MEDICAL PHYSIOLOGY

Detailed explanation-1: -The I bands contain only thin (actin) filaments, whereas the A bands contain thick (myosin) filaments. The myosin and actin filaments overlap in peripheral regions of the A band, whereas a middle region (called the H zone) contains only myosin.

Detailed explanation-2: -I-band is a thin line in a sarcomere that shortens during muscle contraction. The I-band consists of only thin myofibrils having actin protein. When the actin and myosin forms cross-bridge during contraction, the I-band decreases its size so that two Z-lines come closer.

Detailed explanation-3: -I bands (or isotropic bands): it is called the light band that contains only the thin filament (actin). The thin filament lies between the two thick filaments. Z disc: it is the area where two actin filaments connect and transverse the I bands.

Detailed explanation-4: -Thick filaments are anchored in the middle of the sarcomere at the M-line. The I-band is the region on either side of a Z-disc that contains only thin filaments and titin.

Detailed explanation-5: -In physiology, isotropic bands (better known as I bands) are the lighter bands of skeletal muscle cells (a.k.a. muscle fibers). Isotropic bands contain only actin-containing thin filaments. The darker bands are called anisotropic bands (A bands).