Digestive System Disorders Flashcards
1
Q
Functions Of Digestive System
A
Processes ingested food and fluids
Breaks them down into their units
Controlled by enzymes
Absorbs necessary components
Membrane transport mechanisms
Mostly in small intestine
2
Q
Gut wall(4 layers)
A
Mucosa
Epithelium, including mucus-producing cells
Submucosa
Connective tissue—including blood vessels, nerves, lymphatics, secretory glands within connective tissue
Circular smooth muscle layer
Longitudinal smooth muscle layer
(in place to allow peristalsis to move along the path of the digestive track)
Serosa
Visceral peritoneum(Inner lining)
3
Q
Upper Gastrointestinal Tract
A
Oral Cavity
Esophagus
Stomach
4
Q
Oral cavity
A
Initial phase of mechanical breakdown of food
Mastication by teeth
Initial chemical digestion
Salivary amylase—starts chemical breakdown of carbohydrates
Formation of bolus
5
Q
Salivary amylase
A
starts chemical breakdown of carbohydrates
6
Q
Pharynx
A
Swallowing (deglutition)
7
Q
Esophagus Function
A
Closed except during swallowing, skeletal muscle at superior end—followed by smooth muscle
Swallowing:
The soft palate is pulled upward
The vocal cords are approximated
The epiglottis covers the larynx
Respiration ceases
The bolus is seized by the constricted pharynx
Bolus of food moves into the esophagus
8
Q
Stomach
A
Expansible muscular sac—acts as reservoir for food and fluid
9
Q
The Stomach contains how many smooth layer muscle?
A
Three smooth muscle layers
10
Q
Stomach Full Description
A
Expansible muscular sac—acts as reservoir for food and fluid
Three smooth muscle layers
Constant mixing and churning of food
Initial digestion of proteins
By pepsin
Formed by combination of pepsinogen and HCl
Production of intrinsic factor
Essential for absorption of vitamin B12 in the ileum
Formation of chyme
Absorption of small and lipid-soluble molecules
11
Q
Production of intrinsic factor is Essential for absorption of vitamin B12 in the ileum
A
B12 in the ileum
12
Q
Pepsin
A
Causes Initial digestion of proteins
Formed by combination of pepsinogen and HCl
13
Q
Where is chyme produced
A
Stomach
14
Q
What organ receives blood from hepatic portal vein
A
Liver
15
Q
Liver Function
A
“Metabolic factory” of the body
Receives blood from hepatic portal vein
Transport of nutrients from intestine to liver
Hepatocytes store nutrients
Play role in carbohydrate, protein, fat metabolism
Production of plasma proteins and clotting factors
Breakdown of old and damaged erythrocytes
Bile production
16
Q
Hepatocytes
A
primary cells in the liver
store nutrients
Play role in carbohydrate, protein, fat metabolism
17
Q
Pancreas
A
Exocrine pancreas arranged in lobules
Secretes digestive enzymes, electrolytes
Trypsin
Chymotrypsin
Carboxypeptidase
Ribonuclease
Pancreatic amylase
Bicarbonate ions
Pancreatic duct joins bile duct to enter duodenum
18
Q
Small intestine
A
Major site for absorption of nutrients
19
Q
Lacteal—lymphatic vessel
A
specialized lymphatic capillaries in the small intestine that absorb dietary fats and transport them to the bloodstream
20
Q
Peyer patches
A
They are considered the gut’s immune system, helping to identify antigens and produce antibodies.
21
Q
Small intestine Structure
A
Duodenum, jejunum, ileum
Villi (folds of the mucosa) and microvilli(On top of villi)(folds of cell membranes)
Increase surface area for absorption
22
Q
Site of production of:
Mucus
Enterokinase, peptidases, nucleosidases, lipase, sucrase, maltase, lactase, cholecystokinin (hormone)
A
Small intestine
23
Q
Malnutrition issues occur with problems with
A
Villi
24
Q
Lower Gastrointestinal Tract
A
Large intestine
Small Intestine
25
Large intestine
Resident normal flora
Breakdown of certain food materials
Vitamin K synthesis by bacteria
Fluid and electrolyte reabsorption
Formation of solid feces
Mass movements
26
Parasympathetic nervous system (PNS) involves what vagus nerve
Vagus nerve (cranial nerve
[CN] X)
27
Parasympathetic nervous system (PNS)
Primarily through vagus nerve (cranial nerve
[CN] X)
Increased motility
Increased secretions
28
Sympathetic nervous system (SNS)
(Fight Or Flight)
Stimulated by factors such as fear, anger
Inhibits gastrointestinal activity
Causes vasoconstriction
Reduced secretions and regeneration of epithelial cells
29
A nerve that maintain continuous flow of saliva in mouth
Facial (CN VII) and glossopharyngeal (CN IX) nerves
30
Neural and Hormonal Controls
(2 of 2)
Facial (CN VII) and glossopharyngeal (CN IX) nerves
Maintain continuous flow of saliva in mouth
Distention and stretching of stomach
PNS activation
↑ Peristalsis and gastric secretions
Stomach empties within 2 to 6 hours after meal.
