Control of Mastication

Question 1

how many teeth do you require to chew adequately?

Answer 1

20 or more

Question 2

remember -> hinge and slide

Question 3

remember

Question 4

remember

Question 5

what is the sequence of muscle activation in opening?

Answer 5

mylohyoid
digastric
lateral pterygoid - last because is causes the slide

Question 6

what is the sequence of muscle activation in closing?

Answer 6

temporalis
masseter
medial pterygoid

Question 7

what are the 3 levels of control for mastication?

Answer 7

reflex
pattern generation
voluntary

Question 8

what is a reflex?

Answer 8

predictable response to a stimulus

Question 9

how many synapses does a reflex usually have?

Answer 9

one -> monosynaptic

Question 10

what is reflex latency?

Answer 10

reaction time
conduction time + synaptic delay

Question 11

conduction time is dependant on what?

Answer 11

neurone speed and distance

Question 12

synaptic delay time is dependant on what?

Answer 12

the number of synapses (more = slow)

Question 13

what do stretch jaw reflexes do?

Answer 13

stabilise the jaw during vigorous head movements e.g. running

Question 14

what do inhibitory jaw reflexes do?

Answer 14

inhibitory jaw opening in response to noxious stimulus
Prevent overloading of the masticatory system

Question 15

what do jaw unloading reflexes do?

Answer 15

inactivation of closing muscles and activation of opening muscles in response to sudden closure

Question 16

what is the motor nucleus?

Answer 16

collection of cell bodies in the CNS

Question 17

what does the chewing centre do?

Answer 17

pattern generation

Question 18

what does the higher centres do?

Answer 18

tell the pattern generator to start, stop, speed up or slow down chewing

Question 19

what feeds back to the motor nucleus?

Answer 19

receptors -> PDLMs
e.g. froce required to bite through a carrot

Question 20

remember