Cuz this stuff is difficult! More Examples for Lab 3 Cuz this stuff is difficult!

Questions to ask for identifying tissues: Does it have an edge? Is it composed of cells tightly packed together (little or no intercellular material)? Epithelial Tissue Are cells few and scattered, separated by intercellular material? Connective Tissue What is it? What is it?

Types of Epithelium Simple Squamous Simple Cuboidal Simple Columnar Pseudostratified Stratified Squamous Stratified Cuboidal Stratified Columnar Transitional

Simple Squamous Epithelium What is it? Single layer of flattened cells Diffusion and filtration of materials Found in… Kidney glomeruli Air sacs of lungs Blood vessels Serous membrane

Simple Columnar Epithelium What is it? Single layer of tall cells Some may have cillia Absorption, secretion of mucus and enzymes Found in… Digestive tract Bronchi

Stratified Squamous What is it? Several layers of flattened cells on top of a layer of cuboid or columnar cells May be keratinized or non keratinized Protection in areas subject to abrasion Found in… Esophagus, mouth Epidermis

Stratified Cuboidal Typically only 2 layers of cells Very rare What is it? Typically only 2 layers of cells Very rare Found in… Ducts of large glands

Pseudostratified Single layer of cells differing in heights What is it? Single layer of cells differing in heights May contain cilia or goblet cells Secretion and propulsion of mucus Found in… Trachea Sperm carrying ducts Large glands

Stratified Columnar What is it? Several layers of cells with columnar cells at the apical surface Protection and secretion Found in… Pharynx Male urethra Lines some glands

Simple Cuboidal Epithelium What is it? Single layer of cube-like cells Secretion and absorption Found in … Kidney tubules Glands

Transitional Several layers of cells; variable shapes (“plumpy”) What is it? Several layers of cells; variable shapes (“plumpy”) Designed to stretch and permit distention of the organ Found in… Bladder Ureters

To identify Epithelial Tissue types: Layers Is it a single layer of cells or multilayered (2 or more)? Shape Single layer: What is the shape of the cells? Multilayered: What is the shape of the apical cells? Note the difference between psudostratified columnar and stratified columnar

REVIEW Epithelial Tissue Connective Tissue Forms an ____ Is composed of ________________ with little or no _________________ Connective Tissue Cells are ______________ Dominated by _________________ Usually _____ are abundant edge tightly packed cells extracellular material few and scattered intercellular material fibers

Types of Connective Tissue Areolar CT Adipose CT Reticular CT Dense Regular CT Dense Irregular CT Hyaline Cartilage Elastic Cartilage Fibrocartilage Mesenchyme

Adipose Connective Tissue What is it? Sparse matrix Closely packed together adipocytes Stores food fuel; protects organs Found… Under skin Around organs In abdomen

Fibrocartilage Thick collagen fibers What is it? Thick collagen fibers Tensile strength and can absorb compression Found Intervertebral discs Pubic symphysis

Dense Irregular Irregularly arranged collagen fibers What is it? Irregularly arranged collagen fibers Withstand forces from many directions Found Dermis Joint capsules

Reticular Connective Tissue What is it? Reticular fibers; variety of cells Form soft, internal skeleton of some organs Found… In lymphoid organs

Elastic Cartilage Elastic fibers in the matrix Maintains structure with flexability Found External ear What is it?

Hyaline Cartilage Amorphous collagen matrix with chondrocytes Supports, reinforcement and cushioning Found Embryonic skeleton Covers ends of long bones Costal cartilage What is it?

Dense Regular Parallel collagen fibers Withstands great pulling force What is it? Parallel collagen fibers Withstands great pulling force Attach muscles to bones; bones to bones Found Tendons ligaments

Areolar Connective Tissue What is it? Gel like matrix with collagen and elastic fibers Fibroblasts Cushions organs; important for inflammation Found… Under epithelium Surrounds organs and capillaries

To identify Connective Tissue types: Are there chondrocytes inside lacunae? If YES = Is the matrix smooth-looking? Or: Are chondrocytes large and is matrix composed of short, messy fibers? Or: Are chondrocytes small and is matrix composed of long, wavy fibers? If NO = Cartilage Connective tissue proper

To identify Connective Tissue Proper: Are fibers thin & scattered or nearly absent? Is matrix a network of fibers mixed with cells? Or: Are cells large and packed together with nuclei shoved to the outer rim? Or: Is matrix filled with small, round cells and some fibers (looks like a bunch of grapes)? Are fibers thick, filling the matrix? (Loose Connective Tissue) (Dense Connective Tissue)

To identify Connective Tissue Proper: Fibers thick, filling the matrix (Dense Connective Tissue) Are fibers thick, long and smooth? Or: Are fibers thick and messy appearing?

And now.. Time for a Quiz!!

Adipose

Simple Squamous

Hyaline Cartilage

Pseudostratified

Simple Cuboidal

Areolar

Stratified Columnar

Dense Irregular

Stratified Squamous

Fibrocartilage

Dense Regular

Stratified Cuboidal

Hyaline Cartilage

Reticular

Simple Cuboidal

Areolar

Elastic Cartilage

Simple Columnar

Transitional

Simple Squamous

Adipose