Endocrine System & Second Messenger EXAM II

What is the primary function of hormones? a. cause allergic reactions b. influence metabolic activity of glands by electrochemical impulses c. alter cell activity d. activate extracellular enzymes

c. Alter cell activity

What gland secretes growth hormone? a. adrenal cortex b. posterior pituitary (lobe) c. anterior pituitary (lobe) d. thyroid gland

c. Anterior pituitary (lobe)

What is the function of the ventral hypothalamic neurons? a. control secretion of oxytocin b. control secretion of thyroid hormones c. control secretion of thyroid stimulating hormone (TSH) d. control secretion of antidiuretic hormone (ADH)

c. Control secretion of thyroid stimulating hormone (TSH)

Insulin-like growth factors (IGFs) are intermediary hormones stimulated by which of the following hormones? a. thyroid hormones b. oxytocin c. GH (growth hormone) d. prolactin (PRL)

c. GH (growth hormone)

Hypersecretion of what hormone can produce the effects of gigantism a. thyroid hormones (TH) b. aldosterone c. growth hormone (GH) d. thyroid-stimulating hormone (TSH)

c. Growth hormone (GH)

Which hypothalamic hormone stimulates the release of growth hormone from the anterior pituitary (lobe)? a. growth hormone-inhibiting hormone (GHIH) b. adrenocorticotropic hormone (ACTH) c. growth hormone-releasing hormone (GHRH) d. thyroid-stimulating hormone (TSH)

c. Growth hormone-releasing hormone (GHRH)

Virtually all of the protein or amino acid-based hormones exert their effects through intracellular ________. a. calcium b. nucleotides c. second messengers d. deactivating ions

c. Second messengers

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

c. Steroid hormones, because both diffuse easily into target cells.

Which of the following is NOT a change that may be caused by hormonal stimulus? a. the stimulation of a genetic event resulting in protein synthesis b. a change in membrane potential c. an increase in enzymatic activity d. direct control of the nervous system

d. Direct control of the nervous system

Which of the following is not a category of endocrine gland stimulus? a. neural b. humoral c. hormonal d. enzyme

d. Enzyme

The hypothalamus regulates secretion of how many hormones from the anterior pituitary?

7

Name 6 functions regulated by the hypothalamus:

Body temperature Thirst Hunger Sexual behavior Fear Rage

What organ/cells does GH target?

Bones Tissues

Pituitary gland embryology?

Ectoderm

What are the 2 gonadotropins?

FSH LH

Direct gene activation involves a second-messenger system. TRUE OR FALSE?

False

The pituitary gland develops from two different parts of ectoderm. The Posterior pituitary forms from where?

Floor of brain Neural ectoderm downward

FSH

Follicle Stimulating hormone

GH

Growth hormone

Somatotrophs are affected by what?

Growth hormone

hGH

Growth hormone

Where is the Pituitary gland located?

Hypophyseal fossa of the sella turcica

What is another name for the Pituitary gland?

Hypophysis

Integrates nervous and endocrine systems.

Hypothalamus

Major integration center.

Hypothalamus

Receives input from many parts of the brain.

Hypothalamus

Receives sensory signals from retina, viscera

Hypothalamus

Responds to pain, stress & emotions.

Hypothalamus

10 Major Endocrine Gland & Tissue Locations

Hypothalamus Pituitary Pineal Thyroid Parathyroids Thymus Adrenals Pancreas Ovaries Testicles

What is ADHs target organ/cells?

Kidney tubules

LH

Luteinizing hormone

Gonadotrophs

Luteinizing hormone Follicle stimulating hormone

What is prolactin's target organ/cells?

Mammary glands

2 ways in which anterior pituitary hormones are regulated:

Negative feedback Hypothalamic releasing and inhibiting

2 Names for the Posterior pituitary

Neurohypophysis Pars nervosa

2 names for the Posterior part of the pituitary gland.

Neurohypophysis Pars nervosa

What are the target organs/tissues/cells of FSH?

Ovaries Testes

What does LH target?

Ovaries Testes

PI

Pars Intermedia

Specialized neuroglial cells found in the pituitary.

Pituicytes

Lactotrophs

Prolactin

PRL

Prolactin

RP

Rathke's Pouch

Remnant of anterior pit. Formation during development.

