1. 4 Types of Tissues  Epithelial Covers body surfaces and lines hollow organs, body cavities, duct, and forms glands  Connective Protects, supports, and binds organs. Stores energy as fat, provides immunity  Muscular Generates the physical force needed to make body structures move and generate body heat  Nervous Detect changes in body and responds by generating nerve impulses

2. Development of Tissues Tissues of the body develop from three primary germ layers: Ectoderm, Endoderm, and Mesoderm  Epithelial tissues develop from all three germ layers  All connective tissue and most muscle tissues drive from mesoderm  Nervous tissue develops from ectoderm  Internal organs develop from endoderm

3. Tight Junctions Web-like strands of transmembrane proteins  Fuse cells together  Seal off passageways between adjacent cells Common in epithelial tissues of the stomach, intestines, and urinary bladder Help to retard the passage of substances between cells and leaking into the blood or surrounding tissues

4. Desmosomes Contain plaque and cadherins that extends into the intercellular space to attach adjacent cells together  Desmosome plaque attaches to intermediate filaments that contain protein keratin  Prevent epidermal cells from separating under tension and cardiac muscles cells from pulling apart during contraction

5. Gap Junctions Connect neighboring cells via tiny fluid-filled tunnels called connexons  Contain membrane proteins called connexins  Plasma membranes of gap junctions are separated by a very narrow intercellular gap (space) Communication of cells within a tissue Ions, nutrients, waste, chemical and electrical signals travel through the connexons from one cell to another

6. Epithelial Tissues Epithelial tissue consists of cells arranged in continuous sheets, in either single or multiple layers  Closely packed and held tightly together  Covering and lining of the body  Free surface 3 major functions:  Selective barrier that regulates the movement of materials in and out of the body  Secretory surfaces that release products onto the free surface  Protective surfaces against the environment

7. Connective Tissue Most abundant and widely distributed tissues in the body Numerous functions  Binds tissues together (tendons/ligaments)  Supports and strengthen tissue (bone)  Protects and insulates internal organs (fat)  Compartmentalize and transport (blood)  Energy reserves and immune responses

8. Connective Tissue Extracellular Matrix Ground substance  Between cells and fibers Fluid, semifluid, gelatinous, or calcified  Functions to support and bind cells, store water, and allow exchange between blood and cells  Complex combination of proteins and polysaccharides Fibers  Collagen fibers  Elastic fibers  Reticular fibers

9. Muscular Tissue Consists of elongated cells called muscle fibers or myocytes  Cells use ATP to generate force  Functions in movement, generating heat, digestion  Classified into 3 types: skeletal, cardiac, and smooth muscular tissue

10. Skeletal Muscle Tissue  Attached to bones of the skeleton  Have striations  Voluntary movement or contractions by conscious control  Vary in length (up to 40 cm) and are roughly cylindrical in shape

11. Muscular Tissue Cardiac muscle tissue  Have striations  Involuntary movement or contraction is not consciously controlled  Intercalated disc unique to cardiac muscle tissue

12. Smooth Muscle Tissue  Walls of hollow internal structures Blood vessels, airways of lungs, stomach, and intestines  Nonstriated  Usually involuntary control

13. Nervous Tissue Consists of two principle types of cells  Neurons or nerve cells  Neuroglia

14. Cellular Movement

15. Microtubules  cilia & flagella Microfilaments  amoeboid movement & muscle cells

16. Vertebrate skeletal muscle The action of muscle is to always contract Muscles are attached in antagonistic pairs

18. The basic functional unit of muscle )Myofilaments Skeletal muscles: striated & multinucleate I=thin H=thick A=thick + thin AA

23. http://highered.mcgraw- hill.com/sites/0072495855/student_view0/cha pter10/animation__action_potentials_and_mu scle_contraction.html http://highered.mcgraw- hill.com/sites/0072495855/student_view0/cha pter10/animation__action_potentials_and_mu scle_contraction.html