RATIFICATION PAGE
Complete report of Animal Structure experiment with title “Epithelial Tissue”
which written by:
Name : Sureni Hikmawati s
ID : 081404176
Group : VI
Class : D (Biology ICP)
After checked by assistant and coordinator assistant, this report accepted.
Makassar,
Coordinator Assistant Assistant
(Djumarirmanto, S.Pd) (Dian Anggreini)ID: 061404056
CHAPTER IINTRODUCTION
A. Background
Tissue is structure which in form by complete cells which usually has
morphology characteristics and the same function. Epithelium tissue to make
from drugs cells which to compile in the small coat. The tissue to arrange the type
of cavity and the tube in body. These tissues make form skin which to which to
wrapping body. In order that, the epithelium tissue is the constrictor tissue too and
to compile the covering or to compile organ surface, cavity and channel not only
inside but for out side too. The epithelium cells is stick in basic membrane (which
make by fasten tissue) it basic membrane to containing the collagen fiber which
to planted in the matrix. The basic function membrane is to support the epithelium
tissue. The epithelium tissue which compile out body surface is called epidermis
and epithelium tissue which limited the cavity is called mesothelium. Epithelium
to dissociate from it under fastens tissue by flimsy membrane, maybe by basal
membrane (membrane basement), lamina basalis and lamina reticularis or by
lamina basalis. Lamina basalis is located at the generally epithelium is amorf
characteristic, containing the type IV collagen which not make form collagen
fibril, proteoglikan, laminin, fibronykten. Lamina and fibronykten is glycoprotein.
The composition of lamina reticularis is less clear but visible with light
microscope if to colorings with reagents-PAS or silver colorant. Beside at the
epithelium, lamina basalis knows can to surround the muscle cells and neuro
lemosite. Visible too at the corpuscular renalis epithelium kidney which
anticipated has function in blood plasma ultra filtration process in to result primer
urine.
Epithelium tissue is a coat cells which good compile, the extra cells matrix is
little and usually to limited body surface. The epithelium usually called covering
epithelium. The epitheliums tissue can to get at the other gland, so that to called
by gland epithelium. Epithelium tissue and gland consist on other type and for to
observation and to knowing the types from epithelium tissue and the gland, so we
do this experiment
A. Purpose
A. General purpose
This practicum to purpose form to observation types of epithelium tissue
and glands.
B. Special purpose
1. Observation 1 : To observated of simple squamous epithelium.
2. Observation 2 : To observated of simple cuboidal epithelium.
3. Observation 3 : To observated of simple columnar epithelium.
4. Observation 4 : To observated of pseudo stratified epithelium.
5. Observation 5 : To observated of simple cylindrical epithelium.
6. Observation 6 : To observated of simple keratinized epithelium and
none keratinized of goblet cells and craft of liberkhum.
7. Observation 7 : To observated of mucosa and serosa glands at
papilasicumvalata and pancreas.
8. Observation 8 : To observated of adrenal glands (endocrine glands) at
adrenal cortex and adrenal medulla.
9. Observation 9 : To observated sweat glands and sebaceous glands.
C. Benefit
A. We could to observated of structure and each kind the epithelium tissues.
B. We could to explain the part of compound simple squamous epithelium
tissues, cuboidal, cylindrical, and pseudo stratified epithelium and the
function of this part.
C. We could to observated of structure and each kind the epithelium tissues.
D. We could to explain the part of compound stratified squamous non
keratinized and keratinized epithelium, mucosa and serosa glands, adrenal
cortex and adrenal medulla, sweet and sebaceous glands.
CHAPTER IIREVIEW OF LITERATURE
Epithelium tissue is covering the surface of the body, lines the body cavities,
forms the external and internal linings of most organs, and constitutes the bulks most
glands. Basically the surface and function, epithelium tissues dividing into two
groups, closely and glands epithelium. Closely epithelium is a tissue that compound
cells in the layers like membrane and to closely outer membrane or to lining the body
cavity. Epithelium glands, is a tissue that formed by cells specialized to resulting of
liquid secrete that different composition and liquid of intra cells. Epithelium as
commonly lining of cavities in the body or shut of surface of the body, this called
shut epithelium. Epithelium shut found in the several glands, called glands
epithelium. There are kind of epithelium are simple squamous epithelium, simple
cuboidal epithelium, simple columnar epithelium, pseudo stratified epithelium and
stratified squamous epithelium ( Adnan,2008 )
Epithelial tissues are widespread throughout the body. They form the covering of
all body surfaces, line body cavities and hollow organs, and are the major tissue in
glands. They perform a variety of functions that include protection, secretion,
absorption, excretion, filtration, diffusion, and sensory reception. The cells in
epithelial tissue are tightly packed together with very little intercellular matrix.
