Histo Blok 9 Refined

8/6/2019 Histo Blok 9 Refined

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DIGESTIVE SYSTEM

Digestive system is made up of the digestive tract and structures related to the system such as

tongue, teeth, salivary glands, pancreas, heart and vesica fellea.

Based on its structure and topography, the digestive tract can be divided into cavum oris, pharynx,

oesophagus, gaster, small intestine and large intestine.

Cavum oris

Histological structure such as labium oris(lips), buccal(cheeks), dent(teeth), gingivae(gums),

lingua(tongue) and palatum molle(soft palate) and durum(hard palate) can be found here.

Labium oris

Labium oris can be divided into 3 distinct area. The first area is the area cutanea(cutaneous area)

which is made up of thin layer of skin. Skin adnexa or skin appendages can also be found here. Skin

appendages are appendages that are associated with the skin and serve a particular function. In

humans some of the more common skin appendages arehairs (sensation, heat loss, filter for

breathing, protection), arrector pilli (smooth muscles that pull hairs straight), sebaceousglands(secrete sebum onto hair follicle to oil the hair), sweat glands (can be sweat secreted with

strong odour (apocrine) or with a faint odour (eccrine) and nails(protection).

The next area is the intermediate area/vermilion border or area merah bibir which is made up of

epitel berlapis gepeng tanpa lapisan tanduk. The epithelial cells here are transparent because they

contained eleidin granules. Eleidin is clear intracellular protein which is present in the stratum

lucidum of the skin.


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Eleidin can be found in the vermilion border of the lip. The lip is thinly keratinized and has a high

concentration of eleidin. The red appearance of the vermillion border is due toseveral factors, one

of which is the transparent nature of eleidin showing the color of thered blood cells beneath.The

papillae of the connective tissue are tall and contain a lot of capillaries.

The third layer is the oral mucous area or area oral mucosa. This layer has the same histologicalstructure with buccal. The epithelial cells here is the unkeratinized stratified squamous epithelial

cells. The lamina propriae of this layer is quite compact. At the tunica submucosa of this layer, labial

glands with seromucous property can be found. Underneath the tunica submucous is the skeletal

muscle, m. orbicularis oris.

Lingua

The dorsal surface of the tongue is covered with papillae or projections. The epithelial cells here is

either unkeratinized or keratinized stratified squamous epithelial cells. 2/3 of the lingual papillae at

the anterior of the tongue is made up of filiforme papillae, fungiforme papilla and circumvalate

papillae. Fungiforme papillae and filliforme papillae are projections of connective tissues that iscovered with epithelial cells.

Circumvallate papillae (contains taste buds)

Fungiform papilla (contains taste buds)

Filiform papilla (does not contain taste buds)

Foliate papillae (contains taste buds)

Filiform papillae

The filiform papillae (singular: papilla) are one of the four types of lingual papillae, small

prominences on the surface of the tongue. The filiform papillae are thin, long "V"-shaped cones that

don't contain taste buds but are the most numerous, covering most of the dorsum (upper surface).

These papillae are mechanical and not involved in gustation.


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They are small and arranged in lines parallel to the V-shaped row of circumvallate papillae, except at

the tip of the tongue where they are aligned transversely. Projecting from their apices are numerous

filamentous processes, or secondary papillae. These are of a whitish tint, owing to the thickness and

density of the epithelium of which they are composed. This epithelium has undergone a peculiar

modification as the cells have become cornified and elongated into dense, imbricated, brush-like

processes.They contain also a number of elastic fibers, which render them firmer and more elastic than the

papillae of mucous membrane generally. The larger and longer papillae of this group are sometimes

termed papillae conicae or cuneiform. Fungiform papillae are found dispersed throughout the

filiform papillae. It is made up of unkeratinized stratified squamous epithelial cells.

Fungiform papilla

The fungiform papillae are mushroom shaped papillae (projections) on the tongue. They are located

on the top (dorsal) surface of the tongue, scattered throughout the filiform papilla but mainly at the

tip and lateral margins of the tongue. They have taste buds on their superior (upper) surface which

can distinguish the five tastes: sweet, sour, bitter, salty, and umami. The surface of fungiforme

papillae is wider than its base. It is made up of unkeratinized or a little keratinized squamos stratified

epithelial cells. The modification of this papillae is the lentiform papillae.

