Chapter 13 The Endocrine System

The following is a list of events involved in the activation of a cell by a steroid hormone. Which one 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

Luteinizing hormone is considered a gonadotropin because of which one of the following reasons?

It promotes the growth of reproductive organs in both males and females

Which one of the following hormones stimulates the production of testosterone in males?

LH

causes release of the egg from the ovary

LH

________ cells have axons that can transmit nerve impulses in addition to being able to secrete hormones like endocrine cells

Neuroendocrine

Prednisone is a glucocorticoid hormone that is sometimes prescribed to treat rheumatoid arthritis, asthma, and severe allergic reactions. If prednisone were taken for several weeks, which one of the following might occur?

Production of natural cortisol may decrease.

Calcitonin and PTH have opposing effects on blood calcium levels.

TRUE

Disorders associated with the endocrine system can be caused by problems with hormone production or lack of receptors for the hormones on the target cells.

TRUE

During prolonged fasting, cortisol assists in maintaining blood glucose levels by stimulating the conversion of proteins to amino acids in muscle.

TRUE

Graves disease is an autoimmune disorder in which a person's thyroid is stimulated to produce too much thyroxine.

TRUE

Nitric oxide helps regulate blood flow in many tissues and is involved in the development and control of penile erection.

TRUE

Somatostatin functions to inhibit both insulin and glucagon.

TRUE

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

TRUE

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

TRUE

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

TRUE

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

TSH.

GnRH

anterior pituitary

A goiter results from low dietary iodine levels

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

Nonsteroid hormones differ from steroid hormones in that they

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

prolactin

breasts

lowers blood calcium levels

calcitonin

Which one of the following is caused by the secretion of atrial natriuretic hormone by the heart?

decrease in blood pressure

Hyposecretion of ADH results in

diabetes insipidus

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

dwarfism.

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 which one of the following?

epinephrine from the adrenal medulla

The ovaries of women function as endocrine organs by producing

estrogen and progesterone

Nonsteroid hormones are ________ acting than steroid hormones because they activate molecules that are already present in the target cell in an inactive form

faster

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 secretes ________.

insulin

stimulates cell uptake of glucose by cells throughout the body

insulin

Uptake of blood glucose by liver cells is stimulated by

insulin.

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

iodine

The endocrine cells of the pancreas are located in small groupings throughout the organ known as the ________.

islets of Langerhans or pancreatic islets (either answer is correct)

The pituitary gland is often called the "master of the endocrine system" because

it secretes eight different hormones that in turn regulate many of the other endocrine glands.

ADH

kidney

Steroid hormones depend on receptors inside the cell because these hormones are ________ soluble.

lipid

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

melatonin

growth hormone

muscles and bones

Hormones important in internal homeostatic control mechanisms are generally part of a(n) ________ feedback loop

negative

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

raise

Nonsteroid hormones require a(n) ________ on the cell surface to communicate with cells

receptor

Hormones from the anterior pituitary gland are not secreted unless they are stimulated to be released by ________ from the hypothalamus

releasing hormones

Which of the following tissues/organs is NOT a member of the endocrine system?

salivary gland

Every hormone in the human body needs to interact with an appropriate receptor on the target cell's membrane before it can cause a response

FALSE

In females, LH promotes the monthly development of the egg and FSH causes release of the egg from the ovary.

FALSE

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

1

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

FALSE

Nonsteroid hormones cause the production of ATP from cAMP.

FALSE

stimulates the release of glucocorticoids from the adrenal cortex

ACTH

The anterior pituitary gland produces all of the following EXCEPT which one?

ADH

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 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 oxytocin during childbirth stimulates ADH release by the anterior pituitary gland

FALSE

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

FALSE

Erythropoietin, a hormone secreted by the liver, stimulates red blood cell production in the bone marrow.

FALSE

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

GnRH

All of the following statements about the endocrine system are TRUE EXCEPT which one?

Hormones act more quickly than the nervous system.

________ of growth hormone during childhood can result in pituitary dwarfism

Hyposecretion

All of following statements are TRUE regarding estrogen and progesterone, EXCEPT which one?

They are peptide hormones that activate target cells through the cyclic AMP second messenger mechanism

ACTH

adrenal cortex

Although most of the estrogen and testosterone produced in the human body is made by the ovaries and testes, respectively, small amounts of these hormones are also produced by the ________.

adrenal cortex

The thymus produces two peptides that function to

aid in the maturation of T lymphocytes

promotes sodium uptake and potassium excretion

aldosterone

Which one of the following hormone pairs is antagonistic, in that they have opposing effects?

glucagon, insulin

Gigantism is caused by hypersecretion of ________ hormone during childhood and adolescence.

growth

During times of stress, which one of the following glands stimulates the anterior pituitary to release ACTH?

hypothalamus

Neuroendocrine cells can be found in the ________.

hypothalamus, adrenal cortex, posterior pituitary (any term can be used)

All of the following may result from untreated diabetes mellitus EXCEPT which one?

increased susceptibility to cancer

LH

ovary, testis

causes ejection of milk into ducts during breast-feeding

oxytocin

Releasing and inhibiting hormones from the hypothalamus are carried to the anterior pituitary gland by the ________.

pituitary portal system

Cortisol is a glucocorticoid that helps maintain blood glucose levels during fasting by

promoting fat utilization

Insulin helps regulate blood sugar at homeostatic levels by

promoting the entry of glucose into cells

Which one of the following nonhormonal chemical messengers is important in local control of blood flow and blood clotting?

prostaglandins

gastrin

stomach

Which one of the following causes the release of epinephrine and norepinephrine from the adrenal medulla

sympathetic nerves

Hormones act upon specific target tissues because

target tissues display the appropriate receptor for a particular hormone

Thymosin and thymopoietin are secreted by the ________.

thymus

thyrotropin

thyroid

Which two endocrine glands exert the most control over blood calcium levels

thyroid and parathyroid

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.