Self Assessment Chapter 4 Part 1

© 2016 Pearson Education, Inc. ______________ – study of normal structures of tissues (a group of structurally and functionally related cells and their external environment that together perform common functions) © 2016 Pearson Education, Inc.

© 2016 Pearson Education, Inc. Histology – study of normal structures of tissues (a group of structurally and functionally related cells and their external environment that together perform common functions) © 2016 Pearson Education, Inc.

All tissues share two basic components: 1. 2.

All tissues share two basic components: 1. Consist of discrete population of cells that are related in structure and function 2. Have a surrounding material called extracellular matrix (ECM)

Although a cell is often anchored to proteins in the ECM, THE CELLS in a tissue are also often LINKED to one another, by what 2 ways? 1 2

What are the 3 Types of Cell Junctions? 1. Cell Adhesion Molecules- Found in the Ground Substance of the ECM 2. Cell Junctions What are the 3 Types of Cell Junctions? 1. 2. 3.

1. Tight Junctions 2. Desmosomes 3. Gap Junctions Briefly Describe each of the above

1. Tight Junctions-Like a zipper on plastic freezer bag, holds cells tightly together, making spaces between them impermeable. Ex, blood vessel cells 2. Desmosomes-Buttons or snaps, Increase the strength of a tissue by holding the cells together so that mechanical stress is more evenly distributed. Ex, Skin cells 3. Gap Junctions- Small pores in adjacent plasma membranes formy by PROTEIN channels. Allow small substances to pass freely between the cytosol of 2 cells.

© 2016 Pearson Education, Inc. Cell Junctions Figure 4.2 Cell junctions. © 2016 Pearson Education, Inc.

REMEMBER THAT All tissues share two basic components: 1. Consist of discrete population of cells that are related in structure and function 2. Have a surrounding material called extracellular matrix (ECM) What is the ECM?

ECM –Composed of the substances surrounding the cells in a tissue. ECM is made by the cells of the tissue and performs a variety of functions (provides the tissue with strength, directing cells to proper places, regulating development, mitotic activity and survival of cells, and hold cells in their proper positions) What are the 2 main components of the ECM? 1. 2.

1. Ground Substance-(Most of ECM), contains the ECF/Interstitial fluid (consists of H2O, ions, nutrients, and other solutes) as well as 3 families of macromolecules-Glycosaminoglycans, proteoglycans, and glycoproteins. 2. Protein fibers-embedded within the ground substance, 3 types (collagen fibers, elastic fibers, reticular fibers) REMEMBER THIS PICTURE………..

The Extracellular Matrix Figure 4.1 Extracellular matrix. © 2016 Pearson Education, Inc.

What are the 4 Primary Tissue Types? 1. 2. 3. 4.

1. Epithelial Tissues 2. Connective Tissues 3. Muscle Tissues 4. Nervous Tissue

© 2016 Pearson Education, Inc. Name the Tissue _________________– found on every internal and external body surface; barriers between body and external environment; line organs and fluid-filled cavities; serve following additional functions: Protection – shield underlying tissues from mechanical and thermal injury Immune defenses – form physical barriers; prevent invasion by microorganisms; house cells of immune system enhancing protective function © 2016 Pearson Education, Inc.

© 2016 Pearson Education, Inc. additional functions (continued) Secretion – form glands that produce substances like hormones and oils; secreted into blood or through ducts respectively Transport into other tissues – selectively permeable membranes; certain substances are able to cross these barriers by passive or active transport and enter other tissues Sensation – most associated with a rich nerve supply; detects changes in internal and external environments; taste buds are examples of specialized sensory epithelial cells © 2016 Pearson Education, Inc.

© 2016 Pearson Education, Inc. Epithelial Tissues Epithelial tissues – found on every internal and external body surface; barriers between body and external environment; line organs and fluid- filled cavities; serve following additional functions: © 2016 Pearson Education, Inc.

What are the 2 criteria we use to classify epithelia? 1. 2.

1. Number of cell layers (Simple or stratified) 2. Shape of Cells in those layers (Squamous, cuboidal, columnar) REMEMBER THIS…….

Components and Classification of Epithelia Figure 4.4 Classification of epithelial cells. © 2016 Pearson Education, Inc.