Foliate papillae


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Taste-buds, the end-organs of the gustatory sense, are scattered over the mucous membrane of the

mouth and tongue at irregular intervals. They occur especially in the sides of the vallate papillae.

There is a localized area at the side of the base of the tongue, the foliate papillae, in which they are

especially abundant. The taste buds can be found at the walls of the ridges. 2 or more ridges are

parallel to each other. Foliate papillae are not perfectly develop in humans, but develop perfectly in

humans.

Vallate papilla

The circumvallate papillae (or vallate papillae) are dome-shaped structures on the human tongue

that vary in number from eight to twelve. It is made up of unkeratinized stratified squamous

epithelial cells. The shape of circumvallate papillae is nearly similar to that of fungiforme papillae.

They are situated on the dorsum of thetongue immediately in front of the foramen

cecum and sulcus terminalis, forming a row on either side; the two rows run backward and medially,

and meet in the midline. The papilla is shaped like a truncated cone, the smaller end being directed

downward and attached to the tongue, the broader part or base projecting a little above the surface

of the tongue and being studded with numerous small secondary papill and covered by stratified

squamous epithelium. Ducts of lingual salivary glands, referred to as Von Ebner's glands empty

serous secretion into the base of the circular depression (moats). The function of the secretion is

presumed to flush materials from the base of circular depression to ensure that taste buds can

respond to changing stimuli rapidly. The lateral part of these papillae is covered with taste buds, and

there is circular sulcus or cryptus found in the papillae.

Taste buds


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Semidiagrammatic view of a portion of the mucous membrane of the tongue. Two fungiform papill are shown. On some

of the filiform papill the epithelial prolongations stand erect, in one they are spread out, and in three they are folded in .

Taste buds contain the receptors for taste. They are located around the small structures on the

upper surface of the tongue, soft palate, upperesophagus and epiglottis, which are called

papillae. These structures are involved in detecting the five (known) elements of taste

perception: salty,sour, bitter, sweet, and umami. Via small openings in the tongue epithelium, called

taste pores, parts of the food dissolved in saliva come into contact with taste receptors. These are

located on top of the taste receptor cells that constitute the taste buds. The taste receptor cells send

information detected by clusters of various receptors and ion channels to the gustatory areas of the

brain via the seventh, ninth and tenth cranial nerves. On average, the human tongue has 2,000

8,000 taste buds. The average life of a taste bud is 10 days.

The majority of taste buds on the tongue sit on raised protrusions of the tongue surface called

papillae. Contrary to popular understanding that different tastes map to different areas of the

tongue, taste qualities are found in all areas of the tongue, although some regions are more

sensitive than others. The original "tongue map" was based on a mistranslation by Harvard

psychologist Edwin G. Boring of a German paper that was written in 1901.[5]

Varying sensitivity to all

tastes occurs across the whole tongue and indeed to other regions of the mouth where there are

taste buds (epiglottis, soft palate).

The bud is formed by two kinds of cells: supporting cells and gustatory cells.The supporting

(sustentacular) cells are mostly arranged like the staves of a cask, and form an outer envelope for

the bud. Some, however, are found in the interior of the bud between the gustatory cells.

The gustatory (taste) cells, a chemoreceptor, occupy the central portion of the bud; they are spindle-

shaped, and each possesses a large spherical nucleus near the middle of the cell.

Taste buds can be found in the squamos epithelial layer. It contain taste pores which is the canal tothe outer world. With light microscope 3 kinds of cells can be differentiated that is receptor cells,

supporting cells and small basal cells that can be found scattered at the base and lateral of taste

buds.

With M.E taste buds of various type (I-IV) can be differentiated.

Dentine


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The dentine made up the largest part of a tooth, and had undergone mineralization or calcification

like bones. Dentine is a derivative of the mesodermal cells during embryonic stage of life. 80% of

mineral found in a dentine is made up of calcium and the remaining 20% is made up of collagen,

phosphoprotein, glycoprotein and glycoaminoglycan (inorganic nutrient). Dentin is form by

odonthoblast, and the substance between cells that havent undergone mineralization form

predentine (young dentine).

