• Epitel ?Epitel ?

• AvaskularAvaskular

• Terletak pada membrana Terletak pada membrana basalisbasalis

• Menutupi permukaan tubuh Menutupi permukaan tubuh

• FungsiFungsi : : 1. 1. ProteksiProteksi (pd kulit) (pd kulit) 2. 2. AbsorpsiAbsorpsi (pd usus) (pd usus) 3. 3. SekresiSekresi (pd kelenjar) (pd kelenjar) 4. 4. EkskresiEkskresi (pd kelj. keringat) (pd kelj. keringat) 5. 5. Sensoris Sensoris (neuroepitel)(neuroepitel) 6. 6. KontraktilKontraktil (mioepitel) (mioepitel) 7. 7. ReproduksiReproduksi (pd ovarium dan (pd ovarium dan

tub.seminiferi) tub.seminiferi)

• Pembagian EpitelPembagian Epitel : :

1. Epitel Penutup (1. Epitel Penutup (Covering EpiteliumCovering Epitelium))

2. Epitel Kelenjar (2. Epitel Kelenjar (Glandular EpiteliumGlandular Epitelium))

EPITEL PENUTUPEPITEL PENUTUP• Menurut bentuk dibagiMenurut bentuk dibagi::

- pipih = - pipih = squamoussquamous

p & l > t, inti pipihp & l > t, inti pipih

- kubis = - kubis = cuboidalcuboidal

p = l = t, inti bulatp = l = t, inti bulat

- silindris = - silindris = columnarcolumnar

p & l < t, inti lonjongp & l < t, inti lonjong

• Menurut susunan sel dibagiMenurut susunan sel dibagi : :

1. selapis = 1. selapis = simplesimple

1 lapisan sel1 lapisan sel

2. berlapis = 2. berlapis = stratifiedstratified

> 1 lapisan sel> 1 lapisan sel

3. berderet = 3. berderet = pseudostratifiedpseudostratified

1 lapisan sel tetapi tinggi sel 1 lapisan sel tetapi tinggi sel tidak tidak

sama shg tampak berlapissama shg tampak berlapis

• Menurut bentuk dan susunannyaMenurut bentuk dan susunannya : : * Epitel selapis :* Epitel selapis : - Ep. selapis pipih- Ep. selapis pipih - Ep. selapis kubis- Ep. selapis kubis - Ep. selapis silindris- Ep. selapis silindris

* Epitel berlapis :* Epitel berlapis : - Ep. berlapis pipih- Ep. berlapis pipih - Ep. berlapis kubis- Ep. berlapis kubis - Ep. berlapis silindris- Ep. berlapis silindris - Ep. Peralihan- Ep. Peralihan

* Epitel berderet :* Epitel berderet : - Ep. berderet silindris- Ep. berderet silindris

Epitel Selapis PipihEpitel Selapis Pipih - tdd 1 lapisan sel-sel pipih- tdd 1 lapisan sel-sel pipih - Misal :- Misal : > parietal layer capsula Bowman > parietal layer capsula Bowman

(ginjal)(ginjal) > sel-sel alveoli paru, dll> sel-sel alveoli paru, dll -Nama khusus :-Nama khusus : > > EndotelEndotel pd jantung & pembl. darah pd jantung & pembl. darah > > MesotelMesotel pd membran pd membran

serosa(pleura,serosa(pleura, pericard & peritoneum)pericard & peritoneum)

Epitel selapis pipihEpitel selapis pipih

endotelendotel

Epitel Selapis KubisEpitel Selapis Kubis

- tdd 1 lapisan sel-sel kubis- tdd 1 lapisan sel-sel kubis

- Misal :- Misal :

> permukaan bebas ovarium> permukaan bebas ovarium

> sebagian dari sel kelenjar, dll> sebagian dari sel kelenjar, dll

Epitel Selapis SilindrisEpitel Selapis Silindris

- tdd 1 lapisan sel-sel silindris- tdd 1 lapisan sel-sel silindris

- - nuclear free zonenuclear free zone (+) (+)

- ada 2 macam :- ada 2 macam :

