Random Endocrine Questions

Iodination of thyroid hormones is mediated by A. lysosomes in the cell. B. peroxidase enzymes. C. the Golgi apparatus. D. colloid endocytosis

B. peroxidase enzymes.

Which of the following hormones could enter the cell? A. the growth hormone B. thyroxine C. leptin D. insulin

C. leptin

Which of the following signals would affect local cells by releasing chemicals into the extracellular fluid? A. Neural B. Autocrine C. Endocrine D. Paracrine

D. Paracrine

Resistin, an insulin antagonist, is a hormone produced by the A. liver. B. heart. C. hypothalamus. D. adipose tissue

D. adipose tissue

The chemical classification of hormones does NOT include A. cholesterol containing hormones. B. steroid hormones. C. protein-based hormones. D. glucose-containing hormones. E. amino acid-based hormones

D. glucose-containing hormones.

Proopiomelanocortin (POMC) has 3 types of receptors. What are they?

- ACTH receptor - Melanocortin - Beta-endorphin

What 2 hormones are part of the Somatotropin family?

- GH - Prolactin

POMC is a prohormone for ___. A) ACTH B) TH C) GnRH D) Prolactin

A) ACTH

Select the correct statement about testosterone control. A) GnRh from the hypothalamus causes FSH and LH release from the anterior pituitary. B) FSH stimulates testicular production of testosterone. C) Inhibin and testosterone exert positive feedback on the hypothalamus and pituitary. D) The pineal gland is believed to be the gland that exerts the most influence in testosterone control.

A) GnRh from the hypothalamus causes FSH and LH release from the anterior pituitary.

Steroid hormones exert their action by ________. A) entering the nucleus of a cell and initiating or altering the expression of a gene B) finding an appropriate cell receptor and initiating cAMP activity C) stimulating the synthesis of a glycogen D) increasing blood pressure

A) entering the nucleus of a cell and initiating or altering the expression of a gene

Which of the following organs is affected by thyroid hormone in adults? A) liver B) spleen C) thyroid gland D) brain

A) liver

Cellular responses to hormones that initiate second-messenger systems include ________. A) possible activation of several different second-messenger systems B) cyclic AMP phosphodiesterase formation of an active second messenger C) formation of a specific protein kinase that acts on a series of extracellular intermediates D) hormone binding to intracellular receptors

A) possible activation of several different second-messenger systems

The seminal vesicles ________. A) produce a yellowish fluid rich in fructose B) produce about 90% of the volume of semen C) encircle the upper part of the urethra D) attach at the base of the penis

A) produce a yellowish fluid rich in fructose

The corpus luteum is ________. A) the ruptured follicle following the ejection of an oocyte from the ovary B) the ovarian ligament that anchors the ovary medially to the uterus C) the mesovarium D) part of the uterine tube

A) the ruptured follicle following the ejection of an oocyte from the ovary

The metabolic rate of most body tissues is controlled directly by A. TH. B. ACTH C. ADH. D. FSH. E. TSH

A. TH.

Somatostatin is considered paracrine because it acts on A. acts locally on cells other than those that secrete it. B. distant target organs. C. the cells that secrete it. D. the hypothalamus to inhibit or activate the secretion of other hormone

A. acts locally on cells other than those that secrete it.

Hormonal action is characterized by all of the following EXCEPT A. degrading and removal of other hormones. B. selectivity for specific protein receptors. C. antagonistic effects between some hormones. D. mechanism of up-regulating or down-regulating. E. cooperative effect with other hormones

A. degrading and removal of other hormones.

A hormone produced by the pancreas that decreases blood sugar levels is A. insulin. B. aldosterone. C. thyroid hormone. D. calcitonin. E. glucagon

A. insulin.

Which of the following hormones would suppress insulin release? A. somatostatin B. growth hormone C. thyroxine D. epinephrine

A. somatostatin

Which of the following organs is not affected by thyroxin? A. spleen B. liver C. kidney D. ovaries

A. spleen

Which of the following organs is considered a neuroendocrine organ? A. the hypothalamus B. the pancreas C. the pituitary D. the adrenal gland

A. the hypothalamus

Tropic Hormones _____ A.include ACTH and TSH B.do NOT regulate the function of other endocrine glands C.exert their effects on cells by direct gene activation D.include GH and PRL

A.include ACTH and TSH

ACTH

Acts on adrenal glands to release Cortisol. HPA axis.