Dentine (AE: dentin) is a calcified tissue of the body, and along with enamel, cementum, and pulp is

one of the four major components of teeth. Usually, it is covered by enamel on the crown and

cementum on the root and surrounds the entire pulp. By weight, seventy percent of dentin consists

of the mineral hydroxylapatite, twenty percent is organic material and ten percent is water. Yellow

in appearance, it greatly affects the color of a tooth due to the translucency of enamel. Dentin,

which is less mineralized and less brittle than enamel, is necessary for the support of enamel.

The formation of dentin, known as dentinogenesis, begins prior to the formation of enamel and is

initiated by the odontoblasts of the pulp. Unlike enamel, dentin continues to form throughout life

and can be initiated in response to stimuli, such as tooth decay or attrition.

There are different types of dentin, differentiated by appearance and stage of development. Primary

dentin forms most of the tooth. Secondary dentin develops after root formation is complete and

forms much more slowly than primary dentin. Tertiary dentin forms as a biological response to

stimuli.

Tooth enamel


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Tooth Enamel (pronounced /tu nml/) along with dentin, cementum, and dental pulp is one

of the four major tissues which make up the tooth invertebrates. It is the hardest and most highly

mineralized substance in the human body.[1]

Tooth enamel is also found in the dermal

denticles of sharks. It is the normally visible dental tissue of a tooth because it covers the anatomical

crown and must be supported by underlying dentin. Ninety-six percent of enamel consists of

mineral, with water and organic material composing the rest. In humans, enamel varies in thicknessover the surface of the tooth, often thickest at the cusp, up to 2.5 mm, and thinnest at its border

with the cementum at the cementoenamel junction (CEJ).

The normal color of enamel varies from light yellow to grayish white. At the edges of teeth where

there is no dentin underlying the enamel, the color sometimes has a slightly blue tone. Since enamel

is semitranslucent, the color of dentin and any material underneath the enamel strongly affects

theappearance of a tooth. The enamel on primary teeth has a more opaque crystalline form and

thus appears whiter than on permanent teeth.

Enamel's primary mineral is hydroxylapatite, which is a crystalline calcium phosphate. The large

amount of minerals in enamel accounts not only for its strength but also for its brittleness. Dentin,

less mineralized and less brittle, 34 in hardness, compensates for enamel and is necessary as asupport. Enamel does not contain collagen, as found in other hard tissues such as dentin and bone,

but it does contain two unique classes of proteins -amelogenins and enamelins. While the role of

these proteins is not fully understood, it is believed that they aid in the development of enamel by

serving as a framework for minerals to form on, among other functions. Enamel is avascular and has

no nerve supply within it and is not renewed, however, it is not a static tissue as it can undergo

mineralization changes.

Enamel is a derivative of the ectodermal layers during embryonic stage and is the hardest structure

in our body. Is made up of 99% inorganic material, especially Ca phosphate in the form of

hydroxylapatite crystal and the remaining 1% is made up of organic material. Does not contain

collagen but rich in enamelin which is a protein rich in proline. It is formed from ameloblast.

Periodontium

Is made up of cementum, periodontal membrane(periodontal ligament), alveolar process and

gingival. Periodontium refers to the specialized tissues that both surround and support the teeth,

maintaining them in the maxillary and mandibular bones.


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The tissues of the periodontium combine to form an active, dynamic group of tissues. The alveolar bone (C) is surrounded

for the most part by the subepithelial connective tissue of the gingiva, which in turn is covered by the various characteristic

gingival epithelia. The cementumoverlaying the tooth root (B) is attached to the adjacent cortical surface of the alveolar

bone by the alveolar crest (I), horizontal ( J) and oblique (K)fibers of the periodontal ligament.

Cementum

The cementum is the surface layer of the tooth root (B). Rather than being a passive entity like paint on a wall, cementum

is a dynamic entity within the periodontium. It is attached to the alveolar bone(C) by the fibers of the periodontal

ligament and to the soft tissue of the gingiva by the gingival fibers(H).

