Within Human Lungs,the Apical Surface of the Epithelium Produces a Growth

question 29

Essay

Within human lungs,the apical surface of the epithelium produces a growth factor called heregulin.The receptors for heregulin are located on the basolateral surface of the same cells.When the lung epithelial lining is intact,the tight junctions create a barrier that separates the heregulin from its receptors.However,when the epithelial lining is compromised,the heregulin is able to reach its receptors,where it stimulates mitosis and thereby leads to wound healing.Based upon this information,explain what happens with smoking cigarettes,which is known to increase the permeability of airway epithelium.

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Definitions:

Advance Payment

Advance Payment is the money paid before it is due or before the goods or services are received, often used to secure orders or as a guarantee against non-payment.

Subsidiary Ledger

A secondary ledger that provides detailed information to support accounts listed in the general ledger, such as customer or vendor details.

Revenue Journal

An accounting ledger that records incoming revenue transactions or sales made by a company.

General Ledger

A complete ledger detailing every fiscal activity during the lifespan of a business.