prevent ulcer formation?
Misoprostol
139
What is misoprostol?
Synthetic analog of natural prostaglandin E1
140
What is the function of thromboxanes?
A vasoconstrictor and potent hypertensive agent, and it facilitates platelet aggregation
141
What is arachidonic acid?
Eicosanoic acid – saturated fatty acid with a 20-carbon chain
142
What happens in the body when the vomiting reflex is activated?
Contraction of diaphragm and abdominal muscles, lower oesophageal sphincter relaxation, stomach squeezed, antiperistalsis, closure of glottis, respiration stop
143
What do muscarinic receptor antagonists do?
Block ACh receptors
144
What is 5HT3 (hydroxytryptamine) used for?
Prevent chemotherapy and radiotherapy induced NandV by reducing activity of the vagus nerve
145
On inhalation and exhalation where does the liver move?
Inhalation – down below rib cage
| Exhalation – as high as the 4th IC space
146
List the 6 main functions of the liver.
Nutrient metabolism, protein synthesis, storage, excretion, filters blood and phagocytosis
147
What are transaminase enzymes?
Enzymes that amino groups are transferred to. They transfer the amino group to a different keto-acid forming the amino acid corresponding to that keto-acid
148
What are the following: ALT, AST and glutamate aminotransferase?
Transaminases (enzymes)
149
What is carried from the liver and gallbladder to the duodenum?
Liver – bile salts and bilirubin
| Gallbladder – bile (concentrated)
150
What are the 3 types of amino acids?
Essential – cannot be synthesised by the body
Semi-essential – can be synthesised in body, demand may exceed synthetic capacity under metabolic stress/trauma.
Nonessential – can be synthesised by transamination
151
What does the cystic duct from gallbladder join to form the common bile duct?
Common hepatic duct
152
Name some of the proteins synthesised by the liver.
Albumin, coagulation factors, complement factors, transferrin, protease inhibitors
153
Adipose issues take up glucose and turn it into what?
Glycerol which binds to fatty acids --> triglycerides
154
What 2 ducts anastomose to form the common hepatic duct from liver?
R and L hepatic ducts.
155
What does the liver store?
Iron (ferritin), copper, vitamins A, B12, D, E, K, glycogen.
156
What is the peritoneum divided into?
Greater and lesser peritoneal sacs.
The greater sac comprises most the peritoneal cavity. The lesser sac (also known as the omental bursa) is smaller and lies posterior to the stomach and lesser omentum.
157
What does the liver excrete?
Bile salts, bilirubin
158
What is the function of bile?
Helps SI digest fats and absorb fats, cholesterol, fat soluble vitamins.
159
What does the liver filter the blood for?
Oestrogen, aldosterone, vasopressin, alcohol, amphetamines barbiturates, steroids.
160
What does aldosterone do?
Hormone that acts mainly in the kidneys to aid in the conservation of sodium, secretion of potassium, water retention and to stabilize blood pressure.
161
What is copper needed for in the body?
Copper works with iron to help the body form RBCs.
162
What does vitamin K do in the body?
Important role in blood clotting
163
What does vitamin B12 (cobalamin) do in the body?
Production of RNA and DNA. Works with B9 to make RBCs.
B9 - folate
164
Which vessel(s) can be found in the perivenous end of a liver sinusoid?
Central vein
165
Where is pain from gallstones referred to?
Right hypochondriac region
166
What is hypercalcitoninemia associated with?
Low calcium levels
167
Name the 4 semi-essential amino acids
Glutamine, arginine, glycine, proline
168
Where does deamination take place?
Primarily in the liver, glutamate also deaminated in kidneys
169
When does deamination occur?
If there is an excess of protein intake.
Amino acid is converted to ammonia.
170
What’s the difference between deamination and transamination?
Deamination – removal of an amine group from molecule.
Transamination – release of amino group from amino acid
171
What is cholelithiasis?
Presence of gallstones (concentrations that form in the biliary tract, usually in gallbladder)
172
What is left when an amino group is removed from an aa?
Keto-acid
173
What does the transaminase enzyme accept?
Amino group
174
What does the transaminase enzyme transfer onto an acceptor?
Amino group
175
Is biotransformation phase 1 or 2 of drug metabolism?
Phase 1
176
Is synthesis phase 1 or 2 of drug metabolism?
Phase 2
177
In immune damage to gastric parietal cells which intestinal secretion is affected?
HCl and intrinsic factor
178
What is intrinsic factor?
