Covers body surface and lines body cavities.
Covering and lining epithelium
covers and lines exterior and interior visceral surfaces
Most or all produce secretions. Discharging them onto the surface of the epithelium or into the interstitial fluid and blood.
5 special characteristics of epithelial tussue
Cellularity (bound together by cell junctions)
Polarity (refers to the structural and functional differences between the apical surface and basal surface)
Attachment (to the basement membrane/basal lamina)
Avascularity (receive nutrients by diffusion/ absorption from exposed or attached epith. surfaces)
Regeneration (damaged and lost cells are replaced by the division of stem cells in the epithelium)
Inner and outer surfaces with different structure and function. Called apical-basal polarity
An upper free surface exposed to the body exterior or the internal organ cavity. Include Microvilli and Cilia
Lower attached surface.
Finger like extentions of the plasma membrane that greatly increase exposed surface area
Tiny hairlike projections that propel substances along their free surfaces
A line supporting sheet adjacent to the basal surface. Selective barrier and scaffolding for cells to repair wounds
Close lateral connections including tight connections and desmosomes.
Supported by connective tissue
Reticular lamina:beneath the basal lamina, fine network of fibers Basement membrane is formed by the two laminae
Avascular but innervated
no blood vessels but is supplied by nerve fibers.
protective covering replaces it's self rapidly
Epithelial classification by number
Simple: single layer found where absorption, secretion, and filtration occur. Stratified: Two or more layers in high friction areas like lining of the mouth.
Epithelial classification by shape
Squamous: Flat, scale like Cuboidal: boxlike Columnar: tall column shaped.
2 types of glands
Endocrine (ductless) and Endocrine (have ducts)
Where do you find epithelial tissue
Covering, lining and glands
3 Epithelial cell shape
squamous cuboidal columnar
Types of connective tissues
Connective tissue proper: loose and dense Fluid connective tissue: blood and lymph Supporting connective tissue: cartilage and bone
Connective Tissue Proper
1. Loose Connective tissue 2. Dense connective tissue
Loose connective tissue
"packing materials" for the body, fill spaces between organs, cushion and stabilize cells in many organs: Areolar Adipose Reticular (mucus connective tissue in embryos)
Dense connective tissue
Collagen fibers are the dominate fiber type Regular Irregular Elastic ie. tendons
Hyaline Cartilage (tough but flexible ie. between ribs & sternum) Fibrocartilage (resists compression and absorbs shock ie. invertebral discs) Elastic cartilage(resilient and flexible ie. ear)
Most common,tough and somewhat flexible: Articular cartilages Connect ribs to sternum Conducting airways and nasal cartilages
Elastic tissue, extremely resilient and flexible: Outer ear Epiglottis
3 components of connective tissue
Specialized cells Extracellular protein fibers A fluid ground substance
4 membranes in the body
serous cutaneous mucous synovial
2 cell populations that make up neural tissue