Name: epithelial tissue shapes and layers
Uploaded: 2023-06-23T15:38:46.000Z
Duration: 1 min 22 s
Channel: JoVE

K12 Standards

Florida Department of Education

High School

Life Science

SC.912.L.14

SC.912.L.14.11

classification-of-epithelial-tissues-overview

Classification of Epithelial Tissues: Overview

Epithelial tissues are classified by cell shape and the number of cell layers, both of which determine their function in the body.
Epithelial cells can have three shapes: squamous, cuboidal, and columnar. Squamous cells look like flat, irregular pieces of a jigsaw puzzle and have disc-shaped nuclei.
Cuboidal cells appear square-like with centrally located spherical nuclei. Columnar cells are tall rectangles containing elongated nuclei located near the basement membrane.
All epithelial cell types are arranged either as a monolayer or in multiple layers.
A simple epithelium is a thin monolayer of cells covering the basement membrane. They line the internal compartments of various organs like lungs, kidneys, and intestines, facilitating the rapid exchange of gases and nutrients.
The stratified epithelia consists of several layers of cells on a basement membrane. They are present in the skin surface, esophagus, mouth lining, or anus lining, where they overcome extreme mechanical abrasions and chemical stresses of the environment without losing their integrity.

classification of epithelial tissues: overview

Epithelial tissues are classified according to the shape of the cells and the number of cell layers formed. Cell shapes can be squamous (flattened and thin), cuboidal (square-like, as wide as it is tall), or columnar (rectangular, taller than it is wide). Additionally, the nucleus shape helps identify the type of epithelial cells. Squamous cells have flattened disc-shaped nuclei, cuboidal cells have spherical nuclei, and columnar cells have elongated nuclei.
Based on the number of cell layers, epithelial tissues can be further classified as simple or stratified. Simple epithelium consists of a single layer of cells resting on a basement membrane. If more than one layer is present, it is called stratified epithelium and only the bottom layer of cells rests on the basal membrane.
Simple epithelium contains cells of the same shape in a single layer. This thin and fragile epithelium lines the internal compartments, body cavities, and blood vessels. The thinness of simple epithelia facilitates rapid absorption and secretion of substances - such as nutrient absorption in the intestines or the exchange of gases in alveoli.
In contrast, the stratified epithelium can have different cell shapes in each layer. Hence, it is named after the shape of the cells in the top layer. It covers exposed body areas such as the skin surface or mouth lining and protects against mechanical abrasions, chemical attacks, and invading pathogens.
This text is partially adapted from <a href="https://openstax.org/books/anatomy-and-physiology/pages/4-2-epithelial-tissue">Openstax, Anatomy and Physiology 2e, Section 4.2: Epithelial Tissues</a><a href="https://openstax.org/books/anatomy-and-physiology/pages/4-2-epithelial-tissue">.</a>

Epithelial tissues are classified according to the shape of the cells and the number of cell layers formed. Cell shapes can be squamous (flattened and ...

Education

JoVE Core

Anatomy and Physiology

Unit 1

Tissues of the Human Body

KEY TERMS AND CONCEPTS

epithelial tissue shapes and layers

Epithelial tissue is identified by cell shape and by the number of cell layers. The main cell shapes are squamous, cuboidal, and columnar. Squamous cells are flattened and thin. Cuboidal cells are square-like, and columnar cells are rectangular and taller than they are wide.

The nucleus shape also helps with identification. Squamous cells have flattened, disc-shaped nuclei. Cuboidal cells have spherical nuclei. Columnar cells have elongated nuclei.

Epithelial tissue is also grouped as simple or stratified based on layers. Simple epithelium has one cell layer resting on a basement membrane. Stratified epithelium has more than one layer, and only the bottom layer rests on the basal membrane. Simple epithelium contains cells of the same shape in a single layer. It is thin and fragile.

This thin simple epithelium lines internal compartments, body cavities, and blood vessels. Its thinness helps with fast absorption and secretion of substances. It plays a role in nutrient absorption in the intestines and gas exchange in the alveoli.

