Digestive System Flashcards
Site of production of saliva
Mouth
Function of saliva
- Contributes to starch digestion via saliva amylase
- Lubricates the inside of the mouth to assist in swallowing
Site of production of mucous
- Mouth
- Stomach
- Small intestine
- Large intestine
Function of mucous
- Protects the cells lining the innermost portion of the digestive tract
- Lubricates food as it travels through the digestive tract
Site of production of enzymes
- Mouth
- Stomach
- Small intestine
- Large intestine
Function of enzymes
Promote digestion of food masses into particles small enough for absorption into the bloodstream
Site of production of acid
Stomach
Function of acid
Promotes digestion of protein
Site of production of bile
Liver-stored in gall bladder
Function of bile
Suspends fat in water (emulsifies) using bile salts, cholesterol, and lecithin to aid digestion of fats in small intestine
Site of production of bicarbonate
- Pancreas
- Small intestine
Function of bicarbonate
Neutralizes stomach acid when it reaches the small intestine
Site of production of hormones
- Stomach
- Small intestine
- Pancreas
Function of hormones
- Stimulate production/release of acid, enzymes, bile, and bicarbonate
- Help regulate peristalsis
Salivary amylase:
- Where does it act
- pH
- What does it act on (substrate)
- Products of digestion
- Origin
- Mouth
- 7
- Starch, glycogen
- Maltose (disaccharide)
- Salivary glands
Pancreatic amylase:
- Where does it act
- pH
- What does it act on (substrate)
- Products of digestion
- Origin
- Small intestine
- 8
- Starch, glycogen
- Maltose
- Pancreas
Sucrase:
•Carbohydrase
- Where does it act
- pH
- What does it act on (substrate)
- Products of digestion
- Origin
- Small intestine
- 8
- Sucrose
- Glucose and fructose
- Small intestine
Pancreatic lipase
- Where does it act
- pH
- What does it act on (substrate)
- Products of digestion
- Origin
- Small intestine
- 8
- Lipids
- Fatty acids and glycerol
- Pancreas
Pepsin:
•Protease
- Where does it act
- pH
- What does it act on (substrate)
- Products of digestion
- Origin
- Stomach
- 1-2
- Protein
- Peptides
- Stomach
Trypsin:
•Protease
- Where does it act
- pH
- What does it act on (substrate)
- Products of digestion
- Origin
- Small intestine
- 8
- Peptides
- Smaller peptides
- Pancreas
Chymotrypsin:
•Protease
- Where does it act
- pH
- What does it act on (substrate)
- Products of digestion
- Origin
- Small intestine
- 8
- Peptides
- Smaller Peptides
- Pancreas
Maltase:
•Carbohydrase
- Where does it act
- pH
- What does it act on (substrate)
- Products of digestion
- Origin
- Small intestine
- 8
- Maltose
- Glucose
- Small intestine
Lactase:
•Carbohydrase
- Where does it act
- pH
- What does it act on (substrate)
- Products of digestion
- Origin
- Small intestine
- 8
- Lactose
- Glucose and galactose
- Small intestine
Peptidases:
- Where does it act
- pH
- What does it act on (substrate)
- Products of digestion
- Origin
- Small intestine
- 8
- Peptides
- Smaller Peptides and amino acid
- Pancreas and small intestine
Nucleases:
- Where does it act
- pH
- What does it act on (substrate)
- Products of digestion
- Origin
- Small intestine
- 8
- Nucleic acid
- Nucleotides and components
- Pancreas
Nucleosidases:
- Where does it act
- pH
- What does it act on (substrate)
- Products of digestion
- Origin
- Small intestine
- 8
- Nucleotides
- Bases, sugars, and phosphates
- Small intestine
Accessory organs
- Pancreas, liver, and gall bladder
- Called “accessory” because their role in the process of digestion is vital, but they are not physically apart of the digestive tract
Amylase
-Enzyme in Davis that breaks down starch into simpler sugars
Carbohydrase
Enzyme that catalysts the hydrolysis of carbohydrates
Catalyst
Chemical that speeds up a chemical reaction but is not used in the reaction
Hydrolysis
- Chemical reaction in which the addition of a water molecule cleaves a macromolecule into subunits
- One hydrogen atom from water is attached to one subunit and a hydroxyl group is bonded to the other subunit, breaking a covalent bond in a macromolecule
Chyme
Thick liquid formed by mixing food with gastric juice in the stomach
