Body of Human

The body is a Latin word that refers to the physical appearance of any organism. The organism may be multicellular or unicellular or dead or alive. A dead human body is called a corpse, whereas the dead body of animals or insects is known as a carcass.

Body language is known as non-verbal communication and is defined as the movements or gestures that help communicate with other organisms present in this world. Its study is referred to as kinesics. 

Human bodies contain a head, neck, two arms, internal organs, and reproductive parts that are different for males and females. 

Study of bodies

The branch of biology that deals with the study of the physique of an organism is known as Morphology. Anatomy, a sub-branch of morphology, helps study the structure of an organism at a higher level. It is related to the history of bodies and how they have evolved at different stages of life. Cytology helps in studying specific cells’ characteristics and functions. The study of all the mechanisms and functions of the organism is known as physiology. There are many biological systems that help in the different functions of living organisms. Some of these are the nervous system, digestive system, circulatory system, endocrine system, and many more.

Body system

Digestive system

In man, the nutrients are utilised in a specialised digestive system. It is formed of two parts. Alimentary canal and digestive glands.Alimentary canal of higher organism’s shows regional differentiation in which different parts are specialised differently functions so there is physiological division. The alimentary canal is about 8 to 10 m long tube extending from the mouth to the anus. It is differentiated into following parts

(i)Mouth    (ii)  Buccal cavity           (iii) Pharynx             (iv) Oesophagus

 (v)Stomach     (vi) Small intestine         (vii) Large intestine  (viii) Anus.

Respiratory system

Breathing is the process of inhaling fresh air into the lungs and exhaling foul air. In breathing about ½ l of air enters the lungs. The normal breathing rate is 15 to 18 per min during rest. Two types of respiratory muscles: Ribs, diaphragm and intercostal muscles. Lungs as in humans (Pulmonary Respiration).

The major passages of the human respiratory system are the nasal cavity, pharynx, larynx and trachea. Within the lungs, the trachea branches into bronchi, bronchioles and finally pulmonary alveoli.

External nostrils→  Nasal cavity→  Pharynx→  Larynx→ Trachea→ Bronchi → Bronchioles → Alveolar sacs

Circulatory system

Heart is a hollow muscular organ that lies obliquely in the thoracic region in a cavity between the two lungs that is pericardial cavity. It is lined by 2 layers outer and inner pericardial membranes. These are filled with a fluid called “pericardial fluid”. It protects the heart from shock and injury.Heart is made up of 4 chambers : upper 2 chambers are auricles(left and right) and the lower 2 chambers are ventricles(left and right). Auricles are the receiving chambers and ventricles are the pumping chambers.

Excretory system

Excretion-The elimination of these waste nitrogenous products form the body is called excretion. Waste material is ammonia, urea, uric acid, carbon dioxide, pigments, salts, digestive wastes, excess of water etc. Ammonia, urea and uric acid are waste nitrogenous products, The excretory products are both volatile and non-volatile. These are removed from the body by different methods.

Excretory organs are also termed as organs of homeostasis.The main excretory organ in humans is the kidney. Human excretory system consists of: 

–          Two kidneys & their blood supplies.

–          A pair of ureters.

–          Urinary bladder

–          Urethra 

Nervous system

System which regulates the various activities of the body through nerve –impulses is called the nervous – system. Through this system the messages are transmitted at a faster rate.The nervous – system controls and also co –ordinates of the organs of the animals. Brain and spinal cord are part of the human nervous system. Neuron is the basic unit of the nervous system.

Reproductive system

 Sexual Reproductiopn- Reproduction resulting from the fusion of male and female gametes is called sexual reproduction.Reproductive system of each organism consists of many reproductive organs.These can be primary sex organs or secondary sex organs.The primary sex organs  are called as gonads. They produce sex cells or gametes and also secrete sex hormones.

The gonads of males are called a testis, which produce sperm.The gonads of females are called as ovaries, which produce ova or female gametes.Secondary sex organs include the reproductive ducts which transport gametes and reproductive glands which help in process of reproduction. These organs do not produce gametes.e.g., In males : Vasa efferentia, epididymis, seminal vesicles, ejaculatory duct, urethra etc. In females : Fallopian tube, uterus, vagina, mammary glands etc.

Endocrine gland(system)

The endocrine glands and hormone producing diffused tissues/cells located in different parts of our body constitute the endocrine system. Pituitary, pineal, thyroid, adrenal, pancreas, parathyroid, thymus and gonads (testis in males and ovary in females) are the organised endocrine bodies in our body.In addition to these, some other organs, e.g., gastrointestinal tract, liver, kidney, heart also produce hormones.

The neural system and the endocrine system jointly coordinate and regulate the physiological  functions in the body.Endocrine glands lack ducts and are hence called ductless glands. Their secretions are called hormones. The classical definition of hormone as a chemical produced by endocrine glands and released into the blood and transported to a distantly located target organ has current scientific definition as follows: Hormones are non-nutrient chemicals which act as intracellular messengers and are produced in trace amounts.

Skeletal system

Skeletal system consists of a framework of bones and a few cartilages. This system has a significant role in movement shown by the body. Imagine chewing food without jaw bones and walking around without the limb bones. Bone and cartilage are specialised connective tissues. The former has a very hard matrix due to calcium salts in it and the latter has a slightly pliable matrix due to chondroitin salts. In human beings, this system is made up of 206 bones and a few cartilages. It is grouped into two principal divisions – the axial and the appendicular skeleton.              

Conclusion 

The body is defined as the physical matter of an organism that directly or indirectly interacts with the outer world. There are different ways by which a person can interact with other organisms. Human body consists of cells, tissues, organs, and organ systems. There are many biological systems that help in the different functions of living organisms(humans). Some of these are the nervous system, digestive system, circulatory system, endocrine system, and many more.