Animal Nutrition Flashcards
What is the importance of food
- Supply energy
- Provision of materials for growth and repair of damaged tissue
- Maintaing body processes
Incisors
For cutting and biting
Canines
For tearing
Premolars
For chewing and grinding
Molars
For chewing and grinding
Characteristics of the dentition of an omnivore
- chisel-shaped incisors
- pointed canine for tearing meat
- fairly flattened pre-molars and molars to chew both meat and plant material effectively
What is the function of the accessory organs in the digestive system
To secret substances into the alimentary canal to facilitate digestion
Ingestion
The intake of food through the mouth
Digestion
The mechanical and chemical break down of food
Absorption
The diffusion of simple food molecules through the intestine walls and into the blood
Assimilation
Intake of nutrients into the cells
Egestion
The removal of undigested food particles and waste from the body through the anus
The mouth
The mouth is bounded by two lips that keep the food in the mouth
Structures in the mouth
- Teeth
- Tongue
- Salivary glands
Function of teeth
To chew food into smaller pieces. This will increase the surface area of the food that is exposed so that enzymes can break it down further
Mastication
The process of chewing
Tongue
A strong muscular organ that has taste buds that are sensitive to chemicals in food
Function of the tongue
Helps to force food between teeth for chewing and rolls it into a ball
Bolus
A ball of chewed up food
Function of Salivary glands
Secretes saliva which contains an enzyme called salivary amylase that breaks down cooked starch. Saliva keeps the pH of the mouth at 7.2 for optimal enzyme functioning
The three types of salivary glands
1.parotid
2.submadibular
3. Sublingual
Position of the parotid gland
Just below and in front of the ear
Position of the submandibular gland
Lies in the lower jaw
Position of the sublingual gland
Lies below the tongue
Pharynx
The point at which the nasal and mouth cavity meet
Epiglottis
A structure that prevents entry of food or liquid particles into the air passages when we swallow
The oesophagus
A long tube extending from the pharynx to the stomach.
The structure of the oesophagus
It consists of smooth muscle and is lined with columnar epithelial that contains goblet cells
What is the function of the goblet cells in the oesophagus ?
The goblet cells secrete mucous that lubricates the oesophagus for ease of passage
Peristalsis
Waves of contractions
How does food move from the oesophagus into the stomach?
As food passes down the oesophagus, waves of contractions follow the food bolus, pushing the food into the stomach
The stomach
An organ that follows on the oesophagus and is bounded by circular muscles called the cardiac sphincter and the pyloric sphincter
What is the function of the cardiac sphincter?
Stops the food from moving back into the oesophagus
What is the function of the pyloric sphincter?
Prevents food from moving into the small intestines until it is ready to do so.
What hormone does the stomach wall secret?
Gastrin
What is the function of gastrin?
It stimulates glands in the wall of the stomach to secrete gastric juice that helps to digest food