BIO 202 Lecture Notes - Lecture 2: Collagen, Stratum Basale, Respiratory Tract
Tissue: The Living Fabric
- Individual body cells specialized
- Each type performs specific functions that maintain homeostasis
-Tissues
oGroups of cells similar in structure that perform common or related function
-Histology
oStudy of tissues
Types of Primary Tissues
- Epithelial tissue
oCovers
oForms boundaries between different environments, protects, secretes, absorbs, filters
oLining of digestive tract organs and other hollow organs
oEpidermis
Skin surface
- Connective tissue
oSupports, protects, binds other tissues together
oEX:
Bones
Tendons
Fat and other soft padding tissue
- Muscle tissue
oProduces movement
oContracts to cause movement
oEX:
Skeletal
Muscles attached to bones
Cardiac
Muscles of heart
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Smooth
Muscles of walls of hollow organs
- Nerve tissue
oControls
oInternal communication
EX: Brain, Spinal cord, Nerves
Tissue Under Microscopy
- Tissue is fixed
oPreserved
- Cut
oSliced thin enough to transmit light or electrons
- Stained
oEnhances contrast
Epithelial Tissue
- Functions
oProtection
oAbsorption
oFiltration
oExcretion
oSecretion
oSensory reception
- Characteristics
oPolarity
Cells have polarity
Apical surface (upper free) exposed to exterior or cavity
Basal surface (lower, attached)
Both surfaces differ in structure and function
oSpecialized contacts
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Document Summary
Each type performs specific functions that maintain homeostasis. Tissues: groups of cells similar in structure that perform common or related function. Epithelial tissue: covers, forms boundaries between different environments, protects, secretes, absorbs, filters, lining of digestive tract organs and other hollow organs, epidermis. Connective tissue: supports, protects, binds other tissues together, ex: Fat and other soft padding tissue: produces movement, contracts to cause movement, ex: Cut: sliced thin enough to transmit light or electrons. Functions: protection, absorption, filtration, excretion, secretion, sensory reception. Apical surface (upper free) exposed to exterior or cavity. Both surfaces differ in structure and function: specialized contacts. Covering and lining epithelial tissues fit closely together. Desmosomes: supported by connective tissues, avascular, but innervated, can regenerate. Noncellular basal lamina: glycoprotein and collagen fibers lies adjacent to basal surface, adhesive sheet, selective filter, scaffolding for cell migration in wound repair. All epithelial tissues have two names: one indicates number of cell layers.
