Ch. 16 Endocrine Flashcards
What is a feature that characterizes the endocrine system?
It stimulates any cell in the body that has the appropriate hormone receptor
Which statement correctly describes the interaction between a hormone and it’s target cell?
A) Insulin, a water soluble hormone, binds to a receptor in the plasma membrane of the target cell
B) Prolactin, a water soluble hormone, binds to a receptor in the cell nucleus
C) Testosterone, a lipid soluble hormone, binds to a G protein in the cell that activates a gene
D) Estrogen, a lipid soluble hormone, exerts signalling effects on the cell through an intracellular second messenger
A) Insulin, a water soluble hormone, binds to a receptor in the plasma membrane of the target cell
Action potentials require ____ channels, whereas graded potentials require ____ channels.
Voltage gated; chemically gated
Elevated blood glucose stimulates the cells of the pancreas to secrete the hormone insulin. The pancreas is responding to what type of stimulus?
Humoral
____ stimulus includes nutrients and critical ions.
Humoral
Persistently low levels of a hormone can cause its target cells to form additional receptors for that hormone.
Up-regulation
Which of the following is NOT a major endocrine organ but produces hormones in addition to its major excretory function?
A) Pituitary
B) Thymus
C) Kidneys
D) Pancreas
Kidney cells produce the hormones renin and erythropoietin, but their primary function is excretion of body waste.
Steroid hormones influence cellular activities by ________.
binding to DNA and forming a gene-hormone complex
Steroid hormones enter the cell and form a DNA-hormone complex before they change cellular function.
Sympathetic nerve stimuli are responsible for the release of ________.
epinephrine
The preganglionic fibers of the sympathetic neurons stimulate the adrenal medulla to produce epinephrine and norepinephrine.
The chemical classification of hormones does NOT include ________.
glucose-containing hormones
The chemical classification of hormones is either amino acid–based hormones or steroids.
The metabolic rate of most body tissues is controlled directly by ________.
TH
Thyroid hormones control the consumption of oxygen by all body tissues by way of an increase in glucose metabolism.
The stimulus for secreting parathyroid hormone is a good example of a ________.
humoral stimulus
The declining levels of calcium ions in the blood control secretion of PTH, which is a humoral stimulus.
The transcription of new messenger RNA is a function of ________.
steroid hormones
A steroid hormone complex controls the formation of new messenger RNA.
Which of the following elements is required for the synthesis of thyroid hormone?
A) Copper B) Sulfur C) Zinc D) Iron E) Iodine
Iodine
The hypophyseal portal system transports releasing and inhibiting hormones from the hypothalamus to the ________.
anterior pituitary gland (adenohypophysis)
It is through the hypophyseal portal system that releasing and inhibiting hormones secreted by neurons in the ventral hypothalamus circulate to the adenohypophysis, where they regulate secretion of its hormones.
Which of the following signals would affect local cells by releasing chemicals into the extracellular fluid?
A) Autocrine
B) Paracrine
C) Endocrine
D) Neural
paracrine
What describes a hormone that CANNOT exhibit its full effect without the presence of another hormone?
permissiveness
In permissiveness, a hormone needs another hormone to be fully effective.
Oxytocin and ADH are synthesized in the _____.
hypothalamus
The hypothalamus is considered a _____ organ.
neuroendocrine
Eicosanoids are NOT true hormones because they ________.
act locally
How do protein kinases affect enzymes?
They cause phosphorylation of the enzyme that either activates or inhibits it.
Which hormone is NOT being synthesized if a goiter forms?
TH
What is true about water-soluble hormones?
Water-soluble hormones exhibit the shortest half-life.
The normal endocrine controls can be directly overridden by the ________ system.
nervous
Pro-opiomelanocortin (POMC) is a prohormone for ________.
ACTH
Hypersecretion of antidiuretic hormone (ADH) can occur in all of the following situations EXCEPT ________.
A) ectopic ADH secretion by pulmonary cancer
B) damage to the pineal gland
C) after neurosurgery
D) after general anesthesia
damage to the pineal gland
____ enzymes mediate iodination of thyroid hormones.
Peroxidase
A congenital condition that includes mental retardation; short, disproportional body size; and a thick tongue and neck is caused by ________.
deficiency of thyroxin
A deficiency of thyroxin during fetal development would lead to a congenital condition known as cretinism, which includes mental retardation; short, disproportional body size; and a thick tongue and neck.
Osteitis fibrosa cystica is caused by ________.
an increase in parathyroid hormone
Insulin enhances the membrane transport of glucose in all tissues except the ____.
brain
Resistin, an insulin antagonist, is a hormone produced by the ________.
adipose tissue
Which of the following hormones does the skin produce?
A) Renin
B) Melatonin
C) Erythropoietin
D) Cholecalciferol
Cholecalciferol
Atrial Natriuretic Peptide is a hormone that is secreted by the ________ and targets the kidneys and adrenal cortex.
heart
Down-regulation involves the loss of receptors and prevents the target cells from overreacting to persistently high hormone levels.
T/F
True
When one hormone opposes the action of another hormone, the interaction is called ________.
Antagonism
The ____ ____ has traditionally been called the “master endocrine gland” because many of the numerous hormones it produces regulate the activity of other endocrine glands. In recent years, however, it has been dethroned by the ____, which is now known to control the activity of the anterior pituitary.
anterior pituitary; hypothalamus
Which of the following homeostatic imbalances results from hyposecretion of growth hormone?
A) Gigantism
B) Acromegaly
C) Pituitary dwarfism
D) Elephantiasis
Pituitary dwarfism
Which of the following hormones stimulates gamete (sperm or egg) production?
A) GH
B) Prolactin
C) TSH
D) FSH
FSH
As blood levels of ________ rise, the expulsive contractions of labor gain momentum and finally end in birth.
oxytocin
What is NOT one of the areas in which thyroid hormone (TH) plays an important role?
Helping the body avoid dehydration and water overload
Because TH provokes an increase in the number of adrenergic receptors in blood vessels, it plays an important role in maintaining blood pressure. Additionally, it is important in regulating tissue growth and development. It is critical for normal skeletal and nervous system development and maturation and for reproductive capabilities.
Which of the following conditions, if left untreated, progresses to respiratory paralysis and death?
A) Hypoparathyroidism
B) Hypothyroidism
C) Hyperparathyroidism
D) Hyperthyroidism
Hypoparathyroidism
Hypoparathyroidism, or PTH deficiency, most often follows parathyroid gland trauma or removal during thyroid surgery. However, an extended deficiency of dietary magnesium (required for PTH secretion) can cause functional hypoparathyroidism. The resulting hypocalcemia increases the excitability of neurons and accounts for the classical symptoms of tetany, such as loss of sensation, muscle twitches, and convulsions. Untreated, the symptoms progress to respiratory paralysis and death.
Which of the following homeostatic imbalances usually results from deficits in both glucocorticoids and mineralocorticoids?
A) Graves’
B) Cushing’s
C) Addison’s
D) cretinism
Addison’s disease
Addison’s disease, the major hyposecretory disorder of the adrenal cortex, usually involves deficits in both glucocorticoids and mineralocorticoids. Its victims tend to lose weight; their plasma glucose and sodium levels drop, and potassium levels rise. Severe dehydration and hypotension are common.
