Where to find simple squamous

King, D. Epithelium Study Guide. Tamarkin, D. Glomerular Filtration. Simple Squamous Epithelium Structure. Simple squamous epithelial cells are thin and flat the thinnest of all epithelial cell-types , which allows them to have a large surface area that is exposed to the lumen on one side the apical surface , and to the basement membrane i.

The cells, scale-like in appearance, tend to have larger, elliptically-shaped nuclei. As a simple type of epithelium, simple squamous epithelium is one cell-layer thick, and thus every cell of the tissue comes in direct contact with the basement membrane. As with other types of epithelia, simple squamous epithelial cells are bound together by tight junctions, forming a selective barrier, which is crucial to its function.

Simple columnar epithelium consist of a single layer of cells that are taller than they are wide. This type of epithelia lines the small intestine where it absorbs nutrients from the lumen of the intestine. Simple columnar epithelia are also located in the stomach where it secretes acid, digestive enzymes and mucous. Stratified squamous epithelia consist of multiple layers of cells with the outer most layer being squamous. This type of epithelium provides protection to mechanical stress and dessication and is found in the skin.

Pseudostratified epithelia consist of a single layer of cells, but due to the different heights of the cells, it gives the appearance of having mutliple layers of cells, hence the name pseudostratified. Importantly, all cells are attached to the basement membrane.

This type of epithelium is found in the respiratory tract and functions to secrete mucous and move material up the respiratory tract through the beating of cilia.

Cilia are long extensions of the cell membrane that contain a microtubule-based structure called the axoneme. Dynein motors within the axoneme generate force that cause a wave-like motion in the cilia. All epithelia rest on a basement membrane. The basement membrane provides structural support and integrity to epithelia by providing a common framework of proteins to which epithelial cells adhere. The basement membrane separates the epithelia from the underlying or surrounding tissue.

Importantly, because epithelia lack blood vessels and depend upon capillaries in surrounding tissues, all nutrients, hormones and other proteins must diffuse across the basement membrane before reaching an epithelia.

Pseudostratified ciliated columnar epithelium containing goblet cells lines most of the major airways. This is an example of pseudostratified epithelium, from the trachea. All the cells are attached to the underlying basement membrane, but the nuclei are at different heights, giving the appearance of a 'stratified' epithelium.

Hence this is a 'pseudostratified' epithelium, as it is in reality a single layer of cells. Make sure you can identify the goblet cells. What shape do the rest of the epithelial cells have? Epithelium: Types of simple epithelium Squamous Squamous means scale-like.