Tissues, Part 1: Epithelial Tissue Chapter 4 Introduction to the Human Body

Chapter Objectives Describe the characteristics of the 4 basic types of tissue that make up the human body. Describe the structure & function of squamous, cuboidal, and columnar epithelium. Differentiate between simple and stratified epithelium.

Warm Up #1 Which type of tissue (epithelial, connective, muscle, or nervous): Contracts to move things? Covers the body’s exterior? Communicates information? Holds things together? Produces body heat? Lines body cavities?

Tissues All about tissues Tissue Histology Pathology

4 Types of Tissues Tissues & functions Epithelial Connective Muscular Nervous

Epithelium Epithelial Tissue (epithelium, epithelia) 2 types: Covering and lining Glandular

Epithelium, cont. Features: Closely packed cells arranged in sheets 3 surfaces: Apical Lateral Basal Basement membrane underneath Avascular Innervated High capacity for renewal

Covering & Lining Epithelium 3 cell types: Squamous Cuboidal Columnar Simple or stratified Simple Stratified

Simple Epithelium Simple squamous Function: Diffusion, osmosis, filtration, secretion, and absorption. Endothelium Mesothelium Simple cuboidal—secretion & absorption Simple columnar Contain goblet cells that secrete mucus May have microvilli (fingerlike projections) to absorb substances. May be ciliated to move substances like mucus.

Epithelium: Simple Squamous

Epithelium: Simple Cuboidal

Epithelium: Nonciliated Simple Columnar

Epithelium: Ciliated Simple Columnar

Stratified Epithelium Stratified squamous Keratinized Nonkeratinized Stratified cuboidal & stratified columnar (uncommon) Transitional Stratified Changes shape (cuboidal to squamous) Elastic / stretching

Epithelium: Stratified Squamous

Epithelium: Stratified Cuboidal

Epithelium: Stratified Columnar

Epithelium: Transitional

Stretched vs. Relaxed Transitional Epithelium

Pseudostratified Epithelium Pseudostratified columnar Found in upper respiratory tract Contain goblet cells and usually contain cilia

Pseudostratified Columnar

Review Which tissue is: Like a coffee filter? Single tall layer? Not layered, but looks like it? Very stretchy? Found mainly in your skin? Found inside your mouth?

Warm Up #2: Be Creative! Write a non-biological analogy for the following: Simple squamous epithelium Cilia Microvilli Basement membrane Stratified squamous epithelium Transitional epithelium Goblet cells Pseudostratified epithelium

Glandular Epithelium Glandular Epithelium Function: secretion Glands—cells that secrete a substance into a duct, surface, or into blood. Endocrine Secrete hormones into interstitial fluid Ex: pituitary gland, thyroid gland, etc. Exocrine Secrete into ducts that lead to a free surface. Ex: Sweat glands, salivary glands, pancreas, etc.

Glandular Epithelium: Endocrine

Glandular Epithelium: Exocrine

Review Review of epithelium Characteristics: Avascular, innervated, rapid regeneration, has a basement membrane. 3 types: Squamous, cuboidal, & columnar. May be simple or stratified. Functions: protection, secretion, absorption, excretion, sensory reception, & reproduction. Includes covering, linings, & glands.