Food in intestine
Stimulation of intestinal activity
Enterogastric reflex
Inhibition of gastric emptying
31
Gastrin
Secreted by mucosal cells (stomach) in response to distention of stomach or partially digested substances
Increases gastric motility, relaxes pyloric and ileocecal sphincters—promotes stomach emptying
32
Histamine
Increased secretion of hydrochloric acid
33
Secretin
Decreases gastric secretions
34
Cholecystokinin
Inhibits gastric emptying; stimulates contraction of gallbladder
35
Carbohydrates digestion occurs in
Digestion starts in mouth
Followed by digestion in the small intestine
36
Proteins digestion occurs in
Digestion starts in stomach, continues in small intestine
37
Lipids
Emulsified by bile prior to chemical breakdown
Action of enzymes form monoglycerides and free fatty acids
Formation of chylomicrons
38
Fat-soluble vitamins
Vitamins A, D, E, K
Absorbed with fats
39
Water-soluble vitamins
Vitamins B and C—diffuse into blood
40
Electrolytes are absorbed by
active transport or diffusion
41
Drugs are primarily absorbed in the
intestine
Various transport mechanisms
Some (e.g., aspirin) absorbed in the stomach
42
Common Manifestations of Digestive System Disorders
Anorexia, Nausea, Vomiting, and Bulimia
Diarrhea
Constipation
Fluid and Electrolyte Imbalaces
Pain
Malnutrition
43
Anorexia, Nausea, Vomiting,
and Bulimia may be signs of
May be signs of digestive disorder or other condition elsewhere in the body
Systemic infection
Uremia
(a serious condition that occurs when the kidneys are unable to filter waste from the blood, resulting in a buildup of toxins like urea and creatinine)
Emotional responses
Motion sickness
Pressure in the brain
Overindulgence of food, drugs
Pain
44
Anorexia and vomiting
Can cause serious complications
such as
Dehydration, acidosis, malnutrition
45
Anorexia
Often precedes
nausea and vomiting
46
Nausea
Unpleasant subjective feeling
Simulated by distention, irritation, inflammation of digestive tract
Also stimulated by smells, visual images, pain, and chemical toxins and/or drugs
47
Vomiting (emesis)
center located in the
medulla
48
Vomiting (emesis)
Vomiting center located in the medulla
Coordinates activities involved in vomiting
Protects airway during vomiting
Forceful expulsion of chyme from stomach
Sometimes includes bile from intestine
49
Bulimia—eating disorder
Damage to structures of the GI tract caused by recurrent vomiting
Oral mucosa
Teeth
Esophagus
50
Vomiting Center Activation
Distention or irritation in digestive tract
Stimuli from various parts of the brain
Response to unpleasant sights or smells, ischemia
Pain or stress
Vestibular apparatus of inner ear (motion)
Increased intracranial pressure
Sudden projectile vomiting without previous nausea
Stimulation of chemoreceptor trigger zone
By drugs, toxins, chemicals
51
Vomiting Reflex Activities
Deep inspiration
Closing the glottis, raising the soft palate
Ceasing respiration
Minimizes risk of aspiration of vomitus into lungs
Relaxing the gastroesophageal sphincter
Contracting the abdominal muscles
Forces gastric contents upward
Reversing peristaltic waves
Promotes expulsion of stomach contents
52
Hematemesis
Presence of blood in emesis
53
Coffee ground vomitus(Characteristics of Vomitus)
brown granular material indicates action of HCl on hemoglobin
(Hydrochloric acid)
54
Hemorrhage(Characteristics of Vomitus)
red blood may be in vomitus
55
Yellow- or green-stained vomitus(Characteristics of Vomitus)
Bile from the duodenum
56
Deeper brown color(Characteristics of Vomitus)
May indicate content from lower intestine
57
Recurrent vomiting of undigested food(Characteristics of Vomitus)
Problem with gastric emptying or infection
58
Diarrhea
Excessive frequency of stools
Usually of loose or watery consistency
May be acute or chronic
Frequently with nausea and vomiting when infection or inflammation develops
May be accompanied by cramping pain
Prolonged diarrhea may lead to dehydration, electrolyte imbalance, acidosis, malnutrition
59
Prolonged diarrhea may lead to
dehydration, electrolyte imbalance, acidosis, malnutrition
60
Large-volume diarrhea (secretory or osmotic)
Watery stool resulting from increased secretions into intestine from the plasma
Often related to infection
Limited reabsorption because of reversal of normal carriers for sodium and/or glucose
61
Small-volume diarrhea
Often caused by inflammatory bowel disease
Stool may contain blood, mucus, pus
May be accompanied by abdominal cramps and tenesmus
62
Steatorrhea—“fatty diarrhea”
Frequent bulky, greasy, loose stools
Foul odor
Characteristic of malabsorption syndromes
Celiac disease, cystic fibrosis
Fat usually the first dietary component affected
Presence interferes with digestion of other nutrients.
