Muscles are the tissues that have the ability to contract and relax which in turn help in movement and locomotion. The bones can be moved only in the presence of muscles. Muscles are attached to the bones by tendons. The cardiac muscles are responsible for the pumping action of the heart whereas smooth muscles are involved in involuntary movements. The human muscular system includes more than 600 muscles, which make up 30 to 40 per cent of the total body weight.
There are different types of muscles:
Based on the muscle location, muscles are classified into:
- Skeletal or striated muscles
- Cardiac muscles
- Smooth muscles
Based on the muscle action, muscles are further classified into:
- Voluntary muscles
- Involuntary muscles
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Here are a few interesting facts about muscles.
Interesting Facts about Muscles
Muscles are the soft tissue or the flesh that is present on the bone. These muscles work in pairs to bring movement to a bone. Based on contractibility, elasticity, excitability and extensibility, muscles are further classified into different types.
Red and white muscles are two different types of skeletal muscles, which are involved in the various functions of the body.
Also Read: The Muscular System
The smooth muscles and cardiac muscles are called involuntary muscles, as their actions are controlled by the autonomic nervous system in the body.
The non-striated muscles are involuntary smooth muscles, which are involved in stimulating the contractility of the blood vessels, digestive system, reproductive systems and other organ systems in our body.
The skeletal muscles are called voluntary muscles, as actions are under the control of the somatosensory nervous system.
The masseter muscle, which is situated at the back of the jaw is the strongest muscle in the human body. This is a thick muscle in the cheek and it functions by opening and closing the jaw while chewing food.
Also Read: Human Anatomy
During muscle contraction, the thin filaments slide over the thick filaments and simultaneously the signal is sent to the central nervous system through the motor neuron to initiate the activation within muscle fibres.
Muscle fatigue occurs due to repeated activation of the muscles, leading to an accumulation of lactic acid. This results in the decreased functioning of the muscles.
The gluteus maximus, which is located in the buttocks is called the heaviest and the largest muscle in the body. These muscles function by supporting the trunk, maintaining proper posture, providing the shape of the buttocks and is the main muscle we all use while climbing up the stairs.
Refer more: Locomotion
Along with the various functions, there are some severe muscle disorders, which are caused due to several factors including the age, nutritional deficiency, changes in the hormonal levels, lack of physical activities and other lifestyle changes. Muscular dystrophy, myasthenia gravis, tetanus and tetany are a few examples of muscle disorders in humans.
This article concludes an introduction to muscles, along with their amazing facts. To know more about muscles, their types, functions, important questions and other related topics, keep visiting our website at BYJU’S Biology.
Frequently Asked Questions on Facts about muscles
What is rigor mortis?
The stiffening of muscles and joints in the body after death is known as rigor mortis. It is due to the absence of ATP in muscles.
What is the difference between ligaments and tendons?
Ligaments are connective tissues that join two bones. Tendons are tissues that connect bone with a muscle. E.g.: the Achilles tendon connects calf muscles to the heel bone.
What are Arrector Pili?
Arrector Pili are small muscles that attach the base of hair follicles to the dermis region. Contraction of these muscles helps the hair to stand erect.