Chapter 10 Clicker Questions: The Endocrine System

True or false? Steroid hormones are lipid soluble.

Answer: a. True Explanation: Steroid hormones are lipid soluble. Steroids cross through the plasma membrane of target cells and combine with a receptor molecule inside the cell, forming a hormone-receptor complex.

Inhibiting hormones and releasing hormones are secreted by the _____. a. hypothalamus b. pancreas c. anterior lobe of the pituitary gland d. posterior lobe of the pituitary gland

Answer: a. hypothalamus Explanation: Inhibiting and releasing hormones are produced by the hypothalamus and travel through capillaries to the anterior pituitary, where they regulate activity of the anterior lobe.

Parathyroid hormone stimulates osteoclasts. This would ____ calcium levels in the blood. a. increase b. decrease c. not change d. inhibit

Answer: a. increase Explanation: Osteoclasts break down bone, releasing calcium into the bloodstream.

Prostaglandins are _____. a. one type of local signaling molecules b. examples of releasing hormones c. produced by the posterior lobe of the pituitary gland d. responsible for the development of goiter

Answer: a. one type of local signaling molecules Explanation: Prostaglandins are lipid molecules continually released by the plasma membranes of most cells. Prostaglandins have many diverse effects, but they act locally near the site of their release on adjacent target cells.

True or false? Water-soluble hormones pass through the plasma membrane on their own.

Answer: b. False Explanation: Only small, fat-soluble (hydrophobic) substances can pass through the phospholipid bilayer of the plasma membrane on their own. Water-soluble hormones bind to protein receptors in the plasma membrane and exert their effects through second-messenger systems.

Which type of diabetes mellitus is becoming increasingly more common in American children? a. Type 1 b. Type 2 c. Graves' disease d. All of the above

Answer: b. Type 2 Explanation: Type 2 diabetes mellitus is caused by obesity and inactivity, which is becoming increasingly common in American children.

The chemical messengers of the endocrine system are called _____. a. axons b. hormones c. glands d. neurotransmitters

Answer: b. hormones Explanation: Hormones, the chemical messengers of the endocrine system, contact virtually all cells within the body. However, hormones affect only target cells, those cells with receptors that recognize and bind specific hormones.

The adrenal medulla secretes hormones that function to prolong the effects of the ____ nervous system. a. somatic b. parasympathetic c. sympathetic d. central

Answer: c. sympathetic Explanation: The adrenal medulla secretes epinephrine and norepinephrine as hormones, which prolongs the fight-or-flight response of the sympathetic nervous system.

Growth hormone stimulates growth, especially in muscles and bones. What specific structure in bones contains many target cells for this hormone? a. Periosteum b. Red bone marrow c. Yellow bone marrow d. Epiphyseal plate

Answer: d. Epiphyseal plate Explanation: The epiphyseal plate is the growth plate in children's long bones. It responds to growth hormones, as well as others.

Which pancreatic hormone functions to increase blood glucose levels? a. Parathyroid hormone b. Insulin c. Aldosterone d. Glucagon

Answer: d. Glucagon Explanation: Glucagon stimulates the liver to break glycogen down into glucose, which is then released into the bloodstream.

Red bone marrow cells respond to a hormone called erythropoietin. Why doesn't a liver or kidney cell respond to this hormone? a. The hormone is water-soluble, so kidney and liver cells cannot respond to it. b. Only hormones secreted by the bone marrow are able to act upon the bone marrow. c. Ion channels that allow erythropoietin to diffuse into the cell are missing in kidney and liver cells. d. Kidney and liver cells do not contain the protein receptor that binds erythropoietin.

Answer: d. Kidney and liver cells do not contain the protein receptor that binds erythropoietin. Explanation: Only target cells, which contain the receptors for a hormone, can respond to that hormone.

Oversecretion of which hormone will result in acromegaly? a. Epinephrine b. Growth hormone c. Glucagon d. Testosterone

Answer: b. Growth hormone Explanation: Increased production of growth hormone in adults causes bones to thicken, a condition called acromegaly.

The thymus gland lies on top of the _____ and plays an important role in _____? a. kidney, immunity b. heart, immunity c. pancreas, blood glucose levels d. heart, blood glucose levels

Answer: b. heart, immunity Explanation: The thymus gland lies on top of the heart and plays an important role in immunity. Its hormones influence the maturation of white blood cells called T lymphocytes.

Too little thyroid hormone secretion causes the following symptoms. a. Nervousness and sleeplessness b. Anxiety and weight loss c. Decreased body temperature and heart rate d. All of the above

Answer: c. Decreased body temperature and heart rate Explanation: Undersecretion of thyroid hormone decreases metabolic activity of body cells.

Tropic hormones secreted by the anterior lobe of the pituitary gland include _____. a. oxytocin and ADH b. growth hormone and prolactin c. FSH and LH d. insulin and glucagon

Answer: c. FSH and LH Explanation: A hormone produced by one endocrine gland that influences the activity of another endocrine gland is called a tropic hormone. The anterior pituitary produces several tropic hormones, including TSH, ACTH, FSH, and LH.

Which endocrine gland might be involved in seasonal affective disorder, which occurs in some people during winter, when the days are shorter? a. Pituitary b. Adrenal c. Thyroid d. Pineal

Answer: d. Pineal Explanation: The pineal gland secretes melatonin in response to dark. Melatonin causes lethargy, sleepiness, and depression.

5. When the response of a tissue to the combination of two hormones is much greater than its response to either individual hormone, the interaction is said to be _____. a. antagonistic b. permissive c. tropic d. synergistic

Answer: d. synergistic Explanation: Antagonistic hormones oppose each other. In permissive interactions, one hormone must be present for another hormone to exert its effects. In synergistic interactions, the effects of the two hormones are much greater than additive.