Endocrine System

Where are peptide hormones synthesized?

A. nucleus

B. cytosol

C. rough ER

D. smooth ER

C

• peptide hormones are synthesized in the rough ER

  • glucagon, insulin, calcitonin, parathyroid hormone

• steroid hormones are synthesized in the smooth ER

Which of the following is true of hypothalamic-releasing hormones?

A. they suppress the release of other hormones

B. they are tropic hormones

C. they target the posterior pituitary gland

D. they directly stimulate other organs

B

• releasing hormones from the hypothalamus are considered tropic, as they target the anterior pituitary gland

• tropic hormones target other endocrine glands, which then release other hormones

Which hormone stimulates the production of testosterone in males?

A. FSH

B. LH

C. GH

D. ADH

B

• LH is a tropic hormone that stimulates ovulation in females and the production of testosterone in males

Which of the following is NOT a steroid hormone?

A. norepinephrine

B. mineralocorticoids

C. progesterone

D. estrogen

E. testosterone

A

• norepinephrine is an amino acid-derived hormone

Which of the following is NOT true of steroid hormones?

A. they are lipid soluble

B. they can travel freely in the bloodstream

C. they can diffuse through the cell’s membrane

D. they can directly stimulate the inside of the cell

B

steroid hormones:

• lipid soluble

• cannot travel freely in the bloodstream

• require carrier proteins to shield them away from the water-based blood

• once inside the cell, can bind to receptors in the cytoplasm or directly to receptors in the nucleus

Which of the following accurately describes thyroid-stimulating hormone?

A. direct hormone that targets the thymus

B. direct hormone that targets the thyroid

C. tropic hormone that targets the thymus

D. tropic hormone that targets the thyroid

D

• it targets the thyroid gland which means that it’s tropic

Which of the following is responsible for producing ADH and oxytocin?

A. posterior pituitary

B. hypothalamus

C. anterior pituitary

D. hypophysis

B

• oxytocin and ADH are synthesized by the hypothalamus and transported to the posterior pituitary gland

• the posterior pituitary does not produce the hormones, but instead stores and releases them

What connects the anterior pituitary with the hypothalamus?

A. posterior pituitary

B. neurohypophysis

C. hypophyseal portal system

D. neurosecretory cells

C

Which of the following is FALSE of GnRH?

A. it is secreted by the anterior pituitary

B. it is a hypothalamic releasing hormone

C. it stands for gonadotropin-releasing hormone

D. it causes the anterior pituitary to release LH and FSH

A

• GnRH (gonadotropin-releasing hormone) is a hypothalamic-releasing hormone secreted by the hypothalamus

• it stimulates the anterior pituitary to release LH and FSH, which acts on the gonads

All of the following statements are true of T4 EXCEPT one. Which is the EXCEPTION?

A. it is the more biologically active form of thyroid hormone

B. it is the main form of thyroid hormone circulating in blood

C. it is more stable against decomposition than T3

D. it is readily converted to T3 upon cell uptake

A

• T3 is the biologically active form of thyroid hormone and is more potent than T4

• T4 is more stable and has a longer half-life, making it the predominant form of thyroid hormone in the blood

• once inside cells, T4 is converted into T3

Which disorder results in an increased metabolic rate?

A. hypothyroidism

B. hyperthyroidism

B

• hyperthyroidism is caused by an over secretion of T3 and T4

• this results in an increased metabolic rate

• symptoms include hyperactivity, anxiousness, and weight loss

Where is calcitonin secreted from?

A. parathyroid gland

B. parafollicular cells

C. thymus

D. adrenal gland

B

• calcitonin is secreted from the parafollicular cells of the thyroid

What is the endocrine tissue of the pancreas called?

A. merkel cells

B. islets of langerhans

C. kupffer cells

D. microglial cells

B

Which of the following is NOT secreted by the islets of Langerhans?

