Human Physiology

Physiology is the study of functioning of organs and organ systems. All Physiological activities are aimed at maintenance of homoeostasis, living and reproduction. Homoeostasis differentiates a living being from the non living world. Homeostatic mechanism involve stabilizing an optimum level of water, minerals and other components of the body fluids and other thermal regulations.

Homeostasis is achieved by several bio physical, bio chemical processes, hormonal secretions and related metabolic modifications.

The phenomenon of living is made possible due to several types of evolved organs and their well co- ordinated functions. The functioning of heart as a pumping organ, the oxygen association and dissociation capabilities of blood pigments, cascading effects of minimal amount of hormones at molecular limits, the process of nervous conduction, analyzing and memory maintaining capacities of the brain, the holistic visual perception of the eye are all wonderful inventions of nature towards simple process of living. The process of sexual reproduction producing sex cells is again a complex process.

Thus all the functioning of a living system are highly complicated mechanism with a simple outlook. So physiology helps us to understand the functioning of various organs and organ system in our body.

Laws of nature

The Universe has a fundamental order. The Universe is governed by discrete and precise laws of nature. These laws are universal, unchangeable, and omnipresent. The human organism is ultimately controlled by these laws. The organic body of the human being is essentially operated by the laws of physics and chemistry.

• Gravitational Force and Mass.

  • Gravitational force. As you stand upon the surface of the Earth, your body and its parts experience the force called gravity. The measure of this force is called weight. Gravity is one type of gravitational force, a force which attracts all particles and bodies to each other. Gravity acts upon your body during every instant of your life.
  • Mass. If you were standing on the surface of the Moon, you would weigh 1/6 of your weight on Earth, but your mass would remain the same. Mass is an intrinsic property of a particle or object that determines its response to a given force. In a given location, the weight of an object depends upon its mass.
• Space and Time. Each individual occupies a certain amount of space. We exist over a span of time. During the passage of time, we change--from an infant, to a child, to an adult, to an adult of advanced age.

• Physical States of Matter. The matter around and in us exists in several states. These various states generally reflect the closeness of the molecules that make up the matter.

  • Solid. The most compact organization is the solid, which retains its specific form and shape.
  • Liquid. Liquids tend to flow but still stay together.
  • Gas. Gases also flow but are widely spread and will readily dissipate in many directions.
• Pressure Gradients. Substances that flow (gases and liquids) flow in very specific directions. They flow from an area of higher pressure or concentration to an area of lower pressure or concentration as long as the two areas are freely interconnected. The difference in pressures of two interconnected areas is called a pressure gradient. When plotted on graph paper, it is in the form of a slope. The greater the difference, the steeper is the slope and the faster the material flows