Case Study My Brother Calls Me Bug Eyes

Samantha Fancher

“My Brother Calls Me ‘Bug Eyes’: A Case Study on the Endocrine System”

Part A. Where is the thyroid gland located?

C. adjacent to the trachea in the neck

Part B. Which of the following is NOT secreted by the thyroid?

D. Thyroid-stimulating hormone

Part C. What is the significance of the slight swelling (called a goiter) in Krista’s neck?

B. It is a sign that her thyroid gland is overactive.

Part D. Under normal conditions, increased levels of thyroid hormone in the blood will cause?

B. A decrease in TSH levels.

Part E. Suppose Krista’s hyperthyroidism was a result of a tumor that causes the anterior pituitary gland to become overactive. Which of the following would Krista’s lab reports likely show?

A. High thyroid hormone, high TSH.

Part F. Krista’s treatment will likely involve destroying or surgically removing her thyroid gland. What effect will this have on her level of TSH?

C. TSH will increase.

Part G. Name the two hormones commonly referred to as “thyroid hormone” and describe their general actions.

The two hormones often referred to as “thyroid hormone” are triiodothyronine (T3) and thyroxine (T4). T4 is the major hormone that is secreted by the follicular cells in the thyroid. Most T3 is formed at the target tissues by conversion of T4 to T3 by removing one iodine atom. Effects of thyroid hormone include: increasing basal metabolic rate which in turns increases body temperature. Thyroid hormone turns on transcription of genes concerned with glucose oxidation (calorigenic effect). It is also responsible for tissue growth and development of the nervous, muscular, and skeletal systems. It promotes normal functioning of the heart, gastrointestinal system, reproductive system in women, and normal hydration of the integumentary system. It is also responsible for maintaining blood pressure by increasing the number of adrenergic receptors in the blood.

Part H. Why would an overactive thyroid cause...