muscles of mastication 1

Question 1

name and order of elevator muscles of mastication 3

Answer 1

1. temporalis
2. masseter
3. medial pterygoid muscle

Question 2

name depressor muscles of mastication 4

Answer 2

-digastric x2 (anterior and posterior bellies)
-mylohyoid
-geniohyoid
(+ lateral pterygoid, but this mainly does side to side movements)

Question 3

motor nerve supply to muscles of mastication

Answer 3

all V3 except:
posterior belly of digastric (VII, auriculotemporal branch)
geniohyoid (XII)

Question 4

what other muscles are used in depression of the jaw and how

Answer 4

infrahyoid muscles (esp sternohyoid)
stabilises hyoid bone

Question 5

what makes up a motor unit

Answer 5

muscle fibres innervated by one alpha motoneurone (can be less than 10- several hundred muscle firbres

Question 6

function of

a. extrafusal muscle fibres
b. intrafusal fibres
* SEE WORD DOC*

Answer 6

a. extrafusal muscle fibres: tension development and shortening in skeletal muscle (muscle work, contraction)
b. intrafusal fibres: make up muscle spindle, contain sensory receptors to monitor muscle length