Animal Nutrition Flashcards
(45 cards)
What is a balanced diet?
A balanced diet is one that has the correct proportions of carbohydrates, proteins, fats, vitamins, minerals and Fibre(roughage)
List and explain the 5 processes involved in animal nutrition
- Ingestion- taking in insoluble food into the mouth
- Digestion- breakdown of food mechanically by chewing or chemically by enzymes
- Absorption- taking in simple soluble substances into the blood stream
- Assimilation- taking in simple soluble substances from the blood stream into cells
- Egestion- removal of undigested food from the body in the form of faeces
List the importance of food
- provide energy: come from carbohydrates and fats
- to grow and repair damaged tissue: comes from proteins
- regulation of body processes: vitamins and minerals
Name and explain the modes of nutrition
Animals are classified in 3 groups according to the food they eat
Herbivores- eat plants and plant material
Carnivores- eat othe animals
Omnivores- eat both plants and animals
Energy food chain
Producers > Primary consumers > Secondary consumers > tertiary consumers
List and explain the types of teath
- Incisors: chisel shape(biting and cutting)
- Canines: cone shape(gripping and holding)
- Pre molars: used for grinding
- Molars: uses for grinding and crushing food
Nutrition and dentition in herbivores
- Herbivores are animals that eat plants only (e.g. cows)
- They consume large amounts of food as the food they eat is low energy food
- wide sharp Incisors for cutting grass (biting)
- Molars that are used for grinding(chewing)
- do NOT have Canines
Grass is digested in a rumen(part of alimentary canal), with the aid of bacteria
Nutrition and dentition of Canivores
Carnivores are animals that only eat other animals(e.g. lions)
-food is high in protein therfore don’t have to eat alot
Carnivores have powerful jaws with teeth:
- incisors: sharp to bite off food
- canines: sharp canines to grip prey when hunting
- premolars and
- molars: have protutions=>stick out and are modified to form carnicial teeth
The digestion of proteins occurs mainly within the stomach
Nutrition and dentition of Omnivores
Animals that eat both plants and animals Have: - incisors - canines - premilars and - molars More like carnivores but not as sharp Teeth are not modified
Chemical digestion starts in the mouth and continues in the stomach and small intestine
Human dental formula
- 1.2.3 =8
- ——– - 1.2.3
I.C.P.M ¼ of jaw
Define digestion
Digestion may be defined as the step-wise breakdown of large food particles into molecules, small enough to enter the body’s cells
Overview of the mechanisms of nutrition
a) Ingestion: taking in food into the mouth(eating)
b) Secretion: cells within the walls of the alimentary canal & accessory organs, secrete water, enzymes and acids & alkalis
c) Mixing and Propulsion: alternating contraction & relaxation of smooth muscles in the walls of the alimentary canal, mixing food and secretions and pushing them along.
d) Digestion: mechanical and chemical processes involved, mix secreted fluids with ingested food and breakdown large food particles into smaller particles and molecules
e) Absorption: entry of products of digestion into the epithelial cells lining the lumen of small intestine, thereafter passing into the blood and lump. Mist drugs, alcohol are absorbed in the stomach
f) Defaecation(egestion): the elimination of undigested food and waste material from the large intestine through the anus
Define mechanical digestion
Mechanical digestion involves physical breakdown of food by teeth, the swallowing of food and the action to smooth muscles of the stomach and intestine that churn food so that it is mixed with enzymes
Define chemical digestion
Chemical digestion involves a series of catabolic reactions where enzymes and chemicals breakdown carbohydrates, lipids and proteins into smaller molecules
What is the elementary canal?
A long tubular structure that extends from the mouth to the anus. It consists of:
- mouth and mouth cavity
- pharynx
- oesophogus
- stomach
- small intestine
- large intestine
- rectum
- anus
List the Accessory organs
- tongue/teeth
- salivary glands
- pancreas
- liver
- gall bladder
Mouth?
Mechanical digestion- physical breakdown of food(teeth/tougue)
Chemical digestion: hydrolysis- enzymes + water
Define hydrolysis
The chemical breakdown of a compound due to reaction with water.
Tongue
- tastebuds
- move food side to side
- roll food into bolus(ball of food)
- helps in swallowing
- organ of taste(sweet, sour, salty, bitter)
- stimulates the Secretion of saliva to labrucate for easy swallowing
Teeth
Teach cut, tear and pulverise food into smaller particles for swallowing
- 8 incisors used for biting and snipping food
- 4 canines used for gripping and tearing food
- 8 premilars help in chewing food
- 12 molars used for chewing
2.1.2.3= 8
I.C.P.M- ½ of upper/lower jaw
32 teeth in total(adults)
Salivary Glands
- 3 pairs present in mouth
- secrete saliva which consists of water, mucin and an enzyme
Silava serves to soften and lubricate food which facilitates chewing, mixing and swallowing - produces saliva
- contains mucus- moisten food
- salivary amylase breaks down starch into maltose
- pH in mouth is basic.. only carbohydrates chemically breakdown
The pharynx
Back of mouth cavity, leading to oesophagus and trachea
- common passageway for food(swallowing) and air
- when food is swallowed the epigolttis closes so food doesn’t enter trachea(wind pipe)
The oesophagus(gullet)
Narrow muscular tube links pharynx to stomach behind trachea
- forces the bolus down into stomach by muscular wave-like motion..this is CALLED Peristalis.
- goblet cells secrete mucus- lubricating walls for smooth passage of bolus
The stomach
Muscular bag-like organ, lying in upper part of abdominal cavity just below diaphragm
The cardiac and pylori sphincters control the entry and exit of food