LESSON 3 Flashcards
This type of epithelium covers the various body or organ surfaces as well as line the lumen of
internal tubular organs.
Epithelial Tissue
A _____ _____ consists of a single layer of cells and is typically found covering or lining wet surfaces.
What epithelium is this?
Simple Epithelium
What are the types of Simple Epithelium?
a. Simple Squamous Epithelium
b. Simple Cuboidal Epithelium
c. Simple Columnar Epithelium
It has extremely thin cells with barely visible cytoplasm under the light microscope. The nucleus creates a prominent bulge on the free surface.
Simple Squamous Epithelium
Cells appear polygonal in surface view but spindle-shaped in lateral view.
Simple Squamous Epithelium
Where is Simple Squamous Epithelium found?
a. On the inner surface of the wall of the membranous labyrinth and tympanic membrane of the ear.
b. In the parietal layer of Bowman’s capsule and the thin segment of the loop of Henle in the kidney.
c. In the rete testis.
d. In the smallest excretory ducts of many glands.
e. Lining the air spaces or alveoli in the lungs.
What epithelium is found on Lining the air spaces or alveoli in the lungs.
Simple squamous epithelium
What is the primary function of Simple Squamous Epithelium?
Its primary function is dialyzing or filtering,
How does Simple Cuboidal Epithelium differ from Simple Squamous Epithelium?
Simple Cuboidal Epithelium is thicker compared to Simple Squamous Epithelium.
What epithelium is found on the choroid plexus of brain?
Simple Cuboidal Epithelium
Where is Simple Cuboidal Epithelium found?
a. In many glands.
b. On the choroid plexus.
c. On the inner surface of the lens capsule.
d. On the free surface of the ovary.
e. In the ducts of glands.
f. As the pigmented epithelium of the retina.
Its main function is as a lining membrane, but it may also have absorptive or secretory functions.
Simple Cuboidal Epithelium
Simple Cuboidal Epithelium assumes this shape when they form small spherical glandular secretory units (acini)
Pyramidal / Glandular Epithelia
Has one layer; Found covering or lining wet surfaces.
Simple Epithelium
It is characterized by extremely thin cells with the cytoplasm barely visible under the light
microscope.
Simple Squamous Epithelium
It cannot withstand wear and tear.
What kind of epithelial tissue is this?
Simple Squamous Epithelium
Simple Squamous Epithelium in surface view the cells assume the shape of ______, but appear ______ shaped in lateral view.
polygons ; spindle shaped
This consists of a single layer of thin flat cells of irregular outline that fit together to form a continuous thin membrane.
Simple Squamous Epithelium
This is composed of cells which are taller than they are wide and are joined together side by side with their oval nuclei situated towards their bases.
Simple Columnar Epithelium
It refers to the side appearance of cells when they are sectioned at right angles to the surface they cover.
“Cuboidal”
Subtypes of Simple Columnar Epithelium?
c.1 Simple Columnar Epithelium
c.2 Simple Columnar Epithelium Specialized for Mucus Secretion
c.3 Simple Columnar Epithelium with Goblet and Absorptive Cells
c.4 Simple Columnar Epithelium with Goblet and Ciliated Cells
What does the cytoplasm of Simple Columnar Epithelium cells look like?
The cells resemble one another, and their cytoplasm has an even texture.
Where can you find Simple Columnar Epithelium?
It is found in the lining epithelium of moderately large ducts of glands.
What is the function of Simple Columnar Epithelium c2?
The cells are specialized to secrete mucus.
How does the cytoplasm of this mucus-secreting epithelium appear when stained? (Simple Columnar Epithelium Specialized for Mucus Secretion)
When stained with H & E, the cytoplasm above the nucleus appears pale and vacuolated.
How are these mucus-secreting cells similar to goblet cells?
These cells are similar to goblet cells but cannot assume the goblet shape because all the cells are alike and have no space to bulge.
Where is this type of mucus-secreting epithelium found? (c.2 Simple Columnar Epithelium)
It is found on the surface of the stomach and in the lining of the cervical canal.
What two types of cells make up the C.3 Simple Columnar Epithelium?
Goblet cells (secretory) and absorptive cells.
What is the characteristic shape of goblet cells?
Goblet cells assume a goblet shape because their mucigen granules expand and push against adjacent absorptive cells.
Where is the nucleus located in goblet cells?
The nucleus is located in the narrow, stem-like portion of the goblet cell.
What structures are found in the goblet cells as observed with the electron microscope (EM)?
- Goblet cells contain rough endoplasmic reticulum (ER),
- a few mitochondria below and around the nucleus, *stacks of Golgi saccules near the nucleus,
- and mucin granules in the supranuclear region.
What are the microvilli on absorptive cells, and what do they do?
Absorptive cells have finger-like projections called microvilli, which increase surface area for absorption.
A type of simple columnar found in intestine.
c.3 Simple Columnar Epithelium (Goblet and absorptive cells)
They are characterized by little hair-like surfaces, which projects from their free surfaces.
Ciliated cells
They beat to move mucus along the membrane.
