C.

GASTROINTESTINAL HORMONES
Summary of Digestion
1. Gastrin
A. DIGESTIVE SYSTEM
▪ secreted in
1. Alimentary canal response to
- consist of oral mechanical
cavity, pharynx, ▪ inhibited by
esophagus, acid
stomach, small
intestines, large ▪ stimulates production
intestines, rectum. of gastric acid and pepsin
▪ increase gas motility
2. Secretory glands
- such as glands 2. Cholecystokinin
line the stomach;
others such as ▪ secreted by cells in the
pancreas and liver duodenum and
jejunum
3. Sphincters ▪ small intestinal
a. Esophageal - between hormone that stimulates
esophagus secretion of pancreatic
b. Pyloric - between stomach enzymes and bile.
and small intestines
c. Ileosecal - between small
intestines and large 3. Secretin
intestines
d. Anal - control passage of - produced by duodenum
fluid and fecal material - secreted in response to the presence of free
fatty acid in the intestines - stimulates the
production of pancreatic juice

B. DIGESTIVE PROCESSES 4. Enterogastrone

- hormone of the small intestine
1. Mechanical - food is broken down by teeth, - secreted in response to the presence of acid in
tounge, and peristaltic contractions of stomach the duodenum
and small intestines, sphincters such as the
pyloric sphincter between stomach and duodenum.
2. Chemical
a. Salivary gland
b. Esophagus
c. Stomach- gastric gland produce hydrochloric
acid and enzymes pepsin and renin D. PROPERTIES OF GASTRIC MUCOSA
d. Liver- produces bile 1. Turnover of gastric mucosa
e. Pancreas- produces enzymes 2. Permeability of gastric mucosa
f. Small intestine- produces lipase, 3. Gastric mucosal barrier
aminopedtidases and disaccharides a. Possible causes of barrier breakdown
1. Duodenum 1. Salicylates—aspirin and
2. Jejunum salicylic acid
3. Ileum 2. Ethanol
3. Bile acids regurgitated from
g. Large intestines- site of water resorption
duodenum
h. Rectum- transient storage of feces prior to 4. Injuries or infections
elimination 5. Decreased bicarbonate and
mucus in older adults
 b. Consequences of barrier G. MECHANICS OF GASTRIC
breakdown—acid reaches the mucosal SECRETIONS
injury and bleeding or ulcers.
1. Acid stimulates increased 1. Reception of food— vagally mediated
motility of the stomach by relaxation of the stomach occurs as food
direct stimulation of intrinsic distends the esophagus, resulting in increase in
plexus; the strong contractions pressure
cause pain 2. Missing of chyme—peristaltic waves over the
2. Acid penetrating the mucosa antrum (moving toward the pyloric sphincter) mix
permits histamine release, food and gastric secretions thoroughly
leading to edema of the mucosa.
3. Vomiting—forceful expulsion of stomach
contents
E. RATE AND QUANTITY OF 4. Gerontologic considerations—decreased
GASTRIC SECRETIONS gastric motility, volume, blood flow; stomach
distention and feeling of fullness may contribute
1. Rate and acid secretions rise to a maximum in to appetite loss and weight loss.
the second half hour eating
2. Total amount of acid secreted is proportional II. SOCIOCULTURAL INFLUENCE ON
to the amount of protein ingested
3. Gerontological considerations—gastric
NUTRITIONAL INTAKE
atrophy and decreased intrinsic factor
production; increased risk vitamin 12 deficiency A. Orthodox Jewish
1. Dietary laws based on biblical and rabbinical
F. MALFUNCTIONS INVOLVING GASTRIC regulations
SECRETIONS 2. Laws pertain to selection, preparation of food
3. Laws
1. Loss of gastric juice (ex.vomiting) nowadays to a. Milk/milk products never eaten at
metabolic alakalosis—nor each H+ lost HCO3 is same meal (milk may not be taken until 6
retained hours after eating meat)
b. Two meal contains dairy products and
2. Mucosal atrophy (may involve autoimmunity to one contains meat c. Separate utensils
parietal cells) —no acid or pepsinogen are used for meat and milk dishes
d. meat must be kosher.
secretions; possible lack of intrinsic factor d. Prohibited foods
for B12 absorption in the terminal ileum; - pork
pernicious anemia develops after - diseased animals or animals
approximately 3 years. who die a natural death
- birds of prey
- fish without fins or scales
(shellfish—oysters, crab,
lobsters)

