Clinical Biochemistry

2. Outlines
Anatomy Of Stomach .
Structure
Location
Regions
Layers of stomach Wall
Gastric Secretions.
Main constituents of gastric juice.
Indications.
Functions Of Stomach .
Stomach Disorders.
Gastric Function Test.

3. Anatomy Of Stomach
 Stomach is a part of gastrointestinal tract.
 It is “ J ” shaped elastic muscular bag .
 When stomach receives the food , it contracts and produces
acids and enzymes that break down food. After break down
food passes into small intestine.
Location :
It is situated just below diaphragm on the left side of abdominal
cavity.

4. It stores the gas produced
during digestion
It is large section of stomach.
It contracts and begin to mix food
It contains cardiac sphincter
Also called as lower
esophageal sphincter.
It prevents backflow of
stomach acid and content
into esophagus.
It contains pyloric sphincter.
It contols the release of
chyme from stomach into
duodenum.
Regions Of Stomach

5. Layers Of Stomach Wall

6. Layers of
Stomach
wall
Mucosa :
It is the first and innermost layer.
It contains glands that release
digestive juices.
Submucosa :
It supports mucosa and
muscularis.
It is rich in blood vessles ,
lymphatic vessels and nerves.
Muscularis :
It is 3rd layer.
It helps to mix and break the
contents into suspension of
nutrients called as chyme.
It is made up of three layers :
longitudinal ( outer )
Circular ( middle )
Oblique ( inner )
Serosa :
It’s lining wrap around
stomach to confine it. Rugae :
In the absence of food stomach
walls shrinks and make folds
known as rugae.

7. Gastric Secretions
 Gastric Secretion Comes from Gastric Pit .
 Gastric pit is leading into deep regions called as gastric Glands.
 Gastric gland is made up of secretory cells which release gastric juice.

9. Main Constituents Of Gastric Juice
HCl to kill microbes
Pepsin to break the protein
Intrinsic factors for B12 absorption
Alkaline mucous to lubricate the wall of stomach
Indications Of
Gastric
Analysis
To check achiorohydria
must done for acid secretion
To detect ZES(Zollinger Ellison
syndrome)
To estimate or reflect gastric or peptic ulcer

11. Volume < 50 if high volume above 100 then increase gastrin secretion
PH 3.5 IF High no free acid yellow color
If below 3.5 free acid present red color of juice carcicoma of stomach
Basal acid output 0.5mmol/L WITHOUT stimulant secretion of gastric juice
Peak acid output 20mmol/L after stimulant secretion HIGH IN
%of BAO/PAO <20%
Total titrated acidity 60mmol/l
Reference Ranges

12. NORMAL up to 100ng/l
Duodenal ulcer 100-200ng/l
ZES >200ng/l
Gastrin is a peptide hormone G-34 that control the secretion of gastric acid pepsin secretion growth of gastric mucosa
Secreted by calcium in blood, gastric distension
Inhibited by gastric acidity gastrointestinal hormone i.e secretin
Reference Ranges Or Interpretation Of Gastrin
Hormones

13.  Temporary storage of food to allow the time for digestive
enzyme to act.
 Mechanical breakdown involves the churning of food ,the
gastric juice is added to food and food is liquefied to chyme
 Limited absorption of water , alcohol and lipid soluble
contents
 Non specific defense against microbes by HCL
 Preparation of iron for absorption
 Production and secretion of intrinsic factor needed for
absorption of vitaminB12 in terminal ileum
 Secretion of hormones gastrin
 Regulation of passage of gastrin contents into duodenum
Functions Of Stomach

14. What are stomach diseases
Stomach
Disorders
Gastritis
Gastroparesis
Gastroenteritis
Peptic
Ulcer
Stomach
Cancer

15. Gastritis
 Inflammation of stomach lining
 Acute gastritis may come on suddenly
 Chronic gastritis happens slowly
Causes
 Excess alcohol consumption
 Bacterial or viral infection
 Autoimmune disease
Symptoms
 Nausea
 Vomiting
 Appetite loss
 Black stool due to bleeding in stomach

16. Gastroenteritis
 Common condition that affects the gut(stomach and intestine)
 Highly infectious
 It affects people of all ages
 Common in young children
 In children caused by virus called rotavirus
Causes
 Viruses
 Bacteria
 Toxin produced by bacteria also spread through coughing and
sneezing
Symptoms
 Vomiting
 Diarrhea
 Headache
 Fever

17. Gastroparesis
 Condition in which stomach takes too long to empty
Causes
 Muscle, nervous system and metabolic disorders
 Diabetes
 Stomach surgery
Symptoms
 Vomiting
 Nausea
 Weight loss
 Heart burn

18. Peptic Ulcers
 Sores that develop in the stomach called gastric ulcer
 Usually formed as a result of inflammation caused by H.pylori
Causes
 Helicobacter pylori causes infection and inflammation
 Frequent use of aspirin or anti inflammatory drugs
 Smoking
 Stomach cancer
Symptoms
 Bloody or dark stool
 Vomiting
 Chest pain
 Weight loss

19. Stomach Cancer
 Gastric cancer is a disease in which malignant cells form in the lining
of stomach
 It begins in the innermost layer of the stomach lining
Causes
 Smoking tobacco
 Alcohol consumption
Symptoms
 Indigestion
 Stomach discomfort
 Pain
 Vomiting with or without blood
Untreated stomach cancer can spread to other organs

20. Gastric Function Test

21.  Fractional Test Meal
Pentagastrin Test
Alcohol Meal Test
Insulin Meal Test
Helicobacter pylori
detection test
Augument Histamine test
Tubeless Gastric Analysis
Gastric Emptying Study
Test

22. Sample Collection
Sample is collected with the help of Ryle's tube.
● Nasogastric tube is inserted in the nose and through the
oesophagus it reaches the stomach.

