The cell is the fundamental unit of life. A total of 30 to 40 trillion cells is produced for the human, and about 242 billion new cells are produced every day. When a select cell community with identical functions is merged, the tissue is formed, which aggregates to give rise to various organs and organ systems in the human body.

1. . Digestive system

• Digestion is the intricate mechanism of converting food into nutrients, which your body needs for survival, growth, and cell repair. The process of digestion also includes the production of waste.
• Anatomy – Mouth, teeth, tongue, oesophagus, stomach, liver, pancreas, gastrointestinal tract, small and large intestines, and rectum are parts of the anatomy. 
• The digestive process begins with chewing (chewing food). The saliva then combines with food and produces a bolus which can quickly be ingested. The meal flows down the oesophagus and in the stomach after swallowing. 
• The stomach secretes intense digestive enzymes that disintegrate the food into a slurry.
• The bile secreted in the liver and vital digestive enzymes from the pancreas are then going into the small intestine, where the food is broken down even further. At this point, nutrients in the food are absorbed.
• The remaining substance is then transposed from liquid to solid until water is extracted to the large intestine. It is ready to get removed from the body after the leftover has been pushed to the rectum.

2. Respiratory system

• Respiration is a carbohydrate oxidation process that produces energy used by an individual in sustaining life.
• Anatomy – Nostrils, Pharynx, Larynx, Trachea, Bronchi, Bronchioles, and Alveoli.
• In the process of respiration, glucose is broken down into pyruvate, which is further broken down into pyruvic acid.
• The process of respiration involves two steps – breathing and cellular respiration.
• Breathing is the process of inhaling atmospheric oxygen and giving out carbon dioxide. Simultaneously, cellular respiration is the process of breakdown of simpler foods to generate energy for the body cells.

3. Circulatory system

• The circulatory system transports different substances in individuals. The role of the substance carrier is played by blood in the circulatory system.
• Anatomy – heart, arteries, veins, and blood capillaries
• The heart is a muscular organ that operates through a complex network of blood vessels to pump blood across the body.
• Arteries are the thick-walled blood vessels, which drive away oxygenated blood from the heart, while veins are the blood vessels, which introduce deoxygenated blood into the heart. 
• Capillaries are the narrow blood vessels that facilitate oxygen, nutrients, and waste from the circulatory system and tissues.

4. Excretory system

• Excretion is a body waste and extra water elimination process. It is one of the essential aspects of the body for maintaining homeostasis. The urinary system’s crucial role is to filter and excrete waste and surplus water from the blood.
• Anatomy: While kidneys are the primary excretory organs, many other organs take part in waste excretion, namely the large intestine, kidneys, skin, and lungs. The excretory system consists of all these excretion organs along with the kidneys.
• The structural and functional units of the kidneys are nephrons. More than one million nephrons can be present in a single kidney.
• The kidney has the purpose of filtering blood and forming urine. Urine is a body’s liquid waste substance excreted by the urinary system. 
• The urine enters the ureters that transfer the urine by peristalsis into the bladder from the kidneys’ collection ducts. 
• The bladder is an organ, which gives a nerve impulse to a sphincter which lets the bladder guide the urine into the urethra, removing urine from the body. In the course of urination, the urine exits the body by another sphincter.

5. Nervous system

• The nervous system is a coordinated collection of cells engaged in electrochemical stimuli’ conduction upon a response in the reaction site’s sensory receptors.
• Anatomy: The nervous system is divided into CNS or central nervous system containing the brain and the spinal cord and PNS or peripheral nervous system encompassing all other nerves throughout the body.
• A complex network of specialised cells known as neurons is essential to the functioning of the nervous system. They can interact by chemical or scheme with other cells at synapses.
• The CNS fulfils vital body, organ management functions, and higher brain centres to monitor more advanced knowledge processing, including our ideas and conceptions.
• PNS is further classified into somatic and autonomic nervous systems. 
• The PNS sensory nerves include sensory receptors that sense internal and external transitions. The CNS collects this information from the associated sensory nerves. Peripheral efferent nerves convey signals to the PNS after the information has been processed in the CNS.

Anatomy & Physiology can explain the complexity and combination of the human body’s processes. It is essential for science, and you can enhance other population livelihoods and well-being by studying and mastering this field.

1.  Define human anatomy?
   The study of the components of the human body is referred to as human anatomy. An understanding of anatomy is crucial in medical practice and other disciplines of medicine.
2. What are the different types of anatomy?
   The two major types of anatomy is gross anatomy and microscopic anatomy.
3. What are the different stages of digestion?
   The different stages of digestion are ingestion, breakdown, absorption, and elimination.
4. What is the significance of human CVS?
   CVS functions in oxygen circulation and supplies nutrients to cells. Moreover, it prevents the cells from illness and diseases.
5. Which is the most pivotal organ of the respiratory system and why?
   The lungs, which carry out the gaseous exchange while we breathe, are the main organs of the respiratory system. They are used to distribute oxygen-rich blood into all the tissues of the body.