Because the tissues form coverings and linings, the cells have one free surface that is
not in contact with other cells. Opposite the free surface, the cells are attached to
underlying connective tissue by a non-cellular basement membrane. This membrane
is a mixture of carbohydrates and proteins secreted by the epithelial and connective
tissue cells. Epithelial cells may be squamous, cuboidal, or columnar in shape and
may be arranged in single or multiple layers. Epithelial tissue covers the whole
surface of the body. It is made up of cells closely packed and ranged in one or more
layers. This tissue is specialized to form the covering or lining of all internal and
external body surfaces. Epithelial tissue that occurs on surfaces on the interior of the
body is known as endothelium. Epithelial cells are packed tightly together, with
almost no intercellular spaces and only a small amount of intercellular substance.
Epithelial tissue, regardless of the type, is usually separated from the underlying
tissue by a thin sheet of connective tissue; basement membrane. The basement
membrane provides structural support for the epithelium and also binds it to
neighbouring structures ( Anonym,2009 )
According to Bavelender ( 1989 ), epithelium tissues have general characteristic,
like :
1. These cells have regular shaped and haven’t of many protoplasm process which
large. The epithelium layer much attach one the other and keep in this position by
the special part from the surface of sells which general we known as junction
complex
2. Between the cells have little sheet structural (material extracellular or matrix).
The matrix which has consisted of basic material which compound from
mukopolisakarida acid (glikosaminoglikan) like hyalorunat acid and condroiting
sulfate. Calcium which binds at the matrix has important function in the cells
adhesion
3. Epithelium tissue is haven’t supply nutrition through diffusion from capillary
layer which have in under that.
4. Epithelium tissues bind at the connective tissue which place in under that by thin
membrane which is called lamina basal or basic membrane.
5. At the epithelium can be observed mitosis, and if have they is a code about there
is have renovated cells. Prediction about the strength complete renovated for the
membrane epithelium cells have variation and each day for mucosa intestine until
weeks to each part from membrane of respiration duct.
Simple cuboidal epithelium, called it because a trans-piece toward of surface.
Each cells like as cube. Seem from the surface, the cells certain shaped of polygonal.
This epithelium found in the glands, are the part of the secretary or ducts of gland,
such as this epithelium found attached in the surface of ovary. (Lesson, 1992)
Epithelium tissues it has in layer of cells which firm packed, these tissues kept
the out of part body and pile up the organ and cavity in the body. Epithelium cells
combined with formed, with little material between the cells. At the many
epitheliums the cells become to one by function or tight function. The packed is tight
epithelium has function as obstacle which kept the cells from mechanical break,
attached the organism is entered and lose of liquid. Free surfaces at the epithelium
tissues spread to the air liquid, meanwhile the cells have in basic part of the obstacle
is attached the one basal membrane. (Campbell, 2004)
Goblet cells are the cells secrete of mucus and place in glands lining and the
canal layered of columnar cells. Cilia from columnar cells function to movement of
mucus mixture waste products outer direction. The characteristic of cell goblet is
haven’t nucleus. (Evelyn, 1979)
Mucosa glands have function to protect epithelium thing surface that connected
with outer world. Epithelium cells Serosa glands has middle nucleus and at free polar
to unite particles secretes that result by upper serosa glands called zemago particles.