Cilia
c.4 Simple Columnar Epithelium is commonly found in what areas of the body?
upper respiratory tract
They are between the goblet cells of intestinal epithelium where they present finger-like projection termed microvilli on its border.
Absorptive Cells
The greater part of the supranuclear
regions is occupied by membrane bound mucin granules which may coalesce to form large
granules. What epithelium?
c.3. Simple Columnar Epithelium composed of both secretory (goblet or mucous) and absorptive
cells.
In c.3. Simple Columnar Epithelium, their apical part of the cell membrane is covered with a few _____.
microvilli
The cell membrane ruptures during the release of mucin granules in this epithelium named -
c.3. Simple Columnar Epithelium composed of both secretory (goblet or mucous) and absorptive
cells.
The nuclei of goblet cells in C.3 Simple columnar epithelium is located or found in the narrow ____-like portions of cell.
narrow stem-like portions of the cells.
All cells are in contact with the basement membrane, but not all reach the surface.
Pseudostratified Columnar Epithelium
What types of cells reach the surface in Pseudostratified Columnar Epithelium?
Ciliated or goblet cells reach the surface.
Why does Pseudostratified Columnar Epithelium appear stratified?
It appears stratified because nuclei are at two different levels.
T OR F?
The nuclei of shorter cells are closer to the basement membrane, while the nuclei of longer cells are closer to the surface of Pseudostratified Columnar Epithelium.
TRUE
Where is Pseudostratified Columnar Epithelium found?
Upper respiratory tract, such as the trachea.
What is the function of mucus secreted by goblet cells in the Pseudostratified columnar epithelium?
The mucus forms a film that serves as a dust-catcher to prevent dust from being inhaled into the lungs and moistens dry air.
The ____ part of the epithelium has this structure to move the mucus containing dust particles upward to a point where it can be swallowed or eliminated.
cilia
This cells in pseudo epithelium serve as stem cells which produce new long cells to replace the lost ones.
Short cells that do not reach the surface
This part of the cells called n____ of the shorter cells that do not reach the surface are closer to the basement membrane than the ones of longer cells that reach the surface.
nuclei
This type is found on wet surfaces that are subjected to considerable wear and tear and where
absorptive function is not needed.
Stratified Squamous Nonkeratinizing Epithelium
It consists of several layers of cells: the deepest layer is columnar, followed by layers of polyhedral cells, and the superficial layers are squamous cells.
Stratified Squamous Nonkeratinizing Epithelium
In the Stratified Squamous Nonkeratinizing Epithelium the deepest layers (layer next
to the basement membrane) is composed of:
columnar cells
In the Stratified Squamous Nonkeratinizing Epithelium the superficial layers are called:
Squamous cells
In the Stratified Squamous Nonkeratinizing Epithelium the deepest layers (layer next
to the basement membrane) is composed of columnar cells AND, above these layer is another additional layer composed of ?
polyhedral cells
Stratified squamous nonkeratinizing epithelium is found in the ?
- mouth,
- esophagus,
- conjunctiva,
- part of the epiglottis,
- the cornea,
- the vagina and,
- a portion of the female urethra.
This epithelium resembles the stratified squamous nonkeratinizing epithelium except that its
more superficial cells undergo a metamorphosis into non living layer of keratin
Stratified Squamous Keratinized Epithelium
An example of Stratified Squamous Keratinized Epithelium is?
epithelial part of the skin
Several functions of keratin:
- It is relatively waterproof; hence it prevents fluid from evaporating from living cells that lie beneath it;
it also keeps the body from absorbing water when one takes a bath. - Since it is tough and resilient, i**t protect the underlying living cells from being injured **by ordinary wear
and tear to which the skin is exposed - It is relatively impervious to bacteria and hence is a first line of defense against infection
It consists of two or more layers of cells, with the surface layer composed of typical cuboidal cells.
Stratified Cuboidal Epithelium
It is found lining the excretory ducts of glands.
Stratified Cuboidal Epithelium
The deeper layers are polyhedral, and the superficial layers are prismatic, cuboidal, or columnar. What epithelial tissue?
Stratified Columnar Epithelium
- It is found in the:
- ornix of the conjunctiva,
- cavernous urethra,
- small areas of the anal mucous membrane,
- pharynx,
- epiglottis,
- lacrimal sac and duct, and
- large excretory ducts of some glands (parotid and mandibular ducts).
Stratified Columnar Epithelium
It provides more protection than simple columnar epithelium but less than stratified nonkeratinizing epithelium.
Stratified Columnar Epithelium
It consists of many cell layers: the deepest layers are cuboidal or columnar, and the superficial layers are large rounded cells.
Transitional Epithelium (Contracted state)
Where is transitional epithelium found?
lines hollow organs subject to contraction or distention, such as the:
excretory passages of the urinary system from the renal calyces to the urethra.
How is Transitional Epithelium similar to Stratified Squamous Nonkeratinizing Epithelium?
It has similar structure but differs in the shape of the superficial cells, which tend to be large and rounded unless stretched.
What happens to Transitional Epithelium when it is stretched?
In the stretched state, the epithelium consists of only two layers: a superficial layer of large squamous cells and a second layer of cuboidal cells.
