Jan 8, 2015 Definition: In striated muscle sarcomere, the M line is the attachment site for the thick filaments. The M line is in the center of the A band and, thus, it is in the center of the sarcomere. Related glossary terms/phrases: A band.

Several proteins important for the stability of the sarcomeric structure are found in
the Z-line as well as in the M-band of the sarcomere. Actin filaments and.in
molecules are cross-linked in the Z-disc via the Z-line protein alpha-actinin. The
M-band proteins myomesin as well as C-protein crosslink the thick filament
system …

middle area in the sarcomere where thick and thin filaments are found. A band. I
band. Z disc. H zone. M line sarcomere neuromuscular junction myoglobin
satellite cells transverse tubules sarcoplasmic reticulum sarcolemma sarcoplasm.
I band. lighter, contains thin filaments but no thick filaments. A band. I band. Z
disc