<h1 style="box-sizing: border-box; margin: 0px; font-weight: 500; line-height: 1.5; font-size: 2.4em; font-family: Poppins, sans-serif; color: var(--iq-title-text); letter-spacing: 1px; background-color: #ffffff;">The Structure of the Z-Band</h1>
<p><img style="box-sizing: border-box; vertical-align: middle; border-style: none; max-width: 38%; color: #585858; font-family: Poppins, sans-serif; letter-spacing: 1px; background-color: #ffffff; height: auto; max-height: 298px; margin: 0px 10px; width: auto;" src="https://i.imgur.com/hBfZc1p.png" alt="z band" align="left" /></p>
<p style="box-sizing: border-box; margin-top: 0px; margin-bottom: 1rem; color: #585858; font-family: Poppins, sans-serif; letter-spacing: 1px; background-color: #ffffff;">During muscular contraction, the Z-band serves as an anchor for the myosin filaments. These filaments are antiparallel and crosslink opposite polarities. In addition, the Z-band transmits tension along the myofibrils.</p>
<p style="box-sizing: border-box; margin-top: 0px; margin-bottom: 1rem; color: #585858; font-family: Poppins, sans-serif; letter-spacing: 1px; background-color: #ffffff;">Z-bands are found in skeletal muscle of many vertebrates. Their width and structure vary depending on the type of muscle. For example, in slow skeletal muscles, the Z-band is wider than in cardiac muscle. In fast skeletal muscles, however, the Z-band is narrower than in slow muscle.</p>
<p style="box-sizing: border-box; margin-top: 0px; margin-bottom: 1rem; color: #585858; font-family: Poppins, sans-serif; letter-spacing: 1px; background-color: #ffffff;">In striated muscle, the Z-band borders the sarcomeres. It also connects thin filament arrays in the contractile apparatus. Several studies have investigated the structural details of the Z-band. Some of these studies used electron microscopy. Others used Fourier analysis.</p>
<p style="box-sizing: border-box; margin-top: 0px; margin-bottom: 1rem; color: #585858; font-family: Poppins, sans-serif; letter-spacing: 1px; background-color: #ffffff;">Electron microscopy studies of transverse sections of striated muscle in vertebrates show two distinct structures. The first is a small square lattice. The other is a basketweave lattice. These structures are similar in appearance to the nemaline rods, which are often found in patients with nemaline myopathy.</p>
<p style="box-sizing: border-box; margin-top: 0px; margin-bottom: 1rem; color: #585858; font-family: Poppins, sans-serif; letter-spacing: 1px; background-color: #ffffff;">In the first study, Morris etal. used Fourier methods to generate a three-dimensional (3D) picture of the Z-band. They showed the path of a-actinin, a-actinin layers, and actin binding domains. They used this method to generate 3D images of Z-bands in nemaline rods and in two different types of muscle.</p>
<p style="box-sizing: border-box; margin-top: 0px; margin-bottom: 1rem; color: #585858; font-family: Poppins, sans-serif; letter-spacing: 1px; background-color: #ffffff;">In the second study, Luther etal. studied the Z-band in a rat cardiac muscle. They used Morris's method to generate 3D images of the Z-band in two muscles. They also used tilt series techniques to analyse the white muscles of fishes.</p>