Human Muscular System: Types, Functions & Muscle Tissues

The human muscular system is a network of muscles responsible for movement, posture, and vital functions. It is composed of three types of muscles for controlling different organs in the body. At the cellular level, it is made up of specialized cells called muscle fibres, capable of contraction. Together, the muscular system provides strength, flexibility, and support for overall body function.

What is the Muscular System?

The muscular system is an organ system made up of more than 600 muscles, accounting for half of the body weight of a person. Each of the muscles is considered a distinct organ and is made up of blood vessels, nerves, tendons, and skeletal muscle tissues. Apart from the obvious presence of muscles attached to the skeletal structures, they are also found in blood vessels, the heart, and other visceral systems.

Types of Muscle Tissues

Three types of muscle tissues make up the human muscular system. They are as follows-

Skeletal Muscle

Skeletal muscles are attached to the bones by means of tendons.
Skeletal muscles are multinucleated, cylindrical, and striated. Striations occur due to the differential arrangement of proteins (actin and myosin) within the cells, while multinucleated means each muscle fibres contain multiple nuclei.
We can consciously control their activity, and thus they are voluntary muscles.

Functions

Enable precise movements of the face for expressions and communication.
Support and stabilize joints, preventing dislocations during movement.
Generates heat energy to stabilize the internal temperature of the body.

Visceral Muscle

Visceral muscle cells are uninucleated, spindle-shaped cells with a uniform smooth appearance.
Cannot be controlled consciously, and thus they are involuntary muscles
Present within the visceral organs and the associated tracts, like the intestines, stomach, the blood vessels, the respiratory tract, etc.

Functions

Visceral (smooth) muscles perform contraction and relaxation to transport materials within the organs. Moreover, they help in secretion, absorption, vasoconstriction or vasodilation, filtration, and peristalsis within the body cavity.

Cardiac Muscle

Only present in the heart.
Uninucleated, striated, and branched.
Involuntary in function, unlike skeletal muscles.
Firm and striated, unlike visceral muscles. The arrangement of protein fibres within the cells is responsible for the dark and light striations.
Branched cells are connected firmly at intercalated disks.

Functions

It maintains the movement of the heart, specifically pumping blood throughout our bodies.

Types of Muscles

Functions of the Muscular System

The muscular system is a group of tissues that are primarily responsible for the movement of the body. They also assist humans in performing various other types of activities, such as:

Posture maintenance: The muscular system keeps he human frame in the correct position, balancing the physique of the individual to perform all types of movement.
Circulation: Cardiac muscles ensure the flow of blood to every part of the body.
Respiration: Controls the motion of the intercostal muscles of the diaphragm during breathing.
Digestion: Visceral muscles help in the peristaltic motion of the digestive tract.

Frequently Asked Questions (FAQs)

Q1. Can muscles work without blood?

Muscles are supplied with blood vessels, which provide oxygen and nutrients. Using these resources, muscles generate energy, which they use to contract. Thus, without a good supply of blood, the muscles of the body would not work efficiently.

Q2. Is the muscular system associated with heat production?

Muscle contractions produced almost 85% of the total body heat. Thus, when a person feels cold, the muscles contract involuntarily (shivering) to try to warm the body.

Q3. What is the difference between aerobic and anaerobic muscle functioning?

Aerobic wmuscles use oxygen to produce energy for long-lasting activities like walking or jogging. Anaerobic muscles work without oxygen, giving quick energy for short, intense activities like sprinting. They produce lactic acid as a byproduct.