BIOL 2402 - Ch. 16 Endocrine System

Colloid

(1) A mixture in which the solute particles (usually proteins) do not settle out readily. (2) Substance in the thyroid gland containing thyroglobulin protein.

Antagonist

(1) Muscle that reverses, or opposes, the action of another muscle. (2) Hormone that opposes the nation of another hormone.

Follicle

(1) Ovarian structure consisting of a developing egg surrounded by one or more layers of follicle cells (2) Colloid-containing structure of the thyroid gland (3) B cell-rich region n lymphoid tissue

Norepinephrine

A catecholamine neurotransmitter and adrenal medullary hormone, associated with sympathetic nervous system activation.

Paracrines

A chemical messenger that acts locally within the same tissue and is rapidly destroyed. Examples are prostaglandins and nitric oxide.

Atrial Natriureti Peptide (ANP)

A hormone released by certain cells of the heart atria tat reduces blood pressure and blood volume by inhibiting nearly all events that promote Na+ and water retention and vasoconstriction.

Melatonin

A hormone secreted by the pineal gland; secretion peaks at night and helps set sleep-wake cycles; also a powerful antioxidant.

Androgen

A hormone such as testosterone that controls male secondary sex characteristics.

Insulin

A hormone that enhances the carrier-mediated diffusion of glucose into tissue cells, thus lowering blood glucose levels.

Tropic Hormones

A hormone that regulates the secretory action of another endocrine organ.

Pineal Gland

A hormone-secreting part of the diencephalon of the brain through to be involved in setting the biological clock and influencing reproductive function.

Angiotensin II

A potent vasoconstrictor activated by renin; also triggers release of aldosterone.

What is the mechanism of action of lipid-soluble hormones? A. Increasing protein kinases B. Phosphorylation of intracellular proteins C. Activation of genes, which increases protein synthesis in the cell

Activation of genes, which increases protein synthesis in the cell.

After a lipid-soluble hormone is bound to its intracellular receptor, what does the hormone complex do? A. Phosphorylates a protein B. Activates a protein kinase C. Directly alters protein synthesis at the ribosome D. Acts as a transcription factor and binds to DNA, activating a gene

Acts as a transcription factor and binds to DNA, activating a gene.

Prolactin (PRL)

Adenohypophyseal hormone that stimulates the breasts to produce milk.

Glucocorticoids

Adrenal cortex hormones that increase blood glucose levels and aid the body in resting long-term stressors.

Which of the following glands is found atop the kidneys? A. Adrenal B. Parathyroid C. Thyroid D. Pituitary

Adrenal.

Which of the following hormones stimulates the adrenal cortex to release glucocorticoids that help the body to resist stressors? A. Adrenocorticotropic hormone B. Thyroid-stimulating hormone C. Prolactin D. Follicle-stimulating hormone

Adrenocorticotropic Hormone.

What tropic hormone stimulates cortisol from the adrenal gland? A. Luteinizing hormone (LH) and follicle stimulating hormone (FSH) B. Growth hormone (GH) C. Thyroid stimulating hormone (TSH) D. Adrenocorticotropic hormone (ACTH)

Adrenocorticotropic hormone (ACTH).

What is the primary function of hormones? A. Cause allergic reactions B. Activate extracellular enzymes C. Alter cell activity D. Influence metabolic activity of glands by electrochemical impulses

Alter cell activity.

Adenylate Cyclase

An enzyme, usually activated by a G protein, that converts ATP to the second messenger cyclic AMP.

Luteinizing Hormone (LH)

Anterior pituitary hormone that aids maturation of cells in the ovary and triggers ovulation in females. In males, causes the interstitial endocrine cells of the testis to produce testosterone.

Thyroid-Stimulating Hormone (TSH)

Anterior pituitary hormone that regulates secretion of thyroid hormones.

