Physiology is the study of normal function within living creatures. It is the most fascinating and ancient branch of science.
Physiology is fascinating because, it unfolds the mystery of complicated functional aspects of individual organ in the body.
It is ancient because it exists ever since the origin of life. even before knowing the language, culture, and society, the man knew about hunger, thirst, pain, and fear which are the basic of physiology.
Physiology is defined as the study of functions of various system and different organs of the body. physiology has the latin roots. the latin roots physio- generally means ‘physical‘, logy- means ‘ study’, so physiology is the study of the function of body parts and the body as a whole.
Physiology deals with just about alive everything that keeps us active and working.
Jean Fernel (1497-1558) a French physician, who first introduced the term “physiology” from ancient Greek meaning ‘study of nature, origins’.
Biological Systems

The major systems covered in the study of human physiology are as follows:
- Circulatory system – including the heart, the blood vessels, properties of the blood, and how circulation works in sickness and health.
- Digestive/excretory system – charting the movement of solids from the mouth to the anus; this includes the study of the spleen, liver, and pancreas, the conversion of food into fuel, and its final exit from the body.
- Endocrine system – the study of endocrine hormones that carry signals throughout the organism, helping it to respond in concert. The principal endocrine glands – the pituitary, thyroid, adrenals, pancreas, parathyroids, and gonads – are a major focus, but nearly all organs release endocrine hormones.
- Immune system – The body’s natural defense system is comprised of white blood cells, the thymus, and lymph systems. A complex array of receptors and molecules combine to protect the host from attacks by pathogens. Molecules such as antibodies and cytokines feature heavily.
- Integumentary system – the skin, hair, nails, sweat glands, and sebaceous glands (secreting an oily or waxy substance).
- Musculoskeletal system – the skeleton and muscles, tendons, ligaments, and cartilage. Bone marrow – where red blood cells are made – and how bones store calcium and phosphate are included.
- Nervous system – the central nervous system (brain and spinal cord) and the peripheral nervous system. The study of the nervous system includes research into the senses, memory, emotion, movement, and thought.
- Renal/urinary system – including the kidneys, ureters, bladder, and urethra, this system removes water from the blood, produces urine, and carries away waste.
- Reproductive system – consisting of the gonads and the sex organs. The study of this system also includes investigating the way a fetus is created and nurtured for 9 months.
- Respiratory system – consisting of the nose, nasopharynx, trachea, and lungs. This system brings in oxygen and expels carbon dioxide and water.
Anatomy vs Physiology: What is the Difference?
The relationship between anatomy and physiology are that they will always correlate with each other, anatomy being the study of the actual physical organs and their structure as well as their relationship to each other. while physiology studies how those organs work to function the whole body as organ systems.