Cell Specialization

Histology PowerPoint

Remember...

Cell Tissue Organ Organ System

Histology is the study of tissue– Each tissue has a specific function

Four Types of Tissue

1. Connective– Connects different tissues, organs, and organ

systems

2. Muscle– Produces force and motion

3. Nervous– Controls body function and movement

4. Epithelial– Consists of layers that cover and protect

Connective Tissue-Proper and Specialized

Proper Connective Tissue

– Areolar (loose) CT– Dense CT– Elastic CT– Reticular CT– Adipose

Specialized Connective Tissue

– Blood– Bone– Cartilage

Areolar (loose) CT

Holds organs in place Lots of proteinaceous

fibers

Dense Regular CT

Ligaments and tendons– Ligaments- bone to bone– Tendons- muscle to

bone

Parallel orientation of fibers to resist tension in one direction

Dense Irregular CT

Skin, hollow organs, joints

Fibers run in numerous directions to resist tension in multiple directions

Elastic CT

Allows for stretching and recoil in muscles and arteries

Reticular CT

Supports delicate glands and organs

Adipose

Fat Cushion, insulation,

energy storage

Blood

Transport nutrients, waste, O2, CO2, etc. between systems

Red blood cells, white blood cells, platelets

Bone

Strong structural support

Cartilage

Three types- hyaline, elastic, fibrocartilage

Mainly found in joints, also in ear, nose

“Soft” support and cushioning

Muscle Tissue-

Skeletal, Cardiac, Smooth

Skeletal Muscle

Voluntary motion Parallel striations Majority of muscle

Cardiac Muscle

Found only in heart Involuntary Branched striations

Smooth Muscle

Involuntary movement No striations Found in hollow organs

(intestines, blood vessels, etc.)

Nervous Tissue-

Neurons, Neuroglia

Neurons

Transmit impulses to communicate to body parts

Neuroglia

Support cells of the nervous system– Many types

Functions– Support, form myelin sheaths, signal

transmission

Epithelial

Classified by– Shape: squamous, cuboidal, columnar– Stratification: simple, stratified,

pseudostratification Simple squamous, cuboidal, columnar Ciliated columnar Stratified squamous, cuboidal, columnar Pseudostratified Transitional

Simple Squamous Epithelium

One layer (simple) Irregular (squamous) Lining of cavities and

outer layer of skin

Simple Cuboidal Epithelium

One layer Cube (cuboidal) Lining of ducts, glands,

urinary tract

Simple Columnar Epithelium

One layer Columns (columnar) Lining of stomach and

intestines

Ciliated Columnar Epithelium

Simple Columns Cilia (hair-like

projections) Respiratory system

Stratified Squamous Epithelium

Multiple layers (stratified)

Irregular Areas of abrasion

(mouth, skin)

Stratified Cuboidal Epithelium

Multiple layers Cube Line ducts and glands

Stratified Columnar Epithelium

Multiple layers Columns Functions in secretion

and protection (uterus, urethra)

Transitional Epithelium

Stratified Cuboidal to squamous Allows for stretching

and compression; only in urinary bladder