CTB 3 – Tooth morphology and mastication Flashcards Preview

Craniofacial and Tooth Biology > CTB 3 – Tooth morphology and mastication > Flashcards

Flashcards in CTB 3 – Tooth morphology and mastication Deck (28)
Loading flashcards...
1
Q

Why do humans have a higher metabolic rate than replies?

A

Reptiles just grab their food and swallow

Humans need their energy faster, therefore chew food to reduce size, increase SA and hence a faster digestion

2
Q

How long is the masticatory sequence?

A

Cycle is 1 second

3
Q

How is the masticatory sequence controlled?

A

Neural circuitry

4
Q

Describe the masticatory sequence.

A
  • Lower jaw orbits
  • Mouth opens and food collected by tongue
  • Tongue picks up particles and mixes with saliva by pressing into the hard palate
  • Food moves laterally to posterior canine teeth (1 side)
  • Food falls laterally during chewing are put back in the mouth by the contraction of the BUCCINATOR
  • Relax before closing
  • Once tongue and cheek are out of the way there is fast closure of tooth-food contact
  • Mandible slows just before contact to allow for perception of food properties to judge the strength of bite
5
Q

What is the function of the tongue in the masticatory sequence?

A
  • Tongue picks up particles and mixes with saliva by pressing into the hard palate
  • Food moves laterally to posterior canine teeth (1 side)
6
Q

What is the main component of food chewing dependent on?

A

Physical properties of foods

7
Q

What is the function of sensory feedback during the masticatory sequence?

A

Monitors food properties

8
Q

What is the most sensitive part of the oral cavity in the masticatory sequence? What is the discrimination of these?

A

Tongue and hard palate

1-2mm

9
Q

Where are the most important sensors during mouth closing

A

TMJ

10
Q

What type of receptors does the PDL have?

A

Mechanoreceptors

11
Q

What particle size can teeth detect?

A

8 – 15 microns

12
Q

What force reaches a maximum when food is swallowed?

A

When cohesive force is max

13
Q

What forces are applied to cause distortion to food?

A
  • Stress
  • Strain
  • Stiffness
  • Yield strength
  • Brittle
  • Hardness – stress for perm indentation
  • Fracture strength - tough foods have slow feeding rates
14
Q

What is yield strength?

A

Stress at which a solid begins to perm deform

15
Q

What is the function of anterior teeth?

A

Biting and gripping

16
Q

What is the function of posterior teeth?

A

Fracturing food

17
Q

What is the function of secondont teeth? Give an animal example.

A

Slicing function for meat – only peaks in the tooth – e.g. cat

18
Q

What is the function of bunodont teeth? Give an animal example.

A

For eating meat and plants – flattened occlusal surfaces for crushing and grinding – human

19
Q

What animals have selenodont teeth?

A

Cow, deer, sheep, goat

20
Q

What animals have lophodont teeth?

A

Elephant, mouse

21
Q

What animals have selenolophodont teeth?

A

Horse

22
Q

What is the shape of the selenodont, lophodont and selenolophodont teeth?

A

Complex infolding for herbivory to eat plants etc

23
Q

What shapes in the posterior teeth are limited during tooth mastication?

A

Cusps and dips

24
Q

What are the 4 occlusion surfaces of upper and lower teeth to aid different types of mastication?

A
  • Alternation – teeth interdigitate to grip not fracture food
  • Opposition – cusps fit into basins for crushing
  • Shearing – oblique/parallel movement movements of crest past each other
  • Grinding – mortar and pestle motion
25
Q

What are sauguinivore?

A

Blood feeders

26
Q

What type of teeth do tertiary consumers have?

A

Very sharp teeth

27
Q

Give examples of omnivores

A

Hyena and jackal

28
Q

What type of animals have no upper front teeth?

A

Browsers and grazers