Select the correct statement about the hormonal events of the ovarian cycle. A) Rising levels of estrogen start follicle development. B) High estrogen levels result in a surge of LH release. C) The follicle begins to secrete progesterone in response to estrogen stimulation. D) The LH surge stimulates further development of the secondary oocyte.

B) High estrogen levels result in a surge of LH release.

The most important regulator of electrolyte concentrations in extracellular fluids is ________. A) insulin B) aldosterone C) glucagon D) cortisol

B) aldosterone

Normally menstruation occurs when ________. A) blood levels of FSH fall off B) blood levels of estrogen and progesterone decrease C) blood levels of estrogen and progesterone increase D) the corpus luteum secretes estrogen

B) blood levels of estrogen and progesterone decrease

What ion is sometimes used as a second messenger of amino acid based hormones? A) iron B) calcium C) sodium D) chlorine

B) calcium

Spermatogenesis ________. A) is the process of releasing mature sperm cells into the lumen of the seminiferous tubule B) involves a kind of cell division limited to the gametes C) results in the formation of diploid cells D) uses mitosis to produce gamete cells

B) involves a kind of cell division limited to the gametes

The " hormone response element" is located on the cell A. RNA. B. DNA. C. enzymes. D. membrane

B. DNA.

What can disrupt the circadian rhythm?

Blue light

All of the following are classified as glycoproteins except: A) FSH B) TSH C) ACTH D) LH

C) ACTH

Glycoproteins typically share a common ___. A) Beta subunit B) Target cell C) Alpha subunit D) Receptor type

C) Alpha subunit

Prolactin is often inhibited by: A) ACTH B) Oxytocin C) Dopamine D) FSH

C) Dopamine

Human egg and sperm are similar in that: A) about the same number of each is produced per month. B) they have the same degree of motility. C) they have the same number of chromosomes. D) they are about the same size.

C) they have the same number of chromosomes.

Insulin, a small (51-amino acid) protein, is synthesized by the beta cells of the pancreas. This hormone is released _____ A.in excessive amounts in obese people B.in response to severe physical stress (i.e. ten mile run) C.when the body's glucose level rises D.when the body's gllucose level drops

C.when the body's glucose level rises

___ is a hormone released in the morning & prepares the body for stress.

Cortisol

Which of the following is not a cardinal sign of diabetes mellitus? A) polyuria B) polydipsia C) polyphagia D) All of these are signs.

D) All of these are signs.

Gluconeogenesis occurs in the liver due to the action of ________. A) aldosterone B) insulin C) secretin D) cortisol

D) Cortisol

Virtually all of the protein or amino acid-based hormones exert their effects through intracellular ________. A) ions B) deactivators C) nucleotides D) second messengers

D) Second Messengers

Which of the following would be associated with the action of steroids on cells? A) extracellular receptors with a specificity for only a single amino acid sequence on the hormone B) an enzyme that catalyzes the formation of cyclic AMP C) second-messenger systems D) a hormone-receptor complex that interacts directly with the cell's DNA

D) a hormone-receptor complex that interacts directly with the cell's DNA

The second-messenger mechanism of hormone action operates by ________. A) synthesizing more of the hormone than is actually needed B) increasing the basal metabolic rate in the target organ C) not responding to a feedback mechanism D) binding to specific receptors and employing the services of G proteins and cAMP

D) binding to specific receptors and employing the services of G proteins and cAMP

Hormones often cause a cell to elicit multiple responses; this is because ________. A) there are thousands of receptors on the cell membrane B) the receptors bind to several hormones at the same time C) the protein kinases are rapidly metabolized D) during protein kinase activation, enzymes phosphorylate many other enzymes

