Epithelial Tissue - 8 Types and Locations

squamous

flat, like fried eggs

stratified

multiple layers, resists abrasion, sweat secretion, can stretch

Polarity of Epithealial Cells

•Apical surface •Exposed to external environment or internal body space •Microvilli or cilia •Lateral surface with intercellular junctions •Basal surface •Epithelium attached to connective tissue

stratified cuboidal

ducts (sweat and sperm), follicles of ovaries, parotid, and mammary. Stratified cuboidal epithelium allows glands and organs to create a separation between the functioning cells of organ or gland and the vessels that feed it.

stratified squamous keratinized

epidermis, palms and soles. If we just want to look at stratified squamous keratinized epithelium, we look at skin from one of the few areas of the body that does not have hair. This tissue is from the palm of the hand (palmar skin).

simple cuboidal

kidney tubules, liver, thyroid, mammary, salivary glands One layer of cells as tall as they are wide. These cuboidal cells have large, spherical and central nuclei. Simple cuboidal epithelia are found on the surface of ovaries, the lining of nephrons, the walls of the renal tubules, and parts of the eye and thyroid. On these surfaces, the cells perform secretion and absorption.

functions of epithelia

protection, absorption, secretion, filtration, sensory reception

pseudostratified columnar

respiratory tract (nasal cavity to bronchi) an ovum that is propelled along the fallopian tube towards the uterus Vas deferans Lines much of the respiratory tract One layer of tall narrow cells that appear to be stratified. These tissues can be classified as ciliated or non-ciliated based on a cellular organelle involved with motility and sensory activity.

columnar

tall narrow, often ciliated

stratified squamous non-keratinized

vagina, tongue, esophagus, anal canal. Non-keratinized surfaces must be kept moist by bodily secretions to prevent them from drying out. Examples of non-keratinized stratified squamous epithelium include corneal epithelium, lining mucosa of oral cavity, esophagus, anal canal, ectocervix, vagina, foreskin, and the internal portion of the lips

Epithilial tissue functions

•Composed of one or more layers of closely packed cells •Contains little to no extracellular matrix •Covers body surfaces •Lines body cavities •Forms majority of glands

simple columnar

Single layer of tall cells / Often includes goblet cells, which produce mucus / Lines digestive tract A simple columnar epithelium is a columnar epithelium that is uni-layered. In humans, a simple columnar epithelium lines most organs of the digestive tract including the stomach, small intestine, and large intestine. Simple columnar epithelia line the uterus.

stratisfied columnar

Stratified columnar epithelium is a rare type of epithelial tissue composed of column shaped cells arranged in multiple layers, they are as tall and narrow. Stratified columnar epithelia are found in the conjunctiva of the eye, in parts of the pharynx, anus, the uterus, and the male urethra and vas deferens

pseudostratified columnar

These tissues can be classified as ciliated or non-ciliated based on a cellular organelle involved with motility and sensory activity. Nearly every eukaryotic cell has a single, primary cilium that plays a crucial role in developmental signaling pathways, and is involved in maintaining tissue homeostasis. In spite of the presence of a primary cilium, however, most cells are often called 'non-ciliated' to distinguish them from cells containing numerous motile cilia. These specialized structures are made of microtubules and can beat in a coordinated manner to move particles in a particular direction. These particles could be dust and pathogens in the respiratory tract, or could be an ovum that is propelled along the fallopian tube towards the uterus.

transitional

Transitional epithelium is a type of stratified epithelium. This tissue consists of multiple layers of epithelial cells which can contract and expand in order to adapt to the degree of distension needed. Transitional epithelium lines the organs of the urinary system and is known here as urothelium.bladder, urinary tract •Binucleated cells (two nuclei)

simple squamous

alveoli of lungs one layer of flattened cells Forms thin serous membranes; a single layer of flattened cells Simple squamous epithelia are found in capillaries, alveoli, glomeruli, and other tissues where rapid diffusion is required.[2] Cells are flat with flattened and oblong nuclei. It is also called pavement epithelium due to its tile-like appearance. This epithelium is associated with filtration and diffusion. This tissue is extremely thin, and forms a delicate lining. It offers very little protection...