1. 1. Epitel Selapis SilindrisEpitel Selapis Silindris

- Misal :- Misal :

> sebag. besar traktus > sebag. besar traktus digestivusdigestivus

> permukaan dalam uterus, dll> permukaan dalam uterus, dll

2. Epitel Selapis Silindris Bersilia2. Epitel Selapis Silindris Bersilia - pd permukaan bebas sel terdapat silia- pd permukaan bebas sel terdapat silia

a. Epitel selapis silindris dgn a. Epitel selapis silindris dgn striated striated borderborder tampak suatu garis/ pita tampak suatu garis/ pita tipis (mikrovili)tipis (mikrovili)

pd intestinumpd intestinumb. Epitel selapis silindris dengan b. Epitel selapis silindris dengan kinosiliakinosilia dpt bergerak, ditandai dpt bergerak, ditandai basal granulbasal granul pd pd dasar siliadasar silia pd tuba falopii, sinus paranasalispd tuba falopii, sinus paranasalis

- pd ep. silindris, terdapat beberapa sel- pd ep. silindris, terdapat beberapa sel kelenjar kelenjar disebut disebut sel gobletsel goblet > bentuk: piala> bentuk: piala > letak: tersebar diantara sel ep. > letak: tersebar diantara sel ep.

silindrissilindris

Terminal bar

Epitel selapis silindris dgn striated borderEpitel selapis silindris dgn striated border

Epitel Berlapis PipihEpitel Berlapis Pipih - Bentuk sel : - Bentuk sel : > basal : silindris/kubis> basal : silindris/kubis > tengah : polihedral> tengah : polihedral > permukaan : pipih> permukaan : pipih - Ada 2 macam :- Ada 2 macam : 1. Ep. Berlapis Pipih Tanpa 1. Ep. Berlapis Pipih Tanpa

TandukTanduk > sel-sel permukaan memiliki inti> sel-sel permukaan memiliki inti

- Misal :- Misal : rongga mulut & esofagusrongga mulut & esofagus vagina, dllvagina, dll

2. Epitel Berlapis Pipih Bertanduk2. Epitel Berlapis Pipih Bertanduk

- sel-sel permukaan tdd sel mati - sel-sel permukaan tdd sel mati

(tidak berinti)(tidak berinti)

- Misal : > epidermis kulit- Misal : > epidermis kulit

Epitel Berlapis KubisEpitel Berlapis Kubis

- ep. berlapis, sel permukaannya kubis- ep. berlapis, sel permukaannya kubis

- misal :- misal :

> sal. keluar kelenjar keringat> sal. keluar kelenjar keringat

> folikel de graff (ovarium), dll> folikel de graff (ovarium), dll

Epitel Berlapis SilindrisEpitel Berlapis Silindris

- ep. berlapis, sel permukaannya silindris- ep. berlapis, sel permukaannya silindris

- ada 2 macam:- ada 2 macam:

1.Epitel Berlapis Silindris Tak Bersilia1.Epitel Berlapis Silindris Tak Bersilia

> didapatkan pd tempat peralihan > didapatkan pd tempat peralihan

antara ep. selapis/berderet silindris antara ep. selapis/berderet silindris

dgn ep. berlapis pipih dgn ep. berlapis pipih

> misal : peralihan rektum ke anus> misal : peralihan rektum ke anus

2. Epitel Berlapis Silindris Bersilia2. Epitel Berlapis Silindris Bersilia

- pd permukaan bebas sel terdapat - pd permukaan bebas sel terdapat

siliasilia

- misal :- misal :

> permukaan nasal palatum molle> permukaan nasal palatum molle

> sebagian larynx, dll> sebagian larynx, dll

Epitel PeralihanEpitel Peralihan

- variasi ep. berlapis- variasi ep. berlapis

- pd ddg organ yang mampu teregang - pd ddg organ yang mampu teregang &&

kontraksikontraksi

- tdd 3 macam sel :- tdd 3 macam sel :

> > sel basalsel basal

> > sel raketsel raket

> > sel payungsel payung

- misal :- misal :

