The Digestive System Flashcards
Digestion
Breakdown of food into a form that can be used by an animal. It includes both mechanical digestion and chemical digestion.
Mechanical digestion
Digestion that uses physical factors such as chewing with the teeth.
Chemical digestion
The chemical reactions changing food into simpler substances that are absorbed into the bloodstream for use in other parts of the body.
Alimentary canal
Passage from the mouth to the anus. Digestion of food occurs as it moves through the canal.
Enzymes
Special chemicals that speed up reactions but are themselves not used up in the reaction.
Saliva
Watery substance in the mouth that moistens food before swallowing.
Salivary glands
Glands in the mouth that produce saliva.
Bolus
Round, chewed-up ball of food made in the mouth that makes swallowing easier.
Oesophagus
Part of the digestive system composed of a tube connecting the mouth with the stomach.
Peristalsis
The process of pushing food along the oesophagus or small intestine by the action of muscles.
Stomach
A large muscular organ that churns and mixes food with gastric juice to start to break down protein.
Small intestine
The part of the digestive system between the stomach and large intestine, where much of the digestion of food and absorption of nutrients take place.
Absorption
The taking in of a substance, for example from the intestine to the surrounding capillaries.
Villi
Tiny finger-like projections from the wall of the intestine that maximise the surface area of the structure to increase the efficiency of nutrient absorption.
Nutrient
Substances that provide energy and chemicals that living things need to stay alive, grow and reproduce.
Bile
A substance produced by the liver that helps digest fats and oils.
Gall bladder
A small organ that stores and concentrates bile within the body.
Lipids
Type of nutrients that include fats and oils
Lipase
Enzymes that break fats and oils down into fatty acids and glycerol.
Amylases
An enzyme in saliva that breaks starch down into sugar.
Proteases
Enzymes that break proteins down into amino acids.
Pancreas
A large gland in the body that produces and secretes the hormone insulin and an important digestive fluid containing enzymes.
Colon
A part of the large intestine where a food mass passes from the small intestine, and where water and other remaining essential nutrients are absorbed into the body.
Large intestine
The penultimate part of the digestive system, where water is absorbed from the waste before it is transported out of the body.
Vitamin D
A nutrient that regulates the concentration of calcium and phosphate in the bloodstream and promotes the healthy growth and remodelling of bone.
Cellulose
A natural substance that keeps the cell wall of plants rigid.
Rectum
The final section of the digestive system, where waste food matter is stored as faeces before being excreted through the anus.
Anus
Final part of the digestive system, through which faeces are used as waste.
Emulsify
Combine two liquids that do not normally mix easily.
Denatured
Describes the condition of proteins after they have been overheated.
Substrate
Substance acted upon by an enzyme.
Product
New chemical substance that results from a chemical reaction.
Epiglottis
A part in the oesophagus that blocks off the trachea so that food doesn’t go into the respiratory system.
Incisors
Like scissors, used for biting and cutting food. Front of mouth.
Canines
Fang-like, tear and grasp food. Used for ripping and tearing meat.
Premolars and Molars
Molars are found further back than premolars. Molars have between 3 and 5 cusps, whereas premolars have 2. Used for grinding and crushing food.
Which digestive reaction does amylase speed up?
Starch into Sugar
Nutrients that are absorbed by villi in the small intestine.
Glucose and Fatty acids
Singular form of villi
Villus
Chyme is the mixture of substances in the stomach, and is made up of…
Food, Hydrochloric acid, enzymes
What part of digestion occurs in the stomach?
Digestion by acids, and crushing
What do the hormones released by the small intestine the pancreas do?
Release digestive enzymes into the duodenum
Which food group does the digestive enzyme amylase act on?
Carbohydrates
Which food group does the digestive enzyme lipase act on?
Fats.