Rathke's pouch

The pituitary gland develops from two different parts of ectoderm. The Anterior Pituitary forms from where?

Roof of mouth Ectoderm upward

What is Oxytocin's target organ/cells?

Smooth muscle of the uterus Mammary glands

Which bone is the sella turcica located in?

Sphenoid

Infundibulum

Stalk

What is TSHs target organ/cells?

Thyroid

TSH

Thyroid stimulating hormone

Thyrotrophs

Thyroid stimulating hormone

Which is the correct order of events for hormones activating Gs proteins? a. activation of G protein, binding of GTP, activation of adenylate cyclase, conversion of ATP to cAMP b. activation of G protein, binding of GTP, activation of phospholipase C, activation of DAG and IP3 c. activation of a G protein, tyrosine kinase receptor, phosphorylation of intracellular proteins

a. Activation of G protein, binding of GTP, activation of adenylate cyclase, conversion of ATP to cAMP.

What is the mechanism of action of lipid-soluble hormones? a. activation of genes, which increases protein synthesis in the cell b. increasing protein kinases c. phosphorylation of intracellular proteins

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

What tropic hormone stimulates cortisol from the adrenal gland? a. adrenocorticotropic hormone (ACTH) b. growth hormone (GH) c. luteinizing hormone (LH) and follicle stimulating hormone (FSH) d. thyroid stimulating hormone (TSH)

a. Adrenocorticotropic hormone (ACTH)

What keeps intracellular receptors from binding to DNA before a hormone binds to the receptor? a. chaperone proteins (chaperonins) b. transcription factors c. Receptors can't enter the nucleus until the hormone is bound to it.

a. Chaperone proteins (chaperonins)

One of the least complicated of the endocrine control systems directly responds to changing blood levels of ions and nutrients. Which of the following describes this mechanism? a. humoral stimulation b. protein synthesis c. carbohydrate oxidation d. catabolic inhibition

a. Humoral stimulation

Where is antidiuretic hormone (ADH), also known as vasopressin, synthesized? a. hypothalamus b. posterior pituitary c. kidney d. anterior pituitary

a. Hypothalamus

What is the most important regulatory factor controlling the circulating levels of thyroid hormone? a. negative feedback b. thyrotropin-releasing hormone (TRH) c. thyroid-stimulating hormone (TSH) d. a circadian rhythm of release

a. Negative feedback

Which of the following hormones is regulated by a neuroendocrine ("letdown") reflex? a. oxytocin b. cortisol c. antidiuretic hormone (ADH)

a. Oxytocin

_____ is the situation when one hormone cannot exert its full effects without another hormone being present. a. Permissiveness b. Antagonism c. Synergism d. Activism

a. Permissiveness

Which intracellular substance degrades cAMP, thus inactivating the response to a hormone? a. phosphodiesterase b. phospholipase C c. adenylate cyclase d. protein kinase C

a. Phosphodiesterase

Which of the following occurs in situations where more than one hormone produces the same effects at the target cell and their combined effects are amplified? a. synergism b. summation c. antagonism d. permissiveness

a. Synergism

Which of the following is NOT a property of endocrine glands? a. They have ducts. b. They drain vascularly. c. They drain lymphatically. d. They produce hormones.

a. They have ducts.

Hormones that regulate the secretory action of other endocrine glands are called __________. a. tropins b. GHIH c. somatotropin d. somatostatins

a. Tropins

In circumstances where the body requires prolonged or increased levels of a hormone, the DNA of target cells will specify the synthesis of more receptors on the surface of the cells of the target organ. This is known as ________. a. up-regulation b. cellular affinity c. sensitivity increase d. a stressor reaction

a. Up-regulation

After a lipid-soluble hormone is bound to its intracellular receptor, what does the hormone complex do? a. phosphorylates a protein b. acts as a transcription factor and binds to DNA, activating a gene c. activates a protein kinase d. directly alters protein synthesis at the ribosome

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

What hormone released into the blood by the posterior pituitary inhibits or prevents urine formation? a. oxytocin b. antidiuretic hormone (ADH) c. thyroid-stimulating hormone (TSH) d. cortisol

b. Antidiuretic hormone (ADH)

Which of the following hormones has intracellular receptors? a. insulin b. cortisol c. epinephrine

b. Cortisol

Steroid hormones exert their action by ___. a. binding cell receptors and initiating cAMP activity b. entering the nucleus of a cell and initiating or altering the expression of a gene c. entering the cell and activating mitochondrial DNA d. activating the hypothalamic release of regulating hormones

b. Entering the nucleus of a cell and initiating or altering the expression of a gene.