A glycoprotein produced by the parietal cells of stomach. It’s necessary for absorption of vitamin B12 (cobalamin) later in the small intestine.
179
What is pepsinogen?
A substance secreted by stomach wall and converted into the enzyme pepsin by gastric acid.
180
What is secretin?
A hormone released into bloodstream by duodenum (especially in response to acidity) to stimulate secretion by the liver and pancreas. Inhibits gastric acid production.
181
Which muscles retract the mandible?
Temporalis
182
What is impedance?
Obstruction / opposition to passage or flow, as of an electric current or other form of energy.
The resistance in alternating current circuits.
183
Which structure is normally bimanually palpable?
Kidneys
184
Which structures does the transpyloric plane cut?
The pylorus of stomach, tips of 8th costal cartilages, lower border of 1st lumbar vertebra
185
What does the gallbladder store?
Bile from the liver
186
What is the function of bile?
Absorption of the fat-soluble substances (e.g. vitamins A, D, E, K).
Besides its digestive function, bile serves also as the route of excretion for bilirubin, a by-product of RBCs recycled by liver.
187
What do you ballot?
Kidneys
188
What happens in phase 1 of drug metabolism?
Biotransformation: oxidation, hydrolysis, hydroxylation, deamination. Involves cytochrome P350 enzymes.
189
What is hypercalcaemia?
High calcium (Ca2+) level in the blood serum.
Major cause = overactive parathyroid glands (hyperparathyroidism).
190
The parathyroid gland is the major control mechanism for what?
Parathyroid – calcium.
191
What does the thyroid control?
Thyroid – metabolic rate, heart and digestive functions.
192
Which muscles move the mandible side-to-side?
Lateral and medial pterygoid
193
What muscles are found in the lateral walls of the oral cavity?
Buccinator
194
Failure to re-absorb bile salts is caused by what?
Several gut-related problems, main 1 = chronic diarrhoea.
195
Which nerve(s) innervate the muscles of mastication?
Branches of the mandibular nerve which is a branch of the trigeminal nerve
196
What is the inside of the oral cavity lined by?
Mucous membrane, non-keratinised stratified squamous
197
What effect will obstruction of the common bile duct have?
Bile builds up in liver and jaundice develops due to the increasing levels of bilirubin in the blood.
198
What separated the oral cavity from the nasal cavity?
Front – hard palate and back – soft palate
199
What are D2 receptor antagonists?
Examples include: chlorpromazine, metoclopramide
They bind to D2 dopamine receptors in the chemoreceptor trigger zone and competitively inhibits dopamine. Controls NandV.
200
What is perphenazine?
D1 and D2 receptor antagonist.
Controls severe NandV in adults.
201
What is ondansetron?
5-HT3 receptor antagonist.
Prevents NandV associated with chemotherapy and radiation.
202
What do PPIs inhibit?
H+/K+-ATPase enzyme in gastric parietal cells and blocks final step in gastric acid secretion.
Treatment of peptic ulcers, benign gastric ulcers, heartburn, GERD.
203
What do histamine receptor antagonists treat?
H1 R An – competitively inhibits H1 receptors in vomiting centre in the CTZ. Treats NandV and dizziness.
H2 R An – competitive H2 inhibitor at parietal cells supresses normal secretion of gastric acid.
204
Promethazine, cinnarizine and cyclizine are all examples of what?
H1 receptor antagonists. Treatment of N+V.
205
Which classes of drug treat peptic ulcer diseases?
H2 R An – e.g. ranitidine
(PPIs) H+/K+-ATPase An – e.g. omeprazole, esomeprazole
Antacids – e.g. Mg trisilicate, gaviscon
206
What is orlistat?
Lipase enzyme inhibitor.
Treats hyperlipidaemia.
207
Where does absorption of most nutrients takes place in the intestines?
Jejunum
208
Where does the external oblique originate and insert?
Origin – 8 digitations from inferior 8 ribs
| Insertion – iliac crest, pubic tubercle, linea alba
209
Which abdominal muscle originates from the lumbar fascia and iliac crest?
Internal oblique
210
What is the difference between the duodenum, jejunum and ileum in terms of glands found and secretions.
Duodenum – Brunner’s glands – alkaline secretion to neutralise stomach acid, nutrients are broken down, fats --> micelles,
Jejunum – Lining specialised for absorption for the nutrients which were broken down in duodenum,
Ileum – Peyer’s patches – pathogens, lining secretes proteases carbohydrase enzymes
211
What is the difference between the duodenum, jejunum and ileum in terms of diameter.