Stratified epithelium can have different cell shapes in different layers. It is named after the shape of the cells in the top layer. This tissue covers exposed body areas such as the skin surface and the lining of the mouth. It helps protect against mechanical abrasions, chemical attacks, and invading pathogens.

Epithelial Tissue Shapes and Layers

tissues

Four Tissue Types in the Human Body

Tissues are groups of cells with a common embryonic origin. Under a microscope, the cells in a tissue often look similar and are arranged in an orderly pattern. This structure helps the tissue carry out a specific function. In the human body, many different cells are organized into four broad tissue categories: epithelial, connective, muscle, and nervous. These tissue types each have a distinct role in keeping the body working properly. They also show how cells can be specialized for different...

epithelial tissues and their functions

Epithelial Barriers, Secretion, and Senses

Epithelial tissue forms the body’s protective barrier and covers both internal and external surfaces. It is found on the skin, in the airways, the digestive tract, the urinary system, and the reproductive system. In hollow organs and body cavities that do not open to the outside, such as blood vessels and serous membranes, the lining is called endothelium. This tissue acts as the body’s first line of defense against physical, chemical, and biological wear and tear. It also works as a...

cell adhesion molecules - types and functions

cell-adhesion-molecules-types-and-functions

Cell Adhesion Molecules in Cell Interactions

Cell adhesion molecules help cells attach to one another and to the surrounding environment. These proteins are an important part of cell-cell interactions and cell behavior. Several major types of cell adhesion molecules are involved in these connections. They differ in structure and in the way they help cells bind, but they all support adhesion between cells or between cells and other surfaces. Cell adhesion molecules also play a key role in how tissues stay organized. By helping cells stay...

overview of cell-cell junctions

Cell-Cell Junctions in Animal Cells

Cell-cell junctions help animal cells connect, communicate, and stay organized in tissues. These junctions are specialized structures that hold cells together and support tissue function. Some junctions provide strong attachment between neighboring cells. Others create channels that let cells share small molecules and signals. These links help tissues act as coordinated units instead of separate cells. Cell-cell junctions are important in many body tissues. They help maintain structure,...

Epithelial tissue is identified by cell shape and by the number of cell layers. The main cell shapes are squamous, cuboidal, and columnar. Squamous cells are flattened and thin. Cuboidal cells are square-like, and columnar cells are rectangular and taller than they are wide. The nucleus shape also helps with identification. Squamous cells have flattened, disc-shaped nuclei. Cuboidal cells have spherical nuclei. Columnar cells have elongated nuclei. Epithelial tissue is also grouped as simple...

classification of epithelial tissues: simple epithelium

classification-of-epithelial-tissues-simple-epithelium

Simple Epithelium: Types and Cell Shapes

Simple epithelium is a single layer of cells that lines body cavities and blood vessels. The shape of each cell matches the job of the tissue. In the body, this means flat, box-like, and tall cells each help in different ways. Simple squamous epithelium is made of thin, scale-like cells with flat, elliptical nuclei. Because these cells are so thin, they are found where chemicals must pass quickly. This tissue lines capillaries and blood and lymph vessels as endothelium, where nutrients are...

classification of epithelial tissues: stratified epithelium

classification-of-epithelial-tissues-stratified-epithelium

Stratified Epithelium Types and Locations

Stratified epithelium is made of several stacked layers of cells. These layers add durability and help the tissue handle constant physical and chemical stress. The tissue is named by the shape of the most apical, or top, cell layer. Stratified squamous epithelium is the most common type in the human body. Its apical cells are squamous, while the basal layer contains cuboidal or columnar cells. Basal cells divide to make new daughter cells. As these new cells move upward, they become flatter...

classification of epithelial tissues: glandular epithelium

classification-of-epithelial-tissues-glandular-epithelium

Glandular Epithelium: Secretory Cell Types

Glandular epithelium is epithelial tissue made of cells that are modified to make and release chemical substances. In high school biology, it is often studied by how many secretory cells it contains and how it sends out its products. Unicellular glands contain single secretory cells scattered within an epithelial layer. Multicellular glands have a hollow tubular duct connected to a group of secretory cells that sit in deeper pockets. These multicellular glands begin during early development...

