Читать книгу Understanding Anatomy and Physiology in Nursing - John Knight - Страница 37

Histology is the study of biological tissues. A tissue can be defined as a collection of one or more cell types that work together for a common purpose. In the human body tissues can be thought of as the building blocks of organs. As highlighted in Josie’s case study at the beginning of this chapter, tissue samples can be collected via biopsy to screen for disease.

Although the human body is incredibly complex, only four major categories of tissue are present: epithelial tissues, connective tissues (e.g. bone, cartilage, blood, adipose tissue and fat), muscle (skeletal muscle, cardiac muscle and smooth muscle) and nervous tissue (neurons and neuroglial cells).

As we move through this list from epithelial tissue through to nervous tissue, there is a gradual increase in complexity, with epithelial tissues regarded as the simplest human tissues and nervous tissue the most highly organised and complex. In this chapter we will only examine the nature of the epithelial tissues since the other tissue types are explored throughout the book.