Sliding filament hypothesis class 12 in Pashto| Mechanism of muscles contraction| MDCAT Biology

Hello dear students welcome to my You Tube channel ‪@Ziatutorials‬. In this section of video lecture you will learn the Sliding filament hypothesis of class 12 MDCAT Biology in Pashto language. This hypothesis explain the mechanism of muscles contraction, here is the overview
The sliding filament hypothesis, also known as the sliding filament theory, is a widely accepted model that explains the mechanism of muscle contraction. It was first proposed by Hugh Huxley and Jean Hanson in the 1950s.

Key points of the sliding filament hypothesis:

1. Muscle fibers consist of sarcomeres, the functional units of muscle contraction.
2. Sarcomeres contain thick filaments (myosin) and thin filaments (actin).
3. The thick filaments are anchored at the M-line, while the thin filaments are anchored at the Z-line.
4. The sliding filament hypothesis proposes that muscle contraction occurs when the thin filaments slide over the thick filaments, resulting in a shortening of the sarcomere.
5. This sliding movement is driven by the hydrolysis of ATP, which binds to the myosin head and causes a conformational change, leading to the sliding of the filaments.
6. The sliding filament hypothesis explains the mechanism of muscle contraction, where the muscle fibers shorten and relax, allowing for movement and relaxation of the muscle.

The sliding filament hypothesis has been widely accepted and supported by numerous experiments and observations, and it remains a fundamental concept in understanding muscle physiology and contraction.

Here's a simple analogy to help illustrate the sliding filament hypothesis:

Imagine a series of stairs (thin filaments) and a bunch of people (myosin heads) standing on the stairs. When the people move up the stairs, the stairs appear to slide downward, causing the distance between the people and the ground to shorten. Similarly, in muscle contraction, the thin filaments (stairs) slide over the thick filaments (people), causing the sarcomere to shorten, resulting in muscle contraction.
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