Chapter 4 - Organization of body systems. In this chapter, the following content will be discussed: Types of tissues, connective tissue connects and supports, muscle tissue moves the body, nervous tissue communicates, epithelial tissue protects, integumentary system, organ systems, body cavities, and body membranes, homeostasis. | Chapter 4 Biology 25: Human Biology Prof. Gonsalves Los Angeles City College Loosely Based on Mader’s Human Biology,7th edition I. Life is based on many structural levels Levels of animal structure: Atoms and molecules Cells Tissues Organs Organ systems Organism: May consist of a single cell or a complex multicellular organism. Levels of Structural Organization in an Animal TISSUES: Most animal cells are organized into tissues. Cooperative unit of very similar cells that perform a specific function. Tissue comes from Latin word meaning “weave”. Cells of tissues may be held together by: Fibers Glue-like substance Plasma membrane structures Tissue structure is related to its function. TISSUES: There are four main types of animal tissue: 1. Epithelial 2. Connective 3. Muscle 4. Nervous 1. Epithelial Tissue Cells are tightly fitted together in continuous layers or sheets. Cover outside of body (skin), line organs and internal body cavities (Mucous membranes of digestive, respiratory, and reproductive systems). Tight packaging allows tissue to act as a barrier to protect against mechanical injury, infection, and fluid loss. Two surfaces: Free surface: Exposed to air or fluid. Bottom surface: Attached to underlying tissues by a basement membrane, a dense layer of protein and polysaccharides. 1. Epithelial Tissue Can be classified based on two criteria: A. Number of layers: Simple: One layer. Stratified: Several layers B. Shape of cells: Squamous: Flat cells. Cuboidal: Cube shaped cells Columnar: Column shaped cells Example: Simple squamous epithelium Stratified columnar epithelium 1. Epithelial Tissue Some epithelial tissues, such as mucous membranes, absorb and secrete chemical solutions. Mucous membranes: Digestive tract epithelium (mucous membranes) secretes mucus and digestive enzymes. Respiratory tract epithelium secretes mucous that helps trap dust particles before they reach the lungs. Cell Surfaces B. Extracellular matrix: Sticky layer of glycoproteins found in . | Chapter 4 Biology 25: Human Biology Prof. Gonsalves Los Angeles City College Loosely Based on Mader’s Human Biology,7th edition I. Life is based on many structural levels Levels of animal structure: Atoms and molecules Cells Tissues Organs Organ systems Organism: May consist of a single cell or a complex multicellular organism. Levels of Structural Organization in an Animal TISSUES: Most animal cells are organized into tissues. Cooperative unit of very similar cells that perform a specific function. Tissue comes from Latin word meaning “weave”. Cells of tissues may be held together by: Fibers Glue-like substance Plasma membrane structures Tissue structure is related to its function. TISSUES: There are four main types of animal tissue: 1. Epithelial 2. Connective 3. Muscle 4. Nervous 1. Epithelial Tissue Cells are tightly fitted together in continuous layers or sheets. Cover outside of body (skin), line organs and internal body cavities (Mucous membranes of digestive, respiratory, and
