The human body is made of bone, flesh and water. 70% of the human body is made up of water. 30% of the body fluid consists of plasma, lymph, cellular fluids, etc. A fluid that is formed by the body for its metabolic reactions is called body fluid. These body fluids are classified into two groups: intracellular fluid and extracellular fluid.
Intracellular Fluid
The intracellular fluid is a bodily fluid within the cell(s). Intracellular fluid accounts for 67% of total body water content in humans. It is made up of water, dissolved ions, and several other compounds.
Extracellular Fluid
The extracellular fluid is the body fluid located outside the cell. 26% of the total body fluids are present in the form of extracellular fluids. The components of the extracellular fluids are-
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Intravascular fluid (blood plasma)
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Interstitial fluid
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Lymph
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Transcellular fluid
The fluids present in between the cells are called interstitial fluid. E.g., lymph and plasma.
Transcellular Fluids
It is a fluid that contains the secretion of the secretory cells and cavities of the body. E.g., saliva, sweet, pericardial fluid, bile, etc. Transcellular fluid volume is relatively small – it is about 1.5% of body weight and in 1L of a person of 70kg.
Mesenchymal Tissue Fluid
The mesenchymal tissue, such as dense connective tissue, cartilage and bones, contains about 6% of the body water. The interstitial body fluid, transcellular fluid and mesenchymal fluid together form 75%. The normal distribution of the total body fluid water in the fluid compartment is kept constant by two opposing sets of forces: osmotic and hydrostatic force.
Lymph
The characteristic of the lymph is as follows:
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The lymph is pale yellow fluid.
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It is present between the tissue, or we can say that it bathes the tissue.
The function of the lymph is as follows:
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It helps maintain the fluid balance in the body fluids.
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It also acts as an immunity barrier that kills and removes the bacteria from the tissue system.
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It helps in transferring the substance from the lymphatic duct and the vessels.
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It helps in the formation of lymph nodes in the lymphatic vessels.
The main constituent of lymph is the macrophage and the lymphocytes, which kill all the pathogens and antigens and generate the immune response.
Blood
Blood helps transfer all the nutrients, oxygen and waste material from the different body parts. There is no substitute for blood. In order to transfer blood to the other organ, a pumping organ is required, and that is the heart.
Components of Blood
The blood comprises four components: red blood cells, white blood cells, platelets and plasma. All of these work together to perform the function of blood.
Red Blood Cells
Red blood constitutes 40%-45% of your blood volume. It is formed from your bone marrow at a rapid rate of formation. The life span of RBC is 120 days in the body.
Platelets
Platelets are also known as thrombocytes. The primary function of the platelets is to help in the clotting of blood. There are 13 types of clotting factors that help platelets control bleeding. It forms the plug at the injury, which stops the bleeding.
Plasma
The excess blood that leaks from the vessels is known as plasma. It plays an essential role in transferring the substances along with the blood. 50% of the blood is made up of plasma. Plasma is light yellow in colour and contains some water, salts, enzymes and some protein. The function of plasma is as follows:
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It transfers protein, nutrients and hormones to the other parts of the body.
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All the cells put their waste into the plasma for disposal.
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Plasma helps to remove body waste.
White Blood Cells
Referred to as leukocytes, they account for barely 1% of your blood. There are five different kinds of white blood cells necessary for optimal health and defence against infections and illnesses. Like red blood cells, they are regularly produced by your bone marrow and through the circulation, attacking foreign things like viruses and bacteria. They have the ability to leave the circulation and fight in tissue.
Saliva
Saliva is secreted from the salivary glands, which are present in the buccal cavity of the mouth.
The character of the saliva is as follows:
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Saliva is thick.
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Saliva is colourless.
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Saliva is an opalescent fluid that is constantly present in the mouth of humans and other vertebrates.
The components of the saliva are as follows:
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Water
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Mucus
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Proteins
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Mineral salts
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Amylase
The saliva is present in the mouth, which helps digest food and prevents the mouth from bacterial infection.
Sweat
The secretion of water and the electrolyte, which helps regulate the body heat, is called sweat. The secretion of sweat is due to the excessive heat present in the body.
Sweat comes from the sweat gland, which is present at the skin’s surface. Sweat glands are present in all mammals and hoofed animals. The secretion of the sweat gland includes –
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Water (usually about 99%)
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Salts
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Amino acids
The sweat signal is under the control of the sympathetic nervous system and stimulates the eccrine sweat glands to secrete water to the skin surface. The human body forms half a litre of sweat.