The Digestive System Flashcards
What is an autotroph?
Get food from environment - chemical or light e.g. photosynthesis
What is a heterotroph?
Rely on plants/animals for nutrients as cannot get energy from environment
What are the key functions of water?
50-70% of animal’s body weight
Allows chemical reactions to happen
Aids thermoregulatory system
What are the key functions of fibre?
Regulate bowel function, aids removal of waste
What are the key functions of carbohydrates?
Broken down into glucose = energy for cells, essential for organ function
What are the key functions of lipids (fats)?
Storage of energy, insulation
What are the key functions of protein?
Growth and maintenance of cells + tissues
What is the key function of vitamins?
Promote chemical reactions
What are the key functions of minerals?
Growth and maintenance of bones + teeth
Muscle contraction
Osmoregulation
What are the 2 types of digestion?
Mechanical - large food pieces physically broken down
Chemical - food broken down by enzymes and acids (stomach)
What are incisors (teeth) and what are they used for?
The front teeth, fine nibbling and cutting, delicate grooming
What are canines (teeth) and what are they used for?
The largest teeth (like fangs), for holding prey and tearing meat
What are premolars and molars (teeth) and what are they used for?
The middle and back teeth, for shearing and grinding food
How are carnivore teeth adapted to their diet?
Meat diet
Canines to hold prey + rip meat
Carnassial teeth to shear meat
Lack the enzyme cellulase
How are herbivore teeth adapted to their diet?
Plant diet
Incisors to cut plant material
Molars continuously grow as worn down by silica in plants
Grind food + mix with saliva
Give 2 ways birds’ beaks are adapted to feed
Beaks adapted depending on diet
Shape of beak - e.g. hummingbird feed on nectar
Generally have a hooked or cured tip
Size of beak - e.g. pelicans feed on larger things
What does the pancreas secrete and why?
Bicarbonate - regulate pH
What is peristalsis?
Muscular contractions to push food along digestive tract
Where is water absorbed?
Large intestine, through villi
Explain hindgut fermenters
Animals who have a single-chambered stomach (monogastric) and a caecum
Eat mostly high fibre plants
fibre = hard to digest
Partially digested food goes to caecum and is fermented by microbes, breakdown cellulose
Give 3 functions of the liver
- Produces bile - emulsifies fats
- Filters out toxins
- Carbohydrate storage - converts glucose to glycogen
What enzyme does saliva contain?
Amylase
What enzymes are added in the stomach and what do they break down?
Protease - proteins
Lipase - fats/lipids
Give 2 functions of the pancreas
- Produce enzymes to aid digestion
- Produce insulin and glucagon (hormones)
Explain the process for detecting high blood glucose levels and subsequently reducing them
• Pancreas detects high blood glucose levels
• Insulin secreted, glucagon secretion decreases
• Insulin travels to liver + muscles
• Body + muscles use excess glucose to make energy
• Excess converted to glycogen by liver and muscle cells, stored
• Blood sugar levels decrease
What is the difference between type 1 and type 2 diabetes?
Type 1 - lack of insulin
Type 2 - insulin resistance (linked to obesity)
Explain the 4 chambers in the ruminant digestive system
Rumen - largest, storage + fermentation, cellulase break down plant material
Reticulum - small food particles move on to omasum, large particles go back
Omasum - absorb water + salt
Abomasum - true stomach
Explain avian digestion
Birds do not have teeth - use tongue to move food to back of mouth
Passes to proventriculus - digestive enzymes + HCl added
Then moves to ventriculus (gizzard) - mechanical digestion, water re-absorbed, food fermented
Waste excreted out of cloaca as one mixed substance
Give 3 causes of vomiting and diarrhoea
Unsuitable type or amount of food / foreign bodies / contaminated food / stress / pathogens
What does chunky or granular vomit mean?
Food related signs
Chunky - undigested food, eaten too quickly or ran around after eating
Granular - partly digested
What does liquid (foamy, slimy or clear) vomit mean?
Disease
What is ruminant bloat?
When gas builds up in rumen
