What makes up the upper GI tract?
- Mouth/ oral cavity
WHat makes up the lower GI tract?
- Gall bladder
- Large intestine
What is the gut wall of the upper GI tract made up of?
What part of the gut wall is the mucosa? And what is its function?
- Inner most layer
- epithelium includes mucus producing cells
What is the submucosa in the gut wall made of?
- - it is the middle layer
- - connective tissue
- - blood vessels
- - nerves
- - lymphatic
- - secretory glands
- - circular and longitudinal muscle layers
What is the serosa layer of the GI tract?
- outer layer
- visceral peritoneum
- fluid (sera)
WHat is the oral cavity function of the GI tract?
- - initial phase of mechanical breakdown of food
- - mastication by teeth
- - initial chemical digestion- salivary amlase
- - formation of bolus
- Swallowing - tounge and pharynx
- Esophagus- closed except for when swallowing, skeletal mm at superior end which gradually replaced by smooth mm
What is swallowing also known as? ANd done by?
- - deglutition
- - tounge and pharynx
What nerve innervates mastication?
CN V- trigeminal
What nerve innervates taste and saliva?
CN IX- glossopharyngeal
What nerve innervates the stimulation of digestion and peristalsis?
CN X- Vagus
What nerve innerates the tounge, esophagus and swallowing?
CN XII- Hypoglossal
What are some disorders of the oral cavity>
- - cleft lift and cleft palate
- - Aphthous Ulcers
- - Inections- opportunistic flora
- - Dental caries- infection
- - Peridontal disease
- - Inflammatory Dysfunction- hyperferatosis, Sialadenitis, infectious parotitis
What is cleft lip and cleft palate disorder?
- - disorder of the oral cavity
- - arise 2-3 months of gestation
- - feeding problems
- - high risk of aspirating fluid
- - speech development impaired
What is the Aphthous Ulcer?
- - An inflmmatory lesions
- - Oral cavity disorder
- - physical injury
- - chemical injury
- - infection- streptococcus sanguis
- - immunological
- - allergy
- - dietary
- - painful, heat, redness, swelling
- - ulceration- intact or ruptured mucosa (cranker)
What are some of the infections of the oral cavity?
- Opportunstic flora
- Dental caries
What are some opportunistic flora of the oral cavity?
- - streptococcus sanguies
- - candida albicans (candidasis- fungal)
- - immunocompromised
What is an infectious organism of theoral cavity?
- - herpes simplex virus 1 (HSV-1)
- - clse contact transmission
- - viruse in sensory ganglion may remain dormant
- - activated by stress, trauma, other infetion
- - formation of blister, ulcers, clear fluid release- virus. Lesions heal spontaneously in 7-10 days
- May spread to eyes- conjunctivitis
What is the oral cavity disorder dental caries?
- - infection
- - initiating microorganism- streptococcus mutans- lactobacillus follows in large numbers
- - bacteria break down sugars- increase LA
- - LA dissolves mineral in tooth enamel- tooth erosion and cavity formation- caries
What promotes dental caries?
- - intake of sugars and acids
- - fissures in tooth surface
- - dry mouth
- - laque formation
- - periodontal disease
What is periodontal disease of the oral cavity?
- - infection and damage to the gingiva, periodontal ligament and bone- poor oral hygiene, systemic factors
- - Gingivitis- local or systemic problem- inflammation of the gingiva- red, soft, swollen, bleeds easily
- - Periodontitis- activity of the destructive microbe, aggravated by smoking, cancer, diabetes, inflammation in tissues/ bone around the tooth
What is the inflmmatory oral cavity dysfunction hyperkeratosis?
- - leukoplakia
- - whitish plaque or epidermal thickening of mucosa
- - occurs on buccal mucosa, palate, lower lip
- -chronic irriation- epithelial may develop into squamous cell carcinoma
What is the inflammatory dysfunction of the oral cavity sialadenitis?
- Inflammation og the salivary glands
- can be infectious and non infectious
- most common- parotid gland
What is infectious parotitis?
- - inflammatory dysfunction of the oral cavity
- - viral infection- mups
What is the muscle types of the esophagus?
- -upper esophagus- striated mm
- -lower " " - smooth muscle
- Longitudinal and circular layers for peristalsis
What are some functional compromise/mobility disorders of the esophagus that leads to dysphagia (swallowing is difficult of painful)?