Which of the following hormones helps the body avoid dehydration and water overload? A. Thyroid-stimulating hormone B. Follicle-stimulating hormone C. Oxytocin D. Antidiuretic hormone

Antidiuretic hormone

The second-messenger mechanism of hormone action operates by _____. A. Altering gene expression in the nuclear DNA 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. Synthesizing more than one hormone at a time

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

Cushing's syndrome and aldosteronism have the same effects on ______. A. Blood pressure B. Gluconeogenesis C. Plasma glucose levels D. All of the listed responses are correct

Blood pressure.

Endocrine System

Body system that includes internal organs that secrete hormones.

What keeps intracellular receptors from binding to DNA before a hormone binds to the receptor? A. Transcription factors B. Chaperone proteins (chaperonis) C. Receptors can't enter the nucleus until the hormone is bound to it

Chaperone proteins (chaperonins).

Epinephrine

Chief hormone produced by the adrenal medulla. Also called adrenaline.

Myxedema

Condition resulting from underachieve thyroid gland.

What is the function of the ventral hypothalamic neurons? A. Control secretion of thyroid stimulating hormone (TSH) B. Control secretion of antidiuretic hormone (ADH) C. Control secretion of thyroid hormones D. Control secretion of oxytocin

Control secretion of thyroid stimulating hormone (TSH).

Which of the following hormones has intracellular receptors? A. Epinephrine B. Cortisol C. Insulin

Cortisol.

Which of the following homeostatic imbalances is characterized by persistent elevated blood glucose levels, dramatic losses in muscle and bone protein, and water and salt retention, leading to hypertension and edema? A. Addison's disease B. Cretinism C. Graves' disease D. Cushing's syndrome

Cushing's syndrome.

Graves' Disease

Disorder resulting from hyperactive thyroid gland.

Endocrine Glands

Ductless glands that empty their hormonal products directly into the blood.

Hormones often cause a cell to elicit multiple responses; this is because _____. A. There are thousands of receptors on the cell membrane B. The protein kinases are rapidly metabolized into functional amino acids C. The receptors bind to several hormones at the same time D. During protein kinase activation, enzymes phosphorylate many other enzymes

During protein kinase activation, enzymes phosphorylate many other enzymes.

Which of the following is NOT a major type of stimulus that triggers endocrine glands to manufacture and release hormones? A. Neural B. Humoral C. Enzymatic D. Hormonal

Enzymatic.

Renin

Enzyme released by the kidneys that raises blood pressure by initiating the renin-angiotensin-aldosterone mechanism.

(T/F) Direct gene activation involves a second-messenger system.

False.

Ketones

Fatty acid metabolites; strong organic acids.

Insulin-like growth factors (IGFs) are intermediary hormones stimulated by which of the following hormones? A. Thyroid hormones B. Oxytocin C. Prolactin (PRL) D. GH (Growth Hormone)

GH (Growth Hormone).

Gonadotropins

Gonad-stimulating hormones produced by the anterior pituitary.

Which of the following is not a homeostatic imbalance related to underactivity of the thyroid gland? A. Cretinism B. Graves' disease C. Myxedema D. Endemic goiter

Graves' disease.

What is required for the production of anterior pituitary gland hormones? A. Humoral stimuli B. Hormonal stimuli C. Neural stimuli (from the sympathetic division of the ANS) D. All of these

Hormonal stimuli.

Glucagon

Hormone formed by alpha cells of pancreatic islet; raises the glucose level of blood.

Progesterone

Hormone partly responsible for preparing the uterus for the fertilized ovum.

Aldosterone

Hormone produced by the adrenal cortex that regulates Na_ reabsorption and K+ secretion by the kidneys.

Follicle-Stimulating Hormone (FSH)

Hormone produced by the anterior pituitary that stimulates ovarian follicle production in females and sperm production in males.

Antidiuretic Hormone (ADH)

Hormone produced by the hypothalamus and released by the posterior pituitary; stimulates the kidneys to reabsorb more water, reducing urine volume.

Parathyroid Hormone (PTH)

Hormone released by the parathyroid glands that regulates blood calcium level.

