Histology Lab Slides

Epithelial Tissue

• Characteristics:

Simple Cuboidal

• Description: Single layer of cube-shaped cells.

• Location: small ducts of glands, kidney tubules, surface of ovary.

• Function: secretion & absorption

Cell is as wide as it is high. Onecentral nucleus

(= single layer)

Simple Cuboidal

• Cells closely packed together and touching one another

• Has a basal surface and apical surface

• Avascular

• Sits on a basement membrane (difficult to see on slide)

Lumen:Inside space of Tubular structure

Nucleus ApicalSurface

BasalSurface

Non- Ciliated Simple Columnar• Description: Single

layer of non-ciliated rectangular cells; contain goblet cells and sometimes microvilli.

• Location: GI tract, ducts, gallbladder

• Function: secretion and absorption

Goblet Cell

Nucleus

Goblet Cell

• Nuclei lie near base of cell• Goblets secrete mucous at

apical surface to lubricate lining of GI, respiratory, reproductive and urinary systems.

• Microvilli increase surface area for absorption.

Simple Columnar Cells

Pseudostratified Ciliated Columnar Epithelium

• Appears stratified because nuclei are at varying levels.

• Ciliated lines airways of upper respiratory tract.

• Mucus from Goblets traps foreign particles and are swept away by cilia.

Goblet Cells

Cilia

Nuclei at varying levels

Goblet Cells secreting mucus

Epithelial and Connective

• 1 – pseudostratified columnar epithelial

• 2- simple cuboidal epithelial

• 3- hyaline cartilage connective tissue

1

2

3

Fibroblast CELLS

MATRIXFIBER

Elastic Fiber

Collagen Fiber (thicker pink ones)

GROUND SUBSTANCELoose Areolar

Connective Tissue

Teased Dense Regular Connective Tissue

• Forms tendons and ligaments and aponeuroses.

• Matrix looks white and shiny.

• Mostly collagen fibers with fibroblasts between rows.

• Strong attachment!

Teased Dense Regular CT (magnified)

Fibers are mostlyCollagen.

Fibroblasts

Reticular Connective Tissue

• Network of interlacing reticular fibers & reticular cells

• Found in stroma (framework) of liver, spleen, lymph nodes, red bone marrow

• Acts as a filter in spleen and lymph nodes.

Blue stainingReticular fibers

Reticular Cells

Reticular Connective Tissue

• Remember that connective tissue is vascular. (Avascular epithelial tissue depends on diffusion of nutrients and waste through blood vessels in CT.

Blood vessel:Single layer of Epithelial cells forms vessel tube.

ReticularCT

• 1- Reticular cells

• 2- Blood vessel

• 3- Reticular fibers

3

1

2

Hyaline Cartilage

• Often called gristle• Bluish white smokey

looking ground substance • Numerous chondrocytes• Location: ends of long

bones, ribs, nose, trachea, larynx, bronchi

• For flexibility and support• Most abundant type of

cartilage in body

chondrocytes

Ground Substance

Elastic Cartilage

• Chondrocytes are located within threadlike network of elastic fibers

• Location: Epiglottis of larynx, external ear, Eustachian tubes

• For support and shape

chondrocyte

Lacuna(hollow spaceholding chondrocyte)

Elastic vs Hyaline Cartilage

Elastic fibers throughoutGround substance

SmootherAppearanceOf groundsubstance

AdiposeTissue

• Adipocytes, “signet ring” cells with peripheral nuclei.

• For storage of triglycerides, to reduce heat loss, and serve as an energy reserve.

• Location: under skin, around heart & kidneys, yellow marrow, behind eyeball

“signet ring” adipocyte

nucleus

Osseous Tissue (Bone)• Compact bone consists of

osteons (haversion systems) that contain:– Lamellae– Lacuna– Osteocytes– Canaliculi– Central (haversion)canals

• Spongy bone consists of thin plates called trabeculae filled with red marrow

HaversionSystem

Lamellae

Central(Haversion)Canal

Lacunae

Lacunae (where osteocytes reside)

Canaliculi: small Tunnels where osteocyteprocesses run for diffusionof nutrients and wastes

Skeletal Muscle Tissue

• Striated– Proteins

• Actin• Myosin

• Multinucleated• Voluntary• Attach to bones• For movement,

communication, posture, heat production

Striations

Skeletal muscle fiber with multiple nuclei

Smooth (Visceral) Muscle Tissue• No striations• Spindle-shaped• Single centrally located

nucleus• Nucleus is long and cigar

shaped• Involuntary• Viscera• Walls of hollow structures

– Blood vessels– Airways to lungs– Stomach– Intestines– Gallbladder– Urinary bladder

Cigar shaped nuclei

Smooth Muscle

Cardiac Muscle Tissue

• Striated, mono-nucleated, branching

• Self excitatory• Intercalated discs

attach fibers together and contain gap junctions (help with conduction of electrical signals)

Intercalated disc

nucleus

Name the tissues and structures you see.

Simple Squamous Epithelial

Stratified Squamous Epithelial

These keratinized epithelial cells willBe sloughed off.

Basal Layer

Apical Layer