Question

Cardiac muscles are different from skeletal muscles as they are a) smooth (b) voluntary c) non-striated (d) striated and involuntary

Short answer

Cardiac muscles are different from skeletal muscles in that they are striated and involuntary.

Step-by-step solution

Understanding Muscle Types

First, recognize the different types of muscles in the human body. There are three main types: skeletal muscles, which control voluntary movements; cardiac muscles, which are found only in the heart; and smooth muscles, which control involuntary movements in various parts of the body.

Identifying Cardiac Muscle Characteristics

Next, understand the characteristics of cardiac muscles. Unlike skeletal muscles, which are voluntary and striated, cardiac muscles are involuntary, meaning they are not under conscious control. They are also striated, which refers to their appearance under a microscope having a pattern of light and dark bands.

Comparing Cardiac and Skeletal Muscles

Finally, compare cardiac muscles to skeletal muscles. Skeletal muscles are voluntary and striated, while cardiac muscles are involuntary though they are also striated. This helps us eliminate the options that do not describe how cardiac muscles differ from skeletal muscles.

Selecting the Correct Answer

Considering the properties discussed, cardiac muscles differ from skeletal muscles in that they are not under voluntary control. Thus, the correct option is (d) striated and involuntary.

Key concepts

Muscle Types

The human body comprises a complex system of muscles, each with specific roles and characteristics.

Muscle tissue can be categorized into three distinct types: skeletal, cardiac, and smooth.

• Skeletal muscles are those associated with the body's movement. They are connected to bones by tendons and can be controlled voluntarily. These muscles enable actions like walking, running, lifting, and other movements you think about before you do them.
• Cardiac muscles are specialized muscles that form the walls of the heart. Unlike skeletal muscles, they operate involuntarily, sustaining the relentless rhythm required to pump blood throughout the body.
• Smooth muscles are found in the walls of hollow organs such as the stomach, intestines, bladder, and blood vessels. Like cardiac muscles, smooth muscles work involuntarily, reacting to signals from the body to aid in various functions such as digestion and blood flow regulation.

Understanding the differences among these muscle types is crucial for identifying how they contribute to the body's overall function.

Involuntary Muscles

Involuntary muscles, which include the cardiac and smooth muscles, play critical roles in maintaining vital bodily functions without conscious thought.

These muscles have the incredible task of working behind the scenes to ensure that essential processes, like the heartbeat and the movement of food through the digestive system, continue unabated.

Involuntary Action

Controlled by the autonomic nervous system, involuntary muscles respond to stimuli and perform their duties independent of our will. This automation is crucial for survival, as it allows the body to focus its conscious efforts elsewhere while still performing necessary physiological functions.

Importance in the Body

Involuntary muscles work tirelessly and rhythmically, contributing to homeostasis by keeping our heart beating and facilitating functions like breathing and digesting, proving that some of the most vital actions our bodies perform require no thought at all.

Striated Muscles

Striated muscles are characterized by their distinct, striped appearance, visible under a microscope due to their highly organized structure of sarcomeres containing actin and myosin filaments.

This banded pattern results in the striations that give these muscles their name.

Types of Striated Muscles

Both skeletal and cardiac muscles are classified as striated due to their texture. Skeletal muscles' striations are associated with the precise and robust control required for movement. On the other hand, the striations in cardiac muscles contribute to the heart's ability to contract and pump blood efficiently.

Function in the Body

The striated pattern in these muscles is more than just a visual trait; it's integral to their function, facilitating the coordinated contractions that propel us through the day, from simple tasks like typing to complex motions like gymnastics, as well as maintaining our heartbeat without rest or interruption.