Chapter 13: Endocrine System

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

1

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

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.

adrenal cortex

ACTH

stimulates the release of glucocorticoids from the adrenal cortex

ACTH

The anterior pituitary gland produces

ACTH. LH. TSH. & PRL.

kidney

ADH

promotes sodium uptake and potassium excretion

Aldosterone

The most accurate statement about FSH is ________.

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

(F/T) The secretion of TSH by the anterior pituitary gland stimulates the thymus to secrete thymosin.

False

(T/F) 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

(T/F) Addison's disease results when the body overproduces cortisol and aldosterone.

False

(T/F) Epinephrine and norepinephrine secreted by the adrenal gland enhance the response of the parasympathetic nervous system.

False

(T/F) Insulin helps regulate blood sugar levels by stimulating the release of glucose from glycogen stores.

False

(T/F) 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

(T/F) The hormone ACTH stimulates hormone production by the adrenal medulla.

False

(T/F) 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

(T/F) The secretion of melatonin by the pineal gland is much greater during the day than during the night.

False

(T/F) The secretion of oxytocin during childbirth stimulates ADH release by the anterior pituitary gland.

False

(T/F) lactation is stimulated by the hormone LH

False

(T/F)In order for all hormones to cause a response, they must first bind to an appropriate receptor on the target cell's membrane.

False

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

False Submit

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

anterior pituitary

GnRH

stimulates cell uptake of glucose by cells throughout the body

Insulin

Ovary, Testis

LH

causes release of the egg from the ovary

LH

The most accurate statement about LH is ________.

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

causes ejection of milk into ducts during breast-feeding

Oxytocin

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

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. Submit

Which of the following is true regarding estrogen and progesterone?

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

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

True

(T/F) Atrial natriuretic hormone is secreted by the heart and helps to regulate blood pressure.

True

(T/F) During fasting, cortisol promotes utilization of fats by stimulating the conversion of proteins to amino acids in muscle.

True

(T/F) Medically, cortisol may be administered to help relieve inflammation.

True

(T/F) Nonsteroid hormones bind to a receptor on the cell membrane of target cells but do not actually enter the target cells.

True

(T/F) Somatostatin functions to inhibit both insulin and glucagon.

True

(T/F) Steroid hormones bind to receptors in the nucleus to activate or deactivate genes.

True

(T/F) Steroid hormones typically move across the cell and nuclear membranes to bind to receptors in the nucleus.

True

(T/F) The levels of potassium and sodium in the body are regulated primarily by the hormone aldosterone.

True

(T/F) 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

(T/F) 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 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.

Receptors for nonsteroid hormones are located in _____.

association with a cell's plasma membrane

A goiter results from low dietary iodine levels

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

lowers blood calcium levels

calcitonin

All steroid hormones are synthesized from ________.

cholesterol

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

cortisol

Hyposecretion of ADH results in

diabetes insipidus.

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

dwarfism

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

epinephrine

Which of these is a nonsteroid hormone?

epinephrine and oxytocin

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 Submit

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

estrogen

stomach

gastrin

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

glucagon Submit

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

glucagon - insulin

Agromegaly is caused by hypersecretion of ________ hormone in adults.

growth

muscles and bones

growth hormone

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

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

Luteinizing hormone is considered a gonadotropin because

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

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

kidney failure neural disorders cardiovascular disorders blindness

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

melatonin

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

breasts

prolactin

Cortisol is a glucocorticoid that helps maintain blood glucose levels by

promoting fat utilization.

Insulin helps regulate blood sugar at homeostatic levels by

promoting the entry of glucose into cells.

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

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

Thyroid

thyrotropin

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

to initiate a cascade of enzyme activations.

(T/F) The thyroid glands secrete calcitonin

true

(T/F) 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

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

uterus