exocrine glands: unicellular and multicellular glands

exocrine-glands-unicellular-and-multicellular-glands

Exocrine Gland Types and Duct Patterns

Exocrine glands are classified by the number of cells and by duct structure. Unicellular glands are single scattered cells, such as goblet cells in the mucous membranes of the small and large intestines. Multicellular exocrine glands form as secretory sheets, like the internal lining of the abdomen or chest, and they release their secretions directly into the lumen of these organs. Some multicellular glands also have deep secretory units and a hollow duct. The secretory units make the product,...

exocrine glands: methods of secretion

Exocrine Glands and Their Secretion Types

Exocrine glands release their products through ducts. Their secretion pattern helps group them into three types: merocrine, apocrine, and holocrine. These types differ in how the gland cell releases its material. Merocrine secretion is the most common type. In this process, the secretory product is packed into vesicles and moved to the apical surface of the cell. The contents are then released by exocytosis. Mucous, a watery secretion rich in the glycoprotein mucin, is one example. The eccrine...

exocrine glands: types of secretions

Exocrine Gland Secretions and Examples

Exocrine glands produce glandular products and release them outside the body or into a duct. These glands are grouped as serous, mucous, or mixed based on the kind of secretion they make. The three categories help show how gland structure relates to function. Serous glands make watery secretions that are rich in digestive enzymes and proteins. Their cells usually have centrally located nuclei and eosinophilic secretory granules in the cytoplasm, which means the granules stain strongly with...

introduction to connective tissues

Connective Tissue Structure and Disorders

Connective tissue is one of the four main tissue types in the human body. It is found throughout the body and helps connect and support different tissues. Its cells sit inside an extracellular matrix, or ECM, which includes a ground substance and protein fibers. The ECM gives connective tissue its different forms and strengths. The ground substance can be watery, jelly-like, or even mineralized and hard. The main protein fibers are collagen fibers, elastic fibers, and reticular fibers.

functions of connective tissues

How Connective Tissues Support the Body

Connective tissues support, connect, and protect the body. They also act as packing material between tissues in many organs. Different connective tissues do these jobs in different ways. Areolar tissue is a connective tissue prototype. It commonly cements different tissue types together in diverse body organs. Adipose tissue cushions internal organs and helps insulate the body from heat loss. Hard connective tissues include bones and cartilage. These tissues provide structure and support.

classification of connective tissues

Connective Tissue Types and Functions

Connective tissues support, connect, and protect body structures. They are grouped into proper, supporting, and fluid connective tissues. Each group has its own cell types, fibers, and matrix features that help it do a specific job. Connective tissue proper is the most abundant type. It mainly joins different tissues in the body. This group is further divided into loose and dense connective tissue based on the cell types, ground substance, viscosity, and fiber types in the extracellular...

embryonic connective tissues

Embryonic Support Tissues in Development

Embryonic connective tissues help shape the body during early development. The main types are mesenchyme and mucoid connective tissue. Both are temporary tissues that appear before birth and help build later structures. Mesenchyme is the first connective tissue to appear in the developing embryo. It is made of loosely arranged multipotent mesenchymal cells and reticular fibers in the extracellular matrix. This loose structure lets cells move easily, which is important for germ layer...

overview of connective tissues proper

Loose and Dense Connective Tissue Types

Connective tissue proper includes the mature connective tissues in the body, except bone, cartilage, blood, and lymph. It is divided into two main subclasses: loose connective tissue and dense connective tissue. These groups are classified by how their protein fibers are arranged and by the amount of ground substance, which is the material that fills the space between cells. Loose connective tissues contain a meshwork of thin collagen and elastin fibers. This arrangement gives support, tensile...

extracellular matrix

Extracellular Matrix in Connective Tissue

The extracellular matrix (ECM) gives connective tissue its support, shape, and signals. Unlike epithelial tissue, where cells are tightly packed with little or no space between them, connective tissue cells are spread out in a matrix. That matrix fills the space around the cells and helps the tissue work as a unit. The ECM contains fibrous proteins such as collagen, elastin, and fibronectin. It also includes a ground substance made of interstitial fluid, cell adhesion proteins, and...

