Chapter 36

The pituitary gland and a part of the hypothalamus are among only a few parts of the brain that are not protected by the blood-brain barrier. One explanation for this could be: -they are not actually part of the brain. -the barrier would block hormone secretion. -the toxic substances blocked by the barrier do not affect them. -they developed from epithelial cells, not neurons. -they cannot produce sufficient hormone quantity without a blood supply.

-the barrier would block hormone secretion.

Within a mammalian body, which of these signals would travel the longest distance to reach its target cell? a pheromone a neurotransmitter an autocrine signal a hormone signal a paracrine signal

a hormone signal

A new hormone has been isolated from an organism. Although the structure of the hormone has not yet been determined, the hormone is known to exert its effects by forming a hormone-receptor complex that acts as a transcription factor within target cells. What type of hormone is this most likely to be? a steroid hormone either a steroid or a peptide hormone a peptide hormone either a steroid hormone or an amine hormone either an amine or a peptide hormone

a steroid hormone

Steroid hormones are derived from: phospholipids. proteins. amino acids. nucleotide bases. cholesterol.

cholesterol.

A type 1 diabetic male gives his wife an injection pen and asks her to inject him with its contents if he ever passes out due to low blood sugar. What hormone does this pen likely contain? oxytocin glucagon glycogen insulin

glucagon

Type 1 and type 2 diabetes mellitus have different underlying causes. Type 1 diabetes is characterized by a loss of the insulin-producing cells of the pancreas, leading to insulin deficiency. Type 2 diabetes, at least in its early stages, is characterized by a loss of sensitivity to the hormone insulin by cells that normally respond to the hormone. Consider the diagram. Which step labeled in the diagram shown is inhibited in both type 1 and type 2 diabetes (either directly or indirectly)? step e: glycogen hydrolysis step a: glycogen synthesis step b: hormone release step d: hormone release step c: sensory input to the pancreas

step a: glycogen synthesis

Muscle and liver cells respond to insulin by: breaking down glucose and releasing glycogen. taking up glucose and storing it as glycogen. breaking down glycogen and releasing glucose. breaking down glycogen and storing glucose.

taking up glucose and storing it as glycogen.

Which of the statements correctly describe(s) the functioning of steroid hormones in the animal endocrine system? Select all that apply. -Steroid hormones can change which mRNAs are produced in a cell. -Steroid hormones bind to cell-surface receptors, which then trigger second messengers. -In general, peptide hormones are slower to act than steroid hormones and their actions last longer than those of steroid hormones. -Steroid hormones have their primary effects in the cell's nucleus.

Steroid hormones have their primary effects in the cell's nucleus. Steroid hormones can change which mRNAs are produced in a cell.

If ACTH secretion is inhibited, which of the outcomes will result? The thyroid gland will not release thyroid hormone. The posterior pituitary gland will not release ADH. The adrenal glands will not release cortisol. The anterior pituitary gland will not release TSH.

The adrenal glands will not release cortisol.

High blood glucose stimulates the _________ cells in the pancreas to secrete _________. beta; insulin beta; glucagon alpha; insulin alpha; glucagon

beta; insulin

Early development in insects is controlled by the interaction of a number of different hormones. These include:

both peptide and steroid hormones.

Insulin injections are an important treatment for some diabetics. A serious potential side effect of insulin injections is hypoglycemia (low blood sugar). This would most likely occur under which of the circumstances? failure to inject enough insulin injecting too much insulin failure to inject any insulin

injecting too much insulin

Which option is an example of a peptide hormone? adrenaline testosterone insulin cortisol progesterone

insulin

Chemical signals that are released by one cell and act locally on neighboring cells are referred to as: neurotransmitters. pheromones. autocrine signals. hormones. paracrine signals.

paracrine signals.

Which of the statements correctly describe(s) peptide hormones? Select all that apply. -The action of peptide hormones can cause changes in gene expression or can affect the function of metabolic enzymes in cells. -Enzymes modify cholesterol compounds to produce peptide hormones. -Most peptide hormones act on cells by binding to receptors on cell surfaces and triggering signaling cascades inside the cell. -Insulin and glucagon are good examples of peptide hormones. -Peptide hormones bind to intracellular receptors and the peptide-receptor complex acts as a transcription factor.

-The action of peptide hormones can cause changes in gene expression or can affect the function of metabolic enzymes in cells. -Most peptide hormones act on cells by binding to receptors on cell surfaces and triggering signaling cascades inside the cell. -Insulin and glucagon are good examples of peptide hormones.