Duodenum – Larger than both jejunum and ileum
Jejunum – larger than ileum, plicae circularis and villi increase SA
Ileum – smaller diameter than ileum and duodenum
212
What is the difference between the duodenum, jejunum and ileum in terms of, things absorbed.
Duodenum – Fe
Jejunum – Mg, most nutrients
Ileum – Vit B12
213
Where in the intestines is Mg and most nutrients absorbed?
Jejunum
214
Where in the intestines is vitamin B12 absorbed?
Ileum
215
Where in the intestines is iron absorbed?
Duodenum
216
What is the difference between the duodenum, jejunum and ileum in terms of blood supply.
Duodenum – coeliac trunk and superior mesenteric artery
Jejunum – superior mesenteric artery
Ileum – superior mesenteric artery
217
What forms the rectus sheath?
By the aponeuroses of the 3 flat muscles (external oblique, internal oblique, transverse abdominis) and encloses rectus abdominis, and pyramidalis muscles.
218
Where are Peyer's patches found?
Ileum
219
Function of Peyer's patches
Fighting pathogens
Secreting proteases and carbohydrases enzymes
220
What forms the anterior wall of the rectus sheath?
Aponeuroses of external oblique and ½ internal oblique
221
What forms the posterior wall of the rectus sheath?
Aponeuroses of ½ internal oblique and transverse abdominus
222
What is the arcuate line?
Area of transition between having a posterior wall and no posterior wall
223
Where is the rectus abdominus directly in contact with the transversalis fascia?
Approx. midway between umbilicus and pubic symphysis; below the arcuate line
224
Where does the submandibular and lesser sublingual gland ducts open into?
Both open into the floor of the mouth
225
What are the phases of gastric secretion?
Cephalic – before food enters tract (stimulated by sight or smell of food due to stimulation of vagus nerve)
Gastric – food is in the stomach
Intestinal wave – food enters the intestines
226
Which salivary glands secrete mostly mucous? What do they have?
Sublingual salivary glands.
They have mostly mucous acini and few serous acini.
227
Which salivary glands secrete mostly serous but have a mucosa acini also?
Submandibular glands.
Have mostly serous acini and few mucosa acini.
228
Which muscles elevate the mandible?
Temporalis, medial pterygoid, masseter
229
What do the enteroendocrine cells of the stomach secrete?
Protein hormones such as VIP and somatostatin.
Gastrin is secreted from a type of these called G cells in the pyloric region of the stomach.
230
Which muscles depress (protrusion) the mandible?
Lateral pterygoid
231
Which cranial nerve innervates the muscles of mastication?
CNV
232
Which artery supplies the masseter muscle?
Masseteric artery
233
Which branches of the maxillary artery supplies the lateral pterygoid and medial pterygoid muscles?
Pterygoid branch
234
Which artery supplies the temporalis muscle?
Deep temporal artery
235
How long is the duodenum and list the 4 parts?
25cm
Superior, descending, inferior, ascending
236
Which part of the duodenum has the major duodenal papilla?
Descending
237
Which part of the duodenum is the ligament of Treitz found at?
Ascending
238
What does intrinsic factor aid?
Absorption of vitamin B12
239
How does H2 receptor stimulation lead to cardiac stimulation?
By the activation of adenylyl cyclase --> activates cAMP --> activates a protein kinase signalling cascade --> proton pump comes to surface of cell --> exchange H+ in to lumen for K+ out.
240
What do H2 receptor antagonists cause?
Less stomach acid.
241
Name all 4 receptors that can be targeted to reduce nausea and vomiting.
Muscarinic receptors
H1 receptors
5HT3 receptors - Ondasterone, Dolasetron
D2 receptors - Metoclopramide,
242
Where liver is in direct contact with the diaphragm.
Caused by the folding of the coronary ligament giving an anterior and posterior ligament.
243
How many surfaces does the liver have?
2, visceral and diaphragmatic
244
What is the hepatorenal recess?
Deepest (lowest) part of the abdominal cavity where fluid will gather when the patient is in the supine position.
Lies between the R lobe of the liver, R kidney, and R colic flexure.
245
What is the ligamentum teres?
The round ligament of the liver (or ligamentum teres, or ligamentum teres hepatis) is a degenerative string of tissue that exists in the free edge of the falciform ligament of the liver.
The round ligament divides the left part of the liver into medial and lateral sections.
246
Superiorly what does the faliciform ligament split into?
The coronary ligament
247
How many hepatic veins drain into inferior vena cava?
