Ch. 18

All of the following are true of the nervous system, except that it doesn't

function independently of the endocrine system. (NOT) respond specifically to stimuli. communicate by the release of neurotransmitters. respond rapidly to stimuli. respond with motor output.

After a steroid hormone binds to its receptor to form an active complex,

gene transcription is initiated.

Hormones that regulate the male and female reproductive organs are collectively called ________.

gonadotropins

The hypophyseal portal system

has two capillary plexuses connected by short veins, carries neurosecretions to the anterior lobe of the pituitary, and carries ADH and oxytocin.

All target cells

have hormone receptors and respond to chemical signals.

Norepinephrine and epinephrine are considered to be ________ when released into the bloodstream, but ________ when released at synapses.

hormones; neurotransmitters

The most complex endocrine responses involve the

hypothalamus

Which of the following organs contain target cells for oxytocin?

mammary glands uterus prostate ductus deferens all of the above

Pinealocytes produce

melatonin

Liver cells respond to growth hormone by releasing hormones called

somatomedins.

The hormone that plays a pivotal role in setting the metabolic rate and thus impacting body temperature is

thyroxine.

Shelly has a hormone-secreting tumor of the suprarenal gland. The tumor is causing her to have a deep voice, to grow extensive body hair, and to stop menstruating. This tumor probably involves cells of the

zona reticularis.

Increased levels of the hormone ________ will lead to increased levels of calcium ion in the blood.

PTH

The zona reticularis of the suprarenal cortex produces

androgens

The C cells of the thyroid gland produce

calcitonin.

Peptide hormones are

composed of amino acids.

Gap junctions

coordinate ciliary movement among epithelial cells. coordinate the contractions of cardiac muscle cells. facilitate the propagation of action potentials from one cell to the next at electrical synapses. all of the above

The suprarenal medulla produces the hormones

epinephrine and norepinephrine.

Which of these statements about melatonin is false?

exposure to light inhibits production exposure to light stimulates production (NOT) inhibits releases of GnRH made from serotonin produced by pinealocytes

The pituitary hormone that promotes egg development in ovaries and sperm development in testes is

FSH

If the median eminence of the hypothalamus is destroyed, the hypothalamus would no longer be able to control the secretion of which of the following hormones?

TSH, ACTH, and PRL

The pituitary hormone that triggers the release of thyroid hormone from the thyroid gland is

TSH.

Each of the following hormones is produced by the pars distalis of the adenohypophysis, except

TSH. oxytocin. (NOT) somatotropin. corticotropin. FSH.

The link between a first messenger and a second messenger in a cell that responds to peptide hormones is usually

a G protein.

A hormone that helps to regulate the sodium ion content of the body is

aldosterone

Cells of the suprarenal cortex produce

aldosterone

Reduction of fluid losses at the kidneys due to the retention of Na+ is the action of

aldosterone

Hormone release may be controlled by which of the following factors?

blood level of glucose nervous stimuli blood level of a hormone blood level of an ion-like potassium any of the above

TSH plays a key role in the ________ of thyroid hormones.

both synthesis and release

Parathyroid hormone does all of the following, except that it doesn't

build up bone. (NOT) stimulate the formation and secretion of calcitriol at the kidneys. inhibit osteoblast activity. stimulate osteoclast activity. enhance the reabsorption of calcium at the kidneys.

Increased activity of phosphodiesterase in a target cell would decrease its level of

cAMP

A hormone that can lower blood levels of calcium ion is

calcitonin

The kidneys secrete

calcitriol. renin. erythropoietin. all of the above

Calcium ions serve as messengers, often in combination with the intracellular protein

calmodulin

The intracellular protein ________ binds calcium ion. This complex can then activate enzymes.

calmodulin

The suprarenal medulla produces

catecholamines

The suprarenal cortex produces steroid hormones called ________.

corticosteroids

A hormone that promotes gluconeogenesis in the liver is

cortisol.

Which of the following substances activates protein kinases and thus acts as a second messenger?

cyclic AMP

Cushing disease results from an excess of

glucocorticoids

The zona fasciculata of the suprarenal cortex produces

glucocorticoids.

Inadequate iodine in the diet may lead to

goiter. cretinism. hypothyroidism. high blood levels of TSH. any of the above

The pancreatic hormone that causes blood sugar levels to fall is

insulin

Which of the following hormones is water soluble and therefore binds to extracellular receptors?

insulin and epinephrine only

Thyroid hormone contains the element

iodine

The two lobes of the thyroid gland are connected by the ________.

isthmus

Destruction of the supraoptic nucleus of the hypothalamus would have which result?

loss of ADH secretion

Regulatory factors that control secretion of adenohypophyseal hormones are released by neurons at the ________ of the hypothalamus.

median eminence

Each of the following hormones is an amino acid derivative, except

melatonin. thyroid hormone. norepinephrine. epinephrine. thyroid-stimulating hormone (NOT)

The two lobes of the pituitary gland together produce how many hormones?

