Tissues

• A group of cells similar in structure and function

• Work together to perform a common function

Epithelial Connective MuscleNervous

Epithelial Tissue

• Composed mostly of cells

• Classified by number of layers and shape

• Regenerative

Simple Stratified Other

Simple Epithelial

• A single layer of cells

• Typically found where absorption and filtration occur

• 3 types

Squamous ColumnarCuboidal Epithelial Tissue

Simple Squamous

• A single layer of flattened cells

• Provide diffusion and filtration

• Provide slick lining

Simple Epithelial

Simple Cuboidal

• Shape is cube-like• Large, spherical

central nuclei• Function in

secretion and absorption

Simple Epithelial

Simple Columnar

• Tall cells• Function in

absorption and secretion

• Ciliated and non-ciliated types

Simple Epithelial

Stratified Epithelial

• Epithelial tissue with multiple layers of cells

Squamous Columnar/Cuboidal Epithelial Tissue

Stratified Squamous

• Forms a thick membrane

• Protection for areas subject to abrasion

Stratified Epithelial

Stratified Columnar/Cuboidal

• Rare/limited distribution

• Highly specific functions

Stratified Epithelial

Other Epithelial

• Transitional, Pseudostratified, Glandular

Pseudostratifed ColumnarTransitional Glandular Epithelial Tissue

Transitional

• Several cell layers• Basal side is

formed of cuboidal cells, surface cells are dome-shaped

• stretches

Other Epithelial

Pseudostratified Columnar• Single layer of cells

with nuclei at differing heights

• Creates illusion of being stratified

• Function in secretion and absorption

Other Epithelial

Glandular

• One or more cells that work together to make and secrete an aqueous liquid

Endocrine Exocrine Other Epithelial

Endocrine• Ductless glands• Produces

hormones

Glandular

Exocrine

• Secrete fluids onto body surface

• More numerous than endocrine

Glandular

Connective Tissue

• Most abundant and widely distributed tissue found throughout body

• Formed from fibers and cells

• Four variations

Connective Tissue Proper Cartilage BloodBone

Connective Tissue Proper

• All mature connective tissues except bone, cartilage, and blood

• Loose and Dense forms

Loose Dense Connective Tissue

Loose

• Areolar, Adipose, and Reticular

Areolar Adipose Reticular Connective Tissue Proper

Areolar• A gel-like matrix

with all 3 fiber types, macrophages, mast cells, fibroblasts, and some white blood cells

• Wraps and cushions most organs

• Widely distributed

Loose

Adipose• Similar to areolar• Fatty• Reserves food stores

(fat), insulates, supports and protects

• Heavily vascularized

Loose

Reticular

• Network of reticular fibers with reticular cells

• Forms a soft internal skeleton (stroma)

Loose

Photo by Akay(Creative Commons)

Dense

• Regular and Irregular

Connective Tissue ProperRegular Irregular

Regular• Consists of parallel

collagen fibers with few elastic fibers and fibroblasts

• Connects muscle to muscle, muscle to bone, and bone to bone

Dense

Irregular• Irregularly

arranged collagen with some elastic fibers

• Fibroblasts• Can withstand

tension in multiple directions

Dense

Cartilage

• Hyaline, Elastic, and Fibrocartilage

Connective TissueHyaline Elastic Fibrocartilage

Hyaline

• An amorphous, firm matrix of collagen fibers

• Supports, reinforces, cushion, resists compression

Cartilage

Photo by Creative Commons

Elastic

• Similar to hyaline but more flexible

• Can maintain shape and structure under stress

Cartilage

Fibrocartilage

• Similar to hyaline but less firm

• Functions in providing tensile strength and absorption of compressive shocks

Cartilage

Bone• A hard calcified matrix

of collagen fibers• Supports, protects,

provides levers for muscular action

• Stores calcium, minerals, and fat

• Marrow in bone is site of hemotopoiesis

Connective Tissue

Blood

• Consists of red and white blood cells in a fluid matrix (plasma)

• Transports respiratory gasses, nutrients, wastes

Connective Tissue

Nervous Tissue• Neurons, branching

cells, with neuroglia, supporting cells

• Function in transmitting electrical signals from receptors to effectors

• Found in brain, spinal cord, peripheral nerves

Muscle Tissue

• Source of most body movements

• Skeletal, cardiac, smooth

Skeletal Cardiac Smooth

Skeletal• Long, cylindrical,

multinucleate cells• Obvious striations• Initiates voluntary

movement• Attached to bone or

skin

Muscle

Cardiac• Branching,

uninucleate, strited cells

• Interlock at intercalated discs

• Specific to heart

Muscle

Smooth

• Visceral muscle• Sheets of spindle-

shaped cells• Central nuclei, no

striations

Muscle

Photo by Blake Allen

Credits • Author- Kyle J. Fleury• All images courtesy

of flickr.com-some by

author and Wesley House

-others by various individuals