Nutrition Flashcards
Autotroph
Makes it’s own food
Heterotroph
Has to consume other organism
Digestion
The physical & chemical breakdown of food into soluble particles small enough to pass through cells
Need for digestive system
Food can be digested in a single location
Individual cells do not have to contain full range of digestive enzymes
Ingestion
Food is taken into the alimentary canal
Digestion
Food is broken down into smaller soluble pieces
Absorption (Assimilation)
Movement of digested food from the alimentary canal into the blood system and cells
Egestion
Removal of unabsorbed waste
Define each
Incisors
Canines
Premolars
Molars
- Cutting and biting
- Ripping and Tearing
- Crushing and grinding
- Crushing and grinding
Human Dental Formula
3[i²/2c¹/1pm²/2m³/3]
Functions of gastric juice 1. mucus
Lines and protects the stomach wall
HCL (Gastric Juice)
Kills bacteria, activates pepsinogen
Pepsinogen (gastric juice)
Converted to the active enzyme pepsin by HCL. Then digests protein into peptides
Cardiac Sphincter
Contracts to close entry from the oesophagus to stomach
Pyloric sphincter
Circular muscle which contracts to close the entry to duodenum from the stomach
Small intestine parts
Duodenum, jejunum, ileum
Duodenum function
Most digestion happens here, place in the duodenum
Jejunum and ileum functions
Absorbs nutrients
Adaptions for absorption
Long tube (gives time for absorption)
Villi (and microvilli)
Infoldings which increase the s.area available for the absorption of food
Large intestine function
Reabsorb water
Produce B group vitamins
Digest cellulose
Prevent growth of harmful bacteria
Bile function
Emulsifies fat
Neutralises acidic chyme from stomach
Pancreatic juice function
Neutralises chyme, and creates enzymes such as amylase and lipase which chemically break down food
Role of fibre
(foods high in cellulose) stimulates peristalsis in colon and prevents constipation