Parotics glands and exocrine part upper of pancreas glands has characteristic purely
serous. (Dellman & Brown, 1988)
Generally , exocrine gland is build buy two types of epithelial, that is secretor
parts, that is group of cells which specially result, and duct part , that group of cells
which form is tubule duct, which result secret to out. According to form of part
secretor of the ecsocrin gland, can be different between monotype gland, which
consist of one layers cells (example sweat gland) and polytypic gland, which consist
of each layer cells. (Subowo, 2002)
CHAPTER IIILAB WORK METHODE
A. Time and Place
Day/Date : Thursday, March 26th, 2009
Time : At 02.00 – 04.00 pm
Place : In Eastern Biology Laboratory of FMIPA of Universitas Negeri
Makassar (UNM)
B. Tool and Materials
1. Tool
a. Microscope
2. Materials
a. Mammal kidney
b. Papilla sirkumvalata
c. Intestine/duodenum
d. Pancreas
e. Trachea of rabbit
f. Adrenal gland
g. Human skin
C. Work Procedures
In this lab work, we did nine observations which the procedures were:
1. Observation I
a. Prepared a mammal kidney object glass.
b. Observed carefully endothelium from vessel. Watched the nucleus of
epithelial cell that was thin and long, contained with endothelium cells and
basal membrane.
c. Observed carefully parietal layer of Bowman’s capsule. Watched the
nucleus from epithelial that had flat and long shape and then basal
membrane.
2. Observation II
a. Prepared a mammal kidney object glass.
b. Observed carefully tubule contortus proximal of kidney, which consisted
of lumen, cube epithelium cells and basal membrane. This structure was
beginning segment from neuron and crooky and bordered by simple
cuboidal epithelium.
c. Observed carefully tubule contortus distal of kidney, which consisted of
lumen, flat epithelial cells and basal membrane. This structure has thinner
epithelial cells than tubule contortus proximal.
3. Observation III
a. Prepared an intestine object glass.
b. Observed carefully the atwarthy slice of intestine, especially in borderer
epithelial layer at mucous layer.
c. Drew cylindered epithelial with 10 x 40 zoom in.
4. Observation IV
a. Prepared a rabbit trachea object glass.
b. Observed carefully the epithelial tissue that bordering lumen. Watched
basal cell position, ciliated cylinder epithelial, goblet cell and basal
membrane.
c. Drew the observation result.
5. Observation V
a. Prepared a human skin object glass and papilla sirkumvalata at tongue.
b. Observed carefully the epithelial tissue at skin epidermis. Watched
stratum germinativum, stratum spinosum, stratum granulosum, stratum
hisidum, stratum corneum and basal membrane positions.
c. Observed carefully the epithelial tissue at tongue papilla sirkumvalata
epidermis zone. Watched the stratum germinativum, stratum spinosum,
stratum granulosum, stratum lusidium, stratum corneum and basal
membrane positions.
6. Observation VI
a. Prepared an intestine object glass.
b. Observed carefully goblet cell position between intestine epithelial cells
and argentafin cell.
c. Observed carefully crypt of lieberkuhn position between intestine viles at
mucosa area.
7. Observation VII
a. Prepared a papilla sircumvalata and pancreas object glasses.
b. Observed carefully papilla sircumvalata, watched lamina propria area and
serosa gland position.
c. Observed carefully serosa and nucleus of sentra-asiner. And also observed
one of Langerhans island.
8. Observation VIII
a. Prepared an adrenal gland object glass.
b. Observed carefully cortex area. Watched glomerulose, vasikulata, and
reticule zones. Those zones were obvious separated.
c. Observed carefully medulla area. Watched epithelia cells which were
chromaffin cell that compose and forming dense fish-net.
9. Observation IX
a. Prepared a human skin object glass.
b. Observed carefully sweat gland. Watched sekretory segment from its duct
segment.
