tissue histology four primary types epithelial connective muscular nervous tissues
TRANSCRIPT
•Tissue
•Histology
•Four Primary TypesEpithelialConnectiveMuscularNervous
Tissues
Epithelial TissueFunctions
*Covering or lining
Protection
Permeability controlSecretion
Absorption
Excretion
Sensory
Function is determined by cell type & number of cell layers.
Basement Membrane
apical
basal
Structural Characteristics of Epithelia
Cellularity
Polarity
Avascular
Innervated
Regeneration
Polarity of Epithelial Cells
Classification of EpitheliaThe function of the epithelium determines which type.
Classified according to1. Number of cell layers
Simple vs. Stratified 2. Shape of apical cell
Squamous, cuboidal, columnar 3. Special features
Cilia, villi
End with epithelium to complete the naming
Arrangements
• Simple
• Stratified
• Pseudostratified
• Transitional
Shapes
• Squamous
• Cuboidal
• Columnar
Special Features
• Cilia
• Goblet Cells
• Villi
• Microvilli
Simple Squamous Epithelium
Diffusion, filtration, secretion, absorption
Location:
• Lining of blood vessels (endothelium)
• Peritoneum
• Alveoli
Simple Cuboidal Epithelium
Functions
Secretion
Absorption
Locations
Lining of ducts
Glands (salivary, pancreas, thyroid)
Kidney tubules
Thyroid Follicle
Simple Columnar Epithelium
• FunctionsSecretionAbsorption
• LocationsGI tractExcretory ductsReproductive tract
• Special Features
Pseudostratified Ciliated Columnar Epithelium
Mixture of cell heights nuclei located at various distances from surface.
All cells touch basement membrane
•FunctionsExcretionMovement
•LocationsRespiratory tract except for lungs Male reproductive ducts
Stratified Squamous Epithelium• Function
Protection (multiple layers = better protection)
• Keratinized vs. non-keratinized
• Location? Where we need protection!Skin surfaceEntrances/exits of body, e.g. mouth, vagina
Stratified cuboidal and columnar: quite rare, found in glands and ducts
Transitional Epithelium
• Layered appearance due to overcrowding.
• Function
Extreme expansion
Recoil
• Location
Bladder
Ureters
stretched
Locations in the Body
Oh…and this tissue type!
Connective Tissue: Supports, protects, binds tissues
Structural characteristics:
• Specialized cells
• Extracellular matrix– Protein fibers – Ground substance (fluid-like)
• Mostly highly vascular
Extracellular matrix – all non-living components
Functions Functions
• Structural framework
• Transport
• Support and protection
• Energy storage
Classification of Connective Tissues
Connective Tissue ProperConnective Tissue ProperTypes:
Areolar Dense regular ReticularAdipose Dense irregular
Types of Fibers:
CollagenElasticReticular
Defense:
MacrophagesPlasma CellsMast CellsOther WBC
Stop
Fluid C. T.
• Blood• Lymph
Supporting C.T.
• Cartilages– Hyaline
– Elastic
– Fibrocartilage
• Bone – Mineral matrix
Study individual types of c.t. in labStudy individual types of c.t. in lab
Membranes = Combination of Membranes = Combination of Epithelia & C.T. Epithelia & C.T.
• Mucous membranes– Lining of cavities that communicate with exterior
• Serous membranes– Lining of sealed, internal cavities
• Cutaneous membranes– Skin
• Need to know membranes
• Parietal vs. visceral
Muscle Tissue
Skeletal
Cardiac
Smooth (not striated)
Skeletal Muscle
•Voluntary
•Heavily striated
•Multinucleated
Cardiac Muscle
•Heart (Only)
•Involuntary
•Striated
•Intercalated disks
•Heavily branched
•Single central nucleus
Smooth Muscle• Involuntary
• No striations
• Single central nucleus
Nervous Tissue
• Neurons– Transmit electrical
impulses
• Neuroglia– Supportive cells of the
nervous system
Neural Tissue