Human Anatomy: Mouth and Stomach

Anatomy of the Mouth

• Teeth chew food to make it easy to swallow.
• Tongue moves food around the mouth and into the opening of the esophagus.
• The esophagus uses muscles to squeeze the food down toward the stomach.

Anatomy of the Stomach

• The stomach expands and contracts to hold food.
• It breaks food into small pieces.
• Stomach muscles located in the stomach's wall help break up the food.
• The stomach lining produces gastric juices that help break down food and kill bacteria.
• Digestion lasts 4 hours in the stomach.
• The stomach is made of smooth muscle which both produces and contains acid and a chemical that breaks down other chemicals (food and bacteria).
• Mucus protects the stomach from acid.
• Food turns to paste in stomach then liquid food out.
• The sphincter is a round muscle that controls flow of food/waste in the digestive tract.
• The esophagus is at the top of the stomach, while the pyloric is at the bottom.

Digestive System Overview

• The small intestine further breaks down food received from the stomach, so the body can absorb all the nutrients.
• Pancreas, liver, and gallbladder aid in breaking down the food by sending different gastric juices to the small intestine.
• The pancreas produces juices that help the body digest fats and proteins.
• The digestive system is nearly 30 feet in order to digest and absorb food, and 8 lbs of bacteria are in your gut (about a gallon).
• There are 3 types of teeth:
  • Incisors cut
  • Canines tear
  • Molars cut
• Tongue is skeletal muscle, esophagus is smooth muscle.
• Peristalsis is involuntary muscle movements that push food and waste through the digestive tract.
• The pancreas releases pancreatic juices, which contains enzymes for digestion and a substance to neutralize stomach acid, and also produces insulin, which can prevent diabetes.
• An enzyme is a protein that does something.
• Most proteins in the body are for structure, these aren't.
• Glucose comes from plants and starch is a long chain of glucose molecules.

Liver and Gallbladder

• The liver produces bile, which helps to absorb fats into the bloodstream.
• The gallbladder stores any extra bile for later use.
• The gallbladder, liver, and pancreas never touch your food.
• The liver further filters nutrients by removing any harmful substances or wastes.
• Some of the waste is turned into more bile, which goes to the small intestine to help with digestion or to the gallbladder for storage.
• The nutrients are then sent through the bloodstream to the rest of the body.
• The 3 functions of the liver:
  • Detoxifies the blood
  • Produces bile
  • Stores glucose as glycogen (chain of glucose)
• Alimentary canal = food tube from mouth to anus - doesn't include gall bladder, liver, or pancreas.

Large Intestine

• The large intestine removes the liquid parts of the food from the small intestine that cannot be used by the body.
• The colon removes the remaining water and some of the remaining minerals from the liquid.
• These materials are then absorbed into the blood.
• The rectum stores the solid waste until it is expelled.
• Small intestine is 15-20 feet long while the large intestine is 5-10 feet long.
• The 3 parts of large intestine:
  • Ascending colon
  • Transverse colon
  • Descending colon
• 11.5 Liters of fluid pass through intestines every day and comes from 6 sources: food/drink, saliva, acid, mucus, pancreatic juices, bile
• Only 0.1 L comes out as solid waste

Physiology of Digestion

• The digestive system performs two processes, digestion and absorption.
  • Breaks down food into small molecules.
  • Absorbs molecules into the body.
• There are 3 organs of the digestive system:
  • Mouth - breaks food into small pieces and using enzymes to digest the starch in the food.
  • Stomach - churns the food and mixes it with mucus and gastric juices that contain enzymes to further break down food.
  • Small Intestines - combines enzymes from the pancreas and liver to continue the breakdown of food.
• The Pancreas releases enzymes that digest carbohydrates, fats and proteins.
• The Liver filters toxins out of the blood from the intestines and produces bile.
• The Large Intestine removes water from food and creates feces.
• Saliva- enzyme named amylase breaks starch into glucose. |Organ| Mechanical | Chemical | |--|--|--| |Mouth| Teeth | Saliva| |Stomach| Muscle| Acid| |Small Intestine|X| Bile and panc. enzys|
• 80% of energy stored is as fats, while 20% is as carbs
• Some water, salt, sugar and alcohol are absorbed directly through the stomach wall.
• Vitamins, minerals, fats, carbohydrates, and proteins are absorbed directly into the bloodstream through the walls of the small intestine.
• Water is absorbed into the blood through the lining of the large intestine.
• There are 3 organs of absorption:
  • Stomach - some water, sugars, alcohol, salt
  • Small Intestine - vitamins, minerals, fats, carbs, proteins
  • Lg Intestine - most water
• 30 tons of food are eaten by you in your lifetime.
• Examples of carbs: sugar, starch, glucose, glycogen.

