GENERAL HISTOLOGY

Detailed explanation-1: -The sarcomeres give skeletal and cardiac muscle their striated appearance, which was first described by Van Leeuwenhoek. A sarcomere is defined as the segment between two neighbouring Z-lines (or Z-discs).

Detailed explanation-2: -The Z-disc acts as a protein-rich structure to tether thin filament in the contractile units, the sarcomeres, of striated muscle cells. Proteins found in the Z-disc are integral for maintaining the architecture of the sarcomere. They also enable it to function as a (bio-mechanical) signalling hub.

Detailed explanation-3: -A sarcomere is defined as the distance between two consecutive Z discs or Z lines; when a muscle contracts, the distance between the Z discs is reduced. The H zone-the central region of the A zone-contains only thick filaments and is shortened during contraction.