BIOLOGY 3.7 TEETH Flashcards
(6 cards)
What are teeth
Teeth are used for biting, chewing and to speak clearly. It is composed of calcium phosphate
The 4 types of teeth
Incisors: front teeth (we have 8 of them)
Uses: it is used for biting and cutting food
Canines (pointed teeth next to incisors) (4 of them)
Uses: It is used for tearing food, particularly when we eat meat.
Premolar (flat teeth, situated right next to the canines) (there are 8 of them)
Use: It is used to crush and grind food
Molars: (Back teeth) (12)
Use: They are used for grinding into smaller pieces for swallowing
Baby teeth: 20
Adult teeth: 32
STRUCTURE OF TEETH
EXTERNAL -
Crown
- visible part above the gum line
- covered by enamel (hardest structure in the body)
Neck
- Area between the crown and the root (protective mechanism to hold our teeth)
Root
- the part embedded in the jawbone
- anchors the teeth in place
INTERNAL
Enamel
- outermost layer of the crown
- extremely hard and protective
Dentine
- contains nerves to transmit sensations
Pulp
- contains blood vessels
- responsible for nourishing the teeth
Cement
- a calcified layer covering the root
- helps anchor the teeth
What causes tooth decay
There are four steps in the process
Plaque formation: Bacteria in the mouth form a sticky film called plaque on the tooth surface
Acid production: These bacteria contain sugar and starches from food and drinks, producing acid as a byproduct. This acid has the potential to corrode away our teeth.
Enamel attack: the acid dissolves the tooth enamel, forming a cavity hole (The enamel is not strong enough to defend itself from the excessive acids). When the hole is open and the dentine is exposed, we will start to feel pain/sensations in our tooth.
Progresses to dentine, then the pulp and then the gum, causing gum diseases.
Result of a tooth decay:
pain, infection and tooth loss.
How is the shape of an incisor and a molar related to its function?
The incisors have a sharp, chisel - like shape which allows them to bite and cut food efficieintly. Similarly, the molars have a broad, flat shape which relates to its function of grinding and crushing food.