Common Ailments Introduction

• Common ailments affecting the digestive system are:
  • Gastroesophageal Reflux Disease (GERD)
  • Ulcers
  • Inflammatory Bowel Disease
  • Constipation/Diarrhea
  • Irritable Bowel Syndrome (IBS)
  • Hepatitis
  • Liver, pancreatic, and stomach cancer
• Chronic lasts a long time, reoccurring; Acute is sudden and intense.
• The following 7 ailments of the digestive tract will be studied.

GERD

• GERD is a chronic disease that affects millions of people around the world.
• The most common symptom is heartburn.
• Other symptoms may include:
  • belching
  • difficulty or pain when swallowing
  • waterbrash (sudden excess of saliva)
  • dysphagia (the sensation of food sticking in the esophagus)
  • chronic sore throat
  • laryngitis
  • inflammation of the gums
  • erosion of the enamel of the teeth
  • chronic irritation in the throat
  • hoarseness in the morning
  • a sour taste
  • bad breath
• Most common symptom is heartburn that's misnamed because of esophagus is behind the heart, and its caused by acid entering from stomach.
• When the esophageal sphincter weakens, it lets acid from the stomach into the esophagus causing burning of the lining and pain.

Ulcers

• Risk factors:
  • Stress
  • Family history of ulcers
  • Smoking
  • Excess alcohol consumption
  • Use of nonsteroidal anti-inflammatory medications (aspirin) or corticosteroids
  • Improper diet, irregular or skipped meals
  • Type O blood (for certain ulcers)
• Ulcers are holes in the stomach lining that bleed.
• They are not caused by stress, but are made worse by stress, and can be found throughout the body, not just the stomach.
• Ulcers are treatable, not contagious and not cancerous.
• Symptoms may include:
  • burning or gnawing feeling in the stomach area
  • loss of appetite
  • loss of weight
• Salt dissolves mucus - a diet with an excess of salt could cause this and mucus is sugar and water.

Inflammatory Bowel Disease

• Is a swelling of the bowels (small and large intestines).
• It is a name given to a group of disorders that cause the intestines to become red and swollen.
• A normal body reaction to infection or damage.
• Inflammation can last a long time and may reoccur through the years.
• When the bowels swell, they don't absorb nutrients or water as well.
• Causes are not known, but those with this are often underweight.
• Not contagious and the immune system is over-reacting to gut bacteria.
• Symptoms include:
  • abdominal cramps and pain
  • diarrhea
  • weight loss
  • bleeding from your intestines

Constipation

• Difficulty in having bowel movements: too much water absorbed which becomes solid too quickly.
• Symptoms may include:
  • difficulty having bowel movements
  • small, dry and hard bowel movements
  • bowel movements less than three times a week
  • feeling bloated, uncomfortable, sluggish
• Causes include:
  • not enough fiber in your diet
  • not enough liquids
  • lack of exercise
  • certain medications
  • irritable bowel syndrome
  • changes in life or routine
  • abuse of laxatives
  • ignoring the urge to have a bowel movement
  • stroke
  • problems with the colon, rectum or intestinal functions
• Laxatives help by relaxing bowels and drinking more water can help, but eating more fiber and staying active is best treatments.

Diarrhea

• Is having loose and watery stools, bowel movements more than three time in one a day where the lg intestines don't remove enough water.
• Causes include:
  • bacterial infections
  • viral infections
  • food intolerances
  • parasites
  • certain medications
  • intestinal diseases and functional bowel disorders
• Could be parasites, cold, flu or eating something your body doesn't like and Amoebic dysentery kills many people every year.