9

The pituitary hormone that promotes ovarian secretion of progesterone and testicular secretion of testosterone is

LH

The hormone produced by the pars intermedia of the adenohypophysis during early childhood is

MSH

The anterior lobe of the pituitary is also known as the ________.

adenohypophysis

Steroid hormones

bind to receptors in the nucleus of their target cells.

All of the following are true of steroid hormones, except that they

bind to receptors within the cell. are produced by the suprarenal medulla. (NOT) are lipids. are produced by reproductive glands. are derived from cholesterol

The action of thyroid hormone on a target cell involves all these steps except one. Identify the incorrect step.

binding to a hormone receptor in the plasma membrane

The primary function of ADH is to

decrease the amount of water lost at the kidneys.

Damage to cells of the zona fasciculata of the suprarenal cortex would result in

decreased ability to convert amino acids to glucose.

Hormones known as "catecholamines" are

derivatives of the amino acid tyrosine.

The adenohypophysis can be divided into three parts, the pars ________, the pars ________, and the pars ________.

distalis,intermedia,tuberalis

The control of calcitonin excretion is an example of direct ________ regulation.

endocrine

The functional organization of the nervous system parallels that of the ________ system in many ways.

endocrine

The hypothalamus acts as both a neural and a(n) ________ organ.

endocrine

Mental and physical sluggishness and low body temperature may be signs of

hypothyroidism.

Melanocyte-stimulating hormone (MSH) is secreted by the human pars intermedia

in some disease processes. during fetal development. during pregnancy. in very young children. all of the above

Where does the chemical reaction between thyroglobulin and iodine take place?

in the lumen of the thyroid follicle

The condition known as seasonal affective disorder (SAD) may be caused by

increased levels of melatonin.

The parathyroid glands produce a hormone that

increases the level of calcium ions in the blood.

The hormone that opposes the release of FSH in both males and females is

inhibin.

Which of the following is not an action of TSH?

inhibits T3 and T4 secretion (NOT) increases cyclic AMP concentration within thyroid follicle cells stimulates T3 and T4 secretion stimulates iodide trapping by thyroid follicle cells stimulates pinocytosis of colloid by thyroid follicle cells

The zona glomerulosa of the suprarenal cortex produces

mineralocorticoids.

The posterior lobe of the pituitary is also known as the ________.

neurohypophysis

A simple endocrine reflex involves ________ hormone(s).

one

When adenyl cyclase is activated,

only ATP is consumed and cAMP is formed.

Hormones can operate on the ________ level of organization.

organismic organ cellular tissue any of the above

The hormone that may be slowly administered by intravenous drip to accelerate labor and delivery is

oxytocin

The hormone that does the opposite of calcitonin is

parathyroid hormone.

The pituitary hormone that stimulates milk production by the mammary glands is

prolactin

Which of the following cooperate to prepare the mammary glands for milk secretion?

prolactin estrogens progesterone placental hormones all of the above

The hormone oxytocin

promotes uterine contractions, is responsible for milk expression from the mammary glands, and triggers prostate gland contraction.

Hormonal actions on cells include those that affect

quantities of enzymes. synthesis of enzymes. gating of ion channels. activities of enzymes. any of the above

Endocrine cells

release their secretions directly into body fluids.

When a catecholamine or peptide hormone binds to receptors on the surface of a cell, the

second messenger appears in the cytoplasm.

Each of the following is true of the pineal gland, except that it

secretes melatonin. contains pinealocytes. responds to light and darkness. is a component of the epithalamus. is a component of the hypothalamus (NOT)

The pituitary hormone that controls the release of glucocorticoids from the suprarenal cortex is

ACTH

Changes in blood osmotic pressure would most affect the secretion of

ADH

The posterior pituitary gland secretes

ADH

Neurons of the supraoptic and paraventricular nuclei of the hypothalamus manufacture

ADH and oxytocin.

The pituitary hormone that causes the kidney to reduce water loss is

ADH.

Before the discovery of these glands, thyroid surgery often led to a rapid drop in blood calcium levels, which triggered muscle contractions and cardiac arrhythmias. What glands are these and which hormone is lacking?

parathyroid glands; parathyroid hormone

Hormones can be divided into different groups based on their chemistry. These categories include

peptides. eicosanoids. amino acid derivatives. steroids. all of the above

A kinase is an enzyme that performs

phosphorylation

Melatonin is produced by the

pineal gland

The hypothalamus controls secretion by the adenohypophysis by

secreting releasing and inhibiting factors into a tiny portal system.

The delta cells of the pancreatic islets produce

somatostatin

The pituitary hormone that stimulates cell growth and replication by accelerating protein synthesis is

somatotropin

The ________ gland sits along the superior border of the kidney.

suprarenal

An activated G protein can trigger

the opening of calcium ion channels in the membrane. a fall in cAMP levels. the production of diacylglycerol. the release of calcium ions from intracellular stores. all of the above

A rise in cortisol would cause an increase in each of the following, except

the rate of glycogen formation by the liver. ACTH levels. (NOT) the rate of glucose synthesis by the liver. the level of fatty acids in the blood. fatty acid metabolism by muscle cells.

Thyroxine and calcitonin are secreted by the

thyroid gland.