Human Anatomy & Physiology: Introduction

Anatomy: The study of the structure of the human body and the relationship of its constituent parts to each other or one or the other is called general anatomy. In regional anatomy, a geographical study is made and each region e.g. arms, legs, head, ears, eyes. nose, trunk, genitalia etc., is being studied in terms of its components. Different regions of human body do have some common structures such as bones muscles, nerves and blood vessels. An anatomical region performing a particular function is called a system. There are a variety of systems in human body. The systematic study of these systems is called the systematic anatomy. The functional relationship of different parts or organs of the body is called the functional anatomy. The anatomical features of our body which could be appreciated by naked eye are covered under the macroscopic anatomy and the finer structures which could be revealed with the help of a microscope are termed as microscopic anatomy. Closely allied to the anatomy are histology and cytology, the study of tissues and cells respectively. Human body is studied from the erect position with the arms by the sides and the palms of the hands facing forwards, the head erect and eyes looking straight in front. This is the universal description of anatomical position. Various parts of the body are described in relation to certain imaginary lines or planes. The median plane runs through the center of the body. Any structure which lies nearer to the median plane of the body is said to be medial to the other. For example the inner side of the thigh is described as the medial aspect and the outer as the lateral aspect. The terms internal and external are used to describe the relative distance of an organ or structure from the center of a cavity. The ribs for example have an internal and external surface. The terms superficial and deep are used to denote relative distance from the surface of the body. The terms superior and inferior are used to denote the positions relatively high or low in relation to trunk and the terms proximal and distal are employed to describe nearness to or distance from a given point particularly in relation to limbs. For example the proximal phalanges are nearer to the wrist and the distal ones are the farthest away. When three structures are running from the medial plane of the body outwards, they are described as being placed in medial, intermediate and lateral position. The terms anterior and posterior are synonymous with ventral and dorsal. These terms are only adapted to man in the erect attitude or anatomical position. For example the anterior and posterior tibial arteries lie in front and back in the leg. In describing hand the terms palmar and dorsal are used instead of anterior and posterior and in describing foot the terms plantar and dorsal are employed. Many parts of the body are symmetrically arranged. For example left and right limbs are similar. The eyes, ears lungs and kidneys too are left and right and symmetrically arranged. There is also a good deal of asymmetry in the arrangement of the body. The spleen lies entirely on the left side; the pancreas lies partly on each side and the larger part of the liver lies on the right side. Physiology: It is the study of the internal functions of the normal human body and closely linked to the study of internal functions of all the living creatures in the subject of biology. The body is made up of many tissues and organs each having its own particular function to perform. The cell is the smallest unit of the body of which all the body parts are comprised. The cells and/or organs are adapted to perform the special functions in a system. The cells of the nervous system and muscle are very specialized. Other cells such as those in the connective tissue are not so highly developed as compared to muscle and nerve cells. Bioenergetic pathways, cellular interactions and their biochemical products such as enzymes and hormones are at the core of the physiology.