Test #2 Flashcards
What is Digestion?
process of breaking food into components small enough to be absorbed by the body (Vitamins, minerals, debris, etc.)
What is Absorption?
process of taking substances into the interior of the body
What is the Gastrointestinal Tract (GI Tract)?
What organs/body parts does it contain?
hollow tube consisting of the mouth, pharynx, esophagus, stomach, small intestine, large intestine, and anus
What is Transit Time?
amount of time it takes food to pass the length of the GI tract
(24-72 hours)
What is layers of smooth muscle?
Helps mix and
propel food through
the gut wall
What is external layer of connective tissue?
Provides strong structural support and
substantial protection. Wants to keep out
foreign particles and invaders
What is the lumen?
Inside portion of the hollow tube (food in
lumen has not yet been absorbed) – not gotten
Into circulation.
What is the mucosa?
Layer of tissue lining the lumen; mucosal cells provide protection and aid
in absorption; have a short life span of 2-5 days; require nutrients to
survive; provide mucus.
What is connective tissue?
Contain nerve and blood vessels; Provide structural support & deliver Nutrients to mucosa; help with nutrient Secretion and muscle contractions.
Digestion in GI tract is assisted by?
Digestion inside the GI tract is assisted by digestive secretions
What is mucus?
viscous material produced by cells in the mucosal lining of the gut; mucus moistens, lubricates and protects the GI tract
What are enzymes?
What organs secrete these?
protein molecules that speed up chemical reactions; enzymes are not changed during reactions (pancreas, stomach, small intestines)
What is the barrier function?
What cells are involved?
The protective role that gastrointestinal cells have in limiting the absorption of harmful substances (by mucosal cells) and disease-causing organisms. (by immune cells which reside under the mucosa and respond to antigens.)
The GI tract limits absorption of toxins and disease-causing organisms.
What is an antigen?
A foreign substance (almost always a protein) that, when introduced into the body, stimulates an immune response.
Some cells of the immune system are present in the GI tract are?
Phagocytes
Lymphocytes
Antibodies
Process of The Gastrointestinal Tract and Barrier Function?
See slide.
Phagocyte engulfs antigen and then lets it open so the antigen expose its harmful products.
Lymphocytes form the the antigens. It is the hero and saves the phagocytes.
Sleep, healthy diet, and exercise are some examples of what makes the immune system healthy.
This is the same process with allergens.
What is a hiatal hernia?
Pressure on the abdomen from persistent or severe coughing or vomiting, pregnancy, straining while defecating, or lifting heavy objects
What are ulcers?
Infection of stomach by H. pylori, acid-resistant bacteria that penetrate the mucous layer and damage the epithelial lining; chronic use of drugs such as aspirin and ibuprofen that erode the mucosa; GERD
What causes diarrhea?
Bacterial and viral infections, medications, food intolerance
What causes constipation?
Low fibre intake, low fluid intake, high fibre in combination with low fluid intake, weak intestinal muscles
What is IBS?
When the muscle contractions in the intestines are stronger and last longer than normal, or are slower and weaker than normal
What is pancreatic disease?
Cystic fibrosis or pancreatitis
What is gallstones?
Deposits of cholesterol, bile pigments, and calcium in the gallbladder or bile duct
What are nephrons?
Kidneys contain millions of nephrons-
functional unit of the kidney which filters
the blood and maintains fluid balance.
What are glomerlus?
Nephrons contain glomerulus (ball of
capillaries) which ultra-filtered blood
and initiates urine production
What do renal tubules do?
Renal tubules reabsorb compounds that are important for normal body functions (i.e. salts, glucose, amino acids).
What does the collecting duct do?
transports
wastes to bladder for subsequent
excretion.
What does selectively permeable mean?
Describes a membrane or barrier that will allow some substances to pass freely but will restrict the passage of others. The smaller the molecule, the easier it is to gain access.
What is the cellular respiration cycle?
1 In the presence of oxygen, glucose, fatty acids, and amino acids can be metabolized to produce
acetyl-CoA (C-C-CoA).
2 Acetyl-CoA is broken down by the citric acid cycle (aka Kreb’s Cycle) to yield carbon dioxide (CO2) and high-energy electrons (in the form of hydrogen ions). – link with something to produce water .
3 The electrons are shuttled to the electron transport chain, where their energy is used to generate
ATP and they are combined with oxygen and hydrogen to form water.
Explain the elimination of wastes?
The digestive system takes in nutrients and the respiratory system takes in oxygen, which are then
distributed to all body cells by the circulatory system.
The urinary, respiratory, and integumentary systems
transfer metabolic wastes to the external environment.
AMDR for carbohydrates?
45 to 65%of energy.
