Chapter 1 Flashcards
movement of a fibrous joint
no movement
example of a fibrous joint
suture
movement of a cartilaginous joint
limited movement
example of a cartilaginous joint
intervertebral
movement of a synovial joint
free movement
example of a synovial joint
shoulder, knee
example of a uniaxial joint
elbow
example of a biaxial joint
wrist
example of a multiracial joint
shoulder
what is epimysium
surrounds entire muscle
what is perimysium
surrounds fascicle (fasciclus)
what is endomysium
surrounds individual muscle fibers/cells
what is a motor unit
motor neuron+ muscle fibers it innervates
what is a sarcolemma
cell membrane
what is a sarcoplasm
cytoplasm
what is the function of a sarcoplasmic reticulum
Ca storage
___ are thick filaments
myosin
___ are thin filaments
actin
function of Z lines
move closer together during contraction
function of I bands and the H zone
shortens during contraction
when does the muscle have the most cross bridges
at rest
5 stages of the sliding-filament theory
- resting
- situation-contraction coupling
- contraction
- recharge
- relaxation
what happens during the resting phase
lower Ca-> decrease interaction between actin and myosin
what happens during the excitation-contraction phase
action potential-> Ca release from SR; Ca binds to troponin; tropomyosin shifts position and reveals binding sites
what happens during the contraction phase
power stroke-> ATP needed
what happens during the recharge phase
stronger contraction as long as Ca and ATP are present
what happens during the relaxation phase
ends when motor neuron stops firing
what is the direct relationship with a cross sectional area of muscle
force production
details of a type 1 muscle fiber
slow twitch aerobic high mitochondrial density red high endurance
details of a type 2a muscle fiber
fast twitch
low myoglobin
fast contraction
details of a type 2b muscle fiber
anaerobic
low mitochondrial density
white
low endurance
function of muscle spindles
length/stretch
function of Golgi tendon organs
muscle tension
