chapter 16
Endocrine System
Q: What are the main functions of the endocrine system?
A: Produces hormones that regulate body functions and travel through the bloodstream to target tissues.
Q: Why do hormones have longer-lasting effects than the nervous system?
A: Hormones travel through the blood and remain active longer.
Q: What are endocrine glands?
A: Ductless glands that produce hormones.
Q: What are the three factors that affect target cell activation?
A: Amount of hormone, number of receptors, and strength of hormone-receptor bond.
Q: What are the three types of hormone release stimuli?
A: Humoral, neural, and hormonal stimuli.
Q: What is an example of humoral stimulus?
A: Low blood calcium causes release of parathyroid hormone.
Q: What is an example of neural stimulus?
A: Sympathetic nerves stimulate adrenal medulla release of catecholamines.
Q: What is an example of hormonal stimulus?
A: TSH stimulates the thyroid gland to release thyroxine.
Pituitary Gland
Q: What is another name for the pituitary gland?
A: Hypophysis (master gland).
Q: How many hormones does the pituitary gland secrete?
A: Eight hormones.
Q: What connects the pituitary gland to the hypothalamus?
A: The infundibulum.
Q: What hormones are stored and released by the posterior pituitary?
A: Oxytocin and ADH.
Q: What are the functions of oxytocin?
A: Uterine contractions, orgasm, milk let-down, and bonding behaviors.
Q: What does ADH do?
A: Causes kidneys to reabsorb more water and produce concentrated urine.
Q: What hormone stimulates growth and protein production?
A: Growth hormone (GH).
Q: What hormone stimulates milk production?
A: Prolactin.
Q: What does TSH stimulate?
A: Release of thyroid hormones from the thyroid gland.
Q: What does ACTH stimulate?
A: Release of glucocorticoids and androgens from the adrenal cortex.
Q: What are the two gonadotropins?
A: FSH and LH.
Q: What does FSH do?
A: Stimulates gamete production in males and females.
Q: What does LH do in females?
A: Matures follicles.
Q: What does LH do in males?
A: Stimulates testosterone release.
Thyroid & Parathyroid Glands
Q: Where is the thyroid gland located?
A: On the trachea, inferior to the larynx.
Q: What is the largest pure endocrine gland?
A: Thyroid gland.
Q: What are the two thyroid hormones?
A: T3 (triiodothyronine) and T4 (thyroxine).
Q: What do thyroid hormones regulate?
A: Basal metabolic rate, growth, and blood pressure.
Q: Symptoms of hypothyroidism?
A: Low metabolism, cold intolerance, puffy eyes, lethargy, weight gain.
Q: Symptoms of hyperthyroidism?
A: High metabolism, sweating, bulging eyes, nervousness, weight loss.
Q: What hormone lowers blood calcium levels?
A: Calcitonin.
Q: What hormone raises blood calcium levels?
A: Parathyroid hormone (PTH).
Q: What are the three actions of PTH?
A: Breaks down bone, increases kidney calcium reabsorption, and increases intestinal calcium absorption.
Adrenal Glands
Q: What hormones does the adrenal medulla release?
A: Epinephrine and norepinephrine.
Q: What is the function of aldosterone?
A: Maintains sodium balance and regulates salt.
Q: What are glucocorticoids?
A: Hormones that regulate metabolism, stress response, blood glucose, and blood pressure.
Q: Which adrenal layer produces glucocorticoids?
A: Zona fasciculata.
Q: Which adrenal layer produces weak androgens?
A: Zona reticularis.
Pancreas
Q: What hormone raises blood glucose levels?
A: Glucagon.
Q: Which pancreatic cells produce glucagon?
A: Alpha cells.
Q: What hormone lowers blood glucose levels?
A: Insulin.
Q: Which pancreatic cells produce insulin?
A: Beta cells.
Q: What is Type 1 diabetes?
A: Not enough insulin is produced.
Q: What is Type 2 diabetes?
A: Insulin is made but doesn’t function properly.
Q: Common symptoms of diabetes mellitus?
A: Sugar in urine, ketones in urine, weight loss, excessive urination, thirst, and hunger.
Pineal & Thymus
Q: What hormone does the pineal gland produce?
A: Melatonin.
Q: What suppresses melatonin production?
A: Sunlight and blue light.
Q: What is the function of the thymus?
A: Produces hormones needed for T-lymphocyte development.