D) during protein kinase activation, enzymes phosphorylate many other enzymes

The neurohypophysis or posterior lobe of the pituitary gland is not a true endocrine gland because ________. A) it is strictly a part of the neural system and has little or nothing to do with hormonal release B) embryonically it was an endocrine tissue, but in the adult human it is no longer functional C) it is unable to function as an endocrine tissue because it is actually part of the neural system due to its location D) it is only a hormone storage area that receives hormones from the hypothalamus for release

D) it is only a hormone storage area that receives hormones from the hypothalamus for release

Beta-endorphin

Endogenous opioid which provides analgesic & euphoric effects

What 3 substances stimulate GH release?

- GHRH - Free AA's - TH

What 4 substances inhibit GH release?

- Somatostatin - IGF-1 - Free FA's - Glucose

GH works through what type of receptor? A) Gs B) Gq C) Tyrosine kinase D) It's a steroid, so it reacts through an intracellular receptor

A) Gs - Adenylate Cyclase - cAMP - PKA - DNA

The only amine hormone to act like a steroid is ________. A) TH B) ACTH C) GH D) ADH

A) TH

How do glucocorticoids enable the body to deal appropriately with stress? A) by increasing blood glucose, fatty acid, and amino acid levels and enhancing blood pressure B) by decreasing the heart rate, thus decreasing blood pressure C) by stimulating the pancreas to release insulin D) by blocking the neurotransmitters that prepare the body for the stress response

A) by increasing blood glucose, fatty acid, and amino acid levels and enhancing blood pressure

Thyroid hormone exerts its influence by ________. A) entering some cells and binding to intracellular receptors within the nuclei B) exerting only a minor effect on body metabolism C) causing a reduction in the number of blood vessel adrenergic receptors, and therefore decreasing blood pressure D) acting to decrease basal metabolic rate

A) entering some cells and binding to intracellular receptors within the nuclei

Functions of testosterone include ________. A) facilitation of muscle and skeletal growth in mass B) loss of facial hair C) growth of the breasts D) drying of the skin

A) facilitation of muscle and skeletal growth in mass

Oxytocin ________. A) release is an example of a positive feedback control mechanism B) is an adenohypophyseal secretion C) exerts its most important effects during menstruation D) controls milk production

A) release is an example of a positive feedback control mechanism

Factors that inhibit TSH release do NOT include ____ A.presence of ADH B.rising levels of glucocorticoids C.somatostatin D.excessively high blood iodine concentrations

A.presence of ADH

Melanocortin

Acts on the skin to change pigmentation

What stimulates prolactin production? A) Increased Oxytocin B) Breastfeeding/pumping C) LH D) FSH

B) Breastfeeding/pumping

Select the correct statement about male sexual response. A) Sympathetic impulses are responsible for causing penile arteriolar dilation, resulting in erection. B) Erection is the result of vascular spaces in the erectile tissues filling with blood. C) Expansion of the penile tissues results in dilation of the venous outflow. D) Ejaculation is the result of parasympathetic stimulation.

B) Erection is the result of vascular spaces in the erectile tissues filling with blood.

Thyroxine is a peptide hormone, but its mechanism is different from other peptide hormones. Which of the following statements is true concerning this difference? A) It causes positive feedback. B) It does not require a second messenger to effect a response. C) It is very specific in the cell type it targets. D) It is a stimulant of cellular metabolism and targets all cells.

B) It does not require a second messenger to effect a response.

What 2 hormones released in the Anterior Pituitary use a Gq receptor & PLC to increase Ca+ release & stimulate the tropic hormones? A) CRH & Somatostatin B) TRH & GnRH C) GHRH & CRH D) Dopamine & CTRH

B) TRH & GnRH

Which of the following will occur after ovulation? A) The corpus luteum secretes estrogen only. B) The endometrium enters its secretory phase. C) The secretion of anterior pituitary gonadotropins is enhanced. D) The corpus luteum prepares to become a corpus albicans.

