Digestive System Flashcards
4 types of macromolecules
carbs, lipids, proteins, nucleic acids
types of carbs
simple sugars (mono and disaccharides) and polysaccharides
if a word ends in ose…
it is a sugar
if a word ends in ase…
it is an enzyme
examples of polysaccharides
starch (stores energy in plants), cellulose (strength in plants), glycogen (stores energy in animals)
proteins are made up of __________ and joined together by __________. chains are called __________
amino acids, peptide bonds, polypeptides
different functions of protein
structural (muscle, membrane), enzymes (catalysts, speed up chemical reactions), antibodies (fight off disease)
what is hydrolysis
enzymes help break down macromolecules down into simpler parts
examples of enzymes
carbohydrase (breaks down carbs into simple sugars, ex. amylase), lipase (breaks lipids down into glycerol and fatty acids, ex. pancreatic lipase), protease (breaks down proteins into amino acids, ex. pepsin)
mineral and vitamins
can be organic or inorganic
help chemical reactions
aid in tissue growth
aid in immunity
functions of water
transporting dissolved nutrients into the cells that line the small intestine
flushing toxins from cells
lubricating tissues and joints
forming essential body fluids like blood and mucus
regulating body temperature (sweat)
eliminating waste materials (urine and sweat)
filter feeder
take in large amount of surrounding water and filter small organisms to digest
ex. clams, baleen whale, tube sponge
substrate feeder
live in or on their food and eat through it
ex. earthworms
fluid feeder
suck or lick nutrient rich fluids from live plants or animals
ex. mosquitoes, vampire bats
bulk feeder
ingest large pieces of food and swallow whole or chew
four stages of processing
ingestion: taking in or eating food
digestion: chemical and mechanical breakdown into molecules small enough for body to absorb
absorption: transport of digested molecules from the digestive system into the circulatory system, to be distributed to the rest of the body
elimination: removal of undigested solid waste from the body
inflammatory bowel disease
a general name for a group of diseases that cause inflammation in the intestines
Crohn’s disease
a form of IBD that can affect any part of the alimentary canal from the mouth to the anus
ulcerative colitis
a form of IBD that attacks the colon
peptic ulcer
a sore in the lining of the stomach or duodenem, where hydrochloric acid and pepsin are present. ulcers form when the tissues become inflamed because the protective mucus that covers the lining has weakened. most commonly caused by the helicobacter pylori)
hepatitis
inflammation of the liver, most commonly caused by a virus
cirrhosis
the irreversible placement of healthy liver tissue with non-functioning scar tissue; most commonly caused by alcohol intake or hepatitis
diabetes
a condition in which the body is unable to use glucose for energy
nucleic acids
contain the chemical code for growth and development of an organism. made up of nucleic acids, sugar, and phosphate
two types of nucleic acid
DNA (deoxyribonucleic acid) and RNA (ribonucleic acid)
polysaccaride diagrams
starch - chains and branches
cellulose - chains connected together
glycogen - chains with branches on branches
lipid diagram
glycerol backbone with three fatty acids attached
teeth
incisors (bite and chew)
canines (tear and shred)
premolars/molars (grind and chew)
different kinds of teeth (diet)
carnivores: sharp for tearing
herbivore: heavy flat teeth for grinding
omnivore: combo of biting+grinding
what are teeth for
mechanical digestion
3 salivary glands
parotid, sublingual, submaxillary
saliva function
contain enzymes to break down carbs (amylase)
softens and moistens food
chemical breakdown
tongue function
positions food on molars to chew
helps mix food with saliva
rolls food into bolus (food+saliva mixture) and moves it to back of mouth
hard/soft palate function
separates mouth from nasal chamber
uvula function
moves to block nasal passage when you swallow
pharynx function
tube for food and air
epiglottis
closes off trachea when swallowing
esophagus structure
muscular collapsible tube about 25 cm long. contains longitudinal & circular muscles (alternating waves). connects pharynx to stomach
esophagus function
produces mucin to help food move
lower 2/3 involuntary muscle movement
peristalsis: wave-like muscular contractions
alimentary canal
the tube which food is processed
stomach structure
muscular bag
4 layers
2 sphincters
4 layers of the stomach
longitudinal muscle
circular muscle
oblique muscle
inner layer- folded into long ridges (rugae) which contain gastric pits containing glands that secrete gastric juice
small intestine structure
2.5 cm wide and 7m long arranged in loops mesentery: thin, membranous sheets that attach loops that keep from tangling 3 parts 4 layers
small intestine function
enzymes produced by pancreas, liver and small intestine act here (90% absorption)
stomach function
churning breaks down food into smaller pieces and mixes with gastric juice
contract rhythmically to mix food
contains enzymes for chemical breakdown
controls flow of chyme (semi-liquid and partially digested food)
3 parts of small intestine and function
duodenem- shortest and widest, chemical breakdown here
jejunum- more protein and carb breakdown
ileum- most absorption occurs here
4 layers of small intestine and function
mesentary- nerves, arteries, veins, and lymph for transport
longitudinal muscle and circular muscle - muscle contractions move material by peristalsis
mucosa- has many folds with finger like projections (villi and microvilli) that increase surface area of mucosa and allow for more absorption. accept and carry lipid particles that are absorbed from the intestine. villi also contain lacteal (lymph vessels)
large intestine structure
ileocecal valve- sphincter that controls material between the small intestine and large intestine
cecum- pouch from which appendix hangs
3 sections: ascending colon, transverse colon, descending colon
rectum- last segment
anus-complex set of sphincter muscles
large intestine function
complete absorption of food form certain vitamins recover water form and expel feces contains bacteria which feed on food residues and produce certain vitamins (including K)
appendix
blind tube 6-8cm long
no function in humans
rectum function
stores undigested material until it can be eliminated
feces consists of 60% solid material and 40% water
indigestible fibre in diet helps retain water in feces and aid in egestion
anus function
expels waste
stretching of walls of rectum by feces signals ready for egestion
ulcer symptoms and treatments
abdominal pain, bloating, nausea, loss of appetite
antibiotics that kill bacteria, medications that reduce anxiety in the stomach, lifestyle changes
IBD treatment
special diet, medication to reduce pain and inflammation, remove affected part of colon and create new external opening for digestive waste (severe)
gall stones treatment
medication, ultrasound shock waves, losing weight, increasing intake of omega-3 fatty acids, decreasing meal size, surgically remove
hepatitis a b and c
a- drinking contaminated water
b- sexual contact
c- coming in contact with infected blood
Carb function
Short and long term energy storage
Pancreas
fluid contains numerous enzymes that chemically digest carbs, lipids, proteins
contains bicarbonate to alter chyme from acidic to basic
liver
secretes bile - helps digest fat
gall bladder
stores bile between meals
bile salts break up fat droplets into smaller droplets increasing surface area and makes it easier for intestinal cells to absorb the fats
