GI P1 Flashcards
What are the major function of the GI system?
Major fxns:
ingestion (take nutrients in)
Digestion (eliminate solid waste)
Absorption
Of nutrients, vitamins, mineral, electrolytes, water= supply energy to fuel body.
- collection and elimination of solid wastes
The gi tract is an..
Extension of the external environmnt
For something to be considered par of your body,
It had to cross intestinal wall, enter your blood, r your lymph nodes
What are the 4 divisions/sections of the gi tract
- Upper (mouth, esophagus, stomach) **intake valve
- Middle (small intestine:consists of duodenum, jejunum, & ileum) **majority of digestion and absorption
- Lower (cecum, colon, rectum, anal canal & appendix) **mostly storage & waste
- Accessory organs (salivary glans, liver, exocrine pancreas) *food doesn’t actually pass through=produce enzymes and digestive secretions that help food digestion
What is your normal flora?
Bacteria in intestines
Appendix = safe house for normal flora
Probs that could affect different divisions ofGI tract:
Upper: weak or incompetent esophageal sphincter (end of the esophagus that joins the stomach)
Job of esophageal sphincter?
Prevent reflux: you don’t want food in stomach refluxing into esophagus= complaints of heartburn, hoarse voice, dry cough de to acid reflux (inflammation)
If the reflux is CHRONIC…
It is referred to as GERD (Gastrointestinal reflux dz)
Caused by: weak/incompetent esophageal sphincter
Due to chronic inflammation what will we see?
More serious than a heart attack = scar tissue formation in esophagus.
Prob w scar tissue? Narrowing or stricture, which would cause pt to complain of difficulty swallowing.
What is the medical term for difficulty swallowing?
Dysphagia (feeling like food is stuck in your throat/esophagus) ex: taking vitamins, feeling like its stuck)
Probs that could affect different divisions of GI tact:
Lower: Appendicitis (inflammation of appendix)
Why is obstructions in the appendix a problem?
Obstruction is a problem bc secretions can’t get out= increased accumulation and pressure that will compress on the blood vessels in wall of appendix
What will result if pressure compresses on blood vessels in the appendix?
Results in appendix becoming ischemic(impaired blood flow/oxygen)
If appendix is ischemic= death of tissue
If appendix is ischemic=death of tissue
What is the medical term for death or tissue?
Gangrenous or necrotic meaning it could rupture or perforate
Upper GI:
When cells are exposed to chronic irritation /inflammation=
Undergo metaplasia in esophagus(changing from one cell type o another that is better able to withstand irritation)
If this happens this could result in……?
Dysplasia!(term used to describe presence of abnormal cells within a tissue or organ) which is a RF for cancer
What are the 5 layers/ structure of the GI Wall?
- Mucosa (very inside layer made up of epithelial cells that produce mucus)
Purpose=lubricate and protect inner lining of GI tract - Submucosa (made of CT, has all blood vessels, nerves, and glands that make DIGESTIVE ENZYMES)
- Circular smooth muscle (mixing action of GI tract)
- Longitudinal smooth muscle (facilitates movement of contents of GI tract)
- Serous a (very outside double-layered membrane called the peritoneum
One layer of the peritoneum is attached to_______ and the other layer is attached to ________
- Outside of GI tract
- Abdominal wall
Between the two peritoneum layers (GI tract & abdominal wall) is the…
Peritoneal space/cavity: has small amount of fluid to decrease friction
PROBS that affects GI wall:
I there is a large amount of fluid in peritoneal space, this is called..
Ascites
PROBS that affect GI wall:
If injured by trauma or disease, like any other tissue, this might cause
GI bleed
Look for pts who have blood in stool or in vomit
Red or black/ tarry stool indicates..
Blood in stool: occult (hidden/cant always be seen w eyes)
If hidden do chemical tests like Guaiac or hemoccult
Black/ tarry stool: Melina (exposure to digestive enzymes)
GI bleeds: vomit also called ______ in medical terminology
Hematemesis (hema: blood, -emesis: vomit)
Hematemesis could be bright red (anal, rectal, or esophageal bleeding) or have a dark/chunky coffee ground look (comes from stomach or small intestine)
What makes vomit look dark/chunky coffee grounds?
Exposure to all acids in digestive enzymes
Sterile questions:
Peritoneum is___
GI tract is _____
STERILE
NOT STERLE
Since GI Tract is not sterile, if the contents were to leak in the peritoneal space, what happens?
Appendix ruptures, stomach ulcer proliferating through stomach wall, or GI surgery/stab or gunshot wound
If content leaks in peritoneal space this means?
We are contaminating a sterile space so we should expect inflammation and infection to occur, fever, high WBC ct., pain (aggravated by movement,etc..)
In the case of peritonitis, third spacing can happen..
By fluid shifting either in the peritoneal space or the GI tract
Why is there fluid shift?
Part of the inflammatory response=blood vessels get “leaky”
Third spacing (fluid leaving blood vessels) →
Hypovolemia (low blood vol.) → hypotension (low BP) → tachycardia (body’s attempt to bring BP back up)
Mobility in the GI tract →
Motility(move from one end to another)
→smooth muscle happens automatically (don’t have to think ab it, it just happens)
2 places that have voluntary skeletal muscle instead of smooth muscle
- Pharynx (upper part of the esophagus) top of gi tract- voluntary control over what you swallow
- External anal sphincter (voluntary control of bowel movement)
PROBS that can affect GI motility (move from one end to another)
- infection/ inflammation in intestines: peristalsis becomes fast = diarrhea
- vomiting (reverse peristalsis) → things are moving through GI tract in wrong direction
Vomiting center in the medulla:
GI tract → vomiting center (vomit to relive dissension) → cerebral cortex (see/smell something horrid) → ‘vesti’bular center (inner ear=balance/carsick,sea sick, air sick) →chemoreceptor trigger zone( job: monitor blood for presence of anything poison/toxic// protective purpose)
If there is a lot of diarrhea what kind of problem happens?
FLUID IMBALANCE, ELECTROLYTE IMBALANCES, & MALNUTRITION/MALABSORPTION
What is the useful purpose of vomiting ?
-tells you something is wrong (dz process)
-gets rid of poisons/toxins
If there’s too much vomiting for a prolonged time, what problems will it cause?
Acid-base imbalances, fluid imbalance, electrolyte imbalance
How GI fxn is regulated: 3 control mechanisms
1.Enteric nervous system (intrinsic)
2. Autonomic NS
3. GI Hormones that regulate digestion