digestive glands l.
Skip this Video
Loading SlideShow in 5 Seconds..
Digestive glands PowerPoint Presentation
Download Presentation
Digestive glands

Loading in 2 Seconds...

play fullscreen
1 / 58

Digestive glands - PowerPoint PPT Presentation

  • Uploaded on

Digestive glands. General outline. small digestive glands. distributed in the wall of digestive tract esophageal glands, gastric glands and intestine glands. large digestive glands. outside the wall of digestive tract salivary glands, liver and pancreas. Large salivary glands.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Digestive glands' - nuala

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
general outline
General outline
  • small digestive glands
  • distributed in the wall of digestive tract
  • esophageal glands, gastric glands and
  • intestine glands
  • large digestive glands
  • outside the wall of digestive tract
  • salivary glands, liver and pancreas
large salivary glands
Large salivary glands
  • Include parotid, submandibular and

sublingual glands

  • are compound tubuloacinar glands
  • are composed of acini and ducts
Acinus :
  • acinar epithelium: simple

cuboidal or pyramidal cells

  • myoepithelial cell
  • basal membrane


Serous acini

Mucous acini


Be divided into

serous acini
Serous acini
  • cytoplasma are deep stained
  • nucleus are spherical in shape and near

the base

  • secretion is thin, contains salivary amylase

and a little mucus

mucous acini
Mucous acini
  • cytoplasma are light-blue stained
  • nucleus are flattened ovoid shaped and

close to the base

  • secretion is thick; contains mucoprotein
mixed acini
  • consist of above two kinds of cells
  • demilunes: several serous cells are

attached eccentrically to the mucous acini

  • Intercalated ducts

diameter: thinnest

wall: simple low cuboidal epithelium


Striated duct (secretory duct)

  • wall: simple columnar epithelium; the nucleus

is near the cell apex; cytoplasm is

acidpphilic; has basal striations

  • EM: the basal striations created by

membrane infolding and mitochondia

  • reabsorbing sodium and excreting potassium;

transport water and ions


Interlobular duct

Wall: pseudostratified epithelium

  • Main duct

Near its orifice become stratified

squamous epithelium

parotid gland
Parotid gland
  • pure serous gland
  • longer intercalated duct
  • secrete 25% of saliva, more salivary

amylase, less mucus

submandibular gland
Submandibular gland
  • mixed gland. Serous acini are more than

mixed or mucous acini

  • short intercalated duct, longer striated duct
  • secrete 70% of saliva, less salivary amylase,

more mucus

sublingual gland
Sublingual gland
  • mixed gland, mucous and mixed acini

predominant, more demilune

  • without intercalated duct, obscure striated


  • secrete 5% of saliva, most mucus

Exocrine portion:

  • the features of the acini
  • a single layer of pyramidal serous cells

surrounded by basal lamina, without

myoepithelial cells

  • centro-acinar cells: the epithelial cells of

intercalated duct penetrating into the

lumen of the acinus


the feature of ducts

  • the intercalated duct is long and has branches
  • no striated duct
  • main duct: lined by simple columnar

epithelium in which a few goblet cells

and endocrine cells can be seen


The functions of exocrine portion

Secret abundant trypsinogen,

chymotrypsinogen, amylase, lipase,

sodium bicarbonate and trypsin inhibitor

endocrine portion pancreatic islet
Endocrine portion (pancreatic islet):
  • rounded clusters of cells embedded within

exocrine pancreatic tissue

  • are divided into three kinds of cells: A, B,

and D cells

  • fenestrated capillaries are among the



Endocrine portion

PP cells: pancreatic polypeptide

G cells: gastrin

Other cells


A cells

B cells

D cells


Hepatic plates


Central vein

Liver lobule

Interlobular arteries

Interlobular veins

Interlobular bile ducts

Portal area


Functions of liver:

  • bile secretion
  • synthesize: protein, glycogen, cholesterin
  • detoxification and inactivation
  • defence
  • hemopoiesis

Human liver

Pork liver

liver lobule
Liver lobule:
  • hepatic plates: are composed of a single

layer of hepatocytes arranged in radial

  • sinusoid: situated between the hepatic

plates, forming a complex network

  • central vein: occupies the centre of the

liver lobule

  • polyhedral in shape, eosinophilic cytoplasm,

one or two large rounded nuclei with one or 2

typical nucleoli

  • EM: Mi, RER, SER, Golgi apparatus,

lysosomes, microbodies, inclusions



provide the energy for the hepatocytes

  • Rough endoplasmic reticulum

synthesize some plasma proteins

  • Golgi apparatus

participate in the formation of bile and lipoprotein


Smooth endoplasmic reticulum

  • synthesize bile, triglyceride and LDL
  • metabolism of the lipid, hormones and


  • inactivate steroid hormone
  • biotransformation of some materials
  • detoxification of noxious substances


  • actively participate the metabolism of

hepatocyte and renewal of organelles

  • play a role in metabolism and transport of


  • storage of iron


detoxification: catalase and peroxidase;

reduce the hydrogen peroxide into H2O

  • Inclusions

include glycogen, lipid droplets, pigment etc;

These contents vary according to physiologic state of human body

bile canaliculi
Bile canaliculi
  • between two adjacent hepatocytes
  • the membrane of hepatocyte projects to

the lumen, forming many microvilli

  • the cell membranes near the bile canaliculi

are firmly bound by junctional complexes

liver sinusoid
Liver sinusoid
  • spaces between the hepatic plates
  • irregular in shape
  • composed of only one discontinuous layer of

fenestrated endothelial cells, no diaphragm,

no basement membrane

  • Kupffer cells are located within the sinusoid


space of disse
Space of Disse
  • separates the endothelium from the


  • contains some reticular fibers and fat-storing


portal space
Portal space:
  • the connective tissue separating the lobules
  • including

Interlobular arteries

Interlobular veins

Interlobular bile ducts

blood circulation
Blood circulation:

portal V.

interlobular V.

(functional vessel)


central V.

hepatic A.

interlobular A.

sublobular V.

(nutrient vessel)

hepatic V.


Blood vessels of liver

(prepared Chinese ink injection through portal vein)

discharge way of bile
Discharge way of bile:

Bile canaliculi

Hering’s canals

Interlobular bile ducts


Hepatic duct

Common bile duct

Cystic duct



Simple columnar Epi. , no Goblet cells

Laminar propria: C.T.

  • mucosa
  • muscle layer: composed of an inner circular,

an outer longitudinal layers of smooth muscle

  • adventitia: most are fibrosa, some are serosa