Module 30 - Muscle Histology Flashcards
list the functions of the skeletal muscle system
Body movement
Maintenance of posture
Respiration
Production of body heat
Communication
what is contractility of a muscle
ability of a muscle to contract forcefully
what is excitability of a muscle
capacity of muscle to respond to a stimulus
by producing action potentials
what is extensibility of a muscle
muscle can be stretched beyond its resting
length and still be able to contract
what is elasticity of a muscle
ability of muscle to recoil to original resting
length after it has been stretched
describe skeletal muscle
muscle cells (fibers), CT, blood vessels, nerves.
Long cylindrical and multinucleated fibers
striated appearance
the tendons in skeletal muscle go from which type of CT to which type to CT
from irregular to regular dense collagenous CT
what is a fascicle
bundles of muscle cells
what is the endomysium
surrounds muscle fibers/separates cells
what is the perimysium
holds together the fascicles/surrounds fascicles
what is the epimysium
holds together all of the muscle/surrounds muscle
what is the muscular fascia
surrounds individual muscles and groups of muscles
what is sarcomere
chains of proteins, highly organized.
what is the transverse T tubule
surrounds myofibril (extension of sarcolemma), allows AP to move through the cell like a subway system
where is calcium stored in the muscle fiber
in terminal cisterna
what are z-disks
proteins that help hold actin and myosin in place (across myofibril)
what is the role of dystrophin
makes the connection between actin myofilaments and proteins in the sarcolemma
what does the M line do
holds myosin myofilaments
the sarcomere is measured from…
z-disk to z-disk
what gives elasticity to the muscle
titin
what is the F actin made of
g actin molecules and active sites
what covers the F actin molecules active sites?
tropomyosin
what are the 3 roles of troponin
- binding to G actin molecules
- binding to tropomyosin
- binding to calcium for muscle contraction
what creates contraction in myosin filaments?
movement of myosin heads that is happening due to a reception of ATP from ATPase.
whats the components of a sarcomere that has no myofilament
Z disk
whats the one band in sarcomere that never changes length
A band
whats the darkest components of the sarcomere
actin + mysoin tg
the I band contains…
actin only
the h band contains…
myosin only no actin
function of m line
middle of h zone; holds myosin in place
whats the region in sarcomere where actin and myosin DO NOT overlap
A band
