Chapter 16- Endocrine System

Steroid hormones exert their action by ___. a. binding cell receptors and initiating cAMP activity b. entering the nucleus of a cell and initiating or altering the expression of a gene c. entering the cell and activating mitochondrial DNA d. activating the hypothalamic release of regulating hormones

b. entering the nucleus of a cell and initiating or altering the expression of a gene

If anterior pituitary secretion is deficient in a growing child, the child will

become a dwarf but have fairly normal body proportions

Several hormones are synthesized in the hypothalamus and transported to the anterior pituitary gland. The mechanism of transportation from hypothalamus to anterior pituitary gland is through the ________. A) hepatic portal system B) general circulatory system C) hypophyseal portal system D) feedback loop

A) hepatic portal system

The anterior pituitary secretes all but A)antidiuretic hormone B)growth hormone C)gonadotropins D)TSH

A)antidiuretic hormone

A hormone not involved in glucose metabolism is A) glucagon B)cortisone C)aldosterone D)insulin

C)aldosterone

Johanna, a 7-year-old girl, is significantly shorter than normal for her age. Her doctor recommends treatment with a hormone before her growth plates ossify in her long bones. Which hormone is recommended? A)cortisol B)parathyroid hormone C)growth hormone D)thyroid stimulating hormone

C)growth hormone

Which anterior pituitary hormone is correctly paired with its effect?

Growth hormone; stimulates growth, especially skeletal muscle and bone -Growth hormone stimulates cell division and growth, particularly within the muscular and skeletal systems.

What is the difference between a hormone and a paracrine?

Hormones are released into the blood and transported throughout the body, whereas paracrines act locally, generally within the same tissue.

One of the least complicated of the endocrine control systems directly responds to changing blood levels of ions and nutrients. Which of the following describes this mechanism?

Humoral stimulation

Which statement correctly describes the interaction between a hormone and its target cell?

Insulin, a water-soluble hormone, binds to a receptor in the plasma membrane of the target cell. -Water-soluble hormones, such as insulin, act on receptors in the plasma membrane. Typically, hormone binding activates G proteins and intracellular second-messenger systems.

MAKING CONNECTIONS: Where in the cell are steroid hormones synthesized? (Hint: Recall cell components from Chapter 3.) Where are peptide hormones synthesized? Which of these two types of hormone could be stored in vesicles and released by exocytosis?

Steroid hormones are synthesized on the membrane of the smooth endoplasmic reticulum. Peptide hormones are synthesized on rough endoplasmic reticulum. Peptide hormones can be stored in vesicles and released by exocytosis.

Which class of hormones consists entirely of lipid-soluble hormones? Name the only hormone in the other chemical class that is lipid soluble.

Steroids are all lipid soluble. Thyroid hormones are the only amino acid-based hormones that are lipid soluble.

major metabolic hormone(s) of the body

T4 and T3

tropic hormone that stimulates the thyroid gland to secrete thyroid hormone

TSH

What would happen to TSH levels in the blood if the body did not produce enough thyroid hormones?

TSH levels would increase

Select the correct statement regarding hypothalamus and pituitary interactions

The posterior pituitary releases oxytocin into the blood in response to action potentials from the hypothalamus -Action potentials travel down axons of hypothalamic neurons resulting in oxytocin release from axon terminals in the posterior pituitary.

Which two endocrine glands are found in the neck?

The thyroid and parathyroid glands are found in the neck.

Which of the following statements is true of amino acid-based hormones?

They require a receptor in the plasma membrane.

Consider the signaling mechanisms of water-soluble and lipid-soluble hormones. In each case, where are the receptors found and what is the result of the hormone binding to the receptor?

Water-soluble hormones act on receptors in the plasma membrane coupled most often via regulatory molecules called G proteins to intracellular second messengers. Lipid-soluble hormones act on intracellular receptors, directly activating genes and stimulating synthesis of specific proteins.

Select the hormone synthesized by the adrenal medulla.

epinephrine -Epinephrine synthesized by the adrenal medulla functions to activate the "fight-or-flight" response, for example, increased heart rate and blood pressure.

Testosterone is to the male as which hormone is to the female?

estrogen

During an afternoon class, Lisa starts to feel hungry and worries that her blood sugar level may be dropping. Which hormone is helping to prevent a drop in blood sugar level?

glucagon

important anabolic hormone; many of its effects mediated by IGFs

growth hormone

Elevated blood glucose levels stimulate cells of the pancreas to secrete the hormone insulin. The pancreas is responding to which type of stimulus?

humoral -Humoral stimuli include nutrients, such as glucose, as well as critical ions. Following a meal, cells of the pancreas detect rising blood glucose levels and respond to this stimulus by releasing the hormone insulin.

A hypodermic injection of epinephrine would

increase heart rate, increase blood pressure, dilate the bronchi, and decrease peristalsis

tropic hormone that stimulates the gonads to secrete sex hormones

luteinizing hormone

How is aldosterone classified?

mineralocorticoid -Aldosterone is classified as a mineralocorticoid. Aldosterone stimulates retention of sodium in the body and release of potassium into the urine.

