Different Types of Tissues

A tissue is - a group of similar cells that perform a particular function e.g. Epithelial tissues (which are animal cells that form sheets covering surfaces). Some examples of epithaelial tissues are the cilliated & squamous tissues

• One cell thick and so it is called simple epithelia

• The cells are of one type and are smooth, flat and very thin

• Packed closely together like tiles on a roof and provide a low friction surface over which fluids can move

• Found in the lining of the cheeks, inside blood vessels, lining the chambers of the heart and forms the alveoli in the lungs

• Made up of cells with cilia and so is often found in areas where it is needed to transport something e.g. lining the oviducts and bronchioles of the lungs

• Provides a short diffusion pathway for the exchange of of oxygen and carbaon dioxide

• Sometimes the cells are shaped like cubes and the tissue is called cuboidal ciliated epithelia. If the cells are tall and narrow, it is referred to as columnar ciliated epithelia

• Consists of xylem vessels with parenchyma cells and fibres

• Walls become reinforced  and water proofed by deposists of ligin, this kills the cell contents

• Xylem tissue well adapted for transporting water and minerals up the plant; it also helps to support the plant

• Consists of sieve tubes & companion cells

• Sieve plates allow the movement of of materials up or down the tubes

• Companion cells metabolically active

• Companion cells activities plays an important part in moving the products of photosynthesis up and down the plant in the sieve tubes

• Found in the leaf and is made up of one type of cell

• The cells are tall and thin and are tightly packed together

• Its function is to harness the light energy required for photosynthesis and so each cell is packed with chloroplasts.