RATIFICATION PAGE
Complete report of Animal Structure experiment with title ³Epithelial Tissue´ which written by:
Name
: Sureni Hikmawati s
ID
: 081404176
Group
: VI
Class
: D (Biology ICP)
After checked by assistant and coordinator coo rdinator assistant, this report accepted.
Makassar, Coordinator Assistant Assistant
Assistant
(Djumarirmanto, S.Pd)
(Dian Anggreini) ID: 061404056
CHAPTER I INTRODUCTION
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 o rder that, the epithelium tissue is the constrictor t issue issue 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 t he 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 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 ce lls 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 o f structure and each kind the t he 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 o f structure and each kind the t he 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 II REVIEW 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 stratified squamous epithelium ep ithelium ( 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 o r 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 III LAB WORK METHODE
A. Time and Place th
Day/Date
: Thursday, March 26 , 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 ob ject glass. b. Observed carefully endothelium from vessel. Watched the nucleus of epithelial cell that was thin and long, contained with endothelium endot helium 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 ob ject 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 t ubule 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 posi po sition. tion. 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 o bject glass. b. Observed carefully cortex area. Watched glomerulose, vasikulata, and reticule zones. Those zones were o bvious separated. c. Observed carefully medulla area. Watched epithelia cells which were chromaffin cell that compose and forming for ming 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 ha ir folikelle
CHAPTER IV OBSERVATION RESULT AND DISCUSSION
A. Observation R esu esult Mammal Kidney (Endothelium blood vessel in kidney)
Notes:
1. Basal membrane 2. Simple Squamous epithelium 3. Nucleus 4. Lumen / Cavity
Mammal Kidney (Cuboidal epithelium at the t he tubulus kontortus proximal)
Notes :
1. Nucleus 2. Lumen 3. Simple cuboidal epithelium 4. Basal Membrane
Mammal kidney (Cuboidal epithelium tubulus ko ntortus distal)
Notes :
1. Simple Squamous epithelium 2. Basal Membrane 3. Nucleus 4. Lumen
Intestine (Intestine diagonal section)
Notes :
1. VIli 2. Lumen
Intestine (Cylindrical epithelium)
Notes :
1. Basal Membrane 2. Nucleus 3. Simple cylindrical epithelium 4. Lumen
Trachea of rabbit (Pseudostratified (P seudostratified epithelium)
Notes :
1. Cilia 2. Goblet cells 3. Nucleus 4. Simple columnar epithelium
Stratified squamous keratinized epithelium
Notes:
1. Stratum corneum 2. Stratum lusidium 3. Stratum granulosum 4. Stratum Spinosum 5. Stratum germinativum 6. Basal membrane
Stratified squamous non keratinized epithelium
Notes :
1. Stratum lusidium 2. Stratum granulosum 3. Stratum spinosum 4. Stratum germinativum 5. Basal membrane
Goblet cells
Notes :
1. Argentfin cells 2. Goblet cells 3. Membrane cells 4. Columnar epithelium cells
Crypt of liberkhum
Notes :
1. Epithelium columnar cells 2. Crypt of Liberkhum
Papilla sirkumvalata
Notes :
1. Epithelium tissues 2. Olfactory hulk 3. Lamina propia 4. Connective tissue 5. Serosa gland 6. Mucosa gland
Pancreas
Notes :
1. Achini serosa 2. Cells 3. Cells 4. Langerhans island
Adrenal cortex
Notes :
1. Cortex 2. Medulla 3. Glomerolous zone 4. Vasikulata zone 5. Retikularis zone
Adrenal medulla
Notes :
1. Kromafin
Sweat glands
Notes :
1. Secretory segment 2. Canal segment
Sebaceous glands
Notes :
1. Epidermis 2. Follicle 3. 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. 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 co ntain 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 w ith 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 duo denum 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 e nzyme 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 t hree zones is: a. Glomerolous zone, cell type more small from other cell and more close together, the composition cell shaped rad ian. 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 do uble lining from cuboidal cells to step on. o n. b. Sebaceous glands interlocked with hair follicle. The cells cuboidal shape and the central formed cells po lygonal.
CHAPTER V CONCLUSION 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 a ll practicant studied practicum matter before doing observation.
