Glandular Epithelium

Glands

Are cells or aggregations of cells whose function is secretion.

Exocrine Glands

-release the secretory product via a system of ducts

that opens upon one of the surfaces of the body which are in contact

with the external world (skin, gastrointestinal tract etc.).

- with ducts because it remains connected to the surface epithelium

- secretions are released through it's ducts

Endocrine Glands

- release their secretory product (typically hormones)

into the spaces between the secretory cells (extracellular space)

from which it enters the bloodstream.

- no ducts/ductless

- secretions are released to the bloodstream(ex. Hormones)

Multicellular Glands

The secretion is either discharged directly from the

secretory portion onto the epithelium or reaches

the epithelium via a duct system.

secretory epithelial sheet

-The simplest form of a multicellular gland

-a surface epithelium consisting entirely of secretory cells (e.g. the epithelium lining the inner surface of the stomach, where the mucous secretion protects the stomach wall from the acidic contents of the stomach).

Myoepithelial cells

are contractile consisting of actin and myosin filaments.

- helps contracting cells and helps glands release their secretions

- found near glands and are contractiles

Unicellular Glands

is a single cell that functions as a gland, secreting substances such as hormones, enzymes, or mucus.

These cells play important roles in various bodily functions, such as digestion, protection, and regulation

Goblet cells

- Goblet cell(releases mucin(glycoprotein) or H2O=mucus)

2 examples of secretory epithelial sheet

- ependyma/ependymal cells

- choroid plexus(releases CSF)

Intraepithelial Gland

- group of epithelial cells surrounding a body orifice/opening

- example is penile urethra

mammary glands, sebaceous glands, pancreas(has both endocrine(insulin, islets of Langerhans) and exocrine function(pancreatic duct(releases pancreatic enzymes))

examples of Exocrine Glands with ducts

Sweat glands, Mammary glands, Lacrimal Glands, Salivary Glands

SMLS to remember for myoepithelial(?)

tubulo-acinar

The pancreas is a ____ gland, in which each section of the secretory system has a specialized function.

acinar

The precursors of digestive enzymes are produced by

the ___cells.

Simple

Multicellular glands with an unbranched excretory

duct are called

compound

We talk about a ___ gland when the excretory duct is branched.

duodenum

Tubular cells secrete the alkaline bicarbonate solution which eventually neutralizes the acidic contents of the stomach that are released into the ____.

Tubular Glands

Straight tubular glands extend from the surface of the colon into the underlying connective tissue.

colon

Tubular Glands are the largest in the ___

Secretory Mechanisms

cellular processes that cells use to release substances, such as hormones, enzymes, and lipids, to their external environmen

Merocrine Glands

corresponds to the process of exocytosis.

Vesicles

___open onto the surface of the cell, and the secretory product is discharged from the cell without any further loss of cell substance.

Major Salivary Glands

example of Merocrine Gland

Apocrine Glands

designates a mechanism in which part of the apical cytoplasm of the cells is lost together with the secretory product.

plasma membrane

The continuity of the ____ is restored by the fusion of the broken edges of the membrane, and the cell is able to accumulate the secretory product anew.

Sweat Glands and Mammary Glands

examples of Apocrine Glands

Holocrine Glands

designates the breakdown and discharge of the entire secretory cell. It is only seen in the sebaceous glands of the skin.