c. Observed carefully sebaceous gland around hair folikelle
Notes:Basal membraneSimple Squamous epitheliumNucleusLumen / Cavity
Notes :NucleusLumenSimple cuboidal epitheliumBasal Membrane
CHAPTER IVOBSERVATION RESULT AND DISCUSSION
A. Observation Result
Mammal Kidney (Endothelium blood vessel in kidney)
Mammal Kidney (Cuboidal epithelium at the tubulus kontortus proximal)
Mammal kidney (Cuboidal epithelium tubulus kontortus distal)
Notes :Simple Squamous epitheliumBasal MembraneNucleusLumen
Notes :VIliLumen
Notes :Basal MembraneNucleusSimple cylindrical epitheliumLumen
Intestine (Intestine diagonal section)
Intestine (Cylindrical epithelium)
Notes :CiliaGoblet cellsNucleusSimple columnar epithelium
Notes:Stratum corneumStratum lusidiumStratum granulosumStratum SpinosumStratum germinativumBasal membrane
Trachea of rabbit (Pseudostratified epithelium)
Stratified squamous keratinized epithelium
Notes :Stratum lusidiumStratum granulosumStratum spinosumStratum germinativumBasal membrane
Notes :Argentfin cellsGoblet cellsMembrane cellsColumnar epithelium cells
Stratified squamous non keratinized epithelium
Goblet cells
Notes :Epithelium columnar cellsCrypt of Liberkhum
Notes :Epithelium tissuesOlfactory hulkLamina propiaConnective tissueSerosa glandMucosa gland
Crypt of liberkhum
Papilla sirkumvalata
Notes :Achini serosaCells βCells αLangerhans island
Pancreas
Adrenal cortex
Notes :CortexMedullaGlomerolous zoneVasikulata zoneRetikularis zone
Notes :Kromafin
Notes :Secretory segmentCanal segment
Adrenal medulla
Sweat glands
Notes :EpidermisFollicleSebaceous glands
Sebaceous glands
B. Discussion
1. Observation I
At the observation I, we observated the simple squamous epithelium
mammal kidney, that is endothelium blood vessel and parietal capsule
Bowman’s. Epithelium tissues compound of endothelium blood vessel consist
of basal membrane, simple squamous epithelium, nucleus, and lumen or
cavity. Basal membrane or basal lamina is the connective tissues that place in
under epithelium tissues. The other as place of attached epithelium cells, basal
membrane has function as blocked to prevent microorganism in the part of the
body, to prevent the lose of the water and cell liquid from the body, worked as
selective filter, and to stand form of epithelium tissues in above. These
membranes contain many kinds of macromolecule like laminas, fibronektin,
and entaktin. A simple squamous epithelium cell, if we look from inside like
string is separated with nucleus place in the center. In this observated type
epithelium cells, we will observated simple squamous epithelium origin from
endoderm. Simple squamous epithelium consist of flat and thin cells in the
Ferrier not regulation, each other to close up formed a layer which complete.
At the horizontal of cell cytoplasm like thin, widened in the nucleus place.
Nucleus from the each cell is circular and concentric place. Parietal capsule
bowman layer generally has structure of tissue at similar, but has oval shaped
or formed like capsule. The cytoplasm nearly saw but we could saw in the
nucleus area, where the cytoplasm seems to blow up.
2. Observation II
At the observation II, we observated simple cuboidal epithelium at the
tubules kontortus proximal and tubules kontortus distal. Between both haven’t
to different structure tissue of contras, that only the tubules kontortus distal
cuboidal epithelium cells smaller than tubules kontortus proximal. We called
simple cuboidal epithelium because the cut Trans section with it surface, each
cells like cornered with circular nucleus in each cell central. Cornered shape
change is trapezium if the cells be group in the lumen around small layer.
These cells cytoplasm is clear particle, and in the last limited cells commonly
not clear in notched material.
3. Observation III
At the observation III, we observated simple columnar epithelium place
the duodenum. At the enlargement 10 × 10, seem diagonal from intestine. At
the lumen seem intestine lining and we found vili, this endothelium
modifications enlargement absorption area. Found connective tissue, these
tissues has functioned as to support of epithelium tissues. Another, connective
tissue enters in the cells area. After that enlargement 10 × 40 and the part of
the vili seem simple columnar epithelium with it part. At the surface like
cuboids epithelium and inside like columns to close up vertical section with
nucleus oval shaped, proximal place toward basal membrane. Membrane
basal lower found basal lamina.
4. Observation IV
At the observation IV, we observated pseudostratified epithelium trachea
of rabbit. This epithelium called pseudostratified because have diagonal trans
section, like pseudostratified. This caused the place nucleus raised nit
strength. This epithelium is build by three types of cells, that is basl cells,
cylindrical cells, and goblet cell basal shaped cuboidal with round nucleus and
higher is lower. Cylindrical cilia at the trachea help to prevent the lung is
cleaned it way to snare the dust and other particle and sweat them back above
trachea. Goblet cell or mucus cells secretion the solution which called mucus,
to smooth or to smear the surface of duct and kept it damp like generally the
epithelium tissue, stratified epithelium so support in basal membrane.