Abdomen often distended
63
Steatorrhea—“fatty diarrhea” is a characteristic of malabsorption syndromes such as
Celiac disease, cystic fibrosis
64
Blood may occur in normal stools with
diarrhea, constipation, tumors, or an inflammatory condition.
65
Frank blood
Red blood—usually from lesions in rectum or anal canal
66
Occult blood
Small hidden amounts, detectable with stool test
May be caused by small bleeding ulcers
67
Melena
Dark-colored, tarry stool
May result from significant bleeding in upper digestive tract
68
Significant bleeding in upper digestive tract may cause which type of blood in stool
Melena
69
Gas
From swallowed air, such as drinking from a straw
Bacterial action on food
Foods or alterations in motility
Excessive gas causes:
Eructation(belch)
Borborygmus(a rumbling or gurgling noise made by the movement of fluid and gas in the intestines.)
Abdominal distention and pain
Flatus(passing gas)
70
Constipation
Less frequent bowel movements than normal
Small hard stools
Acute or chronic problem
May be caused by decreased peristalsis
Increased time for reabsorption of fluid
Periods of constipation may alter with periods of diarrhea.
Chronic constipation may cause hemorrhoids, anal fissures, or diverticulitis.
71
Chronic constipation may cause
hemorrhoids, anal fissures, or diverticulitis.
72
Causes of Constipation
Weakness of smooth muscle because of age or illness
Inadequate dietary fiber
Inadequate fluid intake
Failure to respond to defecation reflex
Immobility
Neurological disorders
Drugs (i.e., opiates)
Some antacids, iron medications
Obstructions caused by tumors or strictures
73
Fluid and Electrolyte Imbalances
Dehydration and hypovolemia are common complications of digestive tract disorders.
Electrolytes
Lost in vomiting and diarrhea
Acid-base imbalances
Metabolic alkalosis
Results from loss of hydrochloric acid with vomiting
Metabolic acidosis
Severe vomiting causes a change to metabolic acidosis because of the loss of bicarbonate of duodenal secretions.
Diarrhea causes loss of bicarbonate.
74
Pain: Visceral Pain
Burning sensation
Inflammation and ulceration in upper digestive tract
Dull, aching pain
Typical result of stretching of liver capsule
Cramping or diffuse pain
Inflammation, distention, stretching of intestines
Colicky, often severe pain
Recurrent sooth muscle spasms or contraction
Response to severe inflammation or obstruction
75
Pain: Somatic Pain
Somatic pain receptors directly linked to spinal nerves
May cause reflex spasm of overlying abdominal muscles
Steady, intense, often well-localized abdominal pain
Involvement or inflammation of parietal peritoneum
Rebound tenderness—identified over area of inflammation when pressure is released
76
Pain: Referred Pain (1 of 2)
Common phenomenon
Pain is perceived at a site different from origin.
Results when visceral and somatic nerves converge at one spinal cord level
Source of visceral pain is perceived as the same as that of the somatic nerve.
May assist or delay diagnosis, depending on problem
77
Source of visceral pain is perceived as the same as that of the
somatic nerve
78
Malnutrition
May be limited to a specific nutrient or general
Causes of limited malnutrition—specific problem
Vitamin B12 deficiency
Iron deficiency
Causes of generalized malnutrition
Chronic anorexia, vomiting, diarrhea
Other systemic causes
Chronic inflammatory bowel disorders
Cancer treatments
Wasting syndrome
Lack of available nutrients
79
Causes of limited malnutrition—specific problem
Vitamin B12 deficiency
Iron deficiency
80
Causes of generalized malnutrition
Chronic anorexia, vomiting, diarrhea
81
Basic Diagnostic Tests
Radiography
Contrast medium may be used.
