Histopedia

 

 

It is the type of epithelium in which cells appear to form several layers, but it is only one layer comprising of cells of different height and shapes and their nuclei are placed in such a fashion which gives pseudo appearance of  multiple layers. Site :  lines Upper Respiratory Passage (trachea & bronchi) Function : Filtration/Humidification of Air in URT Secretion Absorption Other Variants : Non-ciliated pseudo-stratified columnar epithelia (Prostate & Vas deferens) Pseudo-stratified columnar epithelia with   stereo-cilia (Epididymis) Important labels : Cilia Basal cells Apical cells Goblet cells Basement Membrane  

Single layer of tall and slender cells, with oval nuclei at base attached to basement membrane. Lines the most of the organs of Gastrointestinal tract. Functions: Protection (act as barrier)  Secretory (Stomach) Absorptive (Intestine) In stomach, it exhibits numerous temporary folds. Also extends downwards to form numerous indentations called Gastric Pits .

Lines the Body Cavities (Cardiac, Pleural and Peritoneal cavities), the inner surface of blood vessels (endothelium), filtration and diffusion membranes. Primary function is to allow diffusion of small molecules and gases. Important labels: Mesothelium Basement membrane Connective tissue & Smooth Muscle fibres Blood vessels Functions: Allows exchange and transport of fluid/gases Reduces friction Produces transport and lubricating fluids