5. Observation V
At the observation V, we observated human brown skin found simple
epithelium keratinized and none keratinized. At the simple squamous
epithelium keratinized consist of layers are:
a. Stratum Korneum, consist of squamous cell non keratinized without
nucleus and the cytoplasm contain keratin.
b. Stratum lusidium, found at the layers skin of thickened, consist of
epithelium cell with nucleus that to blocked influence degeneration
process.
c. Stratum spinosum, consist of cells polygon cuboidal have nucleus in the
middle cells. The cytoplasm has stuck out filled filament fibroses and the
formed like spine.
d. Stratum Granulosum, consists of 3 – 5 layers polygonal cells, nucleus
place in the middle with cytoplasm contain granule keratin hyaline
(protein rich histidin).
e. Stratum germinativum, basal shape columnar or cuboidal place in the
basal membrane, this layers checked with high meiosis activity.
Simple epithelium non keratinized squamous, the compound consists
of stratum lusidium, stratum spinosum, stratum granulosun, stratum
gernativum, with basal membrane as jumping board. This compound same
with squamous epithelium keratinized but squamous epithelium none
keratinized not found stratum corneum.
6. Observation VI
At the observation VI, we observated duodenum intestine and we found:
a. Goblet cell but not clear, this cells place between intestines, haven’t
nucleus and found secrete granule. In near of goblet cell found
Argentafalin cells but not clear.
b. Crypt of liberkhum gland has one canal branching with the compound as
tubular, until called simple glands.
7. Observation VII
a. To observation mucosa and serosa gland. At this observation that
observed is Papilla sirkumvalata. At preparation look some parts from this
Papilla like, serosa gland and mucosa gland. Mucosa gland shaped round
and around by cuboidal epithelium and can production secret that thick
that consist of glycoprotein that often called mucus. Serosa gland shaped
oval round that around by cuboidal epithelium, this gland is gland that
production secret like liquid that usually shaped enzyme is called serous.
b. Pancreas, we found Langerhans Island, erfariasi shape, generally oval
shape Lagerhans Island out look as small thing with colournes red color.
In the alpha cell compound of different cell are alpha cells found in the
border of Langerhans Island out look as small thing with colournes red
color. In the alpha cells found solid granules formed of ball with lobus
nucleus and result of glakogen, beta cells found in the middle Langerhans
Island that responsibility as insulin secretion, this cell containing polygon
crystal and achini serosa, the structure in the part of basal cell containing
large reticular endoplasm system function to result secrete like enzyme.
8. Observation VIII
Adrenal gland is the small structure that located upper each kidney. Gland
rich prepare blood. In outside adrenal gland is adrenal cortex and inside is
adrenal medulla. Adrenal cortex is example from endocrine gland at cortex
area that observation looks three zones is:
a. Glomerolous zone, cell type more small from other cell and more close
together, the composition cell shaped radian.
b. Vasikulata zone, is layer under glomerolous zone that composition cell
have shaped more large, very elongated and the pale nucleus.
c. Reticules zone, the cell type more small than vasikula zone and found
many space company cell.
9. Observation IX
a. Sweat gland consists of :
1. Segment secretor, place in outermost cell group, function resulting of
secretes.
2. Canal segment, layer by double lining from cuboidal cells to step on.
b. Sebaceous glands interlocked with hair follicle. The cells cuboidal shape
and the central formed cells polygonal.
CHAPTER VCONCLUSION AND SUGGESTION
A. Conclusion
After doing observation, we could take conclusion about that:
1. Simple squamous epithelium consists of one layer cell shaped flat. The
nucleus shaped disk, if we look from the upper shaped not regulation and
compound cells stand of basal membrane.
2. Simple cuboidal epithelium consists of cells shaped cube same wide and
strength, inside tray shaped cube, but from upper look shaped hexagonal, and
have circular nucleus.
