Bio Ch 13 - Endocrine System

When the amount of thyroxine in the body increases, the basal metabolic rate of the body also increases.

True

The incidence of which of the following endocrine disorders is increasing most rapidly?

Type 2 diabetes

Which of the following statements would be the best way to describe or define the concept of the second messenger?

When the binding of the hormone to a membrane receptor (the "first messenger") activates another molecule within the cell (often cyclic AMP), that activated molecule is the second messenger.

Which of these glands secretes releasing hormones?

hypothalamus

A student just finished a delicious breakfast of pancakes with syrup, orange juice, and Danish pastries. Because his blood sugar level has increased, the pancreas will secrete ________.

insulin

Uptake of blood glucose by liver cells is stimulated by

insulin

Which of the following is required in the diet in order for active thyroid hormones to be produced?

iodine

The following is a list of events involved in the activation of a cell by a steroid hormone. Which of the following answers best represents the order in which the steps occur?1. cellular response to the hormone 2. activation of a gene 3. formation of a hormone-receptor complex 4. diffusion of the hormone through a target cell membrane 5. production of a protein

4, 3, 2, 5, 1

The secretion of oxytocin during childbirth stimulates ADH release by the anterior pituitary gland.

False

Type 1 diabetes results from lack of production of insulin and Type 2 diabetes results from insensitivity of the body's cells to insulin.

True

ACTH (adrenocorticotropic hormone) targets the

adrenal cortex

Insufficient production of growth hormone by the anterior pituitary may result in

dwarfism.

The pineal gland secretes ________, also known as the "hormone of darkness."

melatonin

Gastrin targets the

stomach

What hormone promotes water retention by the kidneys?

antidiuretic hormone (ADH)

A goiter results from low dietary iodine levels

because thyroxine cannot be made, which results in high levels of TSH.

Thryotropin Releasing Hormone (TRH) targets the

thyroid

The levels of potassium and sodium in the body are regulated primarily by the hormone aldosterone.

True

The thyroid glands secrete calcitonin.

True

Which disorder results from the excessive secretion of growth hormone in an adult?

acromegaly

The thymus produces two peptides that function to

aid in the maturation of T lymphocytes.

GnRH (gonadotropin-releasing hormone) targets the

anterior pituitary

Receptors for nonsteroid hormones are located in _____

association with a cell's plasma membrane

If diabetes is left untreated, which of the following could develop as a result?

blindness kidney failure cardiovascular disorders neural disorders All of the above are correct.

Adrenocorticotropic hormone (ACTH) triggers the release of _____ in response to stress.

glucocorticoids

Agromegaly is caused by hypersecretion of ________ hormone in adults.

growth

Which hormone stimulates milk production?

prolactin

Cortisol is a glucocorticoid that helps maintain blood glucose levels by

promoting fat utilization.

What determines whether a cell will respond to a specific hormone?

A cell must possess specific receptors for the hormone.

If a gene is activated by a hormone, what is the most likely chain of events?

A strand of mRNA is transcribed in the nucleus. It leaves the nucleus for the cytoplasm. The message is translated into a new protein.

The alpha, beta, and delta cells located in the islets of Langerhans of the thyroid produce three different hormones that are important in the regulation of sodium and potassium levels of the blood.

False

The secretion of melatonin by the pineal gland is much greater during the day than during the night.

False

The most accurate statement about LH is ________.

LH is produced in the anterior pituitary and stimulates both testosterone production and ovulation

How do releasing hormones travel from the hypothalamus to the anterior pituitary gland?

They are released near blood vessels (a capillary bed) in the hypothalamus, travel a short distance, and diffuse out around the cells of the anterior pituitary.

Atrial natriuretic hormone is secreted by the heart and helps to regulate blood pressure.

True

Steroid hormones bind to receptors in the nucleus to activate or deactivate genes.

True

Steroid hormones typically move across the cell and nuclear membranes to bind to receptors in the nucleus.

True

The number of cases of type 2 diabetes is increasing mainly due to an increase in three major risk factors: obesity, insufficient exercise, and unhealthy diets.

True

In _________ diabetes, glucose levels remain higher than normal

both type 1 and type 2

Prolactin targets the

breasts

Which hormone opposes the action of parathyroid hormone?

calcitonin

Hyposecretion of ADH results in

diabetes insipidus.

An individual, driving through his neighborhood, suddenly jams on his car brakes to avoid hitting a child who runs into the road after a ball. A few seconds later, the driver finds that he is shaking and his heart is pounding. This is primarily due to the secretion of

epinephrine from the adrenal medulla.

A deficiency of which hormone secreted by the kidneys would result in anemia?

erythropoietin

Which of these extracellular signal molecules could diffuse through a plasma membrane and bind to an intracellular receptor?

estrogen

All of the following hormones are secreted by organs of the digestive system and directly regulate digestive processes EXCEPT ________.

glucagon

Which of the following hormone combinations hase opposing activity and effects?

glucagon - insulin

When a hormone binds to a receptor, the resulting molecule is called a(n) ________.

hormone-receptor complex

Endocrine products are a class of molecules called ________.

hormones

The structure that controls hormone release by both the anterior pituitary and the posterior pituitary is the ________.

hypothalamus

Insulin helps regulate blood sugar at homeostatic levels by

promoting the entry of glucose into cells.

