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.
Hormones promote homeostasis by ____ of body cells rather than by ____.
altering activity; stimulating new or unusual actvities
What type of hormone:
Binds to receptors in nucleus
Is lipid soluble
Activates a gene to transcribe mRNA
Steroid hormones
What type of hormone:
Binds to a plasma membrane receptor
Acts through a second messenger
Amino acid-based hormones
Inadequate amounts of ____ would result in tetany.
PTH
Inadequate amounts of ____ would lead to a goiter.
Thyroxine
Inadequate amounts of ____ would lead to cretinism, a type of dwarfism in which the individual has child-like proportions and is mentally retarded.
Thyroxine
Excessive amounts of ____ would lead to lantern jaw and large hands and feet
GH
Excessive amounts of ____ would lead to bulging eyes, nervousness, and increased pulse rate (Graves’)
Thyroxine
Excessive amounts of ____ would lead to demineralization of bones.
PTH
Excessive amounts of ____ would lead to a moon face, and depression of the immune system (Cushing’s)
Glucocoricoids
ACTH, FSH, LH, and ____ are tropic hormones.
TSH
What is the adrenal cortex hormone involved in regulating salt levels.
Aldosterone
What is the basal metabolic hormone?
Thyroxine
Oxytocin and ____ are hormones necessary for milk production and ejection.
Prolactin
FSH and ____ are anterior pituitary hormones that regulate the ovarian cycle.
LH
What endocrine structure develops from the brain?
Posterior pituitary
What are 4 tropic hormones secreted by the anterior pituitary?
LH, ACTH, TSH, & FSH
Smooth muscle contractions are stimulated by ?
Oxytocin
ANP, the hormone secreted by the heart, has exactly the opposite function of which hormone secreted by the adrenal cortex?
Aldosterone
Hypothyroidism can cause ?
Cretinism
Which of the following is given as a drug to reduce inflammation?
A) Epinephrine
B) Cortisol
C) Aldosterone
D) ADH
Cortisol
Which of the following hormones are released by neurons?
A) Oxytocin
B) Insulin
C) ADH
D) Cortisol
ADH & Oxytocin
Most hormones are released as needed; the exception to this is ____.
Thyroxine
Name the 3 types of hormones.
Amino acid- most hormones, water soluble; epinephrine
Steroids- synthesized from cholesterol, lipid soluble; cortisol
Eicosanoids- Leukotrines (allergic & inflammatory rxn) and Prostaglandins (coagulation, BP, uterine contractions)
The Anterior Pituitary is also known as ?
Hypophysis
The pituitary connects to the ____ superiorly via the ____.
Hypothalamus; Infundibulum
The posterior pituitary releases two neurohormones:
Oxytocin and Antidiuretic hormone (ADH)
Oxytocin action
Stimulates smooth muscle contractions during childbirth
The anterior pituitary releases six hormones:
- Growth Hormone (GH)
- Thyroid Stimulating Hormone (TSH)
- Adrenocorticotropic Hormone (ACTH)
- Follicle Stimulating Hormone (FSH)
- Luetinizing Hormone (LH)
- Prolactin
GH action
Anabolic, protein synthesis, utilizes fat for energy
TSH action
Normal development of thyroid
ACTH action
Stimulate adrenal cortex to release corticosteroids
FSH action
Stimulates gamete production
LH action
Promotes production of gonadal hormones
Prolactin action
Milk production in breasts
Hormone produced by the hypothalamus and released by the posterior pituitary; stimulates the kidneys to reabsorb more water, reducing urine volume.
ADH
Disease characterized by passage of a large quantity of dilute urine plus intense thirst and dehydration caused by inadequate release of ADH
Diabetes insipidus
Tropic hormones
A hormone that regulates the secretory action of another endocrine organ.
Select the correct statement regarding hypothalamus and pituitary interactions.
A) The hypophyseal portal connects the hypothalamus with posterior pituitary
B) In response to hormone release from anterior pituitary, the hypothalamus releases hormones into circulation
C) Posterior pituitary releases oxytocin into the blood in response to action potentials from hypothalamus
D) ADH travels from hypothalamus through portal veins where it inhibits hormones made in anterior pituitary
C) Posterior pituitary releases oxytocin into the blood in response to action potentials from hypothalamus
____ from the posterior pituitary initiates milk ejection from mammary glands, whereas ____ from anterior pituitary promotes milk production.
Oxytocin; Prolactin
Iodine-containing hormone secreted by the thyroid gland; accelerates cellular metabolic rate in most body tissues.
T4 (Thyroxine)
Severe hypothyroidism is also known as:
Myxedema
Autoimmune disorder in which the thyroid gland is directly stimulated by antibodies; causes markedly increased secretion of thyroid hormone.
Graves’ disease
Hormone released by the thyroid that lowers blood calcium levels when present at high levels; antagonizes PTH.
Calcitonin
Hormone that increases serum calcium by acting on bones, kidneys, and intestines.
PTH
Steroid hormones of the adrenal cortex that regulates Na+ and K+ metabolism and fluid balance.
Mineralcorticoids
Name the chief mineralcorticoid
Aldosterone
Adrenal cortex hormones that increase blood glucose levels and aid the body in resisting long-term stressors.
Glucocorticoids
Name the chief glucocorticoid
Cortisol
Epinephrine, norepinephrine, and dopamine; a class of amines that act as chemical messengers.
Catecholamines
____ is synthesized in the adrenal medulla.
Epinephrine
How is Aldosterone classified?
Mineralcorticoid
____, a glucocorticoid, increases blood glucose, amino acids and fatty acids, and supresses the immune system.
Cortisol
Where is the pineal gland located?
Hangs from the roof of the third ventricle
What does the pineal gland secrete?
Melatonin
In the pancreas, what cells do what tasks?
Alpha cells release glucagon; fewer
Beta cells release insulin; numerous
What is Progesterone’s action?
Promotes breast development and prepares the uterus for fertilization (menstruation)
The heart produces ____, which reduces blood pressure and volume.
Atrial Natriuretic Peptide
The major stimulus for PTH is ?
Humoral
The anterior pituitary secretes all except ?
A) ADH
B) GH
C) Gonadotropins
D) TSH
A) ADH
A hormone not involved in glucose metabolism is ?
A) Glucagon
B) Cortisone
C) Aldosterone
D) Insulin
C) Aldosterone
If anterior pituitary secretion in a child is deficient, the child will ?
become a dwarf, but have relatively normal body proportions
Name the tropic hormone that stimulates the gonads to produce sex hormones.
LH
What hormone causes sodium reabsorption by the kidneys?
Aldosterone
_____ is the situation when one hormone cannot exert its full effects without another hormone being present.
Permissiveness