A. somatotropin

B. insulin

C. somatostatin

D. glucagon

A

• the endocrine tissue of the pancreas is called the islets of Langerhans, and each cell type secretes a key hormone into the bloodstream: insulin, glucagon, and somatostatin

• somatotropin (growth hormone), is released by the anterior pituitary gland

Which of the following is NOT the main target of alpha cells when the blood glucose level is low?

A. muscle cells

B. liver

C. adipose tissue

A

• when blood glucose levels are low, alpha cells secrete glucagon to increase blood glucose levels

• glucagon accomplishes this by stimulating the liver and fat tissue to release glucose stores

Which of the following statements regarding glucose storage is NOT correct?

A. the liver stores glucose as glycogen

B. muscle cells store glucose as glycogen

C. adipose cells store glucose as triglycerides

D. stomach cells store glucose as glycerol

D

• liver stores glucose as glycogen

• muscle cells store glucose as glycogen

• adipose (fat) cells convert and store glucose as triglycerides

Which of the following is true regarding the adrenal gland?

A. the adrenal cortex combats long-term stress, while the adrenal medulla combats short-term stress

B. the adrenal cortex combats short-term stress, while the adrenal medulla combats long-term stress

C. the adrenal cortex combats low blood glucose levels, while the adrenal medulla combats high glucose levels

D. the adrenal cortex combats high blood glucose levels, while the adrenal medulla combats low glucose levels

A

• the adrenal cortex responds to long-term stressors, such as prolonged dehydration or starvation by releasing corticosteroids

  • this response is slower b/c it is indirectly triggered via the hypothalamus and anterior pituitary

  • also, corticosteroids have long-lasting effects on the body compared to catecholamines

• the adrenal medulla responds to short-term stressors, such as an argument or being stuck in traffic

  • it is directly stimulated by the sympathetic nervous system, leading to the rapid release of catecholamines

Which of the following is true of hormones produced by the adrenal cortex?

A. they are direct hormones of the peptide hormone class

B. they are direct hormones of the steroid hormone class

C. they are tropic hormones of the peptide hormone class

D. they are tropic hormones of the steroid hormone class

B

glucocorticoids, mineralocorticoids, androgenic steroids

Which of the following is an example of a mineralocorticoid?

A. cortisol

B. adrenaline

C. norepinephrine

D. aldosterone

D

• the adrenal glands produce several classes of hormones:

  • mineralocorticoids: aldosterone

  • glucocorticoids: cortisol

  • catecholamines: epinephrine, norepinephrine

Which of the following is TRUE of catecholamines?

A. known as the “rest and digest” hormones

B. secreted when facing long-term stress

C. bind to adrenergic receptors

D. cause a decrease in heart rate

C

• catecholamines are epinephrine and norepinephrine which are amino acid-derived hormones secreted by the adrenal medulla (short term)

• they bind to adrenergic receptors on cells

Which of the following is NOT true of LH in females?

A. LH triggers corpus luteum to produce progesterone and estrogen

B. a drop of LH triggers ovulation during the menstrual cycle

C. LH is secreted from the anterior pituitary

D. after LH triggers ovulation, the corpus luteum is formed in the ovary

B

• in both males and females, LH and FSH are secreted from the anterior pituitary

• in females, an increase in LH triggers ovulation during the menstrual cycle

• ovulation leaves behind a corpus luteum in the ovary that produces the sex hormones progesterone and estrogen

Which of the following statements is NOT true?

A. FSH stimulates the development of ovarian follicles

B. developed follicles release estrogen and progesterone

C. all female sex hormones are produced by the ovaries

D. one mature follicle ovulates with a mature egg

C

**** the adrenal glands, also produce some sex hormones like androgens

• in females, FSH stimulates the development of follicles in the ovaries, which will, in turn, produce estrogen and progesterone

• FSH is released by the anterior pituitary in response to GnRH

• a follicle is a premature egg bundled in a fluid-filled sac

• during the menstrual cycle, many follicles develop, but only one successfully ovulates with a mature egg

What type of receptor is an estrogen receptor?