- - stenosis- chromic inflammation, fibrosis, esophagitis
- - tumor- internal or external
- - diverticular formation- outpouching, herniation
- - developmental defects- atresia (narrowing of opening to trachea), fistula (hole betweento organs or surfacesthat isnt to bethere)
- Neurological defects- infection, stroke, achalasia (disorder of esophagus- problems swallowing)
- Muscle impairment- ie diaphragm dystrophy-hiatal hernia
What are the disorders of the esophagus?
- Hiatus hernia
- Gastroerophageal reflux (GORD)
What is a hiatus hernia?
- - part of the stomach protrudes through the diaphragm into the thoracic cavity
- - sliding hernia- more common type, portion of the stomach and gastroesophageal junction slide up above the diaphragm
- - rolling or paraesophageal hernia- part of the fundus of the stomach moves up through an enlarged or weak hiatus in the diaphragm and may become trapped. Food lodges in pouch- inflammation of mucosa, reflux of food up esophagus- obstruction, dyspahgia, blood vessels trapped- ulceration, esophagitis
What is GERD?
- periodic reflux/ flow of gastric contents into distal esophagus- pain, inflammation- errosion of mucosa- ulceration, fibrosisand stricture
- Precipitated by:
- - hiatal hernia
- - lower esophageal sphincter incompetence
- - delayed gastric emptying
- - carreince, fatty/ spicy foods, alcohol, smoking and certain drugs
What are the disorders of the stomach?
- - gastritis- acute and chronic
- - gastroenteritis
- - gastric and peptic (duodenal) ulcers
- - dumping syndrome
- - pyloric stenosis
What is acute gastritis?
- - inflamation
- - acute (self limiting)
- - gastric mucosa inflammation- ulcerated and bleeding (transient or progressive)
- Precipitating events:
- - infection by microorganisms
- - allergies to food
- - spicy or irritating foods
- - excessive alcohol intake
- - ingestion of ulcerogenic drugs eg aspirin
- - ingestion of corrosive or toxic substances
- - radiation or chemotherapy
What is chronic gastritis?
- Chronic inflammation of the stomach mucosa
- Atrophy of the mucosa and loss of secretory glands
- decrease parietal cells- achlorhydria and decrease intrinsic factory- loss of vit B12 absorption
What are the signs and sympoms of chronic gastritis?
- - anorexia, nausea, epigastric discomfort, vomiting, cramps, pain and hematemesis (vomiting blood)
- - infection- headache, fever, diarrhea
- - prolonged vomiting- dehydration, electrolyte loss and metabolic acidosis
- - chronic- peptic ulcers and gastric carcinoma (stomach cancer)
What is gastroenteritis?
- - inflammation of stomach and intestinal mucosa
- stomach- vomiting
- intesting- diarrhea
What is the usual cause of gastroenteritis?
- Usually due to infection
- - enterotoxins
- - inflammation
- - ulceration
- - neurotoxins
- - allergic reactions to food or drugs
Where do gastric and peptic ulcers occur?
- - stomach and duodenum
- -penetrates submucosa
What are some contributing factor to gastric and peptic ulcers?
- - inadequate blood supply
- - increase in glucocorticoid secretion (involed in COH absorption)
- - ulcerogenic substances
- - chromic gastritis (inflammation of the lining of the stomach)
How does a peptic ulcer occur?
- - acid or pepsin penetrates the mucosalbarrier
- - tissue damage into muscularis
- - inflammation around the area
- - blood vessel involvement (perforation)- bleeding or hemorrhage
- - increase in acid and pepsin secretions
- - rapid gastric emptying
What factors lead to mucosal damage?
- - decrease mucosal resistance
- - increase in HCL
- - increase in pepsin secretions
- - helicobacter pylori (bacteria in stomach)
In the stomach what occurs in relation to an increase in acid- pepsin secretions?
- - increase gastric secretions
- - increase vagal stimulation (secretion and peristalsis)
- - increase number of acid- pepsin secretory cells
- - stimulates acid- pepsin secretions- alcohol, caffeine,certain foods
- - rapid gastric emptying
What is the dumping syndrome?
- - stomach syndrome
- - loss of control of gastric emptying
- - due to gastrectomy (removal of pyloric sphincter)
- - dumping of food into intestine
What is pylric stenosis?
- - stomach disorder
- - narrowing and obstruction of pyloric sphincter
- - developmental or acquired
What are the signs and symptoms of pyloric stenosis?
- - projectile vomiting immediately after feeding
- - firm mass at pylorus
- - decrease wieght
- - increase dehydration
- - persistnet hunger
- - persistent feeling of fullness
- - increased incidence of vomiting
What are some lower GI tracts diseases?
