Table of Contents
INTRODUCTION TO THE HUMAN BODY
TABLE OF CONTENTS
- INTERNAL SKELETON
- CHEMICAL COMPOSITION OF THE HUMAN BODY
- ORGANIC COMPONENTS
- NUCLEIC ACIDS
- INORGANIC COMPONENTS
- INTERNAL BODY PARTS
- THE HUMAN SKELETON
- FUNCTIONS OF HUMAN SKELETON
- RESPIRATORY SYSTEM
- NERVOUS SYSTEM
- THE DIGESTIVE SYSTEM
The human body is the physical part of the human entity , which comprises alive cells and extracellular substances which are ordered into tissues , organs and systems. Human beings are also animals . Just like all the other chordates , the human body is also bilaterally symmetrical. The spinal cord in humans is present in the vertebrae which is present throughout their lives.
The human body consists of an internal skeleton that is a characteristic to the form of vertebrae. It also includes the backbone of the vertebrae. Hair , mammary glands and typically developed sense organs are being shown as a characteristic feature by the skeleton. After these same characteristics however, there lies some of the important differences. Among all the mammals , only the humans have a dominant two legged posture . And this is generally a modified body plan of the mammals. However if we look upon the kangaroos , they hope upon two legs but when they walk , they walk on four legs and also they use their tail as a third leg while standing.
The human brain is always considered as the most highly developed organ in the whole animal kingdom. However there are also many other animals in the animal kingdom which are considered as intelligent that includes the chimpanzees and the dolphins. These have achieved the intellectual status of the human species.
CHEMICAL COMPOSITION OF THE HUMAN BODY
If we look chemically , the human body comprises mostly the water and some of the organic components which include the lipids, proteins , carbohydrates and the nucleic acids . During the extracellular fluids of the human body , water is being composed there and also within the cells itself in the blood , plasma , lymph and the interstitial fluids. Water mainly acts as a solvent without which the chemistry of life would not be possible. It is well said that the human body comprises about 60 percent water by mass.
The major structural components of the human body include the lipids which consist of the fat , phospholipids and the steroids. An energy storage for the body is provided by fats , and in addition to, fat pads also provide insulation and shock absorbents. The phospholipids and the steroid component cholesterol are two important compounds of the membrane that encircles every cell.
Proteins also serve as the major components of the human body. Just like the lipids , the proteins are the important compounds of the human body. They are present everywhere and also in the cell membrane. Also adding on , the extracellular components which include the nails , the hair are all composed of the proteins. And so is the collagen. Collagen is a material which is fibrous and it is elastic which is present everywhere in the body that comprises the body’s skin , bone , ligament and the tendons. Various uncountable roles are being performed by the collagen in the human body. Particularly, there are cellular proteins which are known as enzymes and are equally important for the human body to function. These catalyzes the chemical reactions which are important for life.
Carbohydrates are there in the human body in large amounts in the form of fuel , either as simple sugars running through the bloodstream or as glycogen , which is a storehouse found in the liver and also the muscles. Very minimal amounts of carbohydrates also are present in cell membranes, but in disparity to plants and very much invertebrate animals . Humans don’t have much structural carbohydrates in the human body. They have just small amounts of the structural carbohydrates.
The genetic material of the body is made by the nucleic acids in the human body. The body’s hereditary master code is being carried by the deoxyribonucleic acid which is the DNA. The instructions for each cell to function is being taken from the DNA and are followed and cells are therefore operated.
Apart from water and the organic components, the body consists of various other non organic components which are the inorganic minerals. Some of these are calcium, sodium , magnesium and iron. The body’s bones are being supplied by large amounts of calcium and phosphorus in the form of calcium phosphate crystals. Calcium is also found in higher amounts in the blood in the form of ions and interstitial fluid like in sodium. The ions of calcium, sodium and phosphorus are various in numbers and found within the interstitial fluid. In the body’s metabolic process, all of these substances play a major and vital role.
Other mineral components in the body which are found in very small amounts but in absolute composition are the cobalt , copper , iodine , manganese and zinc.
INTERNAL BODY ORGANS
The brain forms the controlling part of the nervous system and is situated within the skull. The function of the brain is proper muscle control and coordination , sensory reception and integration , production of speech , storage of the memory and the elaboration of the emotions and thoughts.
The lungs are paired and are two in number. These are cone shaped and are sponge like . These fill most of the chest cavity. The major function of the lungs is respiration of the human body. Mainly they provide oxygen to the bloodstream from inhaled air and exhale carbon dioxide in return.
The liver is situated on the right side of the abdominal cavity , on the lower side of the diaphragm . The main function of the brain includes processing the components of the blood to make sure that the composition remains the same. The whole procedure now includes breakdown of the fats , production of urea , filtration of harmful substances and the maintenance of a proper level of glucose in the blood.