connective tissue fibers and ground substance

connective-tissue-fibers-and-ground-substance

How Connective Tissue Gets Its Strength

Connective tissue gets its strength and support from cells, ground substance, and protein fibers. Unlike epithelial tissue, which has tightly packed cells, connective tissue cells are spread out in a matrix. The matrix is the extra material outside the cells, and it is made by the connective tissue cells themselves. It is a major part of how this tissue works. The main part of the matrix is ground substance, which is often a fluid but can also be hard and mineralized, as in bone. Connective...

loose connective tissue

Loose Connective Tissue Types and Functions

Loose connective tissue is found between many organs. It helps bind tissues together and absorb shock. It also lets water, salts, and nutrients diffuse into cells that are embedded in it or in nearby tissues. Adipose tissue is a type of loose connective tissue made mainly of fat storage cells called adipocytes. It has very little extracellular matrix, and its many capillaries help move lipid molecules quickly. White adipose tissue is the most common type in adults. It can look yellow because...

dense connective tissue

Dense Connective Tissue Fibers and Support

Dense connective tissue has more collagen fibers than loose connective tissue. That extra collagen makes it more resistant to stretching. It is usually grouped into two main types: dense regular connective tissue and dense irregular connective tissue. Dense regular connective tissue has fibers arranged in parallel. This pattern gives the tissue high tensile strength, or resistance to pulling, in the direction of the fibers. Ligaments and tendons are made of dense regular connective tissue, and...

layers of connective tissue proper

Fascia and Body Movement Support

Fascia is a thin, fibrous connective tissue that supports many parts of the body. It surrounds skeletal muscles, bones, blood vessels, and organs. Because it forms a continuous layer, it helps define and protect these structures. There are three main types of fascia: superficial fascia, deep fascia, and subserous fascia. Each type lies at a different depth in the body. Together, they make up a fascial system that links tissues across the body. Fascia reduces friction so muscles, joints, and...

bone as supporting connective tissue

Bone Matrix and Cell Structure

Bone tissue is the hard connective tissue that forms the internal skeleton of vertebrate animals. It gives the body support and shape. Bone, also called osseous tissue, contains a matrix made of both organic and inorganic material. The organic matrix includes collagen and elastic fibers. These materials help give bone strength and flexibility. The inorganic matrix is made mostly of mineral salts, especially calcium salts. These salts make bone hard. If the organic material is too low, bones...

tissue membranes

Tissue Membranes and Their Functions

Tissue membranes are thin layers that cover the body, protect organs, line passageways that open to the outside, and line movable joint cavities. They fall into two broad groups: connective tissue membranes and epithelial membranes. Connective tissue membranes are made only of connective tissue. They wrap around organs such as the kidneys and also line movable joints. A synovial membrane is a connective tissue membrane found in freely movable joints like the shoulder, elbow, and knee. Inside...

fluid connective tissues: blood and lymph

Blood and Lymph: Transport and Defense

Blood and lymph are fluid connective tissues that help the body transport materials and defend against infection. They contain formed elements, which are cells suspended in a liquid extracellular matrix called plasma. These formed elements come from hematopoietic stem cells in the bone marrow. Blood moves through arteries, capillaries, and veins. Its plasma is made mainly of proteins, solutes, and water. The rest of the blood includes erythrocytes, or red blood cells, leukocytes, or white...

tissue injury: inflammation and repair

Tissue Injury and Wound Healing

Tissue injury triggers inflammation and repair. After tissue is damaged, the body begins a wound healing response that helps protect the area and restore function. Inflammation is the first stage. It helps limit further damage and prepares the tissue for repair. During this time, the body clears injured material and starts the healing process. Repair follows as new tissue forms. In some cases, the damaged area can be replaced by tissue that restores normal structure and function. In other...

the effect of aging on tissues

How Aging Changes Body Tissues

Aging changes body tissues and lowers how well many body systems work. Some of the clearest changes are visible on the outside. Skin can become dry, thinner, and less elastic, which leads to wrinkles. The skin on the face may also look looser because connective tissue has less elastic and collagen fibers. Aging also affects hair, senses, bones, and joints. Melanin production in hair follicles decreases with age, so hair can turn gray. Sight and hearing may decline, and glasses or hearing aids...

key terms and concepts

Learn how epithelial tissue is classified by cell shape and number of layers, with examples of simple and stratified epithelium and their functions.