- Celiac disease
- Chronic inflammatory Bowel disease
- Chroh's disease
- Diverticular disease
- Colorectal Cancer (CRC)
- Interstinal Obstruction
What is celiac disease?
- - lower GI tract
- - malabsorption syndrome
- - primarily a childhood disorder- may occur in adults- middle age
- - defects in intestinal enzymes- might be linked to a genetic factor
- - prevents further digestion of gliadin-breakdown product of gluten- grains
- - immunological response- toxic effect on intestinal villi- atrophy of villi results in a decrease in enzyme production and SA
- - malabsorption and malnutrition- steatorrhea, mm wasting, low weight gain
What are some chronic inflammatory bowel disease?
- - Crohns disease- SI
- -ulcerative colitis- rectu, and proximally in colon
What is crohns diease?
- - inflammation - ulcer- coalesce- fissues/ abscesses/fistulas- fibrosis- stricture and obstructuion
- - involves all layers- granulomas are indicative
- - increase insetinal motility- decrease in digestion and absorption
What is ulcerative Colitis?
- - a lwer GI tract disease
- - inflammation of mucosa and submucosa
- - changein goblet cell activity
- - edematous tissue and ulcerations develop- decrease in absorption of fluid and eletrolytes
- - increased risk of colorectal carsinoma
What is appendicitis?
- - lower GI tract disease
- - inflammation and infection of the appendix
What is the pathophysiology of appendicitis?
- - obstruction of appendiceal lumen - gallstone, foreigb material, twisting, spasm
- - increase fluid build up in appendix
- - microorganisms proliferate- inflammation of wall, purulent exudate, swelling, congestion and pressure within the appendix- ischemia and necrosis- increases permeability
- - bacteria and toxins escape through the wall - infection or peritonitis around the appendix- spread aling the peritoneal membrances
- -increased necrosis and gangrene in the wall- increase pressure
- - appendix ruptures or perforates- release of contents into peritoneal cavity- generalised peritonitis.
What is diverticular disease?
- - lower GI tract disease
- - development of diverticular (pouching)
- - diverticulum- outpuching (herniation) of themucosa through the mm layer of the colon- sigmoid colon
- - diverticulosis
- * asymptomatic diverticular disease
- * imflammation of the diverticular
What is the pathophysiology of the diverticular disease?
- - diverticula form at gaps between mm layers- weak wall
- - when pressure increases wall bulges outwards
- - stasis of feces in diverticula- inflammation and infection (diverticulitis)
- - intestinal obstruction
- - perforation/ peritoitis. abcess formation = cramping, tenderness, nausea, vomiting
What is colorectal cancer? CRC
- - develops from adenomatous polyps- dysplasia of polyp and malignant changes- CRC
- - distributed throughout the colon and rectum
What is the cause of CRC?
- - genetic
- - diet
- - ulcerative colitis
- Which leads to
- - alter bowel function
- - obstruction
- - pain
- - bowel perforation
What are the signs and symptoms of CRC?
What is intestinal obstruction?
- - lower GI tract disease
- - lack of movement of intestinal contents through the intestines- more common in SI
- - Acute or progressive
What are the mechanical obstruction of inestional obstructions?
- twist (volvulus)
What are the functional intesinal obstructions?
- spinal cord injury
- paralytic ileus due to toxins
- abdominal surgery- ischemia
- inflammation or infection
- mesenteric thrombosis
What is the pathophysioogy of the intestinal obstruction?
- - gases and fluids proximal to blockage, distending the intestine
- - strong contractions of proximal intestine
- - pressure increases in lumen- increases secretions into intestine, compression of veins in wal, intestinal wall become edematous= prevention of absorption
- - inestinal distention- persistent vomiting- additional lossof fluid and electrolytes- hypovolemia
- - inetinal wall becomes ischmic and necrotic- decrease arterial blood supply due to the pressure- gangrene ensues, decrease innervation and cessation of peristalsis
- - bacteria leak into the peritoneal cavity or blood- peritonitis or septicemia
What are the effects of intestinal obstruction?
Manifestations of GIT disorders
- - anorexia, nausea and vomitins- ways of eliminating noxious substances- emetic reflex
- - can lead to dehydration, acidosis, malnutrition
- - risk of aspiration- supine, unconsciou, drug/ alcohol
- - diarrhea
- - constipation
- - fluid and electrolyte imbalance
- - pain
- - malnutrition