Define sliding filament theory of muscle contraction.
The sliding filament theory explains the process of muscle contraction during which the thin filaments slide over the thick filaments, which shortens the myofibril.
Each muscle fibre has an alternate light and dark band, which contains a special contractile protein, called actin and myosin respectively. Actin is a thin contractile protein present in the light band and is known as the I-band, whereas myosin is a thick contractile protein present in the dark band and is known as the A-band. There is an elastic fibre called z line that bisects each I-band. The thin filament is firmly anchored to the z line. The central part of the thick filament that is not overlapped by the thin filament is known as the H-zone.
During muscle contraction, the myosin heads or cross bridges come in close contact with the thin filaments. As a result, the thin filaments are pulled towards the middle of the sarcomere. The Z line attached to the actin filaments is also pulled leading to the shortening of the sarcomere. Hence, the length of the A- band remains constant as its original length and the I-band shortens and the H-zone disappears.
NCERT questions are designed to test your understanding of the concepts and theories discussed in the chapter. Here are some tips to help you answer NCERT questions effectively:
This question is important because it tests key concepts from the NCERT syllabus and is frequently asked in CBSE exams.
This question is based on core NCERT concepts explained in the chapter and should be revised thoroughly before exams.
The sliding filament theory explains the process of muscle contraction during which the thin filaments slide over the thick filaments, which shortens the myofibril.
Each muscle fibre has an alternate light and dark ba...
Step-by-step explanation:
• The sliding filament theory explains the process of muscle contraction during which the thin filaments slide over the thick filaments, which shortens the myofibril
•
•
• Each muscle fibre has an alternate light and dark band, which contains a special contractile protein, called actin and myosin respectively
• Actin is a thin contractile protein present in the light band and is known as the I-band, whereas myosin is a thick contractile protein present in the dark band and is known as the A-band
Students often lose marks by skipping steps, writing incomplete explanations, or misunderstanding keywords used in the question.
Stay updated with our latest educational content and study tips
Have you ever noticed that doing activities such as playing outdoors, chilling with your friends, or using the mobile phone feels so effortless and fun? Whenever you might have played sports, you kept on playing even when it felt hard initially just so you could get that feeling after the game, a feeling of accomplishment, […]
Read More
Imagine this; You’re sitting in the test hall, pen in hand, and the question paper has been put in front of you. Rather than freezing, you feel calm, collected, and set. Why? As you have formerly been there in your mind. You’ve seen yourself sitting composibly, reviewing the question paper fluently, performing well in the […]
Read More
Parent-Teacher Meetings (PTMs) are more than quick updates on marks — they’re a chance to build a real partnership between home and school. A good Parent-Teacher Meeting conversation helps parents see beyond grades. It opens up insights about a child’s strengths, struggles, emotions and even hidden talents. When parents participate actively, they don’t just track […]
Read More
In today’s world of endless information , knowing how to think is more important than knowing what to think . From school projects to real – life decisions , critical thinking helps students question ideas , analyze facts and form logical conclusions . But what exactly does critical thinking mean ? Simply put , it’s […]
Read More
Student Discussion
Be the first to comment.
ADD NEW COMMENT