> vesika urinaria> vesika urinaria

> ureter, dll> ureter, dll

Epitel BerderetEpitel Berderet - terdapat 3 macam sel :- terdapat 3 macam sel : > > sel basalsel basal > > sel bulat lonjong/fusiformissel bulat lonjong/fusiformis > > sel silindris tinggisel silindris tinggi - - nuclear free zonenuclear free zone (+) (+)

- Ada 2 macam :- Ada 2 macam : 1.Ep. Berderet Silindris Tak 1.Ep. Berderet Silindris Tak

BersiliaBersilia - misal :- misal :

> pars cavernosa uretra pria> pars cavernosa uretra pria > sal. keluar beberapa kelj.> sal. keluar beberapa kelj.

2. 2. Ep. Berderet Silindris BersiliaEp. Berderet Silindris Bersilia a. Epitel berderet silindris dengan a. Epitel berderet silindris dengan

stereosilia stereosilia (non motile)(non motile) pd duktus epididimis dan deferenspd duktus epididimis dan deferens b. Epitel berderet silindris dengan b. Epitel berderet silindris dengan kinosiliakinosilia (motile)(motile) pd cavum nasipd cavum nasi

• Bentuk-bentuk khusus epitelBentuk-bentuk khusus epitel

1. Sel Epitel Berpigmen1. Sel Epitel Berpigmen

- mengandung butir-butir pigmen- mengandung butir-butir pigmen

- pd retina- pd retina

2. Sel Epitel Alat Indera (neuroepitel)2. Sel Epitel Alat Indera (neuroepitel)

- penerima rangsang sensoris- penerima rangsang sensoris

- ep. pengecap- ep. pengecap

- ep. pembau- ep. pembau

- ep. pendengaran- ep. pendengaran

EPITEL KELENJAREPITEL KELENJAR

- Berdasarkan cara menyalurkan sekret :- Berdasarkan cara menyalurkan sekret :

1. 1. EksokrinEksokrin : sekret keluar melalui suatu : sekret keluar melalui suatu

saluransaluran

2. 2. EndokrinEndokrin : sekret langsung ke pem- : sekret langsung ke pem-

buluh darahbuluh darah

• Kelenjar EksokrinKelenjar Eksokrin

- tdd : > - tdd : > secretory unitsecretory unit sintesa sekret sintesa sekret

> > tubular duct.tubular duct. mengeluarkan mengeluarkan

sekret dr secretory unitsekret dr secretory unit

- - Klasifikasi kelj. EksokrinKlasifikasi kelj. Eksokrin

* * Berdasarkan ikut/tidaknya sel kelj.Berdasarkan ikut/tidaknya sel kelj.

mjd sekretmjd sekret : :

1. 1. merokrinmerokrin menghasilkan sekretmenghasilkan sekret

tanpa merubah bentuk seltanpa merubah bentuk sel

misal: kej. ludah, pancreas, dllmisal: kej. ludah, pancreas, dll

2. 2. apokrinapokrin sebag. sel mjd sekret sebag. sel mjd sekret

misal: kelj. keringat, prostat, dllmisal: kelj. keringat, prostat, dll

3. 3. holokrinholokrin seluruh sel mjd seluruh sel mjd sekretsekret

misal: kelj. lemakmisal: kelj. lemak

* * Berdasarkan jumlah selBerdasarkan jumlah sel : :

1. 1. unicellulerunicelluler misal : sel goblet misal : sel goblet

2. 2. multicellulermulticelluler

Kelenjar multicellularKelenjar multicellular, dibagi :, dibagi :

- - Berdasarkan bentuk unit sekresinyaBerdasarkan bentuk unit sekresinya : :

1. 1. tubulartubular spt pipa spt pipa

2. 2. acinaracinar bulat bulat

3. 3. alveolaralveolar spt kantung spt kantung

- - Berdasarkan sifat sal. keluarnyaBerdasarkan sifat sal. keluarnya::