The bladder is an organ that is situated in the pelvic cavity and is muscular in nature. It’s function is totally based upin urine. It is stretched for the storage of urine and it is contracted to release the urine.
The human kidneys are 2 in number and are bean shaped , which are located at the backward side of the abdominal cavity . Each of them is on the side of the spinal column. The chemical balance of the body is maintained by the excretion of waste products and excess of fluids in the form of urine. This is the main function of the kidneys.
The heart is also a muscular organ that is hollow and which pumps blood to the blood vessels, by rhythmic contractions which are repeated.
The stomach is a bag shaped, elastic , muscular organ which is kept crosswise in the abdominal cavity on the lower side of the diaphragm. The main function of the stomach is the digestion of food through the production of the gastric juices which break down and mix and churn the food and form into a thin liquid.
The small intestine lies on the inner side of the large intestine. And the approximate length of the small intestine is many centimeters in length. The main function of the small intestine is the assimilation of the food and which is then sent to the large intestine. It absorbs the food.
The large intestine is situated between the stomach and the anus. The main function of the large intestine is the absorption of water and solid waste substances are excreted out through this.
THE HUMAN SKELETON
The human skeleton acts as the framework of the body. The framework consists of many bones and cartilages to the body. Also many ligaments and tendons are attached to this.
At birth, 270 bones are present within the human body , which is then decreased to 206 at the time of adulthood. This happens because some of the bones get attached together and fuse. The human skeleton is being divided into the axial skeleton and the appendicular skeleton. The vertebral column , rib cage , skull and all other associated bones form the axial skeleton . The appendicular skeleton is attached to the axial skeleton which is formed by the pelvic girdle and the shoulder girdle and also includes the bones of the upper limb and the lower limbs.
FUNCTIONS OF THE HUMAN SKELETON
The functions which are performed by the human skeleton are the movement, support , protection, storage of minerals , production of the blood cells and the regulation of the endocrines.
Within a given population , the female skeleton is much smaller and less robust than the male skeleton. Also in addition to childbirth, the pelvis part of the female skeleton is different from the male skeleton.
The human skeleton comprises the skull, the humerus, the ulna , the radius , the clavicles , the rib cage , the vertebrae, the femur , the tarsals and the metatarsals. These are some of the bones included in the human skeleton.
THE RESPIRATORY SYSTEM
The human respiratory system is the web of all the organs and tissues which help in breathing. Airways , lungs and blood vessels are being included in these. Also the muscles that help in the respiration are also considered as a part of the respiratory system. All these components work together to move the oxygen all over the body and purify waste gases, for example carbon dioxide.
The functions of the respiratory system include inhalation and exhalation. These include us talking and smell , and delivery of oxygen to the cells in our body. Removal of waste gases which include carbon dioxide in the body , when we exhale. It also protects the airway from dangerous chemicals and irritants.
The parts of the respiratory system include the sinuses , nose , mouth , pharynx , trachea , bronchial tubes and the most important the lungs. The bones which help in respiration are the diaphragm and the ribs.
THE NERVOUS SYSTEM
The nervous system is that component of the human body which controls its behavior and transfers the signals in between the areas of the body.
The nervous system in vertebrates comprises the central nervous system and the peripheral nervous system.
The CNS which is the central nervous system includes the brain and the spinal cord. However the PNS which is the peripheral nervous tissue comprises the nerves that are very long in size and they run throughout the body from one part to the other. The main function of these nerves is to establish a connection between the central nervous system to the other parts of the body. These also include the peripheral ganglia , sympathetic and the parasympathetic ganglia and the whole of the nervous system. There are certain nerve cells present which are also known as the neurons.
THE DIGESTIVE SYSTEM
The digestive system in the human body consists of many organs or parts which include the mouth, the esophagus , the stomach ,the pancreas , the liver , the small intestine, the large intestine , the anus. When the food is taken into the mouth, it is chewed by the teeth and with the help of the saliva , it is formed into bolus , which is then swallowed and it reaches the esophagus. The esophagus starts from the mouth and terminates at the stomach. The esophagus establishes a connection between the both. The food is then entered into the stomach, where it is stored and various bile juices act upon it and then it is passed to the intestines where the food is absorbed and the waste material is finally excreted out through the anus.
In the end it should be concluded that the human body comprises many body parts and the human body is well coordinated, where all the functions are performed by the help of each other. All the components of the human body are to be connected to each other to function properly and to make it work. The various organ systems in the human body are the nervous system, the circulatory system , the digestive system, the respiratory system, the endocrine system , the reproductive system and many more.