7 masticatory muscles (gerstner) Flashcards
originates from the mandible, closes the mouth
masseter
originates from the temporal bone, closes the mouth, retracts jaw
temporalis
protrudes jaw during opening
inferior head of lateral pterygoid
stabilized jaw during closing
superior head of lateral pterygoid
closes jaw, forms sling with masseter
medial pterygoid
jaw closer, two heads, role in swallowing and speech
digrastics
usually darker stained muscle fiber due to more mitochondria and capillary beds
type 1, slow oxidative
masticatory muscle have these two extra types of muscle fubers
alpha cardiac and type 2x
in limb/body muscle, the fibers comprising a motor unit are….
all the same fiber type
______ largely determines contractile speed
MHC, myosin heavy chains
jaw _____ muscles tend to have more hybrids.
closer
one possible reason for hybrid fibers in masticatory muscles is to minimize impact of _____ _____ on oral function.
size principle
type 1 fiber more common in ____ _____ _____.
deep anterior muscles
type 2 fibers more common in _____ _____ _____.
superficial posterior
type 1 increases in a graded way towards _____ ______.
anterior temporalis
type IIx is more common in ____ ______ than _____ ____.
anterior digastric than posterior digastric.
type IIa is more common in ______ _____ than _____ _____.
posterior digastric than anterior digastric.
masticatory muscles are the only muscles that retain ________ in adulthood. these fibers aid in training/adapting.
neonatal fibers
Type I fibers more prevalent in adult ______.
females
type II fibers more prevalent in adult ______.
males
type I fibers _____ with age in masseter.
decrease
type IIa fibers ______ with age.
increase
soft diet can cause an increase in _______ fibers.
type iib
the average diameter in type IIA fibers in the masseter muscle are ________ than type I fibers.
smaller
