EXOCRINE GLANDS

Which are the 6 classifications way for exocrine glands

1. NUMBER OF CELLS

2. LOCATION

3. DUCT SHAPE

4. SHAPE OF SECRETORY PROTION

5. NATURE OF SECRETION

6. RECEPTOR KIND

CLASSIFICATION FOR LOCATIN

Which are intracellular which are extraepithelial?

Intracelullar as goblet cells so between epithelail cells

Extra epithelial : beneath so are in the connective tisue.

Have a secretory part and an duct system to transport the secretion to epithelia

Classifcation based on duct system shape

Duct system can be symple or compund

The compound kind is branched as the one in the salivary gland and pancretaic gland

Compound duct are associated with connective tissue dividing the glands into LOBES

If a gland is divided into lobes which kind of duct is present

A compound duct where ct is associated (septa)

How can you classiy the shape of the secretory portion?

Tubular then can be single, coiled and branched

Acinar that has a rounder shaped singles or branched

Tubuloacinar

Silvary glands and pancreatic glands have what shape of sec. Portion

Tubuloacinar

Gastric glad and sweat gland have what duct shape

Tubuluar

Classification based on the nature of the nature of secretion

1. Serous

2. Mixed

3. Sebaceous

4. Mucous

Serous secretion And glands

Serous secrete is rich in enzyme therephore the serous glands hvae abundant RER basally and secreate granules APICALLY

Appear darker than mucosu cells, small lumen and rich in enzymes

Basophilic cytoplasm for rer abbundant

Es. Exocrine pancreas

Paratyroid

Mucosu secretion

In what is it rich?

How does it appear

Compare mucous to serous

Mucous is rich in GLICOPROTEIN

The acini appear PALE and FLAT LARGE LUMEN Rand larger compared to serous one

How are acinar mucous cell histologically

They appare pale, flat and white a larger lumen compared to serous one ( darker, smaller)

CELL ARE CUBOIDALS

Secrete carbo and glyprottein pas positive

Ex. Mucosu cell of stomach ( simple, branched tubular)

Mucous glands of the oral cavity

Which glands have mixed secretion

How are their cell called

1. Cells of mixed glands are SEROUS DESMILUNES

2. They secrete both serous. And mucosu and are like the SUBLINGUAL AND SUBMANDIBULAR

SEBACEOUS GLANDS

What type of secretion is here?

Sebacosu glands have a big secretion of LIPIDS And antibacterial

As the lipid droplet acculumate they are then secreted by HOLOCRINE SECRETION

CLASSIFICATION BASED ON TYPE OF SECRETION MECHANISM

1. Merocrine: exocytosis whitout cytoplams loss as in PANCRREAS, SALIVARY

2. Apocrine: apical cytoplasm is pinched off SWEAT GLAND AND MAMMARY

3. Holocrine as in sebacous glands

What are the two components of glands?

1. Stroma: ct with blood vessels, nerves and ecm

2. Parenchyme: functional cells

Embryologically which is the differenc ebetween endocrine and exocrine cells

As they form from the invagination of the connective tissue in the underling connnective the endocrine detach completely so do not have the ducts

While xocrine keep the duct connecting to the surface

From which layers do exocrine glands derive

From all three

From those that open into the outer skin from the ECTODERM. Sweat, salivary and lacrimal

For those that open in internal lining dfromthe ENDODERM: ES, PANCREAS, STOMAVH, SALIVARU ECC..

Fro the mesoderm those related to the urogenital system

Unicellular cells goblet

Carcateristic

Location

Secretion

Staining

Goblet cells are intraepithelial and unicellular

Secret mucin ( that with water becomes mucosal)

Mucus traap pathogens

Hitsologically THEY ARE PAS POSITIVE as muscosu is rich in glycoprotein

Why are goblet cell have a polarized structure

Mucus is rich in glycoproteins so basal part is rich in RER and golgi

Apical part in goblet cell is wjere there are the granules

The apical part as it has mucus it is paler

What type of secretion do goblet cell have?

MEROCRINE as the cytoplasm is nt lost and also it can be continuous or stimulates-

Is secreted for esocytosis! ( as those of trachea bronchi and GI)

Which kind of glands are intestines one?

SIMPLE AND TUBULAR

Also called instine cripts

Merocrine secretion

In the large intestine they secrete mucous for fecal lubrigication

What kind of gland are sweat glands? What sdecretion is here?

Simple coiled tubular ( tipo la liquirizia)

Here we have APOCRINE SECRETION with loss of cytoplasm

the odriferous part is optain when the secrete is in contact with the six

It opens into the hair follicle

How do sweat gland appears

It appars clear for water and all the elocrolytesDarker where glycoproteins are

And then with myoepithelia

Which kind of glands are stomach one

What kind of secretion?

Branched tubular

Open into the gastric pts

Merocrine secretion

Secrete mucous to protect from HCL secretion of parietal cell and PEPSIN secretion from chief cells

As mucosu is rich in glycoproteins cells have dev. Golgi and rer and a clear appearance

Which kind of cells are sebacous glands? What kind of secretion is here?

Branched and alvolar

Lipid droplets accumultion leads to HOLOCRINE SECRETION

Sebacous glands are associated with hair follecules

NEAR THE FOLLICLE AND IT LOOKS PALE AND FOAMY

What kind of glands are sweat glands

WHAT ARE THE TWO KINDS AND HOW DO THEY DIFFER?