B) The endometrium enters its secretory phase

Which of the following statements about sperm is not true? A) They contain very little cytoplasm or stored nutrients. B) They are sluggish in an alkaline environment. C) The acrosome is produced by the Golgi apparatus and contains hydrolytic enzymes. D) The sperm midpiece consists of Golgi bodies spiraled tightly around the contractile filaments of the tail.

B) They are sluggish in an alkaline environment.

Leptin is secreted by ________. A) lymphocytes B) adipocytes C) goblet cells D) fibroblasts

B) adipocytes

Aldosterone ________. A) is secreted by the neurohypophysis B) functions to increase sodium reabsorption C) presence increases potassium concentration in the blood D) production is greatly influenced by ACTH

B) functions to increase sodium reabsorption

The constancy of the chromosome number from one cell generation to the next is maintained through ________. A) mitosis B) meiosis C) cytokinesis D) DNA synthesis

B) meiosis

Secretion of progesterone stimulates ________. A) contraction of uterine muscles B) preparation of the mammary glands for lactation C) secretory activity of the uterine myometrium D) development of the female secondary sex characteristics

B) preparation of the mammary glands for lactation

ACTH ________. A) is secreted by the posterior pituitary B) secretion is regulated by a hypothalamic secretion C) causes the release of hormones from the adrenal medulla D) is not a tropic hormone

B) secretion is regulated by a hypothalamic secretion

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

B) steroid hormones, because both diffuse easily into target cells

The parathyroid glands maintain adequate levels of blood calcium. This is accomplished through ________. A) blocking the action of growth hormone B) targeting the bone and activating osteoclasts so that calcium will be released C) antagonizing the synthesis of calcitonin D) slowing the activity of tissues that require calcium for activity

B) targeting the bone and activating osteoclasts so that calcium will be released

Which of the following is NOT a true hormone, but rather a trophic substance? A. Glucagon B. TSH C. Calcitonin D. Aldosterone E. Thyroid hormone

B. TSH

How do protein kinases affect enzymes? A. They increase the secretion of an enzyme. B. They add a phosphate group (phosphorylation) to the enzyme. C. They break down the enzyme. D. They increase the release of an enzyme

B. They add a phosphate group (phosphorylation) to the enzyme.

Steroid hormones influence cellular activities by A. changing the permeability of the cell membrane. B. binding to DNA and forming a gene-hormone complex. C. activating cyclic AMP located outside the cell. D. using calcium ions as a second-messenger. E. activating cyclic AMP located inside the cell

B. binding to DNA and forming a gene-hormone complex.

The adrenal gland produces the following hormones EXCEPT A. androgens. B. renin. C. aldosterone. D. epinephrine. E. cortisone

B. renin

What 4 hormones released in the Anterior Pituitary use a Gs receptor & Adenylate Cyclase/cAMP to stimulate their tropic hormones? A) TRH, GnRH, TSH, ACTH B) GH, TRH, Prolactin, GnRH C) CRH, Somatostatin, GHRH, Dopamine D) LH/FSH, TRH, ACTH, Prolactin

C) CRH, Somatostatin, GHRH, Dopamine

A man has been told that he is not synthesizing enough follicle-stimulating hormone (FSH), and for this reason he may be unable to father a child. Choose the correct statement to explain this problem. A) FSH stimulates estrogen secretion by ovarian cells; therefore it is not synthesized by males. B) The physician is wronga hormone made in the adenohypophysis could not influence fertility. C) FSH stimulates sperm production in the testes. D) The man must be producing progesterone, which inhibits the synthesis of FSH.

C) FSH stimulates sperm production in the testes.

