animal tissues summary

Animal Tissues Kingdom Animalia are consists of multicellular eukaryotic organisms. And they are character ized by complex tissue organization. Animal cells having similar structure and performing definite definite functions in the animal body constitutes tissue. Various animal tissues having different functions are organized to become organs. I.

Epithelial Tissues- composed of cells which form a continuous layer of sheet covering t he body surface or lining cavities within the body. They perform protection secretion, excretion, absorption, lubrication (glandular) sensory rece ption, and reproduction. Examples: skin, lining of digestive tract, lining of kidney tubules, lining of windpipe and lungs A. According to shape of cells: 1.

Squamous Cell- is a thin flattened cell resem bling tiles in a floor or scale-like.

2.

Cuboidal Cell- the height of cell body is about e qual to the width, cube-like appearance.

3.

Columnar Cell- the height greatly e xceeds the width resembling pillars.

4.

Ciliated Cell- bears on its exposed surface numerous short hairlike extensions called cilia.

5.

Flagellated- have one or more w hiplike cytoplasmic processes called flagella on the exposed surface.

6.

Spherical- rounded or oval in shape.

7.

Polygonal- resembles a closed polygon.

B. Arrangement of Cells in Epithelial Sheets: 1.

Simple- composed of a membrane but one c ell in thickness.

2.

Transitional- cells are arranged in two or mor e distinct layers of varied cell shape that is the superficial layer is of large umbrella shaped cells, its middle layer composed of several layers of polygonal cells and the basal layer composed of low columnar cells or small polyhedral cells.

3.

Stratified- cells are arranged in two or more distinct layers.

4.

Pseudostratified- cells are arranged in two o r more indistinct layers.

C. According to Shape and Arrangement: 1.

Simple squamous or pavement epithelium- a single layer of flat cells or thin platelike cells is arranged in a single layer.

2.

Simple cuboidal epithelium- made up of line layer of cuboidal cells lining of ducts, thyroid gland, and the kidney tubules such as the uriniferous tubules.

3.

Simple columnar epithelium- a layer of columnar cells adhere to each other along longitudinal or lateral surface

4.

II.

According to Function:

Connective and Supportive Tissues- composed of cells and interspersed fibers suspended in a semi- fluid amorphous ground substances. There primary function is for support and for binding the different parts of the body toget her.

III.

Muscular and Contractile Tissues- movement of most animals result from the contraction of elongate, cylindrical or spindle- shaped cells. The property of contractility is highly developed in myofibrils in their cytoplasm which are capable of contraction in o ne direction only.

IV.

Nervous and Conductive Tissue- fundamental tissue that integrates the functions of various organs of the body. Properties of irr itability and conductivity (receive and transmit impulses) are highly developed; arise from the ectoderm.

V.

Blood or Vascular Tissue- consist of the blood and a circulating tissue which transport nutrients, gases, waste materials and hormones; protects the body from disease causing organisms (immunity), and blood clotting.