Simple tubular coiled

Apocrine

Coiled part is for the secretion

ECCRINE: for termoregulation and have a merocrine secretion a smaller lumen clear cell where water and electrolites are and darker where glycoproteins are

Eccrine are DEEP INTHE DERMIS and use myoepithelial cells to secrete into duct secreting nacl, ammonia, urea

Apocrine: are in the axilla region and open into haur follicles hand have amuch wider lumer and CUBOIDAL cells

SECRETE ODORIFOURS FLUIS

Describe eccrine sweat glands

Eccrine sweat glands are located deep in the drrmis

Simple ytubular and coiled for the part thatt secretes into the duct secreting nacl, urea, ammonia

They have a narrow lumen

And are for thermoregulation

COLOUMNAR

Which gland is this

Sweat

Stomach glands In detail

Are simple branched tubular

Secrete mucous via merocrine secretion to protect form hcl and pepsine they open int

OPEN INTO gastric pits from tubular secretory portion

GASTRIC GLANDS CONTAIN ALSO: parietal cells that are zymogenic meaningare hat they secrete inactive enzyme precurosor ad pepsinogen and lipase

And enteroendorcirne cells for hormons related to digestion

In the case of cronic acid reflux GERD what happens?

With acid contant exposure the tissue liningthe esophagous changes transforming the squamous epithelium into gastric cells this is called INTESTINAL METAPLASIA

Describe in detail the sebacous gland formation

1. Holocrine secretion

2. Simple branched and alveolar

3. Mostly associated with hair follicles

   1. Basal cells CUBOIDAL AND ARE STEM CELLS with nuclei in the periphery ( the periperical part is darker and cumboidale

   2. Differentiate into secretory cells

   3. Move toawrds the center ( paler) accumulate lipid droplets

   4. Cell dies and disentegrates into sebum

Where is BUNNERS GLAND LOCATED And what type is it

compound and tubular and it is in the duodenum mucosa

As it is mucous it is a merocrine secretion pale, looking cells

Easy to recognize: VILLI

Duodenum submucosa is rich in alkaline secretion

Protecting the doudenum from the acids of the stomach

It serves to 1. Lubrificate the intestinal wall 2. To allow to ave the correct alkaline enviroment to be active for absorption

Which is the min function of the ilium

Are there glands in the ilum?

An of the colon?

Ilium do not have glands but patches PLAQUES OF PEYER that appear very dark and very dense tissue this is LYMPOIOID TISSYE

In colon on the other hand we have mucous membrane to reabsorb a lot of water and micronutrients

What are very dense very dark part of tissue in the ilum

PLAQUES OF PAYERS which are lympoid tissue . Not glands

What type of gland is the mammary glandf?

Alveolar compound gland

As it is compound septa ct is present dividing this tissue into lobes.

The secretory portion is lined with cuboidal epitheliala and myoepithelial cells that if stimulated by oxytocin eject milk into the duct

When the gland is ACTIVE. Alveoli are distendend and the epithelium expands

When is inactive it is less alvoli and more connectuvve tissue

What is milk fomed of and how does the maammary gland change

Is everything secreted in the same way?

The secretory portion is lined with cuboidal epitheliala and myoepithelial cells that if stimulated by oxytocin eject milk into the duct

When the gland is ACTIVE. Alveoli are distendend and the epithelium expands

When is inactive it is less alvoli and more connectuvve tissue

MILK IS RICH IN LIPID,ANTIBODIES, IONS, LACTOSE

Lipid part is SECRETED VUA HOROCRINE

The protein part via merocrine!!!

What kind of gland is pancreas?

How is the basal part different from the apical part?

The pancreas is a mixed gland

It has the exocrine protin to secrete a bicarbonate rich fluid ( secreted in the cells of the duct) and digestive enzymes ( in the acini)

We can find SEROUS ACINI that start from the centroacinal cells and are branched and alveolar,

Acini have a basal part rich in rer basiphilic and a esoinophilc part whcih is the apical part where the zymogenous granules are ( inactive form of amilase and lipase)

How is the structure of exocrine pancreas

Starting with the centroacinar cell the acini deveolp having the nuclei in the periphery and the zymogenous garanules more centrally, connected to the ducts we have the INTERCALTED DISTSC ( squamous epithelial cells) that connect the straiated duct cuboidal cells) that then all lead to the INTERLOBULAR PDUCT

WHAT CAN YOU FIND IN THE PANCREAS AMONG THE EXOCRINE TISSUE

ENDOCRINE langheran islet

Which are the 3 salivary glands?

What kind of secretion do they have?

Which are the mixed and which is serous

1. PAROTID serous compound alveolar

2. Submandibular mixed mainly serous

3. Sublinguale mixed mucous.

Descirbe the parotid gland

Compound alveolar and serous gland

Parotid is repsionisbile for 30 % of the saluva

Adipose tissue can be present

Only serous acini!

Descirbe the sublingual and submandibular glands

Both are miced but the sublinguale is mainly MUCOUS and have few serous demilunes it is also COMPUND but tubular

Pale as it is mucous mainly

Subamandibularis also mixed but it is manily serous

It secretes the resting saliva

It appears darker and it has demilunes arranged in a crescent manner at the end of the acini ( muco spinge le sierose ai lati)

Around the acini we also have the myopeithelia

This is as paroti compund alvolar

What kind of cells are sebacous glands

Holocrine sec.

Alvolar and branched

Stiomach glands are what type

Branched and tubular

Describe goblet cells

Histologically, location, secretion kind ecc

Goblet cells

Unicellular cells that are intraepithelial

Very common in the respiratory tarcat and gi tract

Merocrine secretion ( fusion of granules in the pm for exocytrosis) secreting mucin

Mucous is rich in glycoproten and thri carbo stains with PAS

Cells appear polarized base: rer, golgi ecc and a paler apical part where the granules are.

What is the difference between a simple gland and a compound gland

Compound are does whose DUCT IS BRANCHED

Whidhc are the only apocrine glands

Latte e sudore

Mammary and weat they both loss the apical portion of the cytoplams with their serete