Cementum is the thing layer that covers the root of the dentin, starting from the neck to its end. It

functioned to bind tooth to the periodontal ligament. Histologically similar to bone, made up of

matrix of rough collagen fibre, undergone calcification. Cementum[1] is a specialized calcifiedsubstance covering the root of a tooth. Cementum is excreted by cells called cementoblasts within

the root of the tooth and is thickest at the root apex. These cementoblasts develop from

undifferentiated mesenchymal cells in the connective tissue of the dental follicle. Cementum is

slightly softer than dentin and consists of about 45% to 50% inorganic material (hydroxylapatite) by

weight and 50% to 55% organic matter and water by weight. The organic portion is composed

primarily of collagen and protein polysaccharides. The cementum is light yellow and slightly lighter in

color than dentin. It has the highest fluoride content of all mineralized tissue. It is formed


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The tissues of the periodontium combine to form an active, dynamic group of tissues. The alveolar bone(C) is surrounded

for the most part by the subepithelial connective tissue of the gingiva, which in turn is covered by the various characteristic

gingival epithelia. The cementumoverlaying the tooth root (B) is attached to the adjacent cortical surface of the alveolar.

The periodontal fiber or periodontal ligament, commonly abbreviated as the PDL, is a group of

specialized connective tissue fibers that essentially attach a tooth to the alveolar bone within which

it sits. These fibers help the tooth withstand the naturally substantial compressive forces which

occur during chewing and remain embedded in the bone.

Gingivae

Gingivae is the mucous membrane that covers the periosteum of alveolar bone and attach to the

neck of a toohth. The mucous membrane of gingivae is made up of keratinized stratified squamous

epithelial cells, lamina propriae that forms a tall and slender papillae and a lot of capillary network

the reason of it being red.

Gingiva are part of the soft tissue lining of the mouth. They surround the teeth and provide a seal

around them. Compared with the soft tissue linings of the lips and cheeks, most of the gingiva are

tightly bound to the underlying bone which helps resist the friction of food passing over them.

Healthy gingiva is usually coral pink, but may contain physiologic pigmentation.

Digestive tract

Digestive tract is made up of four layers, namely tunica mucosa, tunica submucosa, tunica

muscularis propriae and tunica adventitia. Tunica mucosa is made up of mucous epithelium,

connective tissue called lamina propriae and smooth muscle that is tunica muscularis mucosa.

Tunica submuscularis mucosa stretch from oesophagus and is the border between lamina propriae

and tunica submucosa.

The submucous layer is made up of compact connective tissue and meissners nerve plexus. Blood

vessels, lymph vessels and nerves can also be found here. Meissners plexus is an autonomic plexus.


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The muscularis externa/propriae is made up of 2-3 layers of muscles and auerbachs plexuses. It is

made up of 2 layers that is tunica muscularis sircular and longitudinal. The autonomic myenteric

auerbachs plexuses are found between these two layers of fibres.

The adventitia layer is the outermost layer and is made up of irregular connective tissue and

epithelium. It is made up of loose connective tissue. Is called tunica serosa when mesothelium

cells/peritoneum can be found outside. Blood vessels and lymphatic vessels can be found here.

Oftentimes, adipose tissue can also be found.

Oesophagus

The mucous layer of oesophagus is made up of keratinized stratified squamos epithelial cells. The

tunica muscularis media is a layer of longitudinal muscle cells. At the lamina propriae, superficial

glands/complex mucous tubulose glands can be found, which is the extension of cardia glands.

Oesophageal glands or submucous gland/complex mucous tubulose glands can be found in the

tunica submucosa.

The tunica muscularis externa or muscularis propria is a composition varies in different parts of the

esophagus, to correspond with the conscious control overswallowing in the upper portions and the

autonomic control in the lower portions. At 1/3 proximal of oesophagus is made up of skeletal

muscles that help in swallowing. 1/3 medial of oesophagus is a mixture of smooth and skeletal

muscles. 1/3 distal of oesophagus is made up of smooth muscle.

Gaster

The entire surface of tunica mucosa of the stomach/gaster is made up of gastric pits or foveola

gastric. The epithelial cells here is the simple thoracical mucous cell without goblet cells.

Gaster is made up of 3 regions, that is cardia, fundus and pylorus. The thick muscle is used to churn

and mix food. Stomach secretes enzymes and acid needed to start digestion. The wall of the

stomach is highly folded, forming rugae.