Which of the following is NOT a major type of stimulus that triggers endocrine glands to manufacture and release hormones? a. humoral b. enzymatic c. neural d. hormonal

b. Enzymatic

Which of the following is not a steroid-based hormone? a. cortisone b. epinephrine c. aldosterone d. estrogen

b. Epinephrine

Which of the following is not a type of hormone interaction? a. synergism b. feedback c. permissiveness d. antagonism

b. Feedback

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 is a stimulant of cellular metabolism and targets all cells. 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 causes positive feedback.

b. It does not require a second messenger to effect a response.

Which of the following hormones mainly serves to stimulate milk production by the breasts? a. follicle-stimulating hormone b. prolactin c. adrenocorticotropic hormone d. thyroid-stimulating hormone

b. Prolactin

Which hormone's receptor is always bound to DNA, even when the receptor is empty? a. insulin b. thyroid hormone c. cortisol

b. Thyroid hormone

Growth factor hormones, such as insulin, bind to which type of receptor? a. intracellular receptors b. tyrosine kinase receptors c. G proteins

b. Tyrosine kinase receptors

What type of hormones bind to receptors located on the cell membrane? a. lipid-soluble hormones, such as thyroid hormones and cortisol b. water-soluble hormones, such as insulin and epinephrine

b. Water-soluble hormones, such as insulin and epinephine

What does hypothalamus mean?

Below thalamus

What is the target organ/cells of ACTH?

Adrenal cortex

Corticotrophs are affected by what?

Adrenocorticotropic Hormone

ACTH

Adrenocorticotropic hormone

ACTH

Adrenocorticotropin

4 Parts of the Pituitary gland

Anterior Posterior Pars Intermedia Rathke's pouch

Which stains darker? Anterior or posterior pit?

Anterior pit

ADH

Antidiuretic hormone

How many hormones are synthesized by the hypothalamus?

At least 9

Which branch of the nervous system is controlled by the hypothalamus?

ANS

2 different names for the Anterior part of the pituitary gland.

Adenohypophysis Pars distalis

2 names for Anterior pituitary

Adenohypophysis Pars distalis

The ability of a specific tissue or organ to respond to the presence of a hormone is dependent on ________. a. the location of the tissue or organ with respect to the circulatory path b. nothing-all hormones of the human body are able to stimulate any and all cell types because hormones are powerful and nonspecific c. the presence of the appropriate receptors on the cells of the target tissue or organ d. the membrane potential of the cells of the target organ

c. The presence of the appropriate receptors on the cells of the target tissue or organ.

The second-messenger mechanism of hormone action operates by ________. a. synthesizing more than one hormone at a time 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. altering gene expression in the nuclear DNA

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

Which of the following hormones stimulates the adrenal cortex to release glucocorticoids that help the body to resist stressors? a. follicle-stimulating hormone b. prolactin c. thyroid-stimulating hormone d. adrenocorticotropic hormone

d. Adrenocorticotropic hormone

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 are converted by cell membranes enzymes into second messengers b. hormones alter cellular operations through direct stimulation of a gene c. the hormone receptor complex moves into the cytoplasm as a unit d. G protein acts as the link between first and second messengers

d. G protein acts as the link between first and second messengers.

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. proteins c. enzymes d. hormones

d. 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. hormonal stimuli c. neural stimuli d. humoral stimuli

d. Humoral stimuli

Which second messenger causes the release of calcium from the endoplasmic reticulum? a. tyrosine kinase b. DAG c. cAMP d. IP3

d. IP3

Acromegaly may be caused by all EXCEPT which of the following? a. hypersecretion of GHRH (growth hormone-releasing hormone) b. pancreatic tumor c. lack of negative feedback by insulin-like growth factors d. positive feedback by GH (growth hormone) on the anterior pituitary

d. Positive feedback by GH (growth hormone) on the anterior pituitary

Which of the following is NOT a change typically produced by a hormonal stimulus? a. activates or deactivates enzymes b. induces secretory activity c. alters plasma membrane permeability d. stimulates production of an action potential

d. Stimulates production of an action potential