Calcitonin

Hormone released by the thyroid. Lowers blood calcium levels only when present at high (therapeutic) levels.

Oxytocin

Hormone synthesized in the hypothalamus and secreted by the posterior pituitary; stimulates contraction of the uterus during childbirth and the ejection of milk during nursing.

Growth Hormone (GH)

Hormone that stimulates growth in general; produced in the anterior pituitary; also called somatotropin.

Erythropoietin (EPO)

Hormone that stimulates production of red blood cells.

Adrenal Glands

Hormone-producing glands located superior to the kidneys; each consists of medulla and cortex areas.

Estrogens

Hormones that stimulate female secondary sex characteristics; female sex hormones.

Chemical substances secreted by cells into the extracellular fluids and that regulate the metabolic function of other cells in the body are called _____. A. Antibodies B. Hormones C. Proteins D. Enzymes

Hormones.

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. Neural stimuli C. Hormonal stimuli D. Humoral stimuli

Humoral stimuli.

Where is antidiuretic hormone (ADH), also known as vasopressin, synthesized? A. Hypothalamus B. Kidney C. Anterior pituitary D. Posterior pituitary

Hypothalamus.

One can predict that a person suffering from diabetes mellitus would probably have _____. A. Increased secretion of ANP (atrial natiuretic peptide) B. Increased secretion of ADH (anti-diuretic hormone) C. Decreased secretion of catecholamines D. Decreased secretion of PTH (parathyroid hormone/parathormone)

Increased secretion of ADH (anti-diuretic hormone).

Thyroxine (T4)

Iodine-containing hormone secreted by the thyroid gland; accelerates cellular metabolic rate in most body tissues.

Which of the following best describes the main effects of insulin? A. Catabolize glycogen into glucose B. Lower blood glucose levels C. Release glucose into the blood by liver cells D. Synthesis of glucose from lactic acid and noncarbohydrate molecules

Lower blood glucose levels.

Thymus

Lymphoid organ active in immune responses; site of maturation of T lymphocytes.

Testosterone

Male sex hormone produced by the testes; during puberty promotes virilization, and is necessary for normal sperm production.

What is the most important regulatory factor controlling the circulating levels of thyroid hormone? A. A circadian rhythm of release B. Thyroid-stimulating hormone (TSH) C. Negative feedback D. Thyrotropin-releasing hormone (TRH)

Negative feedback.

Hypothalamic-Hypophyseal Tract

Nerve bundles that run through the infundibulum and connect the posterior pituitary to the hypothalamus.

Posterior Pituitary

Neural part of pituitary gland; part of the neurohypophysis.

Pituitary Gland

Neuroendocrine gland located beneath the brain that serves a variety of functions including regulation of gonads, thyroid, adrenal cortex, lactation, and water balance.

Which of the following is a hormone produced by the posterior pituitary? A. ADH B. Oxytocin C. HGH D. None of these

None of these.

Thyroid Gland

One of the largest of the bod's endocrine glands; straddles the anterior trachea.

Amino Acid

Organic compound containing nitrogen, carbon, hydrogen, and oxygen; building block of protein.

Which of the following hormones is regulated by a neuroendocrine ("letdown") reflex? A. Antidiuretic hormone (ADH) B. Cortisol C. Oxytocin

Oxytocin.

Which of the following hormones regulates blood calcium ion levels? A. Insulin B. Luteinizing hormone C. Follicle-stimulating hormone D. Parathyroid hormone E. Glucagon F. Thyroid hormone

Parathyroid hormone.

______ is the situation when one hormone cannot exert its full effects without another hormone being present. A. Permissiveness B. Synergism C. Activism D. Antagonism

Permissiveness.

Which of the following enzymes are important in the deactivation of cAMP and termination of signaling? A. Protein kinase B. Phosphodiesterase C. G Protein D. Adenylate Cyclase

Phosphodiesterase.

