The Digestive System Flashcards
What is physical digestion?
The mechanical breakdown of food into smaller pieces
What is chemical digestion?
The chemical breakdown of food into smaller pieces by the help of enzymes
What are all of the organs in the digestive track?
Mouth, esophagus, stomach, small intestine, large intestine, rectum and anus
What are all of the accessory organs?
Salivary glands, liver, gallbladder and the pancreas
What happens in the mouth (initial part of digestion?)
The mouth physically and chemically digests food. It turns food into a bolus, and the tongue pushes the bolus to the throat
What enzymes and/or hormones are used in this process (mouth)?
Enzyme(s): Salivary amalayse enzyme that digests starches (carbs)
Hormone(s): None
What happens in the esophagus?
The bolus of food is pushed into the esophagus and past the uvula. Smooth muscle contractions called peristalsis push the bolus into the stomach
What enzymes and/or hormones are used in this process (esophagus)?
Enzyme(s): None
Hormone(s): None
What happens in the stomach?
The chemical digestion of proteins and the physical digestion of the stomach churning
What enzymes and/or hormones are used in this process (stomach)?
Enzyme(s): Pepsin which comes from peptic cells and digests proteins into enzymes
Hormone(s): Gastrin from gastric cells. Gastrin triggers the release of HCl & pepsinogen
What two things control the entry and exit of food for the stomach?
The esophageal sphincter (entry) and the pyloric sphincter (exit)
What protects the inside of the stomach from being eaten by itself?
Mucous cells which create a thick wall inside the stomach
What role does HCl play in this process (stomach)?
HCl comes from parietal cells. It lowers pH for pepsin and protects the stomach from illness
What happens in the duodenum? (part of the small intestine)
The chemical digestion of all macromolecules and the physical digestion of fats
What enzymes and/or hormones are used in this process (duodenum)?
Enzyme(s): Trypsin, chymotrypsin and pancreatic amalayse that all come from the pancreas. Trypsin and chymotrypsin digest proteins and pancreatic amalayse digests carbs.
Hormone(s): Secretin (triggers release of HCO3), GIP (stops stomach from sending chyme), CCK, triggers release of bile from gallbladder and liver.
What are bicarbonate ions? (still a part of the duodenum)
They come from the pancreas and neutralize stomach acid.
What role does bile play in the duodenum?
Bile is created in the liver, and released from the gallbladder. Its job is to emulsify lipids.
What occurs in the jejunum and ileum? (small intestine)
The absorption of monomers into the bloodstream and lymph vessels.
What occurs in the large intestine?
The absorption of of H2O, and production of B & K vitamins.
What is stored in the colon?
Waste, which is excreted through the rectum.
What are the two types of disorders that can affect the digestive system?
Pyschological and physical
What is Crohn’s disease (Inflammatory Bowel Disease)?
Inflammation of any organ in the GI tract. Crohn’s disease is chronic and inherited.
What is Colitis (Irritable Bowel Syndrome)?
Inflammation and ulceration of the large intestine. Colitis can be treated by medication and sometimes surgery, and can be fully removed whereas Crohn’s cannot.
What are ulcers?
Holes in the wall of the stomach and intestine, caused by a breakdown of the mucous lining.
What is Hepatitis?
Inflammation of the liver
What can Hepatitis lead to?
Hepatitis can cause Cirrhosis which is a chronic liver disease. When a person has cirrhosis, their healthy liver tissue is replaced by fat and scar tissue.
What are gallstones?
Gallstones are crystals of cholesterol, and minerals that build up in the gallbladder.
How do gallstones affect the gallbladder?
They prevent the flow of bile and cause a poor diet.
What is GERD?
GERD is another name for acid reflux. This is a long term condition where the stomach contents come back up into the esophagus.
What is anorexia nervosa?
This is a pyschological eating disorder where a person has a morbid fear of gaining weight. They severely restrict their food intake, and can end up in hospital.
What is bulimia?
A disorder similar to anorexia in terms of weight gain. Instead of restricting their eating, a person with bulimia will purge and then induce vomiting.
What is obesity?
A body mass that is 20% or more above a healthy body mass.
What is high blood sugar?
When a person has an excess amount of glucose in their blood, resulting from a lack of insulin
What is low blood sugar?
When a person has a dangerously low amount of glucose in their blood
What is the role of the liver?
Creating bile, storing sugar, and cleaning out the bloodstream.
