Lecture 4 - Epithelia Flashcards Preview

1060 Human form and function > Lecture 4 - Epithelia > Flashcards

Flashcards in Lecture 4 - Epithelia Deck (22):

What are the 4 basic types of tissue?


Connective tissue

Muscle tissue

Neural tissue


avascular tissue?

Not associated with or supplied by blood vessels


Epithelia functions ?

Cover exposed surfaces Line internal passageways and chambers

Produce glandular secretions

An epithelium may have one or more functions depending on the cell types present.

1 Gas exchange: lungs (simple squamous)

2 Absorption: kidneys and gut (usually columnar, simple)

3 Filtration: kidney, liver (simple)

4 Reabsorption: kidney (simple cuboidal)

5 Secretion: glands (usually columnar, simple)


What is Endothelium, Endocardium and Mesothelium?

Specific names that are given to epithelium in certain locations

Endothelium: blood and lymphatic vessels

Endocardium: atria and ventricles of the heart

Mesothelium: lines the cavities of the body e.g. pleura of lungs


What are 3 surface specialisations of epithelia?





Length of cilia?



The 3 features of the basal domain?

1. Basal lamina between the cell membrane and the underlying connective tissue

2. Cell to extracellular matrix junction which anchors the cell to the extracellular matrix

3. Basal cell infolding which increases cell surface area to increase the interactions between cells and the extracellular matrix

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What are the 3 main functions of the basal lamina?

1. Adhesion interface between the epithelial cells and the extracellular matrix

2. Acts s a sieve (permeability barrier) controlling entry and exit from the cells

3. May control cell organisation and specialisation

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What anchors intermediate filaments into the basal lamina?



Transmembrane proteins mainly the integrin family interact with the basal lamina 

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The terminology used to describe epithelium reflects it structure rather than its function,

what are the terms used?

Simple: A single layer of cells

Stratified: Two or more layers of cells

Squamous: When the cell width is greater than the height

Cuboidal: When the width, depth and height are about the same

Columnar: When the height exceeds the width

Pseudostratified: It appears to be stratified but although all of the cells sit on the basal lamina not all reach the surface

Transitional: The number of layers varies with distension 


What is this??

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Simple Cuboidal tissue

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what is this?

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simple squamous tissue

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What is this??

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Simple Columnar tissue

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What is this??

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Stratified Squamous tissue


What is this??

Pseudostratified tissue

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Cell polarity??

Epithelial cell exhibit polarity. They have an apical, lateral and basal domains each with its own specific characteristics. 

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what are cilia??

Cilia are motile cytoplasmic structures capable of moving particles and fluid along epithelial surfaces. In the light microscope they appear as short fine hair like structures whereas EM shows up their internal structure. They vary in length between 3-9μ. 

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Glycocalyx ??

The glycocalyx consists of glycoproteins projecting from the plasma membrane of absorptive cells. It provides an additional surface for absorption and contains enzymes for the final stages of digestion of proteins and sugars. 


what are stereocilia??

long microvilli


The Lateral Domain ??

The lateral sides of epithelial cells are in close contact with each other with junctional complexes and cell adhesion proteins which ensure the integrity of the tissue. 

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What anchors actin filaments into the basal lamina?

Focal adhesion (contact)


Transmembrane proteins mainly the integrin family interact with the basal lamina 

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Basal domain??

Enfolding of the basal surface of the cell increases the surface area and many mitochondria are found in these finger like areas. The mitochondria provide the energy for active transport of ions across the epithelium.