How many kcal/gram is carbs?
Provides 4kcal/gram
What is sugar free?
Product contains no amount, or a trivial amount, of sugars (less than 0.5 g per serving). Synonyms for “free” include “without,” “no,” and “zero.”
What is reduced sugar?
Nutritionally altered product contains 25% less sugar than the regular or reference product.
What is low in sugar?
Whether altered or not, a food contains 25% less sugar than the reference food. Also “less sugar,” “lower sugar.”
What is no added sugars/ without added sugars?
No sugar or sugar-containing ingredient is added during processing.
What is source of fibre?
Food contains at least 2 g/serving.
What is high source of fibre?
Food contains at least 4 g/serving
What is very high source of fibre?
Food contains at least 6 g/serving.
T or F:
The stomach has active salivary amylase?
False.
Salivary amylase is deactivated so no carb digestion occurs.
What happens during small intestine digestion?
most starch digestion and breakdown of disaccharides.
Pancreatic amylases continue to breakdown starch in monosaccharides, disaccharides, and oligosaccharides.
What component completes the digestion of carbs? What do they do?
Brush border of the small intestinal villi.
They break down the disaccharides and oligosaccharides into monosaccharides.
In the large intestine what products are broken down (what breaks them down)? What do they form?
Fibre and other indigestible carbs are broken down by bacteria.
They form short chain fatty acids and gas.
Some Fibre ends up in feces.
Explain what happens during an insulin spike?
When there is spikes, it releases insulin to jam it into storage. (ex. can of coke) Usually into fat stores. – hypoglycemia
After the jamming, we become hungry again. With multiple spikes in a day, we produce too much insulin and become insulin resistant. – causes type II diabetes.
We want it to be jammed into muscles.
If maintaining blood glucose is so important, why doesn’t glucose from muscle glycogen solve the problem? Explain process of storage.
Glucose gets trapped in the muscle due to phosphorylation and when it is trapped, it provides energy to the muscles during exercises.
I lacks the enzyme that chops it in half (Glucose-6-phosphatase)
This is why the liver cannot trap the glucose.
Liver will break down it’s glycogen stores to chop the glucose-6-phosphate in half. (It sacrifices itself)
Then the glucose can leave the liver and enter the bloodstream to maintain blood glucose levels. (Equilibrium) – 24-hour equilibrium.
T or F:
Saliva in the mouth moistens food and initiates digestion?
True
What is chyme?
The mixture of partially digested food stored/held in the stomach.
Describe the first way the GI barrier can work?
Phagocyte:
1) Phagocyte engulfs harmful organisms
2) Phagocytes break down harmful organisms and present antigens
3) Destruction of harmful organism
Describe the second way the GI barrier can work?
Lymphocyte (Ex. B-Cell, which develops into Helper-T Cells):
1) Synthesis of antibodies
2) Antibodies recognize and bind to antigens present in harmful organisms
3) Antibody binding facilitates the recruitment of phagocytes which engulf organisms (Uses step 1 of phagocyte way)
4) Destruction of harmful organism
Describe the third way the GI barrier can work?
Lymphocyte (Cytotoxic T-Cell):
1) Lymphocytes bind to cells in body infected with harmful organisms.
2) Destruction of harmful organism
What is Somatostatin?
Inhibits the following: stomach secretion, motility, and emptying; pancreatic secretion; absorption in the small intestine; gallbladder contraction; and bile release.
Stomach and duodenal mucosa
What is Gastric inhibitory peptide?
Inhibits gastric secretion and motility.
Duodenal mucosa
What is Rennin?
Found in stomach, Causes the milk protein casein to curdle.
What is Trypsin?
Found in pancreas.
Breaks proteins and polypeptides into shorter polypeptides.
What is Chymotrypsin?
Found in pancreas.
Breaks proteins and polypeptides into shorter polypeptides.
What is Carboxypeptidase?
Found in pancreas.
Breaks polypeptides into amino acids.
What is Pancreatic lipase?
Breaks triglycerides into monoglycerides, fatty acids, and glycerol.
What is pancreatic amylase?
Breaks starch into shorter glucose chains and maltose.
What is Carboxypeptidase, aminopeptidase, and dipeptidase?
Found in small intestine.
Breaks polypeptides into amino acids.
What is lipase?
Found in small intestine.
Breaks monoglycerides into fatty acids and glycerol.
What is sucrase?
Found in small intestine.
Breaks sucrose into glucose and fructose.
What is Lactase?
Found in small intestine.
Breaks lactose into glucose and galactose.
What is Maltase?
Found in small intestine.
Breaks maltose into glucose.
What is dextrinase?
Found in small intestine.
Breaks short chains of glucose into individual glucose molecules.
