Glandular EpitheliumGlandular Epithelium

Glandular EpitheliumGlandular Epithelium

Glandular epithelium is more Glandular epithelium is more complex and varied than the complex and varied than the epithelial cells which cover surfaces epithelial cells which cover surfaces or line tubules or vessels.or line tubules or vessels.

Glandular EpitheliumGlandular Epithelium

Glandular epithelium is more Glandular epithelium is more complex and varied than the complex and varied than the epithelial cells which cover surfaces epithelial cells which cover surfaces or line tubules or vessels.or line tubules or vessels.

Glandular epithelium form glands Glandular epithelium form glands which can consist of one or more which can consist of one or more cells that make and secrete a cells that make and secrete a product. product.

ProductsProducts

Water soluble proteinWater soluble protein

ProductsProducts

Water soluble proteinsWater soluble proteins Nonpolar lipids or steroidsNonpolar lipids or steroids

ClassificationClassification

Glands are classified first based on Glands are classified first based on the presences or absence of a duct the presences or absence of a duct for the secretory products.for the secretory products.

Endocrine GlandsEndocrine Glands

Are ductless glandsAre ductless glands Secrete their Secrete their

products directly products directly into the capillaries. into the capillaries.

Exocrine GlandsExocrine Glands

secrete their products onto a body secrete their products onto a body surface or a cavity. surface or a cavity.

Exocrine GlandsExocrine Glands

secrete their products onto a body secrete their products onto a body surface or a cavity. surface or a cavity.

are classified first based on cell are classified first based on cell numbernumber

Unicellular Exocrine Unicellular Exocrine GlandsGlands

are made of up of single cells which are made of up of single cells which secrete their products directly secrete their products directly through exocytosis onto a surface. through exocytosis onto a surface.

Unicellular Exocrine Unicellular Exocrine GlandsGlands

are made of up of are made of up of single cells which single cells which secrete their secrete their products directly products directly through exocytosis through exocytosis onto a surface. onto a surface.

The only major The only major examples are the examples are the goblet cells goblet cells andand mucous cellsmucous cells

Unicellular Exocrine Unicellular Exocrine GlandsGlands

found mixed with found mixed with the columnar the columnar epithelium in the epithelium in the digestive and digestive and respiratory tracts. respiratory tracts.

They secrete They secrete products called products called mucins (mucous), mucins (mucous), glycoproteins that glycoproteins that lubricate.lubricate.

Multicellular Exocrine Multicellular Exocrine GlandsGlands

are made up many cells and are are made up many cells and are composed of two parts.composed of two parts.

Multicellular Exocrine Multicellular Exocrine GlandsGlands

are made up many cells and are are made up many cells and are composed of two parts:composed of two parts:

A epithelial lined ductA epithelial lined duct A secretory unit called the acinus A secretory unit called the acinus

Multicellular Exocrine Multicellular Exocrine GlandsGlands

Supportive connective tissue Supportive connective tissue surrounds the secretory unit and surrounds the secretory unit and provides blood vessels and nerve provides blood vessels and nerve fibers.fibers.

Multicellular Exocrine Multicellular Exocrine GlandsGlands

Supportive connective tissue Supportive connective tissue surrounds the secretory unit and surrounds the secretory unit and provides blood vessels and nerve provides blood vessels and nerve fibers.fibers.

The shape of the duct and of the The shape of the duct and of the secretory unit provides for another secretory unit provides for another level of classification.level of classification.

Duct StructureDuct Structure

Simple- unbranched, straight ductSimple- unbranched, straight duct

Duct StructureDuct Structure

Simple- unbranched, straight ductSimple- unbranched, straight duct Compound- branched ductCompound- branched duct

Secretory Unit:Secretory Unit:

Tubular- if the secretory unit has the Tubular- if the secretory unit has the same diameter throughout like a same diameter throughout like a tubetube

Secretory UnitSecretory Unit

Tubular- if the secretory unit has the Tubular- if the secretory unit has the same diameter throughout like a same diameter throughout like a tubetube

Alveolar- if the secretory unit is in Alveolar- if the secretory unit is in the shape of a flask the shape of a flask

both of these terms refer to the both of these terms refer to the acinus or secretory unit. acinus or secretory unit.

ExamplesExamples

Method of SecretionMethod of Secretion

Glands regardless of type (unicellular Glands regardless of type (unicellular or multicellular) can have one of two or multicellular) can have one of two types of secretory processes:types of secretory processes:

Method of SecretionMethod of Secretion

Glands regardless of type (unicellular Glands regardless of type (unicellular or multicellular) can have one of or multicellular) can have one of three types of secretory processes:three types of secretory processes:

Merocrine- Merocrine- products are secreted products are secreted by exocytosis. This is seen with most by exocytosis. This is seen with most glands.glands.

Method of SecretionMethod of Secretion

Glands regardless of type (unicellular or Glands regardless of type (unicellular or multicellular) can have one of three types multicellular) can have one of three types of secretory processes:of secretory processes:

Merocrine- Merocrine- products are secreted by products are secreted by exocytosis. This is seen with most glandsexocytosis. This is seen with most glands

Holocrine- Holocrine- the cell ruptures and releases the cell ruptures and releases the product. New cells replace the spent the product. New cells replace the spent cells.cells. The only example in humans are the The only example in humans are the sebaceous (sweat) glandssebaceous (sweat) glands

Method of SecretionMethod of Secretion

ApocrineApocrine-the top of the cell pinches -the top of the cell pinches off. Possibly seen in the lactating off. Possibly seen in the lactating mammary gland although this is mammary gland although this is generally considered merocrine in generally considered merocrine in nature.nature.