3 usually draining from the left, middle, and right parts of the liver
248
What are the extra lobes on the R lobe of the liver?
Caudate (superior) and quadrate (inferior)
249
What separates the caudate and quadrate lobes of the R lobe of the liver?
The porta hepatis
250
Anatomically are the caudate and quadrate lobes on the L or R and why?
Left because they are supplied by the L hepatic artery
251
What is in the porta hepatis?
Ducts, veins and arteries.
252
In the porta hepatis what is the order of its contents as you move left and superiorly?
Ducts, artery, vein
253
Does the hepatic artery enter or leave the liver?
Enter
254
Does the hepatic portal vein enter or leave the liver?
Enter
255
Does the hepatic vein enter or leave the liver?
Leave
256
How many sections does the liver have?
8
257
What is the function of the gallbladder?
Store and concentrate bile
258
What is the function of the pancreas?
Secrete digestive enzymes into duodenum
259
How does the superior mesenteric artery reach the liver?
Via the hepatic portal vein
260
What is the function of the spleen?
Storage and breakdown of RBCs
261
What does the breakdown of RBCs produce?
Bilirubin
262
What makes the origin of the spleen different from other GI structures?
Spleen – mesodermal origin
Other GI structure – endoderm origin
263
What is the diaphragmatic surface of the spleen in contact with?
Diaphragm and ribs 9-11 posteriorly.
264
Where is pain from appendicitis referred to after inflammation has occurred?
Right iliac region
265
Where is pain from kidney stones felt?
R and L lumbar regions
266
Where are chylomicrons formed and why what?
In the ER of the absorptive cells (enterocytes) of the SI.
267
What do alpha and beta pancreatic cells produce?
A – glucagon (increases blood glucose levels)
B – insulin (decreases blood glucose levels)
268
What do Kupffer cells of the liver phagocytose?
Aged RBCs, WBCs and some bacteria.
269
What is the function of lipoproteins?
Transport fatty acids, triglycerides, cholesterol to and from body cells in aqueous blood
270
What is used to make bile salts?
Cholesterol
271
Which cells synthesizes most plasma proteins?
Hepatocytes
272
What is transamination?
Transfer of an amino group to a keto acid. It can convert essential amino acids to non-essential amino acids.
273
How many essential amino acids are there?
9
274
Where are bile acids absorbed and what happens once they are absorbed?
Bile salts (acids) are usually absorbed in the terminal ileum, taken up by the liver and re-secreted.
275
What is the cofactor (a substance whose presence is essential for the activity of an enzyme) for transaminase enzymes?
Vitamin B6
Pantothenic acid
276
What happens in phase 2 of drug metabolism?
Synthesis: conjugation with glycine, sulphate, glucuronic acid.
277
What is the 1st pass effect?
On each liver pass a fraction of the drug is converted into inactive metabolites.
278
Where are ammonia concentrations the highest and why?
Liver
As this is ammonia is produced.
279
Sinusoids in liver drain fluid towards which structure?
Hepatic vein
280
Where do hepatic veins carry blood to?
Inferior vena cava
281
Where is pain from a stomach ulcer is referred?
Epigastric region
282
Where is small bowel pain referred?
Umbilical region
283
Which organ enlarges from the left hypochondrium towards the right iliac fossa?
Spleen
284
What does aldosterone mediate?
It regulates electrocytes and blood pH
285
High aldosterone causes what?
High aldosterone = water retention which increases blood vol which increases BP
286
What is raised concentration of cortisol associated with?
Cushing’s syndrome
287
What is Cushing’s syndrome?
Hypercortisolism – hormonal disorder caused by prolonged exposure of the body’s tissues to high levels of cortisol.
288
What is conjugation?
Conjugation – attachment of an ionised group to the drug
289
What is detoxification?
Detoxification – addition of another substance to drug/toxic substance to render it less effective (harmful).
290
What does phase 2 of drug metabolism lead to?
More polar and less reactive metabolites.
291
What are liver sinusoids lined with?
Primary liver cells (hepatocytes)
292
From which artery does blood enter the liver lobule?
Hepatic artery – oxygen rich
293
What is the ‘terminal hepatic venule end’ a.k.a?
Perivenous end
294
Why is blood in the perivenous end oxygen deprived?
Because the blood has travelled along the sinusoids in the liver lobules which use up much of the oxygen.
295
Is the periportal zone (1) or centrilobaular (perivenous) zone (3) affected greater during a time of ischaemia and why?
Centrilobaular (zone 3) because it has the poorest oxygenation.
