EPITHELIALCONNECTIVE

OSSEOUS (BONE)MUSCLE

HISTOLOGY SLIDE REVIEW

Simple Squamous Epithelial Tissue

NucleusLocation:MesotheliumEndothelium

Function:FiltrationDiffusionSecretion

Stratified Squamous Epithelial

These keratinized epithelial cells willBe sloughed off.

Basal Layer

Apical Layer

Mitotic cells are rounder in appearance

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.

• Location: – Ciliated lines airways of

upper respiratory tract.• Function:

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

Goblet Cells

Cilia

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 of smoothmuscle tissue

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.