Which of the statements are true for the hypothalamus and pituitary gland? Select all that apply. Releasing hormonesfrom neurosecretory cells of the hypothalamus cause release of hormones into the blood from the posterior pituitary gland. The action of the neurons from the hypothalamus is direct for the posterior pituitary, that is, the neurons extend from the hypothalamus to the posterior pituitary where the axon terminal releases hormones that go directly into the blood. Neurosecretory cells of the hypothalamus secrete releasing hormones that enter the anterior pituitary via a portal system to cause release of hormones from the anterior pituitary. The action of the neurons from the hypothalamus is indirect for the anterior pituitary, that is, the action potentials in the neurons in the hypothalamus cause formation of new action potentials in different neurons in the anterior pituitary. Releasing hormones from the posterior pituitary stimulate release of specific hormones into the blood from the anterior pituitary.

-The action of the neurons from the hypothalamus is direct for the posterior pituitary, that is, the neurons extend from the hypothalamus to the posterior pituitary where the axon terminal releases hormones that go directly into the blood. -Neurosecretory cells of the hypothalamus secrete releasing factors that enter the anterior pituitary via a portal system to cause release of hormones from the anterior pituitary.

Which of the statements are correct descriptions about the pituitary gland? Select all that apply. -The anterior pituitary gland is under the control of the hypothalamus. -The pituitary gland acts as the control center for most other endocrine glands in the body. -Even though the anterior and posterior pituitary have distinctly different functions, they formed from the same embryonic tissue. -The posterior pituitary gland is under the control of the hypothalamus. -The pituitary gland controls signaling from the hypothalamus.

-The anterior pituitary gland is under the control of the hypothalamus. -The posterior pituitary gland is under the control of the hypothalamus. -The pituitary gland acts as the control center for most other endocrine glands in the body.

Which of the statements correctly describe(s) the relationship between the classes of hormones and their behavior or function? Select all that apply. The general chemical nature of a hormone can be used to predict: whether the hormone interacts with receptors inside the cell. whether the hormone interacts with receptors on the cell membrane. whether the hormone will increase or decrease aspecific cell function. whether the hormone will be able to move through the cell membrane. how soluble the hormone is in water.

-whether the hormone interacts with receptors inside the cell. -whether the hormone interacts with receptors on the cell membrane. -whether the hormone will be able to move through the cell membrane. -how soluble the hormone is in water.

_____, which is released from _____, acts on the ovaries and testes. Follicle-stimulating hormone; the anterior pituitary gland Testosterone; the posterior pituitary gland Vasopressin; the anterior pituitary gland Estrogen; the anterior pituitary gland Luteinizing hormone; the posterior pituitary gland

Follicle-stimulating hormone; the anterior pituitary gland

Assume you haven't eaten in the last 24 hours. Which of the statements would you predict? Glycogen storage by the liver will increase. Glucagon release from the pancreas will decrease. Insulin release from the pancreas will increase. Glucagon release from the pancreas will increase.

Glucagon release from the pancreas will increase.

A patient with a thyroid tumor has her thyroid gland removed. Without a thyroid gland and without Synthroid, a thyroid hormone replacement drug, which of these results is most likely to occur? Her blood TSH levels will be abnormally high, and her metabolic rate will be low. Her blood TSH levels will be abnormally high, and her metabolic rate will be high. Her blood TSH levels will be abnormally low, and her energy level will be low. Her blood TSH levels will be abnormally low, and her metabolic rate will be high.

Her blood TSH levels will be abnormally high, and her metabolic rate will be low.

Which of the statements is false? High blood glucose levels can result from an overproduction of insulin. The pancreas releases glucagon into the blood in response to low blood sugar and releases insulin into the blood in response to high blood sugar. In the pancreas, the action of the beta cells opposes the action of the alpha cells in regulating blood glucose levels. The actions of both the beta and alpha cells in the pancreas are stimulated or inhibited by the amount of glucose they detect in the blood as it passes through the pancreas.

High blood glucose levels can result from an overproduction of insulin.

Which of the statements do you think is the best prediction of what would happen if juvenile hormone or ecdysone production is disrupted? In grasshoppers, if juvenile hormone production is stopped following the third nymph stage but ecdysone production continues as it would normally, the grasshopper will become an adult at the next molt (fourth nymph stage). Grasshoppers go through five nymph stages before their final molt to the adult form. If the production of juvenile hormone is stopped after the second nymph stage, the grasshopper will continue through many more than five nymph stages of development. In grasshoppers, if ecdysone production is stopped following the second nymph stage but juvenile hormone production continues as it would normally, the grasshopper will become an adult at the next molt (third nymph stage).

In grasshoppers, if juvenile hormone production is stopped following the third nymph stage but ecdysone production continues as it would normally, the grasshopper will become an adult at the next molt (fourth nymph stage).