1. 1. simple simple tidak bercabang tidak bercabang

2. 2. compoundcompound bercabang bercabang

- - Berdasarkan jenis sekretnyaBerdasarkan jenis sekretnya : : 1. 1. serousserous sekret jernih dan encer sekret jernih dan encer sitoplasma : sitoplasma : granula zymogengranula zymogen (+) (+) misal: kelj. parotis, pancreas, dllmisal: kelj. parotis, pancreas, dll 2. 2. mucous mucous sekret licin & kental sekret licin & kental sitoplasma : sitoplasma : vacuola mucigenvacuola mucigen (+) (+) misal: kelj. Weber, brunner, dllmisal: kelj. Weber, brunner, dll 3. 3. seromucousseromucous campuran campuran misal:misal: - kelj. sublingualis : serous<mucous- kelj. sublingualis : serous<mucous - kelj. submaxilaris: serous>mucous- kelj. submaxilaris: serous>mucous

• Kelenjar endokrinKelenjar endokrin

- tidak ada saluran keluar- tidak ada saluran keluar

- difusi ke kapiler- difusi ke kapiler

- penyimpanan :- penyimpanan :

1. 1. intracellular storageintracellular storage

2. 2. ekstracellular storageekstracellular storage folikel folikel

- sekret yang dihasilkan disebut : - sekret yang dihasilkan disebut : hormonhormon

• IKATAN ANTAR SEL/CELL JUNCTIONIKATAN ANTAR SEL/CELL JUNCTION

- - Terminal BarTerminal Bar pd celah antar sel dekat pd celah antar sel dekat

permukaan bebaspermukaan bebas

- Pd M.S. tampak berupa titik tebal didekat- Pd M.S. tampak berupa titik tebal didekat

permukaan dr batas 2 sel yang ber-permukaan dr batas 2 sel yang ber-

sebelahan atau berupa hexagonal linesebelahan atau berupa hexagonal line

- Pd M.E. tampak suatu junctional complex,- Pd M.E. tampak suatu junctional complex,

tdd 3 macam junction/bentuk ikatantdd 3 macam junction/bentuk ikatan

- - Berdasarkan bentuk ikatanBerdasarkan bentuk ikatan : :

1. 1. occludent/tight junctionoccludent/tight junction

lapisan luar ddg sel saling lapisan luar ddg sel saling melekatmelekat

2. 2. adherens junction/desmosomeadherens junction/desmosome

cell coat space (+)cell coat space (+)

tonjolan tonofilamen (+)tonjolan tonofilamen (+)

3. 3. gap junctiongap junction

saluran penghubung (+)saluran penghubung (+)

• Struktur permukaan bebas selStruktur permukaan bebas sel

1. 1. mikrovilimikrovili

2. 2. stereosiliastereosilia

tonjolan sitoplasma tdk bergeraktonjolan sitoplasma tdk bergerak

pd saluran kelamin priapd saluran kelamin pria

3. 3. kinosiliakinosilia

silia yang dapat bergeraksilia yang dapat bergerak

pd dasar silia terdapat pd dasar silia terdapat basal basal granulgranul==

kinetosomekinetosome

• REGENERASI SEL EPITELREGENERASI SEL EPITEL

- Epitel - Epitel kena trauma kena trauma mengalami ke- mengalami ke-

rusakan rusakan daya regenerasi oleh sel-sel daya regenerasi oleh sel-sel

dibawahnya secara mitosisdibawahnya secara mitosis

- misal :- misal :

> kulit : dr sel-sel stratum germinativum> kulit : dr sel-sel stratum germinativum

Figure 4—6. Electron micrograph of a small intestine epithelial cell after cryofracture. In the upper portion, the microvilli are fractured transversely; in the lower portion, the fracture crosses through the cytoplasm. In the middle, the membrane was cleaved showing grooves, which actually lie in the lipid layer of the plasmalemma. These grooves form the zonula occludens. x100,000. (Courtesy of P Pinto da Silva.)

