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:

Norms

Established standards of behavior and beliefs in a group or society.

Behavior

The actions or reactions of an object or organism, usually in relation to the environment or stimuli.

Role Conflict

A situation in which an individual faces conflicting expectations from different roles they fulfill in their life.

Social Dilemma

A situation in which individual decisions lead to outcomes that might be good for the individual but detrimental to the group.