Simple Squamous Epithelium Tutorial
Please read Unit 1 – Introduction to Epithelial Tissues prior to completing the activities in this chapter.
Introduction to Simple Squamous Epithelium
Simple squamous epithelium is composed of a single layer of thin, flat, somewhat roundish cells (shaped like irregular pancakes) that all remain in contact with the basement membrane (simple tissue organization). Simple squamous cells are extremely thin in cross section (like a pancake viewed from the side) and broad in surface area when viewed from the apical surface. These structural properties allow simple squamous epithelium to form thin membranes that are highly permeable and/or broad, smooth membranes that are low in friction when moist, allowing two surfaces covered in simple squamous to slide smoothly against each other inside the human body. In other words, simple squamous coverings are thin and permeable and/or smooth and slippery.
Simple squamous epithelium is found in places requiring efficient diffusion of substances across a thin membrane and thus form the endothelia of capillaries in the bloodstream, alveoli in the lungs, and some tubules in the kidneys. Simple squamous epithelium is also found in places requiring reduced friction (smooth slippery surfaces) and thus form the endothelia of all blood vessels and heart chambers and cover the broad exposed surfaces of the thoracic and abdominal cavities, known collectively as mesothelia (mesothelial linings). Mesothelial linings include the visceral pleura, parietal pleura, epicardium, and pericardium of the thoracic cavity and the visceral peritoneum and parietal peritoneum of the abdominal cavity. Simple squamous epithelia are nearly invisible when viewed from the apical surface due to their extreme thinness, so all images of simple squamous in this chapter will be cross-sectional (side) views which allow cell membranes and nuclei to be visualized.
Tutorial: Use the image slider below to learn more about the characteristics of simple squamous epithelium.
Microscopy: Use the image slider below to learn how to use a microscope to identify and study simple squamous epithelium in renal corpuscles of the renal (kidney) cortex.
Microscopy: Use the image slider below to learn how to use a microscope to identify and study simple squamous epithelium in tubules of the renal (kidney) medulla.
Tutorial: Use the hotspot image below to learn more about the characteristics of simple squamous epithelium in renal corpuscles of the renal (kidney) cortex.
Tutorial: Use the hotspot image below to learn more about the characteristics of simple squamous epithelium in tubules of the renal (kidney) medulla as viewed in cross-section.
Tutorial: Use the hotspot image below to learn more about the characteristics of simple squamous epithelium in tubules of the renal (kidney) medulla as viewed in longitudinal-section.
Tutorial: Use the hotspot image below to learn more about the characteristics of simple squamous epithelium in blood vessel endothelium.
