Skeletal Muscle Contraction Flashcards
Functions of the Skeletal muscle
body movement, respiration, maintenance of posture, communication, constriction of organs and vessels, heartbeat, thermogenesis
Cell membrane of the muscle cell
Sacrolemma
Cytoplasm of the muscle fiber
Sarcoplasm
Oxygen-binding protein
Myoglobin
Narrow tubes that extend into the sarcoplasm at right angles to the surface, filled with extracellular fluid
Transverse tubules (t-tubules)
An elaborate, smooth endoplasmic reticulum. Runs longitudinally and surrounds each myofibril
Sarcoplasmic Reticulum
What stores calcium ions when a muscle is not contracting
Sarcoplasmic Reticulum
It refers to the attachment of myosin heads with the actin within the muscle cell
cross-bridges
Ends of the actin filaments are attached to?
z-disc
What gives the skeletal and cardiac muscle its striated appearance?
Light and dark bands (actin and myosin), differences in size, density, and distribution of thick and thin filaments
Repeating functional unit of a myofibril
Sarcomere
Protein to which myosins attach, the exact midpoint of the sarcomere
M-line
Thick but no thin filaments, region of only myosin myofilaments
H zone
A light band; from z disks to ends of thick filaments, region of only actin myofilaments
I bands
Filamentous network of protein, serves as attachment for actin myofilaments
Z disk