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In some animals, including vertebrates, echinoderms, insects (mid-gut) and molluscs, the stomach is

a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the

digestive tract. It is involved in the second phase of digestion, following mastication (chewing). The

stomach is located between the oesophagus and the small intestine. It secretes protein-digesting

enzymes and strong acids to aid in food digestion, (sent to it via oesophageal peristalsis) through

smooth muscular contortions (called segmentation) before sending partially digested food (chyme)to the small intestines.

Bolus (masticated food) enters the stomach through the oesophagus via the oesophageal sphincter.

The stomach releases proteases (protein-digesting enzymes such as pepsin) and hydrochloric acid,

which kills or inhibits bacteria and provides the acidic pH of 2 for the proteases to work. Food is

churned by the stomach through muscular contractions of the wall - reducing the volume of the

fundus, before looping around the fundus nd the body of stomach as the boluses are converted into

chyme (partially digested food). Chyme slowly passes through the pyloric sphincter and into the

duodenum, where the extraction of nutrients begins. Depending on the quantity and contents of the

meal, the stomach will digest the food into chyme anywhere between 40 minutes and a few hours.

The stomach lies between the oesophagus and the duodenum (the first part of the small intestine).

It is on the left upper part of the abdominal cavity. The top of the stomach lies against the

diaphragm. Lying behind the stomach is the pancreas. The greater omentum hangs down from the

greater curvature.

Two sphincters keep the contents of the stomach contained. They are the esophageal sphincter

(found in the cardiac region, not an anatomical sphincter) dividing the tract above, and the Pyloric

sphincter dividing the stomach from the small intestine.

The stomach is surrounded by parasympathetic (stimulant) and orthosympathetic (inhibitor)

plexuses (networks of blood vessels and nerves in the anterior gastric, posterior, superior and

inferior, celiac and myenteric), which regulate both the secretions activity and the motor (motion)

activity of its muscles.

In adult humans, the stomach has a relaxed, near empty volume of about 45 ml. Because it is a

distensible organ, it normally expands to hold about 1 litre of food,[4] but can hold as much as 2-3

litres. The stomach of a newborn human baby will only be able to retain about 30ml.

The stomach is divided into 4 sections, each of which has different cells and functions. The sections

are cardia (where the contents of the oesophagus empty into the stomach), fundus(formed by the

upper curvature of the organ), corpus(the main, central region) and pylorus(the lower section of the

organ that facilitates emptying the contents into the small intestine).

The cytoplasm of the apical surface contain musigen with an oval nucleus. At the lamina propriae of

cardia, fundus and pylorus, glands can be found. Glands start forming from the base of gastric pit

towards the tunica muscularis media.


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Cardia glands and Pylorus glands

Section ofmucous membrane of human stomach, near the cardiac orifice. X 45.

c. Cardiac glands.

d. Theirducts.

cr. Gland similar to the intestinal glands, withgoblet cells.

mm. Mucous membrane.

m. Muscularis mucosae.

m. Muscular tissue within the mucous membrane.

The cardiac glands can be seen in this region. They can be distinguished from other stomach glands

(fundic glands and pyloric glands) because the glands are shallow and simple tubular.

The pyloric glands and the cardiac glands are both made up of simplex tubulose. Both type of glands

secrete mucuous. They are present in tiny amount. The pyloric glands is relatively shorter, simplex,

and have a branch tubules. Mucous from this glands protect stomach from autodigestion.

The cardiac glands of the stomach secrete primarily mucus. They are few in number and occur close

to the cardiac orifice where the esophagus joins the stomach.


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In general, they are more shallow than those in the other parts of the stomach.

They are of two kinds:

(1) simple tubular glands resembling those of the pyloric end of the stomach, but with short ducts.

(2) compound racemose glands resembling the duodenal glands.

The cardiac gland is both innervated by the parasympathetic and symapthetic nerve fibres of the

autonomic nervous system.

The pyloric glands are found in the pyloric portion of the stomach.

They consist of two or three short closed tubes opening into a common duct or mouth.

These tubes are wavy, and are about one-half the length of the duct.

The duct is lined by columnar cells, continuous with the epithelium lining the surface of the mucous

membrane of the stomach, the tubes by shorter and more cubical cell which are finely granular.

The glands contain mucus cells and G cells that secrete gastrin.

Fundal glands


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Is a simple tubular glands with branches. It starts from the base of the gastric pits to lamina propria

until tunica muscularis media. The gland is divided into neck, corpus and fundus.