Gap junction

Figure 4—7. Gap junction. A: Model of a gap junction in an oblique view. Channels (arrow) are formed by pairs of adjacent connexons, which are in turn composed of six protein subunits that span the lipid bilayer of each cell membrane. The channel measures about 1.5 nm in diameter, limiting the size of the molecules that can pass through it. Nutrients and signal molecules may be transported between cells without loss of material into the intercellular space. (Reproduced, with permission, from Staehelin LA, Hull BE: Junctions between living cells. Sci Am 1978;238:41. Copyright © 1978 by Scientific American, Inc. All rights reserved.) B: Gap junction as seen on a cryofracture preparation. The junction appears as a plaquelike accumulation of intramembrane protein particles. x45,000. (Courtesy of P Pinto da Silva). C: Gap junction (arrow) as seen by transmission electron microscopy of a section of rat liver cells. At the junction, the apposed membranes are separated by a narrow space or gap of about 2 nm. x193,000. (Courtesy of MC Williams.)

Figure 4—8. Apical region of an intestinal epithelial cell seen with transmission electron microscopy. The terminal web is a network that contains mainly actin filaments. Filaments that constitute the core of the microvilli are clearly seen. An extracellular cell coat (glycocalyx) is bound to the plasmalemma of the microvilli. x45,000.

mikrovili

Figure 4—9. Electron micrograph of a section from the apical region of a cell from the intestinal lining showing cross-sectioned microvilli. In their interiors, note the microfilaments in a cross section. The surrounding unit membrane can be clearly discerned and is covered by a layer of glycocalyx, or cell coat. x100,000.

silia

Figure 4—10. Electron micrograph of the apical portion of a ciliated epithelial cell. Cilia are seen in longitudinal section. At the left, arrowheads point to the central and peripheral microtubules of the axoneme. The arrowhead at right indicates the plasma membrane surrounding the cilium. Each cilium has a basal body (B) from which it grows. Microvilli (MV) are shown. x59,000. Inset: Cilia in cross section. The 9 + 2 array of microtubules in each cilium is evident. x80,000. (Reproduced, with permission, from Junqueira LCU, Salles LMM: Ultra-Estrutura e Função Celular. Edgard Blücher, 1975.)

Figure 4—11. Diagrams of simple epithelial tissue. A: Simple squamous epithelium. B: Simple cuboidal epithelium. C: Simple ciliated columnar epithelium. All are separated from the subjacent connective tissue by a basement membrane. In C, note the terminal bars that correspond in light microscopy to the zonula occludens and the zonula adherens of the junctional complex.

Figure 4—14. The simple squamous epithelium that covers the body cavities (the abdominal cavity in this case) is called mesothelium. PT stain. Medium magnification.

Figure 4—21. Formation of glands from covering epithelia. Epithelial cells proliferate and penetrate connective tissue. They may–or may not–maintain contact with the surface. When contact is maintained, exocrine glands are formed; without contact, endocrine glands are formed. The cells of endocrine glands can be arranged in cords or in follicles. The lumens of the follicles accumulate large quantities of secretions; cells of the cords store only small quantities of secretions in their cytoplasm. (Redrawn and reproduced, with permission, from Ham AW: Histology, 6th ed. Lippincott, 1969.)

Figure 4—22. Principal types of exocrine glands. The part of the gland formed by secretory cells is shown in black; the remainder shows the ducts. The compound glands have branching ducts.

Figure 4—23. Section of the secreting portion of a mammary gland; apocrine secretion is characterized by the discharge of the secretion product with part of the cytoplasm (arrows). PSH stain. Medium magnification.

Figure 4—24. Ion and fluid transport can occur in different directions, depending on which tissue is involved. A: The direction of transport is from the lumen to the blood vessel, as in the gallbladder and intestine. This process is called absorption. B: Transport is in the opposite direction, as in the choroid plexus, ciliary body, and sweat gland. This process is called secretion. Note that the presence of occluding junctions is necessary to maintain compartmentalization and consequent control over ion distribution.

Figure 4—25. Diagram of the ultrastructure of a proximal convoluted tubule cell of the kidney. Invaginations of the basal cell membrane outline regions filled with elongated mitochondria. This typical disposition is present in ion-transporting cells. Interdigitations from neighboring cells interlock with those of this cell. Protein being absorbed from the lumen by pinocytosis is digested by lysosomes. Sodium ions diffuse passively through the apical membranes of these cells. These ions are then actively transported out of the cells by Na+/K+-ATPase located in the basolateral membranes of the cells. Energy for this sodium pump is supplied by nearby mitochondria.

