Muscle Module 6 Flashcards
__________ has a great force than slow mhc
Fast Mhc
A mixture of short and long myofibrils will cause what
an inhomogeneity in forces. ! myofibril will stretch unevenly and cause issues
What determines if the mhc and mlc will be expressed.
Motor neuron or muscle fiber is stimulated first.
The alternation of slow and fast MHC shows us that its the _____________ of motor neurons that determine what myosin chain is expressed and determine contractility of muscle fiber
firing pattern of motor neurons
In one muscle fiber there are __________________ muscle fibers
many thousand
One nerve innervates __________________
several muscle fibers
Muscle innervated by the same nerve will have the same
- same myosin expression
- same activation
- same contractile
- similar metabolism
Force and velocity change what 5 things
- change sarcomere length
- cross sectional area
- modify frequency of stimulation
- recruitment
- change MHC expression
Changes in force and velocity are a direct result of what
changes in the number of working cross bridges in parallel
Smooth muscle has ___________________ leadings g to many functions
less specific contraction
Talk about type 1 motor units Vmax: Metabolism: Fatiguability: Fibers: Force; Cross Sectional Area:\ Example:
Vmax: slow Metabolism: oxidative phosphorylation Fatiguability: low Fibers: few Force; low Cross Sectional Area:smaller Example: eye muscle
Type 2 motor units: Vmax: Metabolism: Fatiguability: Fibers: Force; Cross Sectional Area:\ Example:
Vmax: fast Metabolism: glycolysis Fatiguability: high Fibers: many Force; high Cross Sectional Area: larger Example: skeletal limbs
what are the characteristics of a Moto unit with more force
- More fibers
- greater cross sectional aea
- fast MHC
- More Calcium production
All of each type of motor units will ________________
stimulate together
Recruitment is the activation of motor units _________
sequenctially
