Make some observations about the following picture… DO NOW

Chapter 5

1. Explain the 4 types of tissues. 2. Identify the different types of epithelial tissue. 3. List the locations of each type of epithelial tissue. OBJECTIVES

1. Histology: The study of tissues 2. Tissues: Groups of cells which are similar in structure and perform common functions. KEY TERMS

4 BASIC TISSUE TYPES

Locations: 1. Covers the body (skin) 2. Lines cavities, tubes, ducts, blood vessels 3. Covers organs EPITHELIAL TISSUE

Functions: 1. Protection from physical & chemical injury 2. Protection against microbial invasion 3. Contains receptors which respond to stimuli 4. Filters, secretes & reabsorbs materials 5. Secretes serous fluids to lubricate structures EPITHELIAL TISSUE

Facts about Epithelium: - always have one free surface exposed to the outside or open internal space. - attached to a basement membrane on the other side. - tightly packed - **Avascular- LACK BLOOD VESSELS, rely on diffusion from the underlying connective tissue. - Divide rapidly! EPITHELIUM

What characteristics distinguish the following groups of cells? CLASSIFYING EPITHELIUM

1. Layers a) simple = 1 layer b) stratified = multiple layers 2. Shape a) squamous: thin/flat (think “squished”) b) columnar: tall slender rectangles (columns) c) cuboidal: square shaped (like cubes) CLASSIFYING EPITHELIUM

1. Simple Squamous - absorption Ex: 2. Stratified Squamous - physical protection against abrasion - protects against pathogens/chemicals Ex: SQUAMOUS

3. Keratinized Stratified Squamous - layers of dead squamous cells - retards water loss - barrier to organisms SQUAMOUS

1. Simple Columnar - provides some protection - absorption/secretion - usually contain “goblet” cells Ex: 2. Stratified Columnar - *rare - secretion/absorption Ex: small portion of male urethra COLUMNAR

3. Pseudostratified Ciliated Columnar – all cells touch basement membrane COLUMNAR Smoking = goodbye cilia

1. Simple Cuboidal - secretion/absorption - secretes sweat - produces sperm & hormones - line ducts Ex: 2. Stratified Cuboidal - *rare - usually only 2-3 layers - ducts of glands Ex: CUBOIDAL Duct Cuboid Cells

-Stratified -Tolerates repeated stretching -Ex: TRANSITIONAL

Identify the types of epithelium on your worksheet by yourself. Go over your answers with the person sitting next to you to see if you got similar answers. THINK-PAIR-SHARE

1.Take out your cell phones for PollEverywhere! CLOSING

1.How is epithelial tissue classified? 2.What is the main function of epithelial tissue? 3.Which type of epithelium would you find in the intestines that contains goblet cells? DO NOW

1.Identify slides of tissue using the classification of epitheliail tissue. 2.Compare and contrast exocrine and endocrine glands. 3.List and explain the 3 types of exocrine glands. OBJECTIVES

Decide which type of epithelium is being shown on the slide. Try to determine what tissue/organ this is a slide of. IDENTIFYING SLIDES

SLIDES

Endocrine : ductless glands (secreted hormones directly into blood stream) Exocrine: glands contain ducts that connect with surface GLANDULAR EPITHELIUM

1)Merocrine : release fluid through exocytosis (ex: tears, gastric juices) 2)Apocrine: release part of cell ( ex: axillary glands, mammary glands) 3)Holocrine: release and destroy whole cell. (ex: sebaceous glands) TYPES OF GLANDS

Types of Glands Animation GLANDS

Please take a slide and a microscope. Go through each of the powers under the microscope, finding the free space that will contain the epithelial tissue. Move the slide accordingly. Call me over to verify that you are looking at the right thing before you move on to the next power. MICROSCOPE PRACTICE