The nurse is working with a client who is newly diagnosed with hypothyroidism. Diagnostic testing has indicated that the client’s health problem is caused by anterior pituitary dysfunction.
This client’s hypothyroidism is rooted in a deficiency of:

Oxygen cannot diffuse rapidly across the membrane to tissues in the eye. Diabetic retinopathy is caused by damage to the blood vessels of the retina, which is the light-sensitive tissue at the back of the eye. This damage can reduce the oxygen supply to the retina and lead to vision problems.

Choice A is wrong because cells in the eye can reproduce normally, but they may not function properly due to high blood sugar levels or lack of oxygen.

Choice B is wrong because diabetic retinopathy does not affect the production of aqueous humor, which is the fluid that fills the front part of the eye.

However, diabetes can cause another eye condition called glaucoma, which is caused by increased pressure from too much aqueous humor.

Choice C is wrong because diabetic retinopathy does not affect the nerve innervations throughout the eye.

However, diabetes can cause another eye condition called diabetic neuropathy, which is caused by damage to the nerves that control eye movement and pupil dilation.

Guaifenesin is an expectorant that helps thin and loosen mucus in the lungs, making it easier to cough up the sputum. Some possible explanations for the other choices are:

Choice A. Benzonatate is wrong because benzonatate is an antitussive that suppresses the cough reflex by numbing the throat and lungs.

It does not help with sputum production or clearance.

Choice B. Dextromethorphan is wrong because dextromethorphan is also an antitussive that acts on the brain to reduce the urge to cough.

It does not affect the mucus or bronchial secretions.

Choice C. Hydrocodone is wrong because hydrocodone is a narcotic antitussive that works by binding to opioid receptors in the brain and spinal cord, blocking pain signals and decreasing cough.

It can cause sedation, respiratory depression, and dependence, and is not indicated for bronchitis.

Normal ranges for sputum production vary depending on the individual and the cause of the cough, but generally range from 10 to 100 mL per day.

Excessive or abnormal sputum may indicate an infection, inflammation, or obstruction of the airways.