Chapter 11, Problem 9A

Summary Introduction

To conclude:

The relationship of chloride ions to the excessively thick mucus in a patient suffering from cystic fibrosis.

Introduction:

Genetic disorders result from inheritance of traits which are either dominant or recessive. One of the most common recessive genetic disorders among Caucasians is cystic fibrosis. This affects the mucus producing glands, digestive enzymes and sweat glands.

Answer to Problem 9A

A person suffering from cystic fibrosis is not able to absorb chloride ions into the cells but is excreted in the sweat. Without sufficient chloride ions in the cells, water does not diffuse from the cells. This results in secretion of thick mucus.

Explanation of Solution

Cystic fibrosis is a recessive genetic disorder in which the patient secretes thick mucus from glands. This mucus clogs the respiratory pathways and ducts in pancreas which interrupts digestion.

Thick mucus is produced because the cells are unable to absorb chloride ions due to some faulty gene. This makes the cells unable to diffuse out water and so the mucus becomes thick.