B. Moslem
1. Dietary laws based on Islamic teachings in
Koran.
2. Laws
A, Fermented fruits and vegetables
ARTERIAL BLOOD PH: 7.38 TO 7.42. OXYGEN prohibited
SATURATION (SAO2): 94% TO 100% B. Pork prohibited
BICARBONATE (HCO3): 22 TO 28 C. Alcohol prohibited
D. Foods with special values, Figs. Olives,
MILLIEQUIVALENTS PER LITER (MEQ/L dates, honey, milk, buttermilk
E. Humane slaughter of animal meat
C. Hispanic J. Italian
1. Basic foods: Dried beans, chilli peppers, corn 1. Bread and pasta are the basic food
2. Small amounts of meat and eggs 2. Cheese frequently used in cooking
3. Food seasoned with spices, wine, garlic, herbs,
and olive oil
D. Puerto Rican
1. Starchy vegetables and fruits (Plantains and
K.
green bananas)
2. Large amount of rice and beans 1. Bread is served with every meal
3. Coffee amin beverage 2. Cheese (feta) used for cooking
3. Lamb and fish frequent
4. Eggs in main dish, but not breakfast food
E. Native American 5. Fruits for dessert

1. Minimal milk in diet

2. Leafy green (turnips, collards and mustard)
3. Pork common

F. French American
1. Foods are strong-flavored spicy
2. Frequently contain seafood (crawfish)
3. Food preparation starts with roux made from
heated oil and flower; vegetables and seafood
added

G. Japanese
1. Rice is basic food
2. Soy sauce is used for seasoning
3. Tea is the main beverage
4. Seafood frequently used (sometimes raw fish-
sushi)

H. Chinese
1. Freshes food available and cooked in high
temperature
2. Meat ins small amount
3. Eggs and soybeans used for protein

I. Southeast Asian
1. Rice is basic food, eaten in separate bowel
2. Soups
3. Fresh fruits and vegetables frequently part
of diet
Nutritional Parameters
2. Urine
A. Caloric requirement—a calorie is a
measurement unit of energy; persons a. Urinalysis—an elavated level of ketone
height and weight, as well as level of bodies indicated altered fat metabolism
activity, determine energy need, average
adult requires anywhere from 1,500kcal b. Shilling test—diagnoses vit.B12 deficiency
to 3,000kcal/d (pernicious anemia); radioactive vitamin B12 is
administered to the patient, low value is
B. Fluid replacement—average fluid excreted in urine indicates pernicious anemia (NV
replacement for normal healthy adult is is >10% of dose excreted in 24h)
approx. 1,800-2,500 ml/d

C. Nutrient requirements 3. Gastric Aspirate

a. Ph—measures acid/alkaline range (NV 4.5 -
1. CHON- 1st substance utilized for
energy production in starvation, only 7.5); generally overly acidic environment can
source of energy production for the lead to ulcerative activity
brain
2. Fats—2nd source of energy b. Guaiac—tests for presence of blood in
production utilized by the body in aspirate; normally, blood absent
starvation; its waste products are
ketone bodies, which can create an acidic
environment in the blood.
4. Stool
3. Proteins—last energy utilized in a. Fecal occult blood test (FOBT)—test for
starvation: depletion in protein leads to presence of blood; normally blood absent
muscle wasting as well as loss of
pressure in the vascular space: low b. Stool for quantitative analysis—reviewed for
albumin level in the blood indicates color, consistency and amount
protein malnutrition

5. Special Procedures
DIAGNOSTIC TEST
A. UPPER GI SERIES (barium swallow)
1. Blood test - ingestion of barium sulfate to determine
latency and size of esophagus, size and condition
of gastric walls, latency of pyloric valve, and
rate of passage to small bowel

Preparation:

a. Maintain NPO after 12mn, avoid opioids and

anti-cholinergic medications
b. Inform patient that stool will be light color
after procedure

Post test—encourage fluid and or laxative to

prevent constipation
B. ENDOSCOPY D. LOWER GI SERIES (barium enema)
- instillation of barium into colon via rectum for
- visualization of esophagus and/or stomach
fluoroscopy X-ray to view tumors, polyps,
and/or duodenum by means of lighted flexible strictures, ulcerations, inflammation, or
fiber optic tube introduced through mouth to the obstruction of colon.
stomach or from rectus through intestines to
determine the presence of ulceration of tumor
Preparation:
or to obtain tissue or fluid samples.

a. Low residue diet for 1-2 days

Preparation: b. Clear liquid and laxative evening before test
c. Cleansing enemas until clear moribund of test
a. Verify the informed consent from the patient
has been obtained
Postprocedure Nursing Care:
b. Maintain NPO before procedure (at least 8h)
c. Teach the patient about numbness in throat due
a. Cleansing enemas after exam to remove
to local anesthetic applied to posterior pharynx
barium and prevent impaction, laxative
by spray or gargle; conscious sedation used. administer.
b. Xray maybe repeated after all barium is
Post procedure nursing care: expelled.

a. Maintain NPO until gag reflex return

b. Observe for vomiting of blood, respiratory
distress, aspiration
c. Inform patient to expect sore throat for 3-4
days after procedure C. GASTRIC ANALYSIS
- aspiration of gastric contents to evaluate for
presence of abnormal constituents such as
blood, abnormal bacteria, abnormal pH, or
malignant cells.

Preparation:

- patient must be NPO before test; NG tube is

passed; gastric contents aspirated and sent for
evaluation. Pengagasttin is sometimes used to
stimulate acid secretions.