Neurohypophysis

Posterior pituitary plus infundibulum; portion of the pituitary gland derived from the brain.

Gonads

Primary reproductive organ; i.e., the testis of the male or the ovary of the female.

G Protein

Protein that relays signals between extracellular first messengers (such as hormones or neurotransmitters) and intracellular second messengers (such as cyclic AMP) via an effector enzyme.

Hypothalamus

Region of the diencephalon forming the floor of the third ventricle of the brain.

Gonadocorticoids

Sex hormones, primarily androgens, secreted by the adrenal cortex.

Parathyroid Glands

Small endocrine glands located on the posterior aspect of the thyroid gland.

Mineralocorticoid

Steroid hormone of the adrenal cortex that regulates Na+ and K+ metabolism and fluid balance.

Corticosteroids

Steroid hormones released by the adrenal cortex.

Thyroid hormone (a small iodinated amine) enters target cells in a manner similar to _____. A. Growth hormone, because the thyroid works synergistically with thyroid hormone B. Steroid hormones, because both diffuse easily into target cells C. Glucagon, because the structure of glucagon is similar to that of thyroid hormone D. Insulin, because insulin is a small peptide

Steroid hormones, because both diffuse easily into target cells.

Which of the following best describes gluconeogenesis? A. Creation of glycogen from glucose B. Breakdown of glycogen into glucose C. Conversion of glucose to fat D. Synthesis of glucose from noncarbohydrate sources

Synthesis of glucose from noncarbohydrate sources.

Hyperglycemic

Term used to describe hormones such as insulin that decrease blood glucose level.

Hypoglycemic

Term used to describe hormones such as insulin that decrease blood glucose level.

Match the following: 1. Testosterone production 2. Epinephrine production 3. Aldosterone production 4. Parathyroid hormone production A. Humoral and/or hormonal stimulus B. Hormonal stimulus C. Neural stimulus D. Humoral stimulus

Testosterone production - hormonal stimulus Epinephrine production - neural stimulus Aldosterone production - humoral and/or hormonal stimulus Parathyroid hormone production - humoral stimulus

Anterior Pituitary (Adenohypophysis)

The glandular part of the pituitary gland.

Thyroid Hormone (TH)

The major hormone secreted by thyroid follicles; stimulates enzymes concerned with glucose oxidation.

Negative Feedback Mechanism

The most common homeostatic control mechanism. The net effect is that the output of the system shuts off the original stimulus or reduces its intensity.

Which of the following is NOT a property of endocrine glands? A. They drain lymphatically B. They produce hormones C. They drain vascularly D. They have ducts

They have ducts.

Which hormone's receptor is always bound to DNA, even when the receptor is empty? A. Cortisol B. Insulin C. Thyroid hormone

Thyroid hormone.

Triiodothryonine (T3)

Thyroid hormone; secretion and function similar to those of thyroxine (T4).

Hormones that regulate the secretory action of other endocrine glands are called ______. A. Tropins B. Somatostatins C. Somatotropin D. GHIH

Tropins.

(T/F) Both "turn on" factors (hormonal, humoral, and neural stimuli) and "turn off" factors (feedback inhibition and others) may be modulated by the activity of the nervous system.

True.

(T/F) Hormones are long-distance chemical signals that travel in blood or lymph throughout the body.

True.

(T/F) Major hormones circulate to virtually all tissues.

True.

Put the events of cAMP signaling in correct sequence from left to right. 1. Adenylate Cyclase 2. Receptor activates 3. cAMP activates 4. Water-soluble hormone binds receptor 5. G protein activates

Water-soluble hormone binds receptor Receptor activates G protein activates Adenlyate cyclase cAMP activates

Which of the following pairs correctly match the adrenal gland zone or area with the class of hormones it produces? A. Zona fasciculate/gonadocorticoids B. Zona reticularis/catecholamines C. Medulla/glucocorticoids D. Zona glomerulosa/mineralocorticoids

Zona glomerulosa/mineralocorticoids