296
Which zone is most susceptible to viral hepatitis and why?
Zone 1 – periportal zone because it is nearest to the entering vascular supply.
297
What are zone 1 hepatocytes specialised for?
Oxidative liver functions including:
- Gluconeogenesis,
- Beta oxidation of fatty acids
- Cholesterol synthesis.
298
Which type of hepatocytes are specialised for glycolysis, ketogenesis, lipogenesis and cytochrome P450 based drug detoxification reactions?
Centrilobaular zone 3 cells
299
Summary of zone 1 and zone 3 hepatocyte functions.
1 - Gluconeogenesis, beta oxidation of fatty acids, cholesterol synthesis.
3 - Glycolysis, ketogenesis, lipogenesis and cytochrome P450 based drug detoxification reactions
300
Which vessel(s) can be found in the periportal end of a liver sinusoid?
Portal venule and hepatic arteriole
301
How is HCl secreted from gastric parietal cells?
As Cl- and H+
302
Where is peristaltic waves observed in the stomach?
Note where the waves are more frequent.
Antrum (most propulsion occurs) < body < fundus
303
When does retropulsion occur?
When food is too large to fit through the pyloric sphincter and is forced back to the body of stomach
304
What is gastric emptying and how does it occur?
When food particles in chyme are small so they pass through the pyloric sphincter.
305
What is somatostatin?
A hormone released from D-cells in stomach and duodenum in response to acid.
Inhibits gastric secretion.
306
What is gastrin?
A hormone secreted by the stomach in response to food especially protein.
307
What are villi in small intestines made from?
Goblet cells (secrete mucus), arteries, veins (go to the hepatic portal vein), lacteals (used in fat absorption).
308
Why are proteases secreted as inactive precursors?
So, they don’t digest the digestive tract itself.
309
What is glycaemic index?
Relative ability of carbohydrate food to increase blood glucose levels.
310
What is resistant starch?
Starch that escape digestion in SI of healthy people.
311
Where is alcohol absorbed?
20% - stomach
| 80% - small intestine
312
Where are acids and bases absorbed?
Large intestine
313
Name the fat-soluble vitamins.
A, D, E K
314
What is emulsification and where does it occur?
Lipid is liquefied and emulsified into small droplets which increases the SA. In the mouth and stomach at 37 degrees.
315
Where do micelles uptake into enterocytes occur?
Jejunum
316
How are micelles formed?
Lipid droplets are mixed with amphipathic bile salts.
317
What do chylomicrons exocytose into?
Lacteals which are like lymph ducts.
318
What are chylomicrons?
Re-esterified lipids + apoproteins.
319
What is steatorrhea and what causes it?
Presence of excess fat in faeces
Pancreatic insufficiency causes it (or not enough bile)
320
How are bile salts absorbed?
They must be broken down in the ileum then 95% of the breakdown products are reabsorbed into lymphatics and transported back to liver to be remade and reused.
321
What does omega 3 do?
Anti-inflammatory
Controls blood clotting
Build cell membranes in the brain
Normal growth and development
322
What is a hepatic lobule?
A small division of the liver defined at the histological scale.
Anatomical liver lobes are not the same thing.
323
What does omega 6 do?
Pro-inflammatory; brain functions, normal growth and dev
324
What enzyme does pancreatic juice stop the action of?
Stomach acid
325
Absorption of what substance may be most affected by disease of the terminal ileum?
Vitamin B12, bile salts
326
What is ranitidine and how does it differ from omeprazole?
Randitdine – H2 receptor antagonist
Omeprazole – PPI
327
Where are most lipids absorbed in the GIT?
Small intestines
328
What is the taenia coli?
3 separate longitudinal ribbons of smooth muscle on the outside of the ascending, transverse, descending and sigmoid colons.
329
What is the vermiform appendix?
A blind-ended tube connected to the cecum, from which it develops in the embryo.
330
What is trypsinogen?
Precursor to trypsin (which is formed in the duodenum).
331
What are Paneth cells?
In the SI, Paneth cells residing at bottom of intestinal crypts are the key effectors of innate mucosal defence.
332
What are enterocytes?
Simple columnar epithelial cells found in the small intestine which are involved in digestion of molecules.
333
The pancreas is the source of what?
Insulin, glucagon, proteases, pancreatic lipase, amylase, bicarbonate
334
What would cause reduced formation of micelles?
Low bile salts
335
What is the exogenous lipid transport pathway?
Dietary lipids are transported from the intestines to the liver through the blood and there their path ends.
