functional anatomy Flashcards
list the parts included in a skeletal muscle
ef pmem
epimysium
fascicle
perimysium
muscle fibre
endomysium
myofibril
define the epimysium
the connective tissue shealth around each muscle
define fascicle
a bundle of skeletle muscles surrounded by the perimysium
define the perimysium
the connective tissue which surrounds seach bundle on muscle fibers
define muscle fibres
surrounded by a plasma membrane called the sarcolemma which contains the sarcoplasm. a muscle fibre is composed of many fibrils, which give the cell its striated appearance.
define endomysium
connective tissue which surrounds each individual muscle fibre
define myofibril
small thread like strands that run through each muscle fibres.
what is the sliding filament theory
explains the shortening of the sacromere (in a concentric contraction) and then resulting in contraction in muscle
describe the first step of the sliding filament theory
when there’s a neurochemical stimulation calcium ions are released from the sarcoplasmic reticulum into sarcomere
prompting reaction in each muscle fibre between myosin and actin filaments
describe the second step in the sliding filament theory
myosin filaments creates cross bridges ( myosin heads) at regular intervals. these cross bridges attach and reattach at different times along the actin. pulling them to create tension.
describe the 3rd step of the sliding filament theory
the actin now moves into the centre of the sarcomere, shortening the myofibril and causing the actin and myosin filaments to be almost fully contracted position causing the H zone and I band to disappear.
describe the 4th step of the sliding filament theory
as each sarcomere shortens so does the total length of each muscle fibre
describe the 5th step of the sliding filament theory
when the contraction finishes the myosin and actin filaments return to a relaxed position
what are the different bands and zones of the sarcomere
h zone- distance between actin and filament
a band- length of myosin filament
I band- disnce from the edge of myosin to the z line
z line- edges of the sarcomere
draw a labeled diagram of a neuron
should include - dendrites, mylin shealth, axon, synaptic bulbs, cell body, nucleus, muscle fibres