3. Simple columnar epithelium consists of liner cells shaped cylinder and stand
up at basal membrane, oval nucleus and place like basal. Like pillars to close
up trans section
4. Pseudostratified epithelium found cilia, goblet cells, pseudostratified
epithelium, basal cells or membrane basal.
5. Stratified squamous keratinized epithelium found in the surface like mouth,
esophagus, epiglottis, and vagina. Stratified squamous non keratinized
epithelium found in dry surface like skin.
6. Unicellular gland consists one layer like goblet cell at intestine, while
multicellular consists of many layers.
7. At Papilla sirkumvalata found mucosa and serous gland and in pancreas
appear langerhans island that around of more one beta cell ( cell that have
only one nucleus in located in the centre ) and alpha cells located in the
peripheral.
8. At adrenal cortex, found three layers like glomerolous zone, fasikularis and
reticularis zone.
9. Sweat glands shaped oval not pocked at hair follicle, while sebaceous land is
pocked gland that shaped like resemble bottle and centre at hair follicle.
B. Suggestion
1. We hoped preparation tools like peparat multipicated, so that practicum can
be clear
2. We hoped all practicant studied practicum matter before doing observation.
BIBLIOGRAPHY
Adnan.2008. Struktur Hewan.Makassar: Biology Department FMIPA UNM
Anonym.2008. Epithelium Tissues. (http://id.wikipedia.org/wiki/Epithelium-Tissue).
Accessed date March 28th 2009
Bavelender G. and Rameley, M.Judith.1989.Dasar-dasar Histology. (Ahli Bahasa:
Wisnu Gunarso).Jakarta: Erlangga
Campbell, A Neil, Reece, B Jane, Mitchell.2004.Biologi.Jakarta: Erlangga
Delman and Brown.1988.Histologi veterier I.Universitas Indonesia Press. Jakarta.
Leeson, S. Thomas, Paparo, A Anthony.1992.Buku Ajar Histologi. (Ahli Bahasa:
Koesparti Siswojo).Jakarta: Penerbit Buku Kedokteran EGC.
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Subowo, 2002.Histologi umum.Jakarta; Bumi Aksara
Epithelial Tissues
Structure| Sqaumous Epithelium| Cubiodal Epithelium| Columnar Epithelium| Stratified Epithelium| Functions of Epithelium|
Structure
Epithelial tissue covers the whole surface of the body. It is made up of cells closely packed and ranged in one or more layers. This tissue is specialised to form the covering or lining of all internal and external body surfaces. Epithelial tissue that occurs on surfaces on the interior of the body is known as endothelium. Epithelial cells are packed tightly together, with almost no intercellular spaces and only a small amount of intercellular substance. Epithelial tissue, regardless of the type, is usually separated from the underlying tissue by a thin sheet of connective tissue; basement membrane. The basement membrane provides structural support for the epithelium and also binds it to neighbouring structures.
Types of Epithelial Tissue
Epithelial tissue can be divided into two groups depending on the number of layers of which it is composes. Epithelial tissue which is only one cell thick is known as simple epithelium. If it is two or more cells thick such as the skin, it is known as stratified epitheliu
Simple epithelium
Simple epithelium can be subdivided according to the shape and function of its cells.
Squamous (pavement) epithelium.
Squamous cells have the appearance of thin, flat plates. The shape of the nucleus usually corresponds to the cell form and help to identify the type of epithelium. Squamous cells, for example, tend to have horizontall flattened, elliptical nuclei because of the thin flattened form of the cell. They form the lining of cavities such as the mouth, blood vessels, heart and lungs and make up the outer layers of the skin.
Simple sqaumous epithelium
Simple Cuboidal Epithelium.
As their name implies, cuboidal cells are roughly square or cuboidal in shape. Each cell has a spherical nucleus in the centre. Cuboidal epithelium is found in glands and in the lining of the kidney tubules as well as in the ducts of the glands. They also constitute the germinal epithelium which produces the egg cells in the female ovary and the sperm cells in the male testes.
Simple cuboidal epithelium
Simple Columnar Epithelium
Columnar epithelial cells occur in one or more layers. The cells are elongated and column-shaped. The nuclei are elongated and are usually located near the base of the cells. Columnar epithelium forms the lining of the stomach and intestines. Some columnar cells are specialised for sensory reception such as in the nose, ears and the taste buds of the tongue. Goblet cells (unicellular glands) are found between the columnar epithelial cells of the duodenum. They secrete mucus or slime, a lubricating substance which keeps the surface smooth.
