The three sections along the length of a sarcomere are the A band, the I band, and the H zone. The A band is the dark region in the center of the sarcomere that contains both thick and thin filaments, while the I band is the light region at the ends of the sarcomere that contains thin filaments only. The H zone is the region in the center of the sarcomere where only thick filaments are present.
Yep, you got it.
when the Thick filaments pull the thin filaments toward the center of the sarcomere
The sarcomere itself will become shorter.The sarcomere will shorten.
Sarcomere
1. Arrangement of thick and thin filaments: In each sarcomere two sets of actin filaments extend partway toward the center. The myosin filaments are arranged such that they partially overlap the actin filaments. Myosin heads on each side point away from the center of the sarcomere.2. During contraction, the interaction of myosin heads with the actin filaments pulls the thin filaments toward the center of the sarcomere. The actin and myosin filaments slide past each other.3. Cross-bridges = attachement betwn myosin heads and binding sites on actin filaments.4. When a muscle cell is stimulated, myosin heads are energized by ATP. They attach to adjacent actin filaments, and tilt in a short "power stroke" toward the center of the sarcomere. Each power sroke requires an ATP. With many power strokes in rapid succession, the actin filaments are made to slide past the myosin filaments.
sarcomere and sarcolemma are two different things. a sarcomere is between two d zisks of a myofiber (muscle fiber). a sarcolemma is a plasma membrane. there are many sections of sarcomere under the layer of sarcolemma.
The two main filaments composing the sarcomere are action and myocin.
A sarcomere consists of thin and thick filaments arranged so they can slide over each other. The boundary of the sarcomere are the Z lines. Thin filaments extend from the Z lines and overlap with thick filaments in the middle of the sarcomere. The I band is on each side of the Z line where only thin filaments occur. The A band is the length of the thick filaments and is divided into three parts; the zone of overlap is on each end where thin and thick filaments occur, the H band is in the middle and has only thick filaments, and the M line is the center of the A band.
sarcomere
Muscle
Sarcomere