Epithelial Tissue Shapes and Layers | JoVE K12

anatomy and physiology

JoVE Core Anatomy and Physiology showcases the anatomical and physiological details of the human body in comprehensive, clear, and engaging video animations. This collection of lessons focuses on the structures, components, functions, and requirements of the human body. It is complemented by scientist-in-action videos that demonstrate the application of this knowledge in real-world medical and research settings.

What are Cells?

Cells are the smallest and basic units of life, whether it is a single cell that forms the entire organism, e.g., in a bacterium or trillions of them, ...

Characteristics of Life

Biology is a natural science that studies life and living organisms, including their structure, function, development, interactions, evolution, ...

https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10647.jpg

Animal and Plant Cell Structure

Animal and plant cells not only differ in their structure, function, and mode of nutrition but also in how they reproduce, specialize, and organize into ...

Eukaryotic Evolution

The endosymbiont theory is the most widely accepted theory of eukaryotic evolution; however, its progression is still somewhat debated. According to the ...

Cell Diversity

The concept of a cell started with microscopic observations of dead cork tissue by Robert Hooke in 1665. Hooke coined the term &#34;cell&#34; based on the ...

Chemistry of the Cell

The cell is chemically composed of water, organic molecules and inorganic ions.
Water
The polarity of the water molecule and its resulting hydrogen ...

Describe the scientific theory of cells (cell theory) and relate the history of its discovery to the process of science.

SC.912.L.14.1

Cell Size

Cell sizes vary widely among and within organisms. Bacterial cells range between 1-10 micrometers (&#x3BC;m)and are considerably smaller than most ...

Eukaryotic Compartmentalization

One of the distinguishing features of eukaryotic cells is that they contain membrane-bound organelles, such as the nucleus and mitochondria, that carry ...

Prokaryotic Cells

Prokaryotes are small unicellular organisms that include the domains&#x2014;Archaea and Bacteria. Bacteria include many common organisms, such as ...

Cytoplasm

The cytoplasm consists of organelles and a framework of protein scaffolds called the cytoskeleton suspended in an aqueous solution, the cytosol. The ...

The Nucleus

The nucleus is a membrane-bound organelle that acts as a control center in a eukaryotic cell. It contains chromosomal DNA, which controls gene expression ...

Endoplasmic Reticulum

Endoplasmic ReticulumThe endoplasmic reticulum (ER) is an extensive network of membranous sacs and tubules in eukaryotic cells, continuous with the outer ...

Ribosomes

Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that ...

Golgi Apparatus

As they leave the Endoplasmic Reticulum (ER), properly folded and assembled proteins are selectively packaged into vesicles. These vesicles are ...

Microtubules

There are three types of cytoskeletal structures in eukaryotic cells&#x2014;microfilaments, intermediate filaments, and microtubules. With a diameter of ...

Peroxisomes

Peroxisomes and mitochondria are two important oxygen-utilizing organelles in eukaryotic cells. Mitochondria carry out cellular respiration&#x2014;the ...

Gap Junctions

Multicellular organisms employ a variety of ways for cells to communicate with each other. Gap junctions are specialized proteins that form pores between ...

The Extracellular Matrix

In order to maintain tissue organization, many animal cells are surrounded by structural molecules that make up the extracellular matrix (ECM). Together, ...

Tissues

Cells with similar structure and function are grouped into tissues. A group of tissues with a specialized function is called an organ. There are four main ...

Plant Cell Wall

The plant cell wall gives plant cells shape, support, and protection. As a cell matures, its cell wall specializes according to the cell type. For ...

Plasmodesmata

The organs in a multicellular organism&#x2019;s body are made up of tissues formed by cells. To work together cohesively, cells must communicate. One way ...