Cells that respond to peptide hormones usually do so through a sequence of biochemical reactions involving receptor and kinase activation. In order for cells to respond, it is necessary for first and second messengers to communicate. This is possible because ________. A) peptide hormones always enter the cell membrane and elicit a response without assistance from other messengers B) hormones alter cellular operations through stimulation of a gene directly C) G protein acts as the link between first and second messengers D) the hormone receptor complex moves into the cytoplasm as a unit

C) G protein acts as the link between first and second messengers

Which of the following hormones controls the release of anterior pituitary gonadotropins? A) LH B) FSH C) GnRH D) testosterone

C) GnRH

Which of the following occurs as a result of undescended testes? A) Male sex hormones will not be circulated in the body. B) Sperm will have no means of exit from the body. C) Inadequate or nonviable sperm will be produced. D) Inadequate blood supply will retard the development of the testes.

C) Inadequate or nonviable sperm will be produced.

Which is not a part of the proliferative phase of the female menstrual cycle? A) cervical mucus becomes thin and crystalline B) ovulation C) corpus luteum D) development of endometrial cells

C) corpus luteum

Mineralocorticoid is to aldosterone as glucocorticoid is to ________. A) testosterone B) estrogen C) cortisol D) epinephrine

C) cortisol

All of the following can be considered male secondary sex characteristics except the ________. A) development of body hair B) lowering of the voice C) development of testes as opposed to ovaries D) increasing mass of the skeleton

C) development of testes as opposed to ovaries

Sometimes prolonged excessive exposure to high hormone concentrations causes a phenomenon known as ________. A) diabetes mellitus B) cellular inhibition C) down-regulation D) metabolism of protein kinases

C) down-regulation

Which of the following is not a steroid-based hormone? A) estrogen B) aldosterone C) epinephrine D) cortisone

C) epinephrine

Several hormones are synthesized in the hypothalamus and transported to the anterior pituitary gland. The mechanism of transportation from hypothalamus to anterior pituitary gland is through the ________. A) hepatic portal system B) general circulatory system C) hypophyseal portal system D) feedback loop

C) hypophyseal portal system

The basic difference between spermatogenesis and oogenesis is that ________. A) during spermatogenesis two more polar bodies are produced B) the mature ovum is n, while the sperm is 2n C) in oogenesis, one mature ovum is produced, and in spermatogenesis four mature sperm are produced from the parent cell D) spermatogenesis involves mitosis and meiosis, but oogenesis involves meiosis only

C) in oogenesis, one mature ovum is produced, and in spermatogenesis four mature sperm are produced from the parent cell

Development of male reproductive structures depends on which of the following events? A) that the female hormones are suppressed during pregnancy B) the suppression of inhibin C) secretion of male hormones prenatally and lasting into the first few months after birth D) that human gonadotropin be synthesized in the first week of the pregnancy

C) secretion of male hormones prenatally and lasting into the first few months after birth

Which of the following hormones is produced by the posterior pituitary (neurohypophysis) and causes uterine contractions during childbirth? A. Epinephrine B. Growth hormone C. Oxytocin D. Thyroid hormone E. Insulin

C. Oxytocin

The hypothalamus DIRECTLY controls the secretions of the A. adrenal gland. B. gonads. C. pituitary gland. D. mammary gland. E. thyroid gland

C. pituitary gland.

The transcription of new messenger RNA is a function of A. amino acid-based hormones. B. pituitary gland hormones. C. steroid hormones. D. pancreatic hormones. E. catecholamines

C. steroid hormones.

The binding of a hormone to its "hormone response element" would lead to the A. direct activation of enzymes in the cell. B. direct activation of second messenger agents in the cell. C. transcription of the DNA for the gene that is "turned on" by this event. D. formation of cAMP

C. transcription of the DNA for the gene that is "turned on" by this event.

Select the correct statement about hormonal structure of function A.Prostaglandins are biologically active peptides B.Modified cholesterol forms the main structural component of the peptone hormones C.An amino acid derivative can be a hormone D.an example of local hormone is testosterone

C.An amino acid derivative can be a hormone

Which of the following is true about calcium homeostasis? A) Increased calcitonin levels will cause increased blood calcium levels. B) High calcium levels cause bone resorption. C) Parathyroid hormone causes an increase in osteoblast activity. D) Parathyroid hormone is the single most important regulator of calcium levels in the blood.

D) Parathyroid hormone is the single most important regulator of calcium levels in the blood.