High blood pressure in mammals reflexively causes a decrease in heart rate, which results in lowered blood pressure. This is a _____ feedback loop because response to the signal results in a(n) _____ of that signal. negative; increase negative; decrease positive; decrease positive; increase

NEGATIVE feedback loop; response to the signal results in a DECREASE of that signal

_____ are chemical signals that, instead of being secreted into the bloodstream, are introduced by animals into their habitats. They can be used to attract mates and mark territories. Growth factors Pheromones Neurotransmitters Hormones

Pheromones

Which of the statements best describes the function of the hypothalamus? The hypothalamus produces the hormones that make up the endocrine system. The hypothalamus has endocrine hormone receptors that trigger the action potentials of the neurosecretory cells. The pituitary gland is that part of the hypothalamus that produces hormones. The hypothalamus connects the nervous system to the endocrine system.

The hypothalamus connects the nervous system to the endocrine system.

The same hormone stimulates gene expression in one cell, but inhibits gene expression in another cell. What is the best explanation for this difference? The two cells receive different amounts of the hormone. The hormone is degraded more quickly in one cell than the other. The hormone can diffuse through the plasma membrane of one cell, but not the other cell. The two cells receive the hormone at different times. The two cells have different types of receptors for the hormone.

The two cells have different types of receptors for the hormone.

Oxytocin and cholecystokinin are transported through the bloodstream and arrive at the uterus at the same time. Why does oxytocin cause the uterus to contract, whereas cholecystokinin has no effect? Unlike cholecystokinin, oxytocin is able to diffuse through the plasma membrane of uterine cells. Unlike cholecystokinin, oxytocin alters gene expression patterns. The uterus has receptors for oxytocin, but not for cholecystokinin. Oxytocin blocks the activity of cholecystokinin.

The uterus has receptors for oxytocin, but not for cholecystokinin.

The two main classes of hormones are: polysaccharide hormones and protein hormones. steroid hormones and lipid hormones. nucleic acid hormones and lipid hormones. amine/peptide hormones and steroid hormones.

amine/peptide hormones and steroid hormones

Which of these endocrine organs and hormones are paired incorrectly? anterior pituitary gland: antidiuretic hormone posterior pituitary gland: antidiuretic hormone hypothalamus: releasing factors posterior pituitary gland: oxytocin anterior pituitary gland: growth hormone

anterior pituitary gland: antidiuretic hormone

A scientist is searching for chemical compounds involved in embryonic limb development. He discovers a new compound that is transiently expressed in the limbs and only seems to affect cells in its immediate vicinity (up to a few cell lengths away). How should the scientist classify this chemical compound? as a steroid hormone as a paracrine factor as a peptide hormone as an amine hormone as a neurotransmitter

as a paracrine factor

A new hormone is discovered that appears to play a role in bone development. The hormone is hydrophilic and composed of several amino acids. How should this hormone be classified? as an amine hormone as a steroid hormone as a pheromone as a peptide hormone

as a peptide hormone

Recall that a small amount of releasing factor from the hypothalamus can cause the adrenal cortex to secrete a much greater amount of cortisol. The action of cortisol, in turn, can result in a high final concentration of glycogen in the liver. This is an example of: hormone signal amplification. hormone signal denaturation. hormone signal accumulation. hormone signal degradation.

hormone signal amplification.

In vertebrates, the nervous system directly interacts with the _________ to control endocrine function in the body. hypothalamus anterior pituitary adrenal cortex posterior pituitary

hypothalamus

Which of these structures serves as a connection between the nervous and endocrine systems? hypothalamus pineal gland adrenal gland pancreas thyroid gland

hypothalamus

Imagine that a researcher discovers a new type of chemical signal. This signal can only produce an effect over very short distances of about 10 nm, and is found in close association with synaptic clefts. This signal is most likely a: hormone. bone morphogenic protein. neurotransmitter. growth factor. histamine.

neurotransmitter.

Where would you find a receptor of a target cell for a peptide hormone? in the cytoplasm in the nucleus on the cell surface in the ribosome in the mitochondria

on the cell surface

Ecdysone is released from the _________ in response to _________ from the _________. prothoracic gland; a steroid hormone; brain brain; a peptide hormone; prothoracic gland brain; a steroid hormone; prothoracic gland prothoracic gland; a peptide hormone; brain

prothoracic gland; a peptide hormone; brain

The hypothalamus uses action potentials to directly stimulate hormone release from: neither the anterior nor the posterior pituitary. the posterior pituitary only. the anterior pituitary only. both the anterior and posterior pituitary.

the posterior pituitary only.