A. G protein-coupled receptor

B. ligand-gated ion channel

C. nuclear receptor

D. secondary messenger

E. tyrosine kinase receptor

C

• estrogen freely crosses the cell membrane and binds to nuclear receptors, forming a hormone-receptor complex

• these complexes bind to DNA sequences to regulate the transcription of target genes

Which of the following systems produces a hormone that lowers blood glucose concentrations by stimulating glucose uptake in the body's cells?

A. anterior pituitary

B. posterior pituitary

C. liver

D. adrenal cortex

E. pancreas

E

• the endocrine tissue of the pancreases produces three hormones:

  1. glucagon- secreted by alpha cells in response to low blood glucose levels; it raises glucose levels by stimulating the liver and fat tissue

  2. insulin- secreted by beta cells in response to high blood glucose levels; it lowers glucose levels by stimulating the liver, muscle, and fat tissue to store glucose

  3. somatostatin- secreted by delta cells which inhibit growth hormone, also inhibits the secretion of glucagon

All of the following are qualities of peptide hormones EXCEPT one. Which is the EXCEPTION?

A. travel freely in the bloodstream

B. relay signals through secondary messengers

C. lipid-soluble

D. bind to G protein coupled receptors

E. bind to ligand-gated ion channels

C

• peptide hormones are not lipid-soluble (they are water soluble), but can travel freely in the bloodstream

• steroid hormones are lipid-soluble, but cannot travel freely in the bloodstream (b/c not water soluble)

Which of the following describes the origin and target of glucagon?

A. beta cells - adrenal gland

B. beta cells - small intestine

C. beta cells - pancreas

D. alpha cells - liver

E. alpha cells - stomach

D

Which hormone directly increases cellular metabolism levels?

A. parathyroid hormone

B. thyrotropin-releasing hormone

C. thyroid-stimulating hormone

D. thyroxine

D

• thyroxine is T4 which directly increases cellular metabolism levels

Which organ is responsible for the production of epinephrine?

A. adrenal cortex

B. adrenal medulla

C. kidney

D. pituitary gland

E. thyroid

B

All of the following choices correctly match a hormone and its target EXCEPT one. Which is the EXCEPTION?

A. vasopressin - kidneys

B. gonadotropin releasing hormone - anterior pituitary

C. calcitonin - bone

D. oxytocin - mammary gland

E. adrenocorticotropic hormone - adrenal medulla

E

• ACTH is a tropic hormone that targets the adrenal cortex to release glucocorticoids to combat stress

Which of the following hormones increases blood glucose levels?

A. insulin

B. cortisol

C. growth hormone

D. aldosterone

E. calcitonin

B

• the adrenal glands are organs that help the body deal with stress

• the outer cortex deals with longer term, while the inner medulla deals with short term

• in response to long term, the cortex releases glucocoricoids and mineralocorticoids

• cortisol is a glucocorticoid that results in the breakdown of fat, muscle, and glycogen stores in order to increase the amnt of blood glucose available for immediate consumption

Which of the following methods is used to communicate with a distant cell within an individual?

A. secondary messenger

B. hormone

C. autocrine signaling

D. pheromone

E. gap junctions

B

• endocrine hormones are chemical messengers that travel through the bloodstream to facilitate cell-to-cell communication

All of the following hormones are derived from cholesterol EXCEPT one. Which is the EXCEPTION?

A. aldosterone

B. cortisol

C. epinephrine

D. testosterone

E. progesterone

C

• epinephrine is released from the adrenal medulla

Which of the following pairs of structures share the same primary function?

A. sympathetic nervous system and adrenal cortex

B. sympathetic nervous system and thyroid gland

C. sympathetic nervous system and adrenal medulla

D. parasympathetic nervous system and adrenal cortex

E. parasympathetic nervous system and adrenal medulla

C

• the sympathetic nervous system produces the “flight or fight” response

• the adrenal medulla produces the catecholamines epinephrine and norepinephrine in response to activation of the sympathetic nervous system