What type of epithelial tissue lines the interior of blood vessels

Epithelial Cells. Choose one of the following categories to see related pages: Cells. Share this Page. Written by John Young John K. You can follow John Young Twitter. Science Newsletter:. Full List of our Videos. Teaching Biology? How to Make Science Films. Read our Wildlife Guide. On the Trail of the Egret. Tips for Shooting Smoke Grenade Photos. Pacific Sleeper Shark: Giant of the Deep. The Burmese Python - A docile ish giant. Australia's Most Dangerous Creatures. White-nosed Syndrome in Bats.

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The sebaceous glands that produce the oils on the skin and hair are an example of a holocrine glands Figure 4. Glands are also named based on the products they produce. A serous gland produces watery, blood-plasma-like secretions rich in enzymes, whereas a mucous gland releases a more viscous product rich in the glycoprotein mucin. Both serous and mucous secretions are common in the salivary glands of the digestive system. Such glands releasing both serous and mucous secretions are often referred to as seromucous glands.

In epithelial tissue, cells are closely packed with little or no extracellular matrix except for the basal lamina that separates the epithelium from underlying tissue.

The main functions of epithelia are protection from the environment, coverage, secretion and excretion, absorption, and filtration. Cells are bound together by tight junctions that form an impermeable barrier. They can also be connected by gap junctions, which allow free exchange of soluble molecules between cells, and anchoring junctions, which attach cell to cell or cell to matrix.

The different types of epithelial tissues are characterized by their cellular shapes and arrangements: squamous, cuboidal, or columnar epithelia. Single cell layers form simple epithelia, whereas stacked cells form stratified epithelia. Very few capillaries penetrate these tissues. Glands are secretory tissues and organs that are derived from epithelial tissues.

Exocrine glands release their products through ducts. Endocrine glands secrete hormones directly into the interstitial fluid and blood stream. Glands are classified both according to the type of secretion and by their structure.

Merocrine glands secrete products as they are synthesized. Apocrine glands release secretions by pinching off the apical portion of the cell, whereas holocrine gland cells store their secretions until they rupture and release their contents. In this case, the cell becomes part of the secretion.

The structure of a tissue usually is optimized for its function. Describe how the structure of individual cells and tissue arrangement of the intestine lining matches its main function, to absorb nutrients. Columnar epithelia, which form the lining of the digestive tract, can be either simple or stratified. The cells are long and narrow.

The nucleus is elongated and located on the basal side of the cell. Ciliated columnar epithelium is composed of simple columnar epithelial cells that display cilia on their apical surfaces. Skip to content Learning Objectives Describe the structural characteristics of the various epithelial tissues and how these characteristics enable their functions. By the end of this section, you will be able to: Explain the general structure and function of epithelial tissue Distinguish between tight junctions, anchoring junctions, and gap junctions Distinguish between simple epithelia and stratified epithelia, as well as between squamous, cuboidal, and columnar epithelia Describe the structure and function of endocrine and exocrine glands.

External Website Summary of Epithelial Tissue Cells Watch this video to find out more about the anatomy of epithelial tissues. External Website. Chapter Review In epithelial tissue, cells are closely packed with little or no extracellular matrix except for the basal lamina that separates the epithelium from underlying tissue.

Interactive Link Questions Watch this video to find out more about the anatomy of epithelial tissues. The inside of the mouth, esophagus, vaginal canal, and anus. Review Questions. Critical Thinking Questions The structure of a tissue usually is optimized for its function.

Previous: 4. 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. Epithelial cells interact with the basement membrane via receptors in their cell membrane called integrins.

Systems Cell Biology Yale Epithelia Lab Learning Objectives Distinguish between, simple, stratified, and pseudostratified epithelia List characteristics of squamous, cuboidal, and columnar epithelia Identify some common surface specializations of epithelia. Lab Content Introduction Epithelia are tissues composed of closely aggregated cells that cover most body surfaces, cavities, and tubes.

Simple squamous epithelium Simple squamous epithelia consist of a single layer of flattened cells. Simple cuboidal epithelium Simple cuboidal epithelium consist of a single layer of cells that are approximately as tall as they are wide. Simple columnar epithelium Simple columnar epithelium consist of a single layer of cells that are taller than they are wide. Stratified Squamous Epithelium Stratified squamous epithelia consist of multiple layers of cells with the outer most layer being squamous.

Pseudostratified 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. Basement membrane All epithelia rest on a basement membrane. Virtual Microscope Slides Trachea Identify three different types of epithelia in this slide of the trachea. These protein connections hold the cells together to form a tightly connected layer that is avascular but innervated in nature.

The epithelial cells are nourished by substances diffusing from blood vessels in the underlying connective tissue. One side of the epithelial cell is oriented towards the surface of the tissue, body cavity, or external environment and the other surface is joined to a basement membrane. The basement layer is non-cellular in nature and helps to cement the epithelial tissue to the underlying structures.

Epithelial tissues are identified by both the number of layers and the shape of the cells in the upper layers. There are eight basic types of epithelium: six of them are identified based on both the number of cells and their shape; two of them are named by the type of cell squamous found in them. Epithelial tissue is classified based on the number of cells, the shape of those cells, and the types of those cells.

Learning Objectives Describe the primary functions and characteristics of epithelial tissue. Key Points Epithelial tissue is composed of cells laid together in sheets with the cells tightly connected to one another. Epithelial layers are avascular, but innervated.