The Gastrointestinal System

The Virtual Autopsy

           The Gastrointestinal System~A Major part of the Digestive System~

              

-Digestion -Absorption -Excretion 

                ~Important Organs~1. The Esophagus: Tube that connects the Pharynx with the Stomach. After food is chewed, it is passed through this tube and into the stomach   2. The Stomach: Where both mechanical and chemical digestion occurs, stores food, controls the rate at which food enters the intestines   

             ~Important Organs~

3. The Small Intestine: Finishes process of digestion, absorbs the nutrients, passes residue into the large intestine   4. The Pancreas: Secretes enzymes to aid in digestion of food in the small intestine

 

Important Organs continued...

5.The Large Intestine: Reabsorbs water and maintains the fluid balance of the body, absorbs vitamins, processes undigested material, stores waste 6. Liver: Produces bile and emulsifies fats    BILE: neutralizes chimeBreaks down and recycles red blood cells 7. Gallbladder: accessory gland that stores bile -The body can function without the gall bladder 

 

Specialized Cells 

 • Mucous Cells:

1. specialized to secrete mucus2. movement; protective lining3. located in the mouth, esophagus, stomach,intestine (Goblet Cells)

 • Stem Cells- divide to replace dead

cells so that they can function properly

 

•  lining of the intestine that absorbes the nutrients across the plasma membrane into connective tissues and capillries.

  

• Columnar epithelial cells , scattered individually on the absorptive cells

• Secrete a particular hormone that influences  gastrointestinal secretion and motion.

      Stomach=Enteroendocrine Cells      Intestine= Islets of Langerhans-secrete insulin.

Endocrine Cells

Absorptive Cells

• They secrete digestive enzymes (pepsins) in the stomach

 

Chief Cells

Hepatocytes• cuboidal cells in Liver• Functions: secrete bile,

create urea and plasma proteins, and metabolize cholesterol

I m p o r t a n t ENZYMES

Peptic Ulcers---!!OH NO!!!=[You might ask "What is a peptic ulcer?!"...

Peptic Ulcers are erosions, or open soars, in the inner lining of the stomach.

AND when you talk about peptic ulcers, we cant forget about...H

pylori

A bacterium that infects the stomach or the first part of the small intestine

Peptic Ulcers...                                          

Symptoms & Treatments  

{Symptoms}

-Abdominal Pain (most common)

-Nauseous -Bloody Stool/Vomit-Chest pain

[Treatments]-QUIT SMOKING >:O-Acid blocking medication-Bowel rests-Nasogastric tubes

Gastritis

What causes Gastritis• Heavy consumption of alcohol• Certain medications

o Aspirino Nonsteroidal anti-inflammatory, such as ibuprofen

• Bacterial infections, such as Helicobacter pylori, a bacteria that lives in the mucous lining

• Pernicious anemia – form of anemia that occurs when the stomach lacks a naturally occurring substance needed to properly absorb and digest vitamin B12

• Sometimes after major surgeries• Bile reflux- a backflow of bile into the stomach from the bile

tract 

 

How do you know you have gastritis?

Symptoms:• Nausea• Vomiting• Loss of appetite• Belching or bloating• Burning ache or pain in the stomach• Black stool

 Acute Gastritis brings sudden pain and is more likely to cause nausea. Chronic Gastritis occurs over a period of time associated with gradually increasing pain and loss of appetite

Testing and Treatment

Diagnosis:• Blood test- to check the presence of H. pylori • Breath test- simple test can evaluate if infected by H. pylori• Stool test• Upper gastrointestinal endoscopy• Upper gastrointestinal X-ray

 Treatment:

• Antacids- to reduce stomach acids, which cause the sharp pains.

• Antibiotics- to rid the H.pylori infections• If gastritis is caused by pernicious anemia, B12 vitamin shots

will be given.

Crohn's Disease (IBD)

Etiology:• No real known cause, several

theories but none proven• Hereditary, usually passed down

through families

Symptoms:• More common: Abdominal pain,

diarrhea, weight loss• Less common: poor appetite, fever,

night sweat, rectal pain and bleeding

  

Crohn's Disease (cont.)

Treatment:• Drug therapy: anti-inflammatory

medication, immunosuppressive agents, infliximab

• Surgery: manages possible complications with disease, removes infected, inflamed portion of the digestive tracto Most Crohn's patients will

need surgery at one point during illness.

• No cure for disease, like cancer can only go into remission

CholeraxEtiology:• Bacterium Vibrio cholerae

infects intestines, often mildly• More common in

underdeveloped countries with poor water filtration and sewage systems

Symptoms:• Most display no symptoms• Severe cases: watery diarrhea,

vomiting, muscle cramps• Death only caused in

undetected cases where patient dies of dehydration

Cholera (cont.)Treatment: • Requires immediate treatment,

otherwise death may occur within hours

• Rehydrationo ORT: Oral Rehydration

Therapyo Intravenous Fluid

Replacemento Without rehydration, 50% of

patients die• Antibiotics: used to shorten

illness, but rehydration is still necessary

 ~Connections with Other Systems~

1. With the Circulatory System:The circulatory system transports nutrients throughout the body as well as hormones that control the speed of digestion  2. With the Excretory System:Ejection of undigested material.Digestion system works parallel with system

 

  ~Connections with other systems~

3. With the Endocrine System: Secretion of digestive hormones like gastrin to start digestion or release bile 4. With the Nervous System:Muscles of digestive tract are under control of the autonomic nervous system 5. With the Muscular System:Muscles make up the digestive tract for peristalsis along with stomach for mechanical digestion