Meaning and Types of Heterotrophism
Modes of Feeding in Animals
Types of Mammalian Teeth
Adaptation of Teeth to Feeding
In general, incisors are for cutting, canines for tearing while premolars and molars are for grinding.
However, specific modifications are observed in different mammals as an adaptation to the type of food they eat.
Teeth of Herbivores
Teeth of Carnivores
Internal Structure of tooth
The tooth consists of two main parts:
Crown: The portion above the gum; it is covered by the enamel.
Root: The portion below the gum; it is covered by the cement.
The tooth has two roots.
Neck: Is the region at the same level with the gum.
Cement: Fixes the tooth firmly to the jaw bone.
Common Dental Diseases
Dental carries are the holes or cavities that are formed as acid corrodes enamel and eventually the dentine.
Treatment depends on the extent of the dental caries:
Extraction of Tooth.
This involves replacing the dentine with amalgam, a mixture of hard elements e.g. silver and tin.
Root Canal Treatment
This involves surgery and reconstruction.
It saves severely damaged teeth.
The nerves in the root canal are surgically severed.
The tooth is cleaned and filled up with amalgam.
Care of Teeth
In order to maintain healthy teeth the following points should be observed:
Digestive System and Digestion in Humans
Organs that are involved with feeding in humans constitute the digestive system.
Digestive System and Associated Glands
Ingestion, Digestion and Absorption
Digestion in the Duodenum
Absorption of Fatty Acids and Glycerol
Summary of digestion in humans
Importance of Vitamins, Mineral Salts, Roughage and Water in Human Nutrition
Vitamins, sources, uses and the deficiency disease resulting from their absence in diet
A diet is balanced when it contains all the body's nutrient requirements and in the right amounts or proportions.
A balanced diet should contain the following:
This is faulty or bad feeding where the intake of either less or more than the required amount of food or total lack of some food components.
Deficiency diseases result from prolonged absence of certain components in the diet.
Lack of enough food results in thin arms and legs, severe loss of fluid, general body wasting, sunken eyes.
Lack of protein in the diet of children. The symptoms of kwashiorkor include wasting of the body, red thin hair, swollen abdomen and scaly skin.
Other deficiency diseases are due to lack of accessory food factors (vitamins and mineral salts.). Such diseases include rickets, goitre and anaemia.
Treatment of these deficiency diseases is by supplying the patient with the component missing in the diet.