What is the meaning of Human Anatomy and Physiology?

The systematic study of the human body is performed under two disciplines, i.e., anatomy (structure) and physiology (function). Anatomy is the study of different structures of the human body and their relationship with each other, while physiology is the study of the functioning of these structures. Anatomy is made up of two Greek words, ana means up and temos means to cut. Anatomy is the science of body structures and coordination among the various body structures. It is a general term which includes human anatomy, animal anatomy (zootomy), and plant anatomy (phytotomy).

Anatomy is sub-divided into: 

1) Gross Anatomy: It is also known as topographical anatomy, regional anatomy, or anthropotomy. It includes the study of such anatomical structures which can be seen with the naked eyes. 

2) Microscopic Anatomy: In this type of anatomy, very minute anatomical structures (tissues and cells) are studied with the help of microscopes. 

3) Superficial Anatomy or Surface Anatomy: This type of anatomy is of prime importance as it includes the study of anatomical structures that can be seen from the body. With the knowledge of superficial anatomy, physicians or veterinary surgeons gauge the position and anatomy of the associated deeper structures. 

4) Comparative Anatomy: In this type of anatomy, the comparison of anatomical structures both gross and microscopic present in different animals is studied

The Greek words physics (nature) and logos (study) combine to form the term physiology, which covers the study related to the mechanical, physical, and biochemical functions of living organisms. It can be also defined as the study related to the science of various body functions and their working.

Scope of Human Anatomy and Physiology:- 

The anatomy and physiology together form the foundation of medical sciences; their scope is vast that can be summarised in the following terms: 

 1) Study of human anatomy provides an essential base for the understanding of physiology and pathophysiology, 

2) Helpful in the study of human evolution and development, 

3) Inquiring into the fascinating complexity of the structure and function of the human body, 

4) Mass therapy and athletics health-related field training,

5) As a foundation for advanced scientific studies, 

6) To understand the pathology of disease and pathological changes, 

7) To determine the techniques of surgeries, 

8) To know the parameters of normal health, 

9) To understand the effects of various factors in the physiological processes and its effects like a change in the environment, etc., and 

10) Overall effective maintenance of individual and community health.

Definition of Various Terminologies Used in Anatomy 

For study point of view, medical science divides the body into various anatomical planes (flat surfaces), which are the imaginary lines (vertical or horizontal) drawn through an upright position of the body.

 The anatomical terminology of the body can be studied under three groups: 

1) Directional terms, 

2) Sectional planes/planes of the body, and 

3) Body cavities

Directional Terms 

Directional terminologies are used to locate one body structure with respect to the other. The anatomical position of a human can be described with the help of the following terms: 

1) Superior (Upper, Cranial) End: The end of the head lies in the uppermost position, therefore it is known as the superior end of the extremity. 

 2) Inferior (Lower) End: This part starts from the extremity of the main body or the trunk along the legs in the downward direction or ground. 

 3) Anterior or Ventral End: This includes the body parts present on the front side, like chest, nipples, abdomen, and external genitalia. 

4) Posterior or Dorsal End: This includes the body parts present on the back side, i.e., vertebral column (also known as the backbone), shoulder blades, and buttocks. 

5) Supine Position: In this position, the face is towards the upper side (roof) while the back faces downwards. 

6) Prone Position: In this position, the face focuses downwards or towards the ground. 

7) Medial Position: It is an imaginary line passing through the longitudinal axis of the body, dividing it into two equal halves from the middle, starting from front to the back. 

8) Lateral Position: It is that anatomical position of the body in which it is divided into two fragments through the midline and the body structures remain away. 

9) Proximal: It describes a body part that is closer to a point of attachment or closer to the trunk of the body than another part. For example, the elbow is proximal to the wrist

10) Distal: This position is the opposite of proximal. It means that a particular body part is farther from the point of attachment or farther from the trunk of the body than another part. For example, the fingers are distal to the wrist. 

11) Superficial: This position means situated near the surface. 

12) Peripheral: This position means outward or near the surface

Planes of the Body

 Following are the various planes in which the human body is classified: 

 1) Sagittal: 

In this plane, an imaginary line slicing the body (from head to toes) into two halves with erratic proportion is drawn, from top to the down. A mid-sagittal plane runs parallel to the medial plane, i.e., the plane of sagittal runs from the middle. Distinct to that of coronal plane, it starts from the nose to back of the head and moves vertically from one ear to the other.

2) Horizontal: 

This plane is parallel to the ground and passes through the body at the 90° angle to both coronal and medial plane. 

3) Coronal: 

This plane divides the body into anterior (front) and posterior (back) portion, by passing through the body at a right angle to the medial system. Medically, anterior means the front portion and posterior means the back potion. Some terms can be used interchangeably like ventral for front and dorsal for the back. 

4) Lithotomy Position:

 In this position, the individual is lying on the back with thighs fully stretched and knees directing towards the roof.

Body Cavities

 Cavities are the spaces of the body, containing viscera and internal organs. The two main cavities of the body are dorsal cavity and ventral cavity. Ventral cavity is a large cavity which is further subdivided into the thoracic and abdominopelvic cavity. Both these cavities are separated by dome shaped respiratory muscles called diaphragm. 

The different types of body cavities are

1) Thoracic Cavity: 

This cavity is present ventrally on the upper side of the body. It is also known as the chest cavity, which is laterally attached to the ribs (covered by costal, pleura) and caudally to the diaphragm (covered by the diaphragmatic pleura). This cavity contains the trachea, lungs, heart, oesophagus, nerves, and large blood vessels. 

2) Abdominal and Pelvic Cavity: 

The ventral cavity is also known as the abdominopelvic cavity. This cavity is further divided into two parts: 

i) Abdominal Cavity: This cavity is laterally attached to the body wall, posteriorly by the pelvic cavity, and anteriorly by the diaphragm. This cavity contains maximum part of the gastrointestinal tract, kidneys, and adrenal glands. 

ii) Pelvic Cavity: This cavity is bounded dorsally by the sacrum, laterally by the pelvis, and anteriorly by the abdominal cavity. The pelvic cavity contains the maximum part of the urogenital system as well as the rectum. 

3) Dorsal Cavity: This cavity is the smallest amongst the other two main cavities. In this cavity, the organs are situated more posteriorly within the body. Further, the dorsal cavity is sub-divided into two parts. The first part includes cranial cavity (upper portion which houses the brain,) and the second part includes spinal cavity (lower portion which houses the spinal cord).