Irritable Bowel Syndrome (IBS)

• Affects the large intestine and not a disease, it's a disorder that does not damage your bowel or large intestines.
• In someone who has IBS the nerves and muscles in the bowel are overly sensitive and bowels contract too much.
• Very sensitive and overwhelmed and don't operate normally
• Symptoms include:
  • cramping
  • diarrhea
  • bloating
  • gas
• There is no cure for IBS, but there are things that people can do to relieve the symptoms such as:
  • relieving stress
  • making diet changes
  • taking medications to relieve or reduce the symptoms
• no injury, but lots of pain, and IBD does damage, IBD does not.

Hepatitis

• Hepatitis is the inflammation of the liver that is typically caused by an infections, and has 5 types A, B, C, D, and E and causes swelling of liver.
• Can also be caused by alcohol.
• A is extremely common in the US; infecting 1 out of 3 Americans at some point in their lifetime and often a person doesn't know they have it.
• Most people recover completely without treatment and might develop a lifelong immunity to the disease.
• Transmitted by a fecal-to-oral route through contaminated food and water, or because of poor hygiene habits, or eating shellfish from contaminated water sources.
• Can be prevented by washing your hands with warm water and soap.
• Symptoms include: loss of appetite, fever, achiness, and fatigue.
• Hepatitis B is the most widespread hepatitis virus and is transmitted by blood.
• Hepatitis C is a common cause of chronic liver disease and is not related to the other Hepatitis viruses.
• It is contagious and transmitted by contact with blood or blood products
• It is a chronic condition where the virus remains in the blood for more than six months that is transmitted by blood, and not related to other forms of hepatitis.
• If left untreated, can lead to serious health problems, and the symptoms of hepatitis C are similar to the symptoms of hepatitis A and B.
• Rare types that occur in a small percentage of the population is hepatitis D & E.

Stomach Cancer

• Stomach cancer is also known as gastric cancer and can start in any area of the stomach and is also known as gastric cancer.
• Symptoms include:
  • indigestion or heartburn
  • discomfort or pain in the abdomen
  • nausea and vomiting
  • diarrhea or constipation
  • bloating after meals
  • loss of appetite
  • weakness and fatigue
  • vomiting blood
  • blood in the stool

Liver Cancer

• Can originates in the liver or spreads to there from cancer elsewhere in the body, where liver cancer is a type of metastatic cancer. which means the disease usually starts somewhere else and spreads to the liver.
• The name given to cancer that has spread to the liver from another area of the body is Metastatic liver cancer
• Symptoms include:
  • weight loss
  • poor appetite
  • enlarged, hard, tender liver
  • fever
  • enlarged spleen
  • jaundice
  • confusion
  • drowsiness

Pancreatic Cancer

• Pancreatic cancer typically impacts people over 50 years of age and called adenocarcinoma.
• It is an adenocarcinoma form of pancreatic cancer, attacking the lining of the pancreatic duct.
• The most common type is called adenocarcinoma.
• Symptoms include:
  • abdominal pain
  • poor appetite
  • weight loss
  • jaundice
  • indigestion
  • nausea and vomiting
  • diarrhea
  • fatigue

Cancer Treatments

• Traditional treatments for cancer:
  • Surgery, to remove cancerous tissue
  • Radiation therapy, uses external beams directed at the cancerous tissue, or internal seeds implanted at the cancerous tissue, or internal seeds implanted into the cancerous tissues, to destroy the cancer cells. With intense/focused radiation to kill cells
  • Chemotherapy, using anticancer drugs to destroy the cancerous tumor uses to flood the body with toxins.
• Cancer cells are always dividing; this makes them weaker than normal cells.
• Doctors put toxins in a high enough level to kill cancer (weaker) cells but not healthy cells.

Cancer Facts

• Cancer occurs when one of your cells' DNA gets broken in just the right way.
• Radiation and chemicals can break DNA.
• When a cell cannot stop dividing = cancer.
• People die from critical organs having their shapes changed = no longer functioning; very painful, especially bone.
• Tumor - dividing cells stay in one place.