Simple columnar epithelium
Ciliated Columnar Epithelium
These are simple columnar epithelial cells, but in addition, they posses fine hair-like outgrowths, cilia on their free surfaces. These cilia are capable of rapid, rhythmic, wavelike beatings in a certain direction. This movement of the cilia in a certain direction causes the mucus, which is secreted by the goblet cells, to move (flow or stream) in that direction. Ciliated epithelium is usually found in the air passages like the nose. It is also found in the uterus and Fallopian tubes of females. The movement of the cilia propel the ovum to the uterus.
Ciliated columnar epithelium
Glandular Epithelium
Columnar epithelium with goblet cells is called glandular epithelium. Some parts of the glandular epithelium consist of such a large number of goblet cells that there are only a few normal epithelial cells left. Columnar and cuboidal epithelial cells often become specialised as gland cells which are capable of synthesising and secreting certain substances such as enzymes, hormones, milk, mucus, sweat, wax and saliva. Unicellular glands consist of single, isolated glandular cells such as the goblet cells. Sometimes a portion
of the epithelial tissue becomes invaginated and a multicellular gland is formed. Multicellular glands are composed of clusters of cells. Most glands are multicellular including the the salivary glands.
Glandular epithelium
Stratified Epithelium.
Where body linings have to withstand wear and tear, the epithelia are composed of several layers of cells and are then called compound or stratified epithelium. The top cells are flat and scaly and it may or may not be keratinised (i.e. containing a tough, resistant protein called keratin). The mammalian skin is an example of dry, keratinised, stratified epithelium. The lining of the mouth cavity is an example of an unkeratinisied, stratified epithelium.
Stratified epithelium
Functions of Epithelial Tissue
Protection
Epithelial cells from the skin protect underlying tissue from mechanical injury, harmful chemicals, invading bacteria and from excessive loss of water.
Sensation
Sensory stimuli penetrate specialised epithelial cells. Specialised epithelial tissue containing sensory nerve endings is found in the skin, eyes, ears, nose and on the tongue.
Secretion
In glands, epithelial tissue is specialised to secrete specific chemical substances such as enzymes, hormones and lubricating fluids.
Absorption
Certain epithelial cells lining the small intestine absorb nutrients from the digestion of food.
Excretion
Epithelial tissues in the kidney excrete waste products from the body and reabsorb needed materials from the urine. Sweat is also excreted from the body by epithelial cells in the sweat glands.
Diffusion
Simple epithelium promotes the diffusion of gases, liquids and nutrients. Because they form such a thin lining, they are ideal for the diffusion of gases (eg. walls of capillaries and lungs).
Cleaning
Ciliated epithelium assists in removing dust particles and foreign bodies which have entered the air passages.
Reduces Friction
The smooth, tightly-interlocking, epithelial cells that line the entire circulatory system reduce friction between the blood and the walls of the blood vessels.
| epithelial tissue | connective tissue | muscle tissue | nervous tissue |
Epithelial tissues are widespread throughout the body. They form the covering of all body surfaces, line body cavities and hollow organs, and are the major tissue in glands. They perform a variety of functions that include protection, secretion, absorption, excretion, filtration, diffusion, and sensory reception.
The cells in epithelial tissue are tightly packed together with very little intercellular matrix. Because the tissues form coverings and linings, the cells have one free surface that is not in contact with other cells. Opposite the free surface, the cells are attached to underlying connective tissue by a non-cellular basement membrane. This membrane is a mixture of carbohydrates and proteins secreted by the epithelial and connective tissue cells.
Epithelial cells may be squamous, cuboidal, or columnar in shape and may be arranged in single or multiple layers.
Simple cuboidal epithelium is found in glandular tissue and in the kidney tubules. Simple columnar epithelium lines the stomach and intestines. Pseudostratified columnar epithelium lines portions of the respiratory tract and some of the tubes of the male reproductive tract. Transitional epithelium can be distended or stretched. Glandular epithelium is specialized to produce and secrete substances.