Anatomy and Physiology - Introduction

Anatomy is the study of body structures and Physiology is the study of body functions. In this subject we can learn about the body structures and how these structures are involved in performing various functions I,e Physiology. 

We can easily learn this subject by studying the basic concepts like levels of organisations.

Levels of organisations: 

1. Chemical level of organisation:  Our body contains many chemicals such as carbon, hydrogen, oxygen, nitrogen, phosphorus, calcium and sulphur. These chemicals are essential for maintaining body life. 

Examples include DNA molecule, glucose and ATP. DNA is made of nucleic acids which includes atoms like 5- carbon sugar, phosphate and nitrogen base.

2. Cellular level of organisation: Group of molecules  combine to form cells. We already know that cells are the basic structural and functional units of our body. The types of cells in our body are epithelial cells, nerve cells and muscular cells.

3. Tissue level of organisation: Similar types of cells form a tissue to do various functions in an organism. The four common types of tissues in human body are:

a. Epithelial tissue (from epithelial cells)

b. Connective tissue

c. Nervous tissue ( from nervous cells)

d. Muscular tissue ( from muscle cells)

4. Organ level of organisation: Organs are formed from the combination  different types of tissues.  Lungs, mouth, oesophagus, heart, bone etc.. are formed by the 1-3 types of tissues. 

For Example stomach is made of epithelial tissue  and smooth muscle tissue. Epithelial tissue lines the stomach and is responsible for the secretion of body fluids which aids digestion while smooth muscle helps in churning food and mixing it by contractions.

5. System level of organisation:  Systems  consists of related organs with a common function.

System level can be explained by the example of digestive system, It includes various organs such as mouth, salivary glands, pharynx, esophagus, stomach, small intestine, large intestine, liver, gallbladder and pancreas. These are related organs which involve in the process of digestion.

6. Organism level of organisation: All the systems in our body form an organism. 

Reference:

Tortora G, Derrickson B. Principles of anatomy & physiology. India: Wiley; 2014.