23. Fractional Test Meal / Fractional Gastric analysis
● Fractional test meal involves the collection of stomach contents
by Ryle's tube in fasting.
● This is followed by a gastric stimulation, giving a test meal (rice
gruel, black coffee etc.).
● The stomach contents are aspirated by Ryle's tube at different
time periods (every 15 min for 2 hrs.)
● The samples are analyzed for free & total acidity.
Interpretation of results:
● UseThe results are normally represented by a graph.
● Free acidity 20 -40 mmol/l
● Normal T.A ( total acidity) 40-60 mmol/l
1.

24. Hyperchlorhydria Hypochlorhydria Achlorhydria
Free acid normal
<50ml mEq/l
If >50mEq/l hperchlorhydria
more hcl
Duodenal ulcer
Gastric cell hyperplasia
Zollinger Ellison syndrome
Free acid less than normal
Less hcl concentration
Cancer of stomach
No concentration of free acidity
(Hcl)
Only pepsin
Later cancer of stomach
Chronic gastritis

25. Pentagastrin Test
● Pentagastrin is a synthetic peptide. It stimulates the gastric secretion in a manner similar to the natural
gastrin.
● The stomach contents are aspirated by Ryle's tube in a fasting condition. This is referred to as residual
juice.
● The gastric juice elaborated for the next one hour is collected and pooled which represents the basal
secretion/ residual juice.
● Pentagastrin (5mg/kg body weight) is now given to stimulate gastric secretion.
● The gastric juice is collected at 15 minute intervals for one hour. This represents the maximum
secretion.
Analysis of samples:
● Each sample of the gastric secretion collected is measured for acidity by titrating the samples with N/10
NaOH to pH 7.4.
● The end point may be detected by an indicator phenolphthalein for BAO and Topfer's indicator for MAO
or a pH meter.
● Basal acid output (BAO) refers to the acid output (millimol per hour) under the basal conditions i.e.
basal secretion.
● Maximal acid output (MAO) represents the acid output (millimol per hour) after the gastric stimulation
by pentagastrin i.e. maximum secretion.
● In normal individuals, the BAO is 4-10 mmol/hr while the MAO is 20-50 mmol/hr.
2 .

26. Alcohol Meal Test
A test meal of 100ml of 7% alcohol is administered.
 Response to alcohol meal is very fast.
 Free acidity level is high compared to FMT.
Easily prepared and administered.
Consumed better.
Specimens are clear.
Easily analyzed.
3 .

27. Insulin Meal Test
 This is also known as Hollander’s test.
 It is mainly done to assess completeness of vagotomy ( vagal resection )
 Insulin 0.1 unit / kg body weight is administered intravenously, which causes
hypoglycemia usually within 30 mints , in normal person.
 If the vagotomy operation is successful , insulin administration does not cause any
increase in acid output .
 This test has to be carefully performed , since hypoglycemia is dangerous.
4 .

28. Helicobacter Pylori Detection Test
H.pylori infection seen in 80% gastric ulcer.
• And 95% of duodenal ulcer.
• Some strains of h.pylori produce specific proteins and toxins .
• Which leading to inflammation and mucosal damage
. • Detection of h.pylori is done by several methods like:
1.Rapid ulcer method
2.Gastric aspirate
3.Culture
 Popular diagnostic test for H.pylori
 Cheap ,rapid and simple.
 Detect the presence of urease in gastric mucosa
1 . Rapid Ulcer Method
5 .

30. Use endoscopy and biopsy to collect stomach lining cells.

31.  The fasting contents withdrawn by syringe, measured and kept for
analysis.
2 . Gastric Aspirate

32. 3 . Culture
For detecting the presence of microorganism.

33. Augment Histamine Test Meal
6 .
 Histamine is a powerful stimulant of gastric secretion.
 The basal gastric secretion is collected for one hour .
 Histamine is administered subcutaneously and the gastric
contents are aspirated for the next one hour at 15 minute
intervals.
 The acid content is measured in all these samples.

34. Tubeless Gastric Analysis
In tubeless gastric analysis test a cation
exchange resin tagged with a dye
Azure A is given orally .
HCL secreted by stomach displaces the
dye, which is absorbed in the intestine
and is then excreted in urine.
The amount of dye excreted in urine is
proportional to acid output.
7 .

35. Gastric Emptying Study
 The most common type of gastric emptying study is a procedure that is done by
nuclear medicine physicians using radioactive chemicals that measure the speed with
which food empties from the stomach and enter the small intestine.
Gastric emptying studies are used for evaluating patients who are having symptoms
that may be due to slow and less commonly rapid emptying of stomach.
The symptoms of slow emptying are primarily nausea,vomiting ,abdominal pain,and
abdominal fullness after eating .
The symptoms of rapid emptying are diarrhea,weakness and light headedness after
eating.
8 .

37. How Is Gatric Emptying Study done
For a gastric emptying study a patient eats a meal in which solid or liquid
component of the meal are mixed with small amount of radioactive material.
A scanner is placed overs the patient stomach to moniter the amount of
radioactivity in the stomach for several hours after the meal is eaten .
 As the radioactively -labelled food empties from the stomach the amount
of radioactivity in the stomach decreases.
The rate at which the radioactivity leaves the stomach reflects the rate at
which food is emptying from the stomach.