Flashcards in Functions Of Digestive System Deck (60):
mixes food with saliva from 3 pairs of exocrine glands (parotid, submandibular and sublingual)
amylase (digestive enzyme) begins chemical breakdown of carbohydrates
propels food downward to stomach through peristalsis (involuntary muscle contraction)
secretes endocrine hormones, insulin and glucagon
secretes digestive enzymes into duodenum that breakdown carbs, proteins and fats
metabolizes and stores nutrients absorbed from small intestines
produces and secretes bile
detoxifies and purifies blood
maintains normal blood glucose levels
makes cholesterol and blood proteins
concentrates and stores bile
releases into duodenum to help breakdown fats
stores and breaks down food by mixing it with gastric secretions such as HCL, pepsins and intrinsic factor
releases the hormones gastrin which stimulate the gastric glands to secrete pepsinogens (protein digesting enzymes), mucus (protects stomach from highly acidic content) and hydrochloric acid (converts pepsinogens into active form
absorbs alcohol and some drugs directly through its wall and into circulatory system
name some gastric secretions
HCL, pepsins and intrinsic factor
what are pepsinogens?
protein digesting enzymes
what does mucus do?
protects stomach fro highly acidic content
what does hydrochloric acid do?
converts pepsinogens into active form
what is small intestine made up of?
duodenum, ileum, jejunum
secretes hormones to stimulate the secreation of pancreatic juices, bile and intestinal enzymes
what are intestinal enzymes?
secretin (stimulates secretion of sodium bicarbonate from pancreas and bile from liver)
Cholecystokinin [CCK] (stimulates release of digestive enzymes from pancreas and bile from gallbladder)
Gastric Inhibitory Peptide [GIP] (decreases stomach churning which slows the emptying of chyme from the stomach and induces insulin secretion)
Motilin (increases gastrointestinal motility and stimulates production of pepsin, secretes mucus and brush border enzymes, chemically digests and absorbs majority of ingested nutrients, water is absorbed by passive diffusion throughout the small intestine, CHOS and proteins are absorbed in blood vessels, lipids are absorbed in lymph vessels, transports food by peristalsis to large intestines)
name the brush border enzymes
maltase, lactase, sucrase, isomaltase, alpha dextrinas
what is large intestine made up of?
cecum, colon (ascending, transverse, descending and sigmoid colon) and rectum
microflora of large intestine break down remaining nutrients (fiber) and make some vitamins (B and K)
absorb most of remaining water, some ions and vitamins
forms and stores feces until eliminated
what are proteins broken down into?
what are fats broken down into?
fatty acids and glycerol
what are carbohydrates broken down into?
what is absorption?
process of nutrients passing from intestines into bloodstream or lymph system
where are secretory glands found?
all along the digestive tract
they release secretions into a duct (exocrine) or directly into bloodstream (endocrine)
what are digestive juices?
various fluids that assist in breakdown of foods
secreted at various points along digestive tract and are necessary catalysts to all metabolic functions
what happens to food when it is chewed
turns into a bolus
is stomach acidic or alkaline?
acidic (if it was alkaline bacteria can grow)
when is bolus referred to as chyme?
in stomach when food is broken down into smaller fragments
how big is stomach when it is emptied?
50ml in size
how big can it expand to?
1-1.5 litres of food
what is between the stomach and small intestine?
what does pyloric sphincter do?
monitors how much chyme can pass from stomach into duodenum (approx. one-five ml twice per minute)
where is primary site of absorption?
what is surface coat of micro-villi referred to?
brush border -hydrolyzes digested material to ready it for absorption
how long does absorption process usually take?
what 3 enzymes does pancreas secrete in order to complete digestion of macronutrients?
amylase to digest carbs
lipase to digest fats
protease to digest proteins
which part of body balances our acid-alkaline levels?
how many different functions does liver have?
food travels to liver via what?
Portal Hepatic Vein
how are toxins in liver exported?
through bile, urine, stool
where are usable nutrients send?
sent through vena cava to heart and pumped into circulation to appropriate parts of body
what are livers other metabolic functions?
production of bile from cholesterol
processing of amino acids into proteins
conversion of glucose into glycogen for storage
regulation of hormones, sugars, proteins and fats in blood
how long is large intestine?
5 feet long
by time food has reached large intestine most of nutrients have already been removed
which ones haven't?
fiber and cells -make up bulk of feces
water -food will lose about 2/3 of weight as water squeezed out and absorbed via the colon
bacteria -help to further break down food and convert to feces
what happens if there is an imbalance of good and bad bacteria in upper GI tract?
Creates fermentation of food and production of gas
in colon it can create health problems such as IBS, constipation and Crohn's disease
what are tips for better digestion, absorption and elimination?
maintain healthy bacterial balance
manage fluids around meals
allow adequate time in between meals for "cleanup"
W5 of eating: with whom, what when, where and why
which organ secretes bile?
which organ is main site for all macronutrient metabolism?
what is secreted by the pancreas?
where are lipids first absorbed?
What is the hub of chemical digestion?
Which enzyme digests fat?
Which enzyme digests proteins ?
What % of digestion is pancreatic enzymes responsible for in carbs, fats and proteins?
50% of carbs
50% of proteins
90% of fats
When food is absorbed in bloodstream can it be delivered directly to the cells?
No, has to travel to liver first so that toxins are neutralized and nutrients are metabolized into an active and usable form
What are tips for Better digestion, absorption and elimination ?
Maintain healthy bacteria balance
Drink enough water
Exercise W5 of eating
Manage fluids are meal
Allow sufficient time around meals for "cleanup"
How long does it take to digest liquids?
A few minutes
How long does it take to digest fruits and vegetables?
Veggies slightly longer than fruit
How long does it take to digest starches?
How long does it take to digest proteins?
4-6 hours. Can take up to 8
How long does it take to digest fats