This document compares the characteristics of three types of muscles: skeletal or voluntary muscles, smooth or involuntary muscles, and cardiac muscle. It outlines key distinctions between their structure, location in the body, nuclear structure, type of contraction, tension during contraction, and ability to perform external work. The main types of muscle are distinguished based on these defining physiological traits.

12. SKELETAL OR
VOLUNTARY
MUSCLES
01
SMOOTH OR
INVOLUNTARY
MUSCLES
02
CARDIAC
MUSCLE
03

18. Characteristic
s
skeletal Smooth Cardiac
movement voluntary Involuntary Involuntary
structure Cylindrical not
branched
Spindle shaped
not branched
Cylindrical
branched
Stripes in
muscle fibre
Present Absent Present
Nucleus Many nucleus
are present
Single nucleus Single nucleus
Location Limbs of our
body
Alimentary
canal,iris of
Heart

25. Characteristics Isometric
contraction
Isotonic contraction
Length of the muscle Remains the same Shortening of the
muscle
Tension Increases during
contraction
No change
Mechanism Only muscles shorten
and not movement of
joints
Shortening of
individual sarcomeres
adds up to the
shortening of whole
muscle
External work No External work Work done