HISTOLOGY Four Basic Types of Tissue 1.Epithelial 2.Connective 3.Muscle 4.Nerve

EPITHELIAL TISSUE  Cells are bound tightly together  Little extracellular material  Arranged in sheets  Cover internal and external surfaces  Often control passage of material  Classified by shape of cells and number of layers

EPITHELIAL TISSUE CELL SHAPE  Squamous shape  Thin, flat cells  Look like fried eggs  Cubodial shape  square shape- cross section  6sided polygon- surface  Columnar  Rectangular- cross section  Polygonal- surface view CELL NUMBER  Simple  Single layer  Stratified  2+ layers  Pseudostratified  Appear stratified- but not  Transitional  Change shape

EPITHELIAL TISSUE SIMPLE SQUAMOUS  Single layer  Squamous shape  Lining of body cavity, lungs, blood vessels

EPITHELIAL TISSUE SIMPLE CUBOIDAL  Single layer  Cuboidal shaped  Kidney tubules, glands

EPITHELIAL TISSUE SIMPLE COLUMNAR  Single layer  Columnar shape  Lining of digestive tract  Modified by presence of cilia

EPITHELIAL TISSUE STRATIFIED SQUAMOUS  Multi layer  Outer most layer- squamous cells  Inner- cuboidal or columnar  Lining of mouth, esophagus, skin

EPITHELIAL TISSUE PSEUDOSTRATIFIED COLUMNAR  One layer  Appears stratified  Respiratory tract

CONNECTIVE TISSUE  Types  Fibrous  Loose – Areolar, Adipose, Reticular  Dense – Regular, Irregular  Cartilage – Hyaline, Elastic, Fibrocartilage  Bone  Blood  Abundant extracellular material  Matix (dominant part)  Fiber, cells in liquid, gel, or solid matrix  Function  Bind and/or support other tissue

Fibrous - CONNECTIVE TISSUE LOOSE Connective  Areolar  Few fibers  Delicate arrangement  Reticular  Loose network of reticular fibers and cells  Forms supportive stroma (framework) for lymphatic organs  Found in lymph nodes, spleen, thymus and bone marrow

CONNECTIVE TISSUE LOOSE Connective  Adipose Tissue  Store large droplets of fat

Connective Tissue Dense Connective –Regular –Densely, packed, parallel collagen fibers Ex: Tendons and ligaments

Connective Tissue Dense Connective –Irregular Densely packed, randomly arranged, collagen fibers and few visible cells Ex: Deep layer of skin & capsules around organs

ConnectiveTissue Cartilage –Supportive connective tissue with rubbery matrix –Chondroblasts produce matrix –No blood vessels heals slowly Types of cartilage vary with fiber types –hyaline, fibrocartilage and elastic cartilage

Hyaline Cartilage Rubbery matrix; dispersed collagen fibers; clustered chondrocytes in lacunae Ends of bones at movable joints; sternal ends of ribs; and fetal skeleton

Elastic Cartilage Hyaline cartilage with elastic fibers Provides flexible, elastic support –external ear and epiglottis

Fibrocartilage Hyaline cartilage with extensive collagen fibers (never has perichondrium) Resists compression and absorbs shock –pubic symphysis, meniscus and intervertebral discs

Connective Tissue BLOOD –Lymph –Liquid matrix –RBC- Red Blood Cells –WBC- White Blood Cells

CONNECTIVE TISSUE BONE  Osteocytes  Small cavities- lacunae  Hardest CT  Impregnated w/ calcium salts  Spongy  Loose rods of bones  Ends of arms and legs  Compact  Shafts of long bones  Tightly organized

MUSCLE TISSUE  Cells have ability to contract  Function  Locomotion  Other body movement

MUSCLE TISSUE SKELETAL  Voluntary movement  Long and cylindrical  Transverse striation  Each fiber is multi-nuclear

MUSCLE TISSUE SMOOTH  Involuntary movement  Predominant  Long, spindle shape  Single nucleus  Internal organs

MUSCLE TISSUE CARDIAC  Striations  Involuntary  One nucleus  Deep center  Heart muscle

NERVE TISSUE  Cells very high ability to  Respond to stimuli  Transmit impulses

NERVE TISSUE NEURON  Cell Body(3)  Dendrites (5)  Axon(1)