Digestive tract
In animals, a long tube that extends from the mouth to the anus, through which food moves and is broken down into simpler compounds that are used for energy, growth, and cell repair
Bolus
Smooth, lump-like mass of food rolled by the tongue to aid swallowing
Macromolecule
-A large, complex assembly of organic molecules
-4 categories are
•carbohydrates
•lipids
•proteins
•nucleic acid
Liver
-Organ found in the abdomen that preforms hundreds of functions as an accessory organ of the digestive system, including the secretion of bile to digest fats, produce plasma proteins, blood detoxifications, and glycogen storage
Disaccharide
Sugar that can be hydrolyzed into two monosaccharides subunits like maltose and sucrose
Monosaccharide
Simple sugar that cannot be hydrolyzed into simpler sugars like glucose, fructose, and galactose
Esophageal sphincter
A muscular ring between the esophagus and the stomach that controls the movement of food into and out of the stomach
Dehydration synthesis
Removing a molecule of water
Gall bladder
Organ that stores bile produced by the liver
Gastrin
Stomach hormone that stimulates the secretion of hydrochloric acid and the inactive precursor molecule of pepsin from glands in the stomach
Homeostasis
The tendency of the body to maintain a relatively constant internal environment
Lipase
Enzyme that catalyzes the hydrolysis of triglycerides into glycerol and fatty acids
Bioavailability
The amount of a nutrient that can be absorbed from a source, rather than the total amount actually in the source
Enzyme
Protein molecule that acts as a catalyst to increase the raw of reaction
Pancreas
Small gland in the abdomen the secretes digestive enzymes into the small intestine, as well as bicarbonate to neutralize hydrochloric acid from the stomach, also secretes the hormone insulin
Inhibitor
Molecule that attaches to an enzyme and reduces its ability to bind substrate; can be competitive and non-competitive
Gastrin
Stomach hormone that stimulates the secretion of hydrochloric acid and the inactive precursor molecule of pepsin from glands in the stomach
Pepsin
- Protein-digesting enzyme secreted in the stomach
- Remains inactive untold hydrochloric acid is present
Peristalsis
- Wave-like series of muscular contractions and relaxations of the circular and longitudinal muscles that surround the various parts of the digestive track
- Aids the movement of food through the digestive track
Polysaccharides
Complex carbohydrate consisting of many simple sugars linked together, like starch, cellulose, and glycogen
4 main component of digestion
- Ingestion (taking in food)
- Digestion (mechanical & chemical breakdown of food)
- Absorption (making nutrients in food available to your circulatory system)
- Eggestion (pooping)
What is absorbed during digestion
- Nutrients
- Vitamins
- Minerals
What is mastication
Mechanical breakdown of food (chewing using teeth & jaw)
Why do we chew?
Chewing food breaks it down into smaller parts to increase surface area to chemical digestion is easier
What does amylase do?
- Enzyme that breaks down carbohydrates
- Turns starch into sugar
What does the epiglottis do?
Closes the trachea when swallowing
What is the pharynx?
“Crossroad” between mouth, nose, trachea, and esophagus
What is peristalsis?
- When the smooth muscle surrounding the digestive tract contract and relax in waves that cause the bolus to move through digestive tube
- Not present in cnidarians and flatworms
- Continues through digestive track-> why you can drink water upside down
Why does food stay in your stomach?
The lower esophageal sphincter opens/closes the upper stomach
What is the upper portion of the stomach called and what does it do?
- Fundus
- Produces inactive enzymes
What do we call the lower portion of the stomach and what happens in it?
- Pylorus
- Where enzymes become active and take part of chemical digestion
What does the stomach produce and what do they do?
- Gastric juices- contain HCL that that kill potential pathogens
- Pepsin enzyme-breaks down protein
- Mucus-protects stomach from its own acid
How many layers of muscle are in the stomach?