Which of the following hormone types enters the target cells, activates genes, and brings about the synthesis of new proteins?

steroid hormones

Hormones are specific to particular tissues because

target tissues display the appropriate receptor for a particular hormone.

Steroid hormone-receptor complexes act in _____.

the nucleus

Nonsteroid hormones differ from steroid hormones in that

they bind to a receptor on the outer surface of the cell membrane.

The primary reason steroid hormones usually act slowly is that _____

they turn genes on or off and it takes time for gene products to build up or become depleted

Diabetes type _____ occurs when the pancreas cannot produce enough insulin.

1

In type __ diabetes, no insulin ins produced

1

In type __ diabetes, target cells do not respond normally to insulin

2

_____ are the main male hormones.

Androgens

The most accurate statement about FSH is ________.

FSH is produced in the anterior pituitary and stimulates both sperm production and egg development

A characteristic that sets the endocrine system apart from the nervous system as a communication system is that endocrine control tends to be faster than nervous control.

False

Addison's disease results when the body overproduces cortisol and aldosterone.

False

Antidiuretic hormone (ADH) decreases the amount of water absorbed by the kidneys and increases the volume of urine output.

False

Epinephrine and norepinephrine secreted by the adrenal gland enhance the response of the parasympathetic nervous system.

False

In order for all hormones to cause a response, they must first bind to an appropriate receptor on the target cell's membrane.

False

Insulin helps regulate blood sugar levels by stimulating the release of glucose from glycogen stores.

False

Lactation is stimulated by the hormone LH.

False

The hormone ACTH stimulates hormone production by the adrenal medulla.

False

The responsiveness of cells to calcitonin increases as an individual ages; maximum responsiveness occurs in elderly individuals as a mechanism to improve the stability and strength of bones.

False

The secretion of TSH by the anterior pituitary gland stimulates the thymus to secrete thymosin.

False

FSH is a hormone important to the proper functioning of the ovary. This hormone will not be released from the anterior pituitary until ________ is released from the hypothalamus.

GnRH

LH (luteinizing hormone) targets the

Ovary, testis

The anterior pituitary gland produces

PRL ACTH TSH LH All of the above are correct.

Blood calcium levels will increase under the influence of ________, and decrease under the influence of ________.

PTH; calcitonin

Thyroxine is released from the thyroid gland in response to the presence of

TSH

Which of the following is true regarding estrogen and progesterone?

They are released during a female's reproductive years They are secreted by the ovaries. They regulate the menstrual cycle. They stimulate development of female secondary sex characteristics. All of the above are correct.

An increase in thyroxine secretion increases the basal metabolic rate (BMR).

True

During fasting, cortisol promotes utilization of fats by stimulating the conversion of proteins to amino acids in muscle.

True

Medically, cortisol may be administered to help relieve inflammation.

True

Nonsteroid hormones bind to a receptor on the cell membrane of target cells but do not actually enter the target cells.

True

Somatostatin functions to inhibit both insulin and glucagon.

True

All steroid hormones are synthesized from ________.

cholesterol

Which glucocorticoid hormone produced by the adrenal glands has anti-inflammatory effects?

cortisol

Which hormone can bring about a "fight-or-flight" response similar to that of the sympathetic nervous system?

epinephrine

Which of these hormones are responsible for the "fight or flight" response to danger?

epinephrine and norepinephrine

Which of these is a nonsteroid hormone?

epinephrine and oxytocin

Luteinizing hormone is considered a gonadotropin because

it promotes growth of reproductive organs in both males and females.

ADH hormone targets the

kidney

Which hormone stimulates hormone production by the ovaries and testes?

luteinizing hormone (LH)

growth hormone targets the

muscles and bones

Hormones important in maintaining homeostasis are generally part of a ________ feedback loop.

negative

How do nonsteroid hormones differ from steroid hormones?

nonsteroid hormones act via signal transduction pathways; steroid hormones do not act via signal transduction pathways

From which part of the pituitary are the hypothalamic hormones (antidiuretic hormone and oxytocin) released?

posterior pituitary

The effect of parathyroid hormone is to ________ blood calcium levels.

raise

Nonsteroid hormones require a ________ on the cell surface to communicate with cells.

receptor

When considering receptors for hormone molecules, we can say that, in general, ________.

receptors for lipid-soluble hormones are inside the cell, whereas receptors for lipid-insoluble hormones are on or in the cell membrane

Which type of hormone is most likely to react with and activate a portion of a DNA molecule?

steroid

The action of nonsteroid hormones often results in conversion of ATP to cyclic AMP, which then functions

to initiate a cascade of enzyme activations.

When oxytocin is released during childbirth, the hormone targets cells in the

uterus