Ultrasound
May show unusual masses
Computed tomography (CT)
Magnetic resonance imaging (MRI)
CT and MRI may use radioactive tracers.
Can be used for liver and pancreatic abnormalities
82
Basic Diagnostic Tests (2 of 2
Fiberoptic endoscopy used in upper GI tract
Biopsy may be done during procedures.
Sigmoidoscopy and colonoscopy
Biopsy and removal of polyps may be done
Laboratory analysis of stool specimens
Check for infection, parasites and ova, bleeding, tumors, malabsorption
Blood tests
Liver function, pancreatic function, cancer markers
83
Common Therapies and Prevention
(Malnutrition)
Dietary modifications
Example—gluten-free diet (celiac disease)
Reduced intake of alcohol and coffee
Increased fiber and fluid intake
Stress reduction techniques
Stress impairs immune function and tissue healing.
Drugs
Variety of medications are available.
84
Antacids
To relieve pyrosis(heartburn)
85
Antiemetics
To relieve vomiting
86
Laxatives or enemas
Treatment of acute constipation
87
Antidiarrheals
Reduction of peristalsis
Relieve cramps
88
Sulfasalazine
Anti-inflammatory and antibacterial
Used for acute episodes of inflammatory bowel disease
89
Clarithromycin or azithromycin
Effective against Helicobacter pylori infection
Usually combined with a proton pump inhibitor
90
Sucralfate
Coating agent
Enhance gastric mucosal barrier against irritants such as nonsteroidal anti-inflammatory drugs (NSAIDs)
91
Anticholinergic drugs
Reduce PNS activity
Reduce secretions and motility
92
Histamine 2 antagonists
Useful for gastric reflux
93
Proton pump inhibitors
Reduce gastric secretion
94
Upper Gastrointestinal Tract Disorders
Disorders of the Oral Cavity
Dysphagia
Esophgeal Cancer
Hiatal Hernia
Gastroesophageal Reflux Disease
Gastritis
Peptic Ulcer
Gastric Cancer
Dumping Syndrome
Pyloric Stenosis
95
Cleft lip and cleft palate
(Disorders of the Oral Cavity)
(Congenital abnormalities)
Arise in sixth to seventh week of gestation
Most likely of multifactorial origin
Feeding problems of the infant
High risk of aspirating fluid into respiratory passages
Speech development impaired
(Treatment)
Surgical repair done as soon as possible
Therapy with speech-language pathologist and orthodontist
96
Inflammatory lesions—aphthous ulcers
Streptococcus sanguis may be involved.
Part of the oral resident flora
Small painful lesions on:
Movable mucosa
Buccal mucosa
Floor of the mouth
Soft palate
Lateral borders of the tongue
Usually heal spontaneously
97
Candidiasis
Candida albicans—causative agent
Often part of the resident flora
Opportunistic organism
Oral candidiasis (thrush)
People receiving broad-spectrum antibiotics
During and after cancer therapy
Immunocompromised individuals or those with diabetes
May appear as red, swollen areas
May be irregular patches of a white curdlike material
98
Herpes simplex type 1 infection
Herpes simplex virus type 1 (HSV-1)
Transmitted by kissing or close contact
Virus remains dormant in sensory ganglion
Activated by stress, trauma, other infection
Formation of blister, ulcers, clear fluid release—contains virus; can be autoinoculated to other areas
Lesions heal spontaneously in 7 to 10 days.
Acute stage may be alleviated by antiviral medication.
May spread to eyes
Conjunctivitis and keratitis
99
Complications of Herpes Type 1 if spread to eyes
Conjunctivitis and keratitis
100
Herpetic Whitlow
a painful infection of the finger or thumb caused by the herpes simplex virus (HSV
101
Syphilis is caused by
Treponema pallidum
102
Primary stage Of Syphilis
Chancre, a painless ulcer on tongue, lip, palate
Heals spontaneously (1 or 2 weeks)
May cause oral lesions
Highly contagious during first and second stages
Both stages treated with long-acting penicillin
103
Secondary stage Of Syphilis
Red macules or papules on palate—highly infectious
Heals spontaneously
May cause oral lesions
Highly contagious during first and second stages
Both stages treated with long-acting penicillin
104
