gastrointestinal Flashcards
(18 cards)
herbivores
plants - high in fibre and starch
cellulose - hard to digest
adapations:
- symbiotic bacteria in guts; long and complex digestive tracts
- grinding teeth: square, flat molars designed to crush and grind plant material witha sideways motion
- amylase is contained with the saliva of the herbivore
Carnivores
- obligate carnivores - rely entirely on animal flesh
- adaptation-
- short digestive tract : high hydrochloric stomach acid quickly digests meat based protein and fat
- sharp tearing teeth: designed for tearing and slicing. elongated front teeth which are used to kill prey and triangular shaped molars which act like a blade and operate in a vertical scissor action
- no amylase is contained within the savlia, burden of digestion carbohydrates is taken
omivores
eat meat and plants
adaptations:
- medium digestive tracts: capable of digesting meat based proteins and fats, but still long enough to cater for vegetable matter
- tearing and griding teeth: sharp carnine teeth at the front of mouth to cater for meat
- amylase is contained within the salvia; along with chewing action this will help to break down the coarse fibres and carbohydrates that make up plant material
carbohydrates
- include sugars and starches
-glycogen from meats - disaccharides from diffrent sugars
- monosaccharides from honey and fruits
cellulose cannot be digested
digestion
breakdown of large insouble food molecules into small water-soluble food molecules into small water-soluble food molecules so they can be absorbed
intracellular digestion- food particles are engulfed by endocystosis and digested within food vesticles; takes place in animals without a digestive tract
extracellular- the breakdown of food particles outside of the cells
- occurs in compartments that are continous with the outside of the animals body
intracellular digestion
a food particle is transfered via vesicle and endocytosis where a lysome merges with the vesicle and exocytic vescile containing undigested material
extracellular digestion
food is ingested by mechanical digestion where the food is chemically digested into small molecules where the nutrient molecules enter the body cells and then leaves the body via undigested material
mouth
the teeth grind food into small pieces. the saliva contains amylase which is a carbohydrase enyme breaking carbohydrates into glucose
oesophagus
at the back of the mouth the food is made into a ball called a bolus. this bolus is pushed down the oesophagus by rings of muscle. this is called perstalsis.
stomach
hydrochloric acid in the stomach gives a good enviroment for enzymes to break food down ready for the small intestines. the stomach muscle churn food
and secretes gastric juice converting a meal to acid chyme
- gastric juice made up of hydrochloric acid and pepsin
parietal calls secrete hydrogen and chloride ions separately
- mucus protects the stomach lining from gastric juice
liver
bile is a green liquid that is made in the liver but stored and released by the gall baldder into the small intestines. helps digest fats and increase PH so enzymes can work well in the small intestine
pancreas
releases enzymes into the small intestine that helps digest food
small intestine
the longest part of the digestion system. it is made from microscopic villi that help increase the surface area so more nutrients can be absorbed more quickly
large intestine
mainly indigestible food and water enter the large intsetine. absorb water back into the body
rectum
defecation is the removal of faeces from the body
chemical digestion of proteins
pepsin to trysin to peptidse
lipid digrestion
fat globule to bile salt to engulfed fat droplets
chemical digestion nucleic
nucleic acids to pentose sugars