What are Membranes?

A key characteristic of life is the ability to separate the external environment from the internal space. To do this, cells have evolved semi-permeable ...

Membrane Fluidity

Cell membranes are composed of phospholipids, proteins, and carbohydrates loosely attached to one another through chemical interactions. Molecules are ...

Fluid Mosaic Model

The fluid mosaic model was first proposed as a visual representation of research observations. The model comprises the composition and dynamics of ...

What is an Electrochemical Gradient?

Adenosine triphosphate, or ATP, is considered the primary energy source in cells. However, energy can also be stored in the electrochemical gradient of an ...

Diffusion

Diffusion is the passive movement of substances down their concentration gradients&#x2014;requiring no expenditure of cellular energy. Substances, such as ...

Osmosis

Approximately 60% to 95% of the weight of living organisms is attributed to water. Therefore, maintaining appropriate water balance within cells is of ...

Tonicity in Animals

The tonicity of a solution determines if a cell gains or loses water in that solution. The tonicity depends on the permeability of the cell membrane for ...

Tonicity in Plants

Tonicity describes the capacity of a cell to lose or gain water. It depends on the quantity of solute that does not penetrate the membrane. Tonicity ...

Introduction to Membrane Proteins

The cell membrane, or plasma membrane, is an ever-changing landscape. It is described as a fluid mosaic where various macromolecules are embedded in the ...

Facilitated Transport

The chemical and physical properties of plasma membranes cause them to be selectively permeable. Since plasma membranes have both hydrophobic and ...

Primary Active Transport

In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or ...

Secondary Active Transport

One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this ...

Receptor-mediated Endocytosis

Overview

Receptor-mediated endocytosis is a process through which bulk amounts of specific molecules can be imported into a cell after binding to cell ...

Pinocytosis

Cells use energy-requiring bulk transport mechanisms to transfer large particles, or large amounts of small particles, into or out of the cell. The cells ...

Phagocytosis

Cells pull particles inward and engulf them in spherical vesicles in an energy-requiring process called endocytosis. Phagocytosis (&#x201C;cellular ...

Exocytosis

Exocytosis is used to release material from cells. Like other bulk transport mechanisms, exocytosis requires energy.

While endocytosis takes particles ...

Relate structure to function for the components of plant and animal cells. Explain the role of cell membranes as a highly selective barrier (passive and active transport).

SC.912.L.14.2

Cell Structure

Background
Cells represent the most basic biological units of all organisms, whether it be simple, single-celled organisms like bacteria, or large, ...

Compare and contrast the general structures of plant and animal cells. Compare and contrast the general structures of prokaryotic and eukaryotic cells.

SC.912.L.14.3

Overview of Microscopy Techniques

The early pioneers of microscopy opened a window into the invisible world of microorganisms. In 1830, Joseph Jackson Lister created an essentially modern ...

Introduction to Light Microscopy

The light microscope is an instrument used by researchers in many different fields to magnify specimens to as much as a thousand times their original ...

Overview of Electron Microscopy

The wavelengths of visible light ultimately limit the maximum theoretical resolution of images created by light microscopes. Most light microscopes can ...

phase-contrast-and-differential-interference-contrast-microscopy

Phase Contrast and Differential Interference Contrast Microscopy

Phase-Contrast Microscopes
In-phase-contrast microscopes, interference between light directly passing through a cell and light refracted by cellular ...

Confocal Fluorescence Microscopy

Confocal microscopy is an advanced microscopic technique. The prime advantage of the confocal microscope over other microscopy techniques is its ability ...

Compare and contrast structure and function of various types of microscopes.

SC.912.L.14.4

A. Cells have characteristic structures and functions that make them distinctive.

B. Processes in a cell can be classified broadly as growth, maintenance, reproduction, and homeostasis.

C. Life can be organized in a functional and structural hierarchy ranging from cells to the biosphere.

D. Most multicellular organisms are composed of organ systems whose structures reflect their particular function.

Epithelial Tissue Shapes and Layers

Description

Transcript

Tags

More videos by Standards