Figure 4—26. Serous secretory cells of the pancreas disposed in acini. One acinus is depicted by a broken line. The basophilic basal region of each cell is rich in RNA and the apex contains light-stained secretory vesicles. PT stain. Medium magnification.

Figure 4—27. Diagram of a serous (pancreatic acinar) cell. Note its evident polarity, with abundant rough endoplasmic reticulum in the basal region and the Golgi complex and zymogen granules are in the apical region. To the right is a scale indicating the approximate time necessary for each step of synthesis and secretion.

Figure 4—28. Electron micrograph of a serous (pancreatic acinar) cell. x13,000. (Courtesy of KR Porter.)

Figure 4—30. Section of intestinal villi stained by the PAS technique, a procedure that detects some polysaccharides. Note the positive reaction in the goblet cells and brush border, which consists of microvilli associated with the sugar-rich cell coat. Counterstained with hematoxylin. Medium magnification.

Figure 4—31. Diagram of a mucus-secreting intestinal goblet cell showing a typically constricted base, where the nucleus, mitochondria, and rough endoplasmic reticulum (RER) are located. The protein part of the glycoprotein complex is synthesized in the endoplasmic reticulum. A well-developed Golgi complex is present in the supranuclear region. To the right is a scale indicating the approximate time necessary for each step of synthesis and secretion. (Redrawn after Gordon and reproduced, with permission, from Ham AW: Histology, 6th ed. Lippincott, 1969.)

Figure 4—33. Mucous secretory gland of the esophagus whose cells have a clear cytoplasm and basal dark-stained nuclei. The lumen of the gland is clearly seen (short arrows). The long arrow indicates a secretory duct.

Figure 2—16. The endoplasmic reticulum is an anastomosing network of intercommunicating channels and sacs formed by a continuous membrane. Note that the smooth endoplasmic reticulum (foreground) is devoid of ribosomes, the small dark dots that are present in the rough endoplasmic reticulum (background). The cisternae of the smooth reticulum are tubular, whereas in the rough reticulum they are flat sacs.

Figure 2—18. The transport of proteins across the membrane of the rough endoplasmic reticulum (RER). The ribosomes bind to mRNA, and the signal peptide is initially bound to a signal-recognition particle (SRP). Ribosomes bind to the RER by interacting with the SRP and a ribosomal receptor. The signal peptide is then removed by a signal peptidase (not shown). These interactions cause the opening of a pore through which the protein is extruded into the RER.

Figure 2—21. Three-dimensional representation of a Golgi complex. Through transport vesicles that fuse with the Golgi cis face, the complex receives several types of molecules produced in the rough endoplasmic reticulum (RER). After Golgi processing, these molecules are released from the Golgi trans face in larger vesicles to constitute secretory vesicles, lysosomes, or other cytoplasmic components.

Figure 2—23. Main events occurring during trafficking and sorting of proteins through the Golgi complex. Numbered at the left are the main molecular processes that take place in the compartments indicated. Note that the labeling of lysosomal enzymes starts early in the cis Golgi network. In the trans Golgi network, the glycoproteins combine with specific receptors that guide them to their destination. On the left side of the drawing is the returning flux of membrane, from the Golgi to the endoplasmic reticulum. (Redrawn and reproduced, with permission, from Junqueira LC, Carneiro J: Biologia Celular e Molecular, 6th ed. Editora Guanabara, 1997.)

Figure 2—27. Current concepts of the functions of lysosomes. Synthesis occurs in the rough endoplasmic reticulum (RER), and the enzymes are packaged in the Golgi complex. Note the heterophagosomes, in which bacteria are being destroyed, and the autophagosomes, with RER and mitochondria in the process of digestion. Heterophagosomes and autophagosomes are secondary lysosomes. The result of their digestion can be excreted, but sometimes the secondary lysosome creates a residual body, containing remnants of undigested molecules. In some cells, such as osteoclasts, the lysosomal enzymes are secreted to the extracellular environment. Nu, nucleolus.