In circumstances where the body requires prolonged or increased levels of a hormone, the DNA of target cells will specify the synthesis of more receptors on the surface of the cells of the target organ. This is known as ________.

up-regulation

Which of the following is correctly matched?

zona reticularis / gonadocorticoids

causes reabsorption of sodium ions by the kidneys

aldosterone

the only steroid hormone in the list The list: aldosterone antidiuretic hormone growth hormone luteinizing hormone oxytocin prolactin T4 and T3 TSH

aldosterone

cause the kidneys to conserve water and/or salt (two choices)

aldosterone AND antidiuretic hormone

The effect of a hormone on a target cell may be decreased by the presence of

antagonistic hormones

secreted by the posterior pituitary (two choices)

antidiuretic hormone AND oxytocin

The heart produces ______, which reduces blood volume and blood pressure.

atrial natriuretic peptide -The upper chambers of the heart, called atria, produce atrial natriuretic peptide in response to rising blood pressure. The excretion of sodium by the kidneys, called natriuresis, lowers blood volume and blood pressure.

How do cells of the pancreas respond to rising glucose levels?

Beta cells release insulin, which stimulates glycogen formation in the liver. -Beta cells of the pancreas release insulin, which stimulates glucose storage as glycogen in the liver. Alpha cells of the pancreas release glucagon, which stimulates glycogen breakdown. Acinar cells are exocrine cells of the pancreas that produce digestive enzymes.

The major stimulus for release of parathyroid hormone is A) hormonal B)humoral C)neural

B)humoral

Which of these substances might act as humoral stimulus for hormone release? A) K+ B)Glucose C) Ca2+ D All of the above

D All of the above

Which of the following is NOT a typical result of a long-term stress response? A)impaired immune function B)elevated blood pressure C)loss of muscle mass D)decreased production of glucocorticoids

D)decreased production of glucocorticoids

Parathyroid hormone A)Increases bone formation and lowers blood calcium levels B)increases calcium excretion from the body C)decreases calcium absorption from the gut D)demineralizes bone and raises blood calcium levels

D)demineralizes bone and raises blood calcium levels

The second-messenger mechanism of hormone action operates by ________. a. synthesizing more than one hormone at a time b. increasing the basal metabolic rate in the target organ c. binding to specific receptors and employing the services of G proteins and cAMP d. altering gene expression in the nuclear DNA

c. binding to specific receptors and employing the services of G proteins and cAMP

Mineralocorticoid is to aldosterone as glucocorticoid is to ________.

cortisol

Which adrenal gland hormone is correctly paired with one of its effects?

cortisol; increases blood glucose level -Cortisol, a glucocorticoid, increases blood levels of glucose, amino acids, and fatty acids. This hormone also suppresses the immune system.

Which of the following is not a category of endocrine gland stimulus? a. neural b. humoral c. hormonal d. enzyme

d. enzyme

The stimuli causing endocrine glands to secrete their hormones in direct response to changing blood levels of certain critical ions and nutrients are called __________. a. endocrinal stimuli b. hormonal stimuli c. neural stimuli d. humoral stimuli

d. humoral stimuli

Oxytocin, a hormone released by the posterior lobe of the pituitary gland, is important for breastfeeding. When the infant suckles on the breast, this sensory input is relayed through the hypothalamus, causing oxytocin release. Oxytocin acts on its target organs, the mammary glands, to make milk available to the suckling infant. (This is called the "let-down reflex.") The stimulus for oxytocin release is a _______ stimulus, and oxytocin release will be terminated by ________.

neural; the stimulus ending -Oxytocin release fits the pattern of hormone release caused by a neural stimulus. The infant suckling at the breast provides a mechanical sensory stimulus that is relayed to the hypothalamus, and this causes oxytocin release. As with all hormone release caused by neural stimuli, the oxytocin release ends when the neural stimulus (suckling) ends.

increases uterine contractions during birth

oxytocin

Enterochromaffin like cells of the gastric mucosa can be triggered to release histamine. Histamine, in this case, causes nearby parietal cells of the stomach lining to produce hydrochloric acid. The effect of histamine on parietal cells would best be described as a(n) paracrine

paracrine

Which hormone is the most important for regulating calcium balance in the blood?

parathyroid hormone -Parathyroid hormone (PTH) is the primary hormone responsible for regulating blood calcium levels. In response to low blood calcium levels, PTH raises blood calcium levels by stimulating bone tissue cells, the kidneys, and the small intestine.

stimulates milk production

prolactin

Oxytocin _______

release is an example of a positive feedback control mechanism

The hypothalamic-hypophyseal tract

runs through the infundibulum

Virtually all amino acid-based hormones exert their signaling effects through intracellular ________.

second messengers

Antidiuretic hormone (ADH) ________.

secretion is inhibited by alcohol

Which of the following is NOT a component of the cyclic AMP signaling mechanism?

steroid

Select the feature that characterizes the endocrine system

stimulates any cell in the body that has the appropriate hormone receptor -The endocrine system has widespread effects, with circulating hormones stimulating any cell in the body that has the appropriate hormone receptor. In contrast, the nervous system acts at specific locations determined by fixed axon pathways.

Which endocrine gland is found in the neck?

thyroid gland -The thyroid gland is a butterfly-shaped gland located in the anterior neck, on the trachea just inferior to the larynx.