Question

The figures given here represent three different conditions of sarcomeres. Identify these conditions and select the correct option.

	$A$	$B$	$C$
(a)	Contracting	Relaxed	Maximally contracted
(b)	Relaxed	Contracting	Maximally contracted
(c)	Maximally contracted	Contracting	Relaxed
(d)	Relaxed	Contracted	Contracting

• A. a
• B. b
• C. c
• D. d

Answer 1

Answer: (B)

In the given figure A, the length of the two sarcomeres is normal i.e., the muscle is in relaxed state. In figure $B$, the length of sarcomeres shortens, $H$-zone narrows and size of $l$-band decreases i.e., the muscle is contracting. In figure $C$, the length of sarcomere further shortens and $H$-zone disappears and $l$-band further decreases i.e., the muscle is maximally contracted.