Part 3 - Epithelium and Connective Tissue lecture.pdf

EPITHELIUM & CONNECTIVE TISSUES Dr Anna Maceri School of Nursing and Midwifery Important Copyright Notice for Western Sydney University Students The material in this presentation has been made available to you by and on behalf of Western Sydney University for your personal use and study only. The ma...

EPITHELIUM & CONNECTIVE TISSUES Dr Anna Maceri School of Nursing and Midwifery Important Copyright Notice for Western Sydney University Students The material in this presentation has been made available to you by and on behalf of Western Sydney University for your personal use and study only. The material contained in this recorded lecture is subject to copyright protection. You may not make any further copies and share the recorded lectures in whole or in part by any hardcopy, digital and or online technologies. Tissues Cell - is the basic structural unit in the human body. Each cell digests nutrients, ejects wastes and carries out activities necessary to stay alive. Cells typically do not operate independently. Work in groups. Tissues – groups of similar cells that perform a common function. 4 basic tissues: Epithelial tissue Connective tissue Nervous tissue Muscle tissue Epithelial Tissue Sheet of cells that covers a body surface or lines a body cavity. Forms the outer layer of skin. Lines the open cavities of the digestive, respiratory, urinary and reproductive systems. Lines glands of the body. Forms a boundary between the inner body and the external environment. General Features 3 cell types: – Squamous (flat) – Cuboidal (boxlike) – Columnar (tall) General Features Simple epithelium – single layer of cell. Stratified epithelium – Two or more layers of cells. Simple Squamous Simple Squamous Endothelium – simple squamous epithelium lining lymphatic and blood vessels and heart Mesothelium – simple squamous epithelium of the serous membrane that lines the ventral body cavity (recall week 1) Simple Columnar Pseudostratified Epithelium Apical cells Short cells Stratified Squamous Connective Tissue Most abundant tissue type in body. Four main classes: – – – – Connective tissue proper (includes fat and ligaments) Cartilage Bone Blood Functions: 1. Binding and support of other tissues. 2. Protection of organs 3. Insulation of organs 4. Storage of energy reserves (fat) 5. Transporting substances within the body Connective Tissue Three elements: – Fibres – Cells – Ground substance Composition and arrangement of these vary depending on function and location. Connective Tissue Fibres: Reticular fibre Provide support Collagen fibres – strength Elastic fibres – stretch and recoil Collagen fibre Elastic fibre Reticular fibres – similar to collagen, finer fibres Connective Tissue Cells: Fibroblast – secrets the fibres Mast cells – activate the inflammatory response Macrophages – dispose of dead cells and foreign substances Fat cells - energy reserve White blood cells -migrate to site in response to infection or injury macrophage fibroblast Mast cell White blood cell Fat cell Connective Tissue Ground substance: Unstructured material that fills the space between the fibres and cells. Contains fluid that enables nutrients and substances to diffuse between blood vessels and cells. Ground substance Connective Tissue Areolar Loose CT Adipose Reticular Connective Tissue Proper Regular Dense CT Irregular Elastic Loose CT Loose irregular arrangement of the fibres Areolar- cushions organs, holds fluid Adipose – energy reservoir Reticular – reticular fibres loosely around cells Adipose Areolar Reticular Dense CT Dense regular CT Closely packages fibres arranged in one direction High strength and resistance to tension eg. Tendon Collagen fibres fibroblast Dense CT Dense irregular CT Bundles of CT arranged irregularly Endure pulling forces from different directions Elastic fibres Collagen fibres Dense CT Elastic CT Dense regular arrangement of elastic fibres Walls of some blood vessels Endure stretch to return blood vessel to original shape