What is olfactory epithelium?
Answers
Epithelial tissue -:
• Epithelial tissue covers most organs and cavities of body.
• Epithelial tissue cells are tightly packed in a single multilayered sheet.
• They have only a small amount of cementing material between them, and almost no intercellular spaces.
• All types of epithelial tissue rest on an extra cellular basement membrane.
• The epithelial cells possesses the power of division and regeneration.
• Epithelium of alveoli of lungs helps in exchange of oxygen and carbon dioxide between the blood and inhaled air.
• It produces exoskeletal structures, such as feather's, nails, etc.
• The tissue facilitates rapid healing of wounds by its regeneration power.
• Sensory epithelium in the olfactory organs and taste buds recieves sensory stimuli.
• Epithelial cells having cilia help in movement of various materials like dust particles in nasal passage, mucus in respiratory tract, urine in uriniferous tubules, etc.
TYPES OF EPITHELIAL TISSUES-:
• Squamous Epithelium
=> It is composed of thin flat cells.
=> Forms a delicate lining.
=> Cells have centrally placed nucleus.
=> It protects the underlying parts of body from mechanical injuries, and also prevent entry of germs and chemicals into the body.
=> In lung alveoli, it allows diffusion of oxygen into the blood and carbon dioxide from the blood into alveoli.
=> It is in lining of blood cells, lung alveoli, oesophagus, lining of mouth.
• Stratified squamous epithelium
=> Arranged in many layers to prevent wear and tear.
=> As they are arranged in a pattern of layers, hence called as stratified squamous epithelium.
=> Occurence - Skin Epithelial cells.
• Columnar Epithelium
=> Tall Epithelial cells.
=> Facilitate movement across the Epithelial barrier.
=> The basal part of the cells resting on the basement membrane bears oval Nucleus.
=> The free end of the cells has large number of microvilli, it increase absorptive surface.
=> Occurence - Present at places where absorption and secretion occurs like in lining of intestine.
• Ciliated columnar epithelium
=> Tall cells with hair like projections on outer surface of epithelial cells.
=> Cilia moved and it's movement pushes the mucus forward to clean it.
=> Occurence - In respiratory tract
• Cuboidal Epithelium
=> Cube shaped cells.
=> Provides mechanical support
=> Occurence - Lining of kidney tubules, ducts of salivary glands.
• Granular Epithelium
=> Epithelial cells often acquire additional specialisation as gland cells which secrete substances at the Epithelial surface.
=> Epithelium is often infolded to form multicellular glands.
=> Occurence - Sweat glands, oil glands , digestive glands, and endocrine glands.
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Hope it helps...!!!
View fullsize. specialized region of tissue lining the nasal cavities that contains olfactory receptor cells. Stimulation of olfactory receptor cells by odorants in the nasal cavity is the first step in the pathway that sends olfactory information to the brain.