The fundus glands (orfundic glands, orgastric glands) are found in the body and fundus of

the stomach.

They are simple tubes, two or more of which open into a single duct.

Location Name Description Secretion Staining

IsthmusMucous neck

cells In gastric pits. mucus gel layer Clear

Neckparietal (oxyntic)

cells

Between the chief cells and the basement

membrane, larger oval cells, which stain deeply

witheosin, are found; these cells are studded

throughout the tube at intervals, giving it a

beaded orvaricose appearance. These are known

as theparietal cells or oxyntic cells, and they are

connected with the lumen by fine channels

which run into their substance.

gastric

acidand intrinsic

factor

Acidophilic

Basechief (zymogenic)

cells

At the point where they open into the duct,

which is termed the neck, the epithelium alters,

and consists of short columnar or polyhedral,

granular cells, which almost fill the tube, so that

the lumen becomes suddenly constricted and is

continued down as a very fine channel. They are

known as the chief cells or central cells of the

glands.

pepsinogen,rennin Basophilic

Baseenteroendocrine

(APUD) cells

G cells are a type of enteroendocrine cell that

secrete the hormone gastrin (gastrin promotes

the secretion of pepsinogen (by chief cells) and

hormones -


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HCl (by parietal cells) and promotes gastric

contractions to mix contents).

Chief cell/pepsinogen cell or zymogenic cells has the highest amount in the fundic glands. It is

pyramid in shape, it has its nucleus at the base, oval and have condense chromatin. At the apex of

the cells are the zymogen granules that contain pepsinogen.

Parietal cells/oxyntic cells or HCl cells produce HCl and intrinsic factor of the stomach. It is oval or

polygonal in shape. They can be mostly found at the korpus of the fundic glands. They have round

nucleus, usually 1 to 2 nuclei. It has acidophilic cytoplasm.

The mucous neck cell of the fundic glands is shape like a cube or a small thorac. It has pale finely-

granulated cytoplasm that contain musigen. It is paler than chief cell. Mucigen functions to secrete

mucopolisaccharide. Mucigen from surface epithelium is harder and is categorized into neutral

polysaccharide.

Argentafin cell/enterochromafin cell or enteroendocrine cell can be found with silver coloring or

chromium salt coloring, brownish yellow in color. In the stomach several enteroendocrine cells

secrete serotonin, histamine, gastrin and enteroglukagon.

Small intestines

Is divided into 3 parts that is duodenum, jejunum and ileum. The epithelium that makes up small

intestine is simple thoracical cells with goblet cells.

At the thoracical cells at the apex brush border/microvilli can be found, and they function to enlarge

the absorption surface. It also contain digestive enzymes like alkaline phosphatase, maltase and

other. The number of goblet cells increase towards the distal.

Intestinal villi can be found in the small intestine. The villi of the duodenum is wider, the one in

jejunum is rounder like the shape of the tongue and at the ileum shape like a finger. The plica

circularis kerkringi is actually the fold of mucosa and submucosa. At the jejunum the plica kerkringi istall.

Along the mucous membrane intestinal glands/cryptus Lieberkuhn which is made up of simple

tubular glands between two villi can be found. At the base of the cryptus Lieberkuhn, paneth cells

which have granules rich with eosinophil can be found at the apex. The cryptic cells replace damaged

surface cells.

Duodenum

Brunners gland which is complex tubular glands with branches can be found here. Mucous can also

be found here.

Jejunum

Brunners gland or agmina peyeri cannot be found here. It is made up of tall and high plica circularis

kerckringi.

Ileum


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Here limfonodus aggregation or agmina peyer/plaque peyeri can be found at the lamina propriae in

the tunica submucosa.

Colon

Tunica mucosa of the colon does not contain any circular plicae or villi. The number of goblet cell

here is higher than that of epithelial cell. Cryptus lieberkuhn can be found here. Paneth cells andargentafin cells are very little here. Solitary lymphnode can also be found here. The tunica

muscularis longitudinal form 3 longitudinal strip, called taenia coli.

Appendix

Appendix is the evagination of the large intestine. It is 2-18cm in length. It has a narrow lumen which

oftentimes contain debris. Many lymphatic follicle can be found in the tunica submucosa. Its

structure is similar to the large intestine. Taenia coli cannot be found here.