BIBLIOGRAPHY
Adnan.2008. Struktur Hewan.Makassar: Hewan.Makassar: Biology Department FMIPA UNM Anonym.2008. Epithelium Tissues. (http://id.wikipedia.org/wiki/Epithelium-Tissue (http://id.wikipedia.org/wiki/Epithelium-Tissue). ). th
Accessed date March 28 2009 Bavelender G. and Rameley, M.Judith.1989.Dasar-dasar M.Judith.1989.Dasar-dasar Histology. 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. Pearce, Evelyn C.1979.Anatomi Dan Fisiologi untuk paramedic. Pt.Gramedia.Jakarta Subowo, 2002.Histologi umum.Jakarta; Bumi Aksara
Epithelial Tissues Structure|| Sqaumous Epithelium| Structure Epithelium| Cubiodal Epithelium| Epithelium| Columnar Epithelium| Epithelium| Stratified Epithelium| Epithelium | Functions of Epithelium| Epithelium |
Structure the body. It is made up of cells closely Epithelial tissue covers the whole surface of 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. Epitheli Ep ithelial al tissue that occurs on surfaces on the interior interior of the bod y is known as endothelium. Epithelial cells are packed tightly together, to gether, with almost no intercellular spaces and only a small amount of interce llular substance. Epithelial tissue, regardless of the type, is usually separated from the underlying tissue by a thin sheet of connective tiss t issue; ue; basement membrane. The basement membrane provides structura l 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. y
Squamous (pavement) epithelium.
Squamous cells have the appearance of lat plates. The shape of the thin, f nucleus usually corresponds to the cell form and help to identify the type of lattened, epithelium. Squamous cells, ce lls, for example, tend to have horizonta ll f 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 o uter layers of the skin.
Simple sqaumous epithelium
y
Simple Cuboidal Epithelium.
As their name implies, cuboidal cells are roughly ro ughly 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 co nstitute the germina l epithelium which produces the egg cells in the female ovary and the sperm cells in the male testes.
Simple cuboidal epithelium y
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 o off 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 y
Ciliated Columnar Epithelium
These are simple columnar epithelial cells, but in add ition, ition, they posses po sses fine hair-like outgro wths, cilia on their free surfaces. These cilia are capable o f rapid, rhythmic, wavelike beatings in a certain direction. This movement of the cilia in a certain direction causes the t he 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 y
Glandular Epithelium
Columnar epithelium with goblet cells is called glandular epithelium. Some goblet parts of the glandular epithelium consist of such a large number of o nly a few normal epithelial cells left. Columnar and cells that there are only cuboidal epithelial cells often become beco me specia lised as gland cells which are
synthesising and secreting certain substances such as enzymes, capable of hormones, milk, mucus, sweat, wax and saliva. Unicellular glands consist of single, isolated glandular cells such as the t he goblet cells. Sometimes a portion of the epithelial tissue becomes invaginated and a multice llular gland is clusters of cells. Most glands formed. Multicellular glands are composed of are multicellular including the the salivary glands.
Glandular epithelium y
Stratified Epithelium.
Where body linings have to withstand wear and tear, the epithelia are composed of severa l layers of cells and are then called compound or lat and scaly and it may or may not stratified epithelium. The top cells are f 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
y
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 . y
Sensation
Sensory stimuli penetrate specialised epithelial cells. cells. Specialised epithelial tissue containing sensory nerve endings is found in the skin, eyes, ears, nose no se and on the tongue. y
Secretion
In glands, epithelial tissue is specialised to secrete specific chemical substances such as enzymes, hormones hor mones and lubricating fluids. y
Absorption
Certain epithelial cells lining the t he small intestine absorb nutrients from the digestion of food . y
Excretion
Epithelial tissues in the kidney excrete waste products from the body and reabsorb needed materials from the urine. urine. Sweat is also excreted from the body by epithelial cells in the sweat glands. y
Diffusion
Simple epithelium promotes the diffusion of gases, liquids and nutrients. nutrients. Because they form such a thin lining, they are ideal for the d iffusion iffusion of o f gases (eg. walls of capillaries and lungs). y
Cleaning
particles and foreign bodies Ciliated epithelium assists in removing dust which have entered the t he air passages.
y
Reduces Friction
The smooth, tightly-interlocking, epithelial cells that line the ent ire circulatory system reduce friction between the blood and the walls of the blood vessels. vessels. | epithelial tissue | connective tissue | muscle tissue | nervous tissue |
Epithelial tissues are widespread throughout the bod y. They form the covering of all body surfaces, line body bod y cavities and hollow organs, and are the major tissue in glands. They perform a variety variet y 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 ce lls have one free surface that t hat is not in contact with other ot her 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 co nnective tissue cells. Epithelial cells may be squamous, cuboidal, or columnar in shape and may be arranged in single or multiple multiple layers.
Simple cuboidal epithelium is found in glandular tissue and in the kidney k idney tubules. Simple columnar epithelium lines the stomach and intestines. intestines. Pseudostratified columnar epithelium lines portions of the respiratory tract and some of the tubes of o f the male reproductive tract. Transitional epithelium can be distended or stretched. Glandular epithelium is spec ialized to produce and secrete substances.