Erection of the penis results from ________. A) a sympathetic reflex B) parasympathetic activation of the bulbourethral glands C) dilation of the veins in the penis D) a spinal reflex mediated by the parasympathetic nervous system

D) a spinal reflex mediated by the parasympathetic nervous system

The major targets of growth hormone are ________. A) the blood vessels B) the adrenal glands C) the liver D) bones and skeletal muscles

D) bones and skeletal muscles

Which of the following is not a change that may be caused by hormonal stimulus? A) a change in membrane potential B) the stimulation of a genetic event resulting in protein synthesis C) an increase in enzymatic activity D) direct control of the nervous system

D) direct control of the nervous system

Fertilization generally occurs in the ________. A) ovary B) uterus C) vagina D) fallopian tubes

D) fallopian tubes

Regulating hormones from the hypothalamus ________. A) enter venous circulation and travel to the heart, which pumps the hormone-containing blood to the pituitary B) enter the hepatic portal system, which feeds the pituitary C) travel by arteries to the pituitary D) first enter into the hypophyseal portal system

D) first enter into the hypophyseal portal system

The cells that produce testosterone in the testis are called ________. A) spermatocytes B) spermatogonia C) sustentacular cells D) interstitial cells

D) interstitial cells

ADH ________. A) increases urine production B) promotes dehydration C) is produced in the adenohypophysis D) is inhibited by alcohol

D) is inhibited by alcohol

The primary function of the uterus is to ________. A) protect the ovaries B) synthesize female hormones C) regulate the ovarian and menstrual cycles D) receive, retain, and nourish a fertilized ovum

D) receive, retain, and nourish a fertilized ovum

Which hormone is NOT secreted by the anterior pituitary gland? A. GH B. FSH C. ACTH D. ADH E. TSH

D. ADH

The general function of parathyroid hormones is A. regulation of blood levels of glucose. B. regulating blood pressure. C. synthesis of Vitamin D. D. regulation of blood levels of calcium. E. regulation of menstrual cycle

D. regulation of blood levels of calcium.

Which of the following would be associated with the action of steroids on cells A.extracellular receptors with a specificity for only a single amino acid sequence on the hormone B.an enzyme that catalyzes the formatinpo of cyclic AMP C.second-messenger systems D.a hormone-receptor complex that interacts directly with cell's DNA

D.a hormone-receptor complex that interacts directly with cell's DNA

Which of the following elements is required for the synthesis of thyroid hormone? A. Zinc B. Sulfur C. Iron D. Copper E. Iodine

E. Iodine

Which of the following organs do NOT have a known endocrine function? A. Heart B. Thyroid C. Kidneys D. Intestine E. Spleen F. Stomach

E. Spleen

The hypophyseal portal system transports releasing and inhibiting hormones from the hypothalamus to the A. ovaries. B. parathyroid glands. C. thyroid gland. D. adrenal glands. E. anterior pituitary gland. (adenohypophysis)

E. anterior pituitary gland. (adenohypophysis)

Adrenal hormones that help control the balance of minerals and water in the blood are A. norepinephrine . B. mineralocorticoids produced by the adrenal medulla. C. Epinephrine D. glucocorticoids produced by the adrenal cortex. E. mineralocorticoids produced by the adrenal cortex

E. mineralocorticoids produced by the adrenal cortex

Acromegaly is a condition resulting from the over-secretion of A. adrenal cortex hormones. B. thymus gland hormones. C. parathyroid hormones. D. thyroid hormones. E. the growth hormone

E. the growth hormone

Acromegaly

Excessive GH after puberty

Gigantism

Excessive levels during childhood leading to bone lengthening

___ is secreted by the placenta for the nutritional benefit of the fetus @ the expense of the mother.

Human Placental Lactogen (HPL)

___ is a substance which is secreted by the liver & has similar effects of GH on muscle & protein (increase AA uptake, increase protein synthesis, increase muscle growth)

IGF-1

___ is a hormone released @ night besides GH.

Melatonin