Cell Specialization and Tissues

Cell Differentiation About 200 different types of cells in the human body Different in size, shape, function Differentiation is the specialization of cell structure and function

Animal Tissues

Epithelial Tissue Epithelial tissue covers the whole surface of the body. It is made up of cells that are closely packed and are composed of one or more layers. This tissue is specialised to form the covering or lining of all internal and external body surfaces. Epithelial tissue that occurs on surfaces on the interior of the body is known as endothelium.

Connective Tissue It is an animal tissue that is characterized by the abundance of extracellular components (such as fibers and intercellular substances). The tissue derives its name from its function in connecting, supporting, surrounding or binding cells and tissues. Connective tissue is composed of: cells extracellular matrix Extracellular matrix is a special feature that distinguishes connective tissue from the other tissues of the body. This matrix may be jelly-like, fluid, dense or rigid. The nature of matrix differs according to the function of that particular connective tissue.

Connective Tissue

Muscular Tissue Muscles of the body are made up of elongated muscle cells also known as muscle fibre. The movement of the body is brought about by the contraction and relaxation of contractile protein present in muscle cells. These contractile proteins are actin and myosin.

Muscle Tissue

Cardiac Muscle Tissue

Smooth Muscle Tissue

Nervous Tissue All living cells have the ability to react to stimuli. Nervous tissue is specialised to react to stimuli and to conduct impulses to various organs in the body which bring about a response to the stimulus. Nerve tissue (as in the brain, spinal cord and peripheral nerves that branch throughout the body) are all made up of specialised nerve cells called neurons.

Plant Tissues Epidermal Tissue - often called the epidermis - a single layer of cells that forms a protective “skin” - secretes a waxy cuticle to prevent water loss Ground Tissue - Provides strength and support in stem - Stores food and water in roots - Photosynthesis occurs in leaves Vascular Tissue - transports water, minerals and sugars between roots and leaves

Vascular Tissue There are two types of vascular tissue: 1)Xylem – transports water and dissolved minerals UPWARD 2)Phloem – transports sugars (food) made in leaves DOWNWARD to roots and to other parts of shoot system

Plant Tissues