Chapter 16 - Endocrine System - Thyroid Gland and Paraythyroid Gland Hormones

Question 1

Triiodothyronine (T3) and Thyroxine (T4)

THYROID GLAND

Answer 1

1. Stimulated by the secretion of Thyroid-Stimulating Hormone (TSH) in the Anterior Pituitary Gland
2. Causes the Follicle Cells in the Thyroid Gland to produce T3 and T4 Hormones.
3. These hormones will effect nearly all cells in the body and will set the basal metabolic rate, control thermoregulations, and enhance growth and development
4. Increased T3 and T4 are inhibited by Thyrotropin-Releasing Hormone (TRH) and TSH

Question 2

Calcitonin

THYROID GLAND

Answer 2

1. Stimulated by an increase concentration in calcium ions in the blood
2. The Parafollicular Cells of the Thyroid Gland will secrete Calcitonin
3. Calcitonin will inhibit osteoCLAST activity under certain conditions, which transiently decreases the blood calcium ion concentration.
4. Calcitonin is inhibited a decrease concentration of calcium ions in the blood

Question 3

Parathyroid Hormone

PARATHYROID GLAND

Answer 3

1. Stimulated by a decrease concentration in calcium ions in the blood
2. Chief cells of the Parathyroid Gland will increase calcium ion reabsorption from the fluid in the kidneys, increase calcium ions absorption from the contents of the small intestine, indirectly increase osteoCLAST activity, and all effects will lead to an increase blood calcium ion concentration
3. PTH is inhibited by an increase in concentration of calcium ions in the blood