DigestionAcid Reflux/Heartburn
If the gastroesophagial sphincter does not close properly, acid from the stomach can enter the esophagus.
This causes a burning sensation .
Smoking can be cause because it relaxes the sphincter and stimulates acid production.
Stomach Ulcers
An open sore in the lining of the stomach causing pain and sometimes bleeding
For a very long time, the medical community believed that ulcers were caused by stress
In fact, they are caused by a bacteria called H. pylori
Stomach Ulcers
H. pylori can enter the body through food or water.
It is able to survive the acid environment in the stomach by burrowing into the mucosa and stopping the production of protective mucus.
Without the protective mucus, HCl will destroy the stomach lining creating the ulcer.
Can be treated with antibiotics
H. pylori may reduce the production of gastric acids because it damages the cells producing gastric juice.
However, gastrin will still be released and attempt to stimulate these cells to produce gastric juice.
As a result, it can lead to gastric cancer (stomach cancer)
H. pylori can increase the amount of gastric acid which can lead to duodenal ulcers (because of the large volume of acid entering the duodenum)
Vomiting is a protective mechanism for removing toxins or foreign substances from the body.
It is a strong muscular contraction that forces the contents of the stomach up through the esophagus and out through the mouth.
Strong contraction of the diaphragm and tightening of the abdominal muscles force the stomach contents upward.
During this process the gastroesophagial sphincter relaxes to allow stomach contents (vomitus) out
During vomiting, breathing stops as the larynx and epiglottis close the entrance to the trachea.
Causes of Nausea and Vomiting
It is a symptom, not a disease
The signal for vomiting comes from the “vomiting center” in the brain
Triggers:
Drugs – ex: chemotherapy, alcohol
Brain – ex: meningitis, tumors
Injury – ex: hemorrhage, concussion
Risks
Dehydration
If vomitus enters the respiratory tract, the individual could develop an infection in the lungs.
(Excessive alcohol consumption and drug use impairs the reflex controlling the closing of the respiratory tract during vomiting)
Diarrhea
Most of the water in the food we eat and in the liquids we drink is absorbed in the colon.
When water is absorbed, feces is formed into a solid mass.
If there is inadequate water absorption, then the feces egested in a watery form known as diarrhea.
Causes and Risks
It is a protective mechanism to flush out foreign substances from the body.
These foreign substances including bacteria, viruses, and parasites enter the GI tract via contaminated food or water.
Aside from other complications due to the invading foreign substance, diarrhea can cause dehydration
Most cases of diarrhea are easily and successfully treated, however, diarrhea kills about 2 million children worldwide each year
This is more than AIDS, malaria, and measles combined.
Food borne illnesses that can cause diarrhea can be reduced by proper hygiene and proper storage and cooking of meat, poultry, and seafood.
After drinking alcohol, each time blood passes through the liver, hepatocytes (liver cells) attempt to remove the alcohol from the bloodstream.
The breakdown of alcohol produces free radicals and other reactive molecules that damage proteins, lipids and DNA.
Alcohol & the Liver
Long term alcohol abuse seems to interfere with normal liver metabolism of proteins, fats and carbohydrates
Long term alcohol abuse can result in: cirrhosis, fat accumulation, inflammation
Alcohol & the Liver
The scar tissue left when areas of hepatocytes, blood vessels and ducts have been destroyed by exposure to alcohol.
Areas of the liver, showing cirrhosis no longer function
Cirrhosis
“Fatty liver”
Damaged areas of the liver will build fat in place of normal liver tissue thus decreasing function.
Fat Accumulation
Inflammation
This is swelling of damaged liver tissue due to alcohol exposure
Sometimes referred to as alcoholic hepatitis
Hepatitis
Often leads to jaundice, lack of appetite, and general discomfort
Most cases are cause by a hepatitis virus; can also be caused by the ingestion of toxins (such as alcohol)
Acute infectious disease of the liver, caused by a hepatitis A virus.
Transmission: oral-fecal route from contaminated water or infected individual.
Greater risk of contracting virus in a developing country (because of inadequate water treatment)
Symptoms: fever, nausea, fatigue, loss of appetite, jaundice
Hepatitis A
Sexually transmitted diseased (transmitted in body fluids: semen, blood, vaginal secretions)
Symptoms: liver inflammation, jaundice, vomiting, death in rare cases, chronic cases may result in cirrhosis
Hepatitis B
Symptoms: asymptomatic (no symptoms) however, if it becomes chronic, cirrhosis, liver cancer, and liver failure may result.
Hepatitis C
Jaundice
Jaundice itself is not a disease but a symptom of liver complications or diseases.
Causes of jaundice:
What Causes Jaundice
When Kupffer cells in the sinusoids break down hemoglobin, the heme group is broken down into Fe atoms and the yellow pigment bilirubin
(Bilirubin is also released from the breakdown of other proteins such as myoglobin)
Bilirubin and Bile
Bilirubin is insoluble
In the liver it reacts with glucaronic acid to make it water soluble
The water soluble form is secreted with water, electrolytes, bicarbonate, cholesterol, phospholipids and salt to make BILE!
Bile is green-brown and is stored in the gall bladder and released into the duodenum to emulsify fats.
Bilirubin is excreted with feces and gives the characteristic brown colour to feces.
Some bilirubin will be released into the blood stream and be excreted with urine giving urine it’s characteristic yellow colour.
When a disease interferes with the normal metabolism or excretion of bilirubin, high amounts build up in the blood.
Normal Blood concentration of bilirubin: 1.2 mg/dl
Jaundice: higher than 2.5 mg/dl
Treatment of jaundice is to treat the underlying cause of the liver problems.
Newborns & Jaundice
Why?
Newborns have a high turnover of red blood cells (body is making new rbcs with normal hemoglobin rather than fetal hemoglobin)
Liver is still developing
Lack of chyme/feces in intestines results in reabsorption of bilirubin
Lack of sun exposure results in low levels of vitamin D which aide in bilirubin metabolism
Newborns & Jaundice
Treatment: exposure to UV light via a “bili lamp” or the sun
Allows babies to make vitamin D
The UV light will allow the excess bilirubin to be converted into products that can be excreted.
Appendicitis
Endoscopy
Medical scientists have developed methods of seeing inside the human body that are much safe and less traumatic than surgery
An endoscope is a tool that is designed to look inside the body
It is a narrow tube, with a light source, a lens, and a camera
It can be inserted through a natural opening in the body such as the mouth or anus or through a small incision into the body cavity
The procedure is called an endoscopy.
Can be used to remove a tissue sample biopsy, remove gall bladders
Compared to regular surgery, this procedure is less painful and has a shorter recovery time.
Technological advancements have allowed for the reaction of a time camera, small enough to fit inside a capsule that can be swallowed.
As the capsule passes through the digestive tract, it takes thousands of pictures that are transmitted wirelessly to a receiver.