2. Body Tissues Overview  Tissues are groups of cells with similar structures and functions.  There are four basic types of tissues that each have their own general function 1. Epithelium (covering) 2. Connective (support) 3. Muscle (movement) 4. Nervous (control)

3. Epithelial Tissues  Epithelial tissues cover and line the body.  The function of epithelial tissues is to protect, absorb, filter and secrete.  Examples of epithelial tissues include: the skin and the linings of organs such as the stomach and kidneys.

4. Classification of Epithelium  Each epithelium tissue has two parts to its name.  The first part classifies the tissue by number of layers: 1. Simple epithelium = one layer of cells 2. Stratified epithelium = multiple layers of cells 3. Pseudo-stratified epithelium = one layer that appears to have multiple layers SIMPLE STRATIFIED PSEUDO-STRATIFIED

5. Classification of Epithelium  The second part classifies the tissue by shape: 1. Squamous cells = flat like fish scales 2. Cuboidal cells = cubes like dice 3. Columnar = tall rectangles like columns SQUAMOUS CUBOIDAL COLUMNAR

6. Types of Epithelial Tissues

7. Connective Tissues  Connective tissues connect body parts and are the most abundant type of tissue.  The function of the connective tissue is to protect, cover and bind.  Examples of connective tissues include bone, cartilage and fat. Cartilage Tendon Fat

8. Types of Connective Tissue  There are five types of connective tissue: 1. Bone – protects and supports body organs 1. Cartilage – softer and more flexible than bone, covers the ends of bones. 1. Dense Connective Tissue – includes “rope-like” structures such as tendons and ligaments 1. Loose Connective Tissue – includes soft tissues such as fat that protect and hold together body organs 1. Blood – blood cells surrounded by blood plasma

9. Muscle Tissues  Muscle tissues contract and shorten to produce body movement.  There are three types of muscle tissue: 1. Skeletal Muscle –controls voluntary movement such as contracting leg or arm muscles or creating facial expressions 2. Cardiac Muscle – controls involuntary movement, which allows the heart to pump and move blood through the body 3. Smooth Muscle – controls involuntary movement, which allows the organs to pass substances to the next organ

10. Nervous Tissues  Nervous tissues are made of cells called neurons.  Neurons receive and conduct electrical impulses from one part of the body to another, which allows messages to be communicated between the brain and other parts of the body.  Neurons and their supporting cells make up the structures of the nervous system: the brain, spinal cord and nerves.