Question

Cardiac muscles are different from that of skeletal muscles as the former are:
A. Striated but involuntary
B. Non-striated and involuntary
C. Smooth or unstriated
D. Voluntary in action

Answer 1

Hint: Muscular tissue is a specialised tissue that causes the movement in animals by applying force in different body parts due its contractile property. The cytoplasm of the muscle fibre is called sarcoplasm whereas the endoplasmic reticulum of the muscle is called sarcoplasmic reticulum which is the storehouse of calcium ions. Muscles have different properties such as contractibility (which causes the muscle to shorten forcefully), extensibility (which causes the muscle to extend), elasticity (ability to regain its natural length after getting stretched) and excitability (ability to respond against a stimulus provided by a motor neuron).

Complete Step by Step Answer:
The muscles are divided into three types on the basis of their location:- skeletal, visceral and cardiac muscles.
The skeletal muscles are present at skeletal organs such as bones, ligaments, tendons and cartilage. These muscles are multinucleated. They have a striated appearance ( light and dark bands) and hence are called striated muscles. The activities of these muscles are under the control of voluntary part of the brain that is we can control them and thus they are called as voluntary muscles.

Visceral muscles are present in the inner walls of the visceral organs like alimentary canal, reproductive tract etc. These muscles does not have any alternates light and dark bands and appears to be smooth and hence they are called non-striated muscles. The activities of these muscles are not under voluntary part of the nervous system and hence called involuntary muscle.

Cardiac muscles are the muscles of heart. These are involuntary muscles. When these muscle contracts heart pumps the blood to the whole body. They are striated.

Hence, the correct answer is A:- striated but involuntary.

Note: Cardiomyocytes are the cells of cardiac muscles. Cardiac muscles are uninucleated.