- Muscle arranged in longitudinal, circular, and diagonal rows
- These muscles allow the stomach to squeeze and churn the food (mechanical digestion)
How are amounts of chyme released into the small intestine?
Pyloric sphincter
What do gastric glands in the wall of the stomach produce?
- HCL
- Rennin
- Pepsinogen
What is pepsinogen?
-Inactive form of an enzyme called a pre-cursor
What is rennin?
- Coagulates/curdles milk protein to keep milk in the stomach longer
- Enzyme
Pepsinogen(inactive) is converted to Pepsin(active) in the presence of what to do what?
- Presence of HCL
- Breaks proteins down into smaller pieces
Chyme stimulates what valve to open for food to move down to small intestine?
Pyloric valve
What are ulcers?
Lesions on the surface of the stomach
What are 2 primary causes of ulcers?
- Bacterial infection (helicobacter pylori)
2. NSAIDS (Non Steroidal Anti-Inflammatory Drugs)
What is a pathologist?
Scientist who studies diseases
What is gastritis?
Inflammation of the lining of the stomach
Where is the site of most digestion and adsorption?
Small intestine
What are the 3 main areas of the small intestine?
- Duodenum
- Jejunum
- Ileum
What is the jejunum?
-Place where most of the absorption of nutrients take place villi on the inner wall
What does the small intestine contain many folds?
- Slow movement of food
- Create surface area for absorption
Many d_________ j______ are added via the common ____ ____ into the d_______ by the p______ and the l_____
Many digestive juices are added via the common bile duct into the duodenum by the pancreas and liver
What are lacteals and what do they do?
- Lymph vessels in villi that intertwine with a capillary network
- transport materials and absorb fat-soluble vitamins, glycerol, and fatty acids
What is prosecretin concerted to as acid enters the small intestine and what does it signal the pancreas to do?
- Secretin
- Signals the pancreas to buffer the HCL with HCO3- ions (bicarbonate)
Pancreatic enzymes promote the break down of what?
- Proteins
- Carbs
- Lipids
What does mother pancreas secrete to the duodenum?
Lipase and amylase
What protease enzymes do the pancreas produce, what must they become, and why?
- Protease enzymes tripsinogen & chymotrypsinogen
- They must becomes actives to turn into trypsin and chymotrypsin
- To break down proteins
Bile works with what to break down and emulsify fats?
Pancreatic lipase
Fats in the small intestine trigger release of cholecystokinin that triggers ____ to release ____ _____
Triggers the gall bladder to release bile salts
What does a patient need to do when the gall bladder is removed?
Limit fat intake
Bile contains pigments, the liver breaks down _____ and stores the products in the _____ for removal
- Breaks down hemoglobin
- Stores products in gallbladder for removal
- That’s why poop is brown
What are gallstones?
Accumulation of cholesterol deposits in gall bladder
What does the liver do? (7 things)
- Stores glucose as glycogen
- Destroys old red blood cells-> detoxifies blood
- Makes some antibodies
- Makes clotting components of blood
- Processes fat
- Largest solid organ in body (after skin)
- Can regenerate part of itself
Products of digestion from fat, protein, and carbohydrates
Fats-> fatty scuds & glycerol
Protein-> amino acids
Carbs-> fructose, glucose, and galactose
Where do the waste products and undigested food particles enter?
Large intestine (colon)
What do the cells lining the large intestine absorb and why?
- Water, salts, vitamins, and minerals
- No villi
What is the largest part of the large intestine and what happens there
- Colon
- Waste storage takes place so enough time can pass to absorb water from waste
The small intestine opens into a blind pouch called ____ with a finger-like extension called the ____ appendix
- Caecum
- Appendix
What is five & why is it important?
- Cellulose, long chain of carbohydrate that cannot be broken down
- Acts as a pipe-cleaner for intestines
Peristalsis only occurs when what builds up?
Waste
Rectum is the what for wastes
“Waiting room”
Wastes are released through what?
Anal sphincter
2 causes for constipation?
- Too much water is absorbed in the large intestine
2. Lack of fiber
Cause of diarrhea
Decreased water absorption and increased peristalsis activity of large intestine
What co tells digestion?
Hormones and nervous system
What can trigger gastric secretions before food is consumed?
Taste, sight, and smell