336
What is the endogenous lipid transport pathway?
Triglycerides and cholesterol produced in liver are transported to tissues where they are metabolised.
337
What do apoproteins regulate?
Which lipoprotein is made
338
How does the size of chylomicrons compare to that of other lipoproteins?
They are larger
339
What are chylomicrons synthesised from?
Triglycerides, lipoproteins and apoproteins
340
In the blood, what digests chylomicrons?
Lipoprotein lipase
341
What can fatty acids be taken up by?
Adipose tissue, muscle cells.
342
What are chylomicron remnants and what happens to them?
They are what’s left to chylomicrons after they’ve been metabolised. They bind to specific receptor (apoE) on liver cells and are endocytosed.
343
Major reduction in lipase production is caused by what?
Pancreatitis
344
Reduced formation of chylomicrons is caused by what?
Poor gut absorbance
345
Where does protein digestion begin?
Stomach – HCl and pepsin
346
Which are the main absorptive cells in the small intestines?
Enterocytes – simple columnar epithelial cells
347
How is LPL (lipoprotein lipase) expression linked to insulin?
When there’s a spike of insulin (after eating) LPL is activated. Insulin upregulates LPL.
348
List the stages in the endogenous pathway.
Triglycerides from liver to peripheral tissues.
VLDL > IDL > LDL forward cholesterol transport.
When cholesterol high LDL > HDL (reverse cholesterol transport).
349
What are VLDL produced from?
From chylomicron remnants in the liver.
350
What is the function of HDLs?
Transport cholesterol from tissues back to liver (turns into bile) when cholesterol is excess.
351
What is forward cholesterol transport?
When cholesterol transported from liver to tissues
352
What can be used to control hypercholesterolemia?
Statins, bile acid sequestrant, fibrates
353
How do statins work?
Targets HMG CoA reductase enzymes and elevates HDL levels.
354
How do bile acid sequestrant work?
Alters the amount of bile acid is secreted.
355
How do fibrates work?
Alters lipoprotein catabolism to alter the levels of HDL and LDL in the body.
356
Free fatty acids are produced and transported to the liver in which 2 stages?
Ketogenesis and beta-oxidation
357
Describe the structure of white adipose tissue.
White – one big droplet.
358
Describe the structure of brown adipose tissue.
Brown – multiple smaller lipid droplets (contain mitochondria)
359
In chronic pancreatitis which intestinal secretion is affected?
Lipase production
360
A raised concentration of what is associated with colicky abdominal pain?
Calcium
361
Why is bile acid needed for action by lipases to occur on dietary fats?
Bile salts must emulsify the fats --> increase SA --> enhance lipase action.
Lipases degrade triacylglycerol --> monoacyglycerols, free fatty acids and glycerol --> taken up by intestinal epithelial cells.
362
What responds to low calcium concentration?
Parathyroid hormone
363
Removal of the gall bladder causes what?
Poor storage and concentration of bile salts.
364
What is the peritoneum made up of?
A layer of mesothelium supported by a thin layer of connective tissue. It’s conduit for blood and lymphatic vessels, nerves of abdo organs.
365
What happens to chylomicrons once they are absorbed by enterocytes?
Secreted through the basolateral membrane into the lacteals where the join lymph.
366
What is a consequence of obstruction to the common bile duct?
Reduced formation of micelles.
367
Where does the foregut run from?
Mid-oesophagus --> 2nd part of duodenum (ampulla of Vater)
368
Where does the midgut from?
Ampulla of Vater --> 2/3rd transverse colon.
369
What is the dentate line?
Embryology changes from endodermal --> ectodermal; it’s in rectum.
370
Which arteries supply the foregut, midgut and hindgut?
Foregut – coeliac trunk
Midgut – superior mesenteric A.
Hindgut – inferior mesenteric A.
371
Name all the intraperitoneal organs
Liver
Stomach
Spleen
First 5cm of duodenum
Jejunum
Ileum
Transverse colon
Appendix
Sigmoid colon
Upper 3rd of rectum
372
Where does the hindgut end?
Point of the rectum known as the dentate line.
373
Which nerves supply the foregut, midgut and hindgut?
Foregut – superior splanchnic
Midgut – lesser splanchnic
Hindgut – least splanchnic
374
Name all retroperitoneal organs.
Organs that lie on posterior abdominal wall and are covered by peritoneum only = retroperitoneal.
Distal duodenum (most)
Caecum
Ascending colon
Descending colon
Pancreas
Kidneys