Rectum

Anal canal is the lower part of the rectum. The tunica mucosa of the rectum is folded into

longitudinally into Rectal column/anal column or column of morgagni that ends 2.5 inches from

orificium anal. It is made up of epitel selapis torak. Cryptus can be found here. Linea pectinata is the

place where rectum and anus meet.

Anus

Anus can be divided into 3 segments, namely zona collumnaris which is made up of stratified

cuboidal epithelial cells without circumanalis glands, zona intermedia which is made up of stratified

squamos epithelial, unkeratinized and zona cutanea which is made up of ordinary skin.

Tunica submucosa of anus contains a lot blood vessels, nerves and vater paccini bodies. The vein

vessel form plexus hemmoroid. Tunica muscularis media/longitudinal layer form. Dilatators ani

internus. Tunica muscularis circular thicken at the end form the m. spinchter ani internus. Outside

this layer of muscle is a layer of skeletal muscle that is m. spincter ani externus.

DIGESTIVE GLANDS

There are 3 most prominent salivary glands ; parotid, submandibular and sublingual glands which are

all complex tubuloalveolar merocrine glands. Other digestive glands include pancrease, liver and

vessica fellea.

Parotid gland

Parotid gland is the largest salivary gland. It is 100% made up of serous liquid. It is arranged by

lobuler syster, interlobe and intralobe connective tissue. The ductal excretory ductal epithelial varies

from stratified squamos, stratified thorax to simple thorax. The secretory duct of the parotid gland isalso called pars striata. It is made up of short cuboidal thoracial epithelial. Isthmus or intercalated

duct secrete secretions from serous pars terminal. The epithelial cells of the isthmus is simple

squamos epithelial to low cuboidal epithelial cells.

Submandibular glands

Submandibular glands are complex tubuloalveolar gland, which is also a merocrine and mukoserous

gland. The excretory duct of submandibular glands is surrounded with loose connective tissue.


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Sublingual gland

The sublingual glands are salivary glands in the mouth.

They lie anterior to the submandibular gland under the tongue, beneath the mucous membrane of the

floor of the mouth.

They are drained by 8-20 excretory ducts called the ducts of Rivinus.

The largest duct, the sublingual duct (of Bartholin) joins the submandibular duct to drain through

the sublingual caruncle.

The sublingual gland consists mostly ofMucous acini capped with serous demilunes and is therefore

categorized as a mucous gland.

Most of the remaining small sublingual ducts open separately into the mouth on an elevated crest of

mucous membrane, the plica fimbriata, formed by the gland and located on either side of the frenulum

linguae.

The chorda tympani nerve (from the facial nerve via the submandibular ganglion) is secretomotorto

the sublingual glands.

Is a tubuloalveolar complex, merocrine and seromucous glands. The

Pancrease

Pancrease is both an exocrine and endocrine gland. It is made up of excretory duct epithelial cells

which varies from short thorax cells with goblet cells/cuboid. Its intercalated ducts/isthmus are tall

and is made up of simple squamos epithelial cells. The shape of the acinar cells here are smaller than

the acinar cells found in the parotid gland.The pars terminalis of pancrease is made up of entirely serous and in the middle of its pars terminals

sentroasini cells which are parts of isthmus can be found. myoepithelial cells cant be found here.

Hepar

Hepar are covered with glissoni capsule. Septa divides hepar into lobuli. The hepatic port is filed with

lymphatic vessel, bile vessel, portae vein and hepatic vein. The functional unit of hepar is 1 lobules.

Hepar is polygone on shape. The central lobule of the liver contained the central vein. The hepatic

cells are arranged in radial. The Kiernan triangle contain hepatic artery, branches from port vein,

biliary duct and lymphatic vessel. Each liver cells one surface is connected to the biliary system and

another has to face the blood vessel. the liver cells are polygonal in shape and they have ovoid

nucleus, granulated cytoplasm with many mitochondria, microvilli, glycogen, protein and lipofuchsin

pigment.

The liver cells are surrounded by reticulin fibres and is colored black from Bielschwosky stain.

Histo Blok 9 Refined

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Transcript of Histo Blok 9 Refined