Organ System in Human (Part 2)

Lets continue our lesson.. Today we will discuss skeletal system, muscular system and nervous system. 

2. Skeletal System

Skeletal system composed by organs: bone, cartilage, tendons, joints, and ligaments. Bones that comprise the human skeleton are divided into two groups. They are the axial skeletal bones and appendicular skeletal bones. An adult human skeleton contains 206 bones, 80 of which are from the axial skeleton and 126 from the appendicular skeleton [1].

The axial skeleton protects numerous vital organs and soft tissues of the body. The skull provides protection for the brain, the vertebral column protects the spinal cord, and the thoracic cage protects the heart and lungs.

The appendicular skeleton is for bodily movement, it also provides protection for organs of the digestive system, excretory system, and reproductive system.

Bones functions are

Structure

Bones compose the skeleton, which provides structure and support for the body.

Protection

Bones provide protection for numerous vital organs and soft tissues of the body. For example, the vertebral column protects the spinal cord, and the thoracic (rib) cage protects the heart and lungs.

Mobility

Bones work in conjunction with skeletal muscle and other skeletal system components to assist in enabling body movement.

Blood Cell Production

Blood cells are produced by bone marrow. Bone marrow stem cells develop into red blood cells, white blood cells, and platelets.

Storage

Bones store important minerals and mineral salts, including calcium, phosphorus, and calcium phosphate. Calcium phosphate gives bone its firmness. Bone also stores fat in yellow bone marrow.

3. Muscular System

The muscular system consists of all the muscles of the body, including skeletal muscle, heart muscle and smooth muscle. The largest percentage of muscles in the muscular system consists of skeletal muscles, which are attached to bones and enable voluntary body movements. There are almost 650 skeletal muscles in the human body [2].

Do you know, muscles make up approximately 40 percent of total weight and can grow larger. It is called by hypertrophy. Physical exercise that involves weight bearing or resistance training can increase the size of skeletal muscles. But actually, it is not only skeletal muscle can grow larger, but also heart muscle. Exercises (such as running) that increase the heart rate may also increase the size and strength of heart muscle.

Muscular system function in

Mobility

The muscular system’s main function is to allow movement. When muscles contract, they contribute to gross and fine movement. Gross movement refers to large, coordinated motions and includes: walking, running, swimming. Fine movement involves smaller movements, such as: writing, speaking, facial expressions.

Posture

Skeletal muscles help keep the body in the correct position when someone is sitting or standing. This is known as posture.

Circulation

The heart is a muscle that pumps blood throughout the body. Do you know, the heart is the hardest-working muscle in the body. It pumps 5 quarts of blood per minute and 2,000 gallons daily. The movement of the heart is outside of conscious control, and it contracts automatically when stimulated by electrical signals. Smooth muscle in the arteries and veins plays a further role in the circulation of blood around the body.

Respiration

Breathing involves the use of the diaphragm muscle.

Digestion

Smooth muscles in the gastrointestinal or GI tract control digestion. The GI tract stretches from the mouth to the anus [3].

4. Nervous System

Skeletal system composed by organs : brain and spinal cord. It is the center of all mental activity including thought, learning, and memory. Nervous system have sensory receptors, which can detect stimulli (such as temperature, light, and sound)  from the external environment. Sensory input is converted into electrical signals called nerve impulses that are transmitted to the brain. There the signals are brought together to create sensations, to produce thoughts, or to add to memory; Decisions are made each moment based on the sensory input [4]. Do you know, the speed of human thinking can be roughly equated to 10 million billion primary thoughts per second [5].

Nervous system function in

Sensation

The first major function of the nervous system is sensation—receiving information about the environment to gain input about what is happening outside the body (or, sometimes, within the body).

Response

The nervous system produces a response on the basis of the stimuli perceived by sensory structures.

Integration

Stimuli that are received by sensory structures are communicated to the nervous system where that information is processed [6].