Which of the following statements about endocrine glands is true?
They do not have ducts.
Which of the following types of signal is released into the environment?
pheromones
Testosterone is an example of a chemical signal that affects, variously, the very cells that synthesize it in the testis, the neighboring cells, and distant cells outside the gonads. Thus, testosterone is an example of ________.
an autocrine signal, a paracrine signal, and an endocrine signal
The chemical structure of prostaglandins is derived from which of the following types of molecules?
fatty acids
Which of the following statements about aspirin and ibuprofen is true?
They inhibit the synthesis of prostaglandins.
Which of the following best explains why the steroid hormone aldosterone affects only a small number of target cells in the body?
only target cells contain aldosterone receptors
Fludrocortisone is a steroid hormone used to treat disease. Which of the following most likely occurs when it encounters a target cell?
It diffuses through the cell membrane and binds to receptors in the cytoplasm or nucleus
A certain hormone activates the cAMP second messenger system in its target cells. Which of the following would yield the greatest response by a target cell?
apply the hormone to the extracellular fluid surrounding the cell
Which of the following statements about growth factors is true?
They are local regulators that stimulate division and development of target cells.
Which of the following statements is true about both steroid and polypeptide?
they travel through the bloodstream
Which of the following types of cell-to-cell signaling describes tumor cells that secrete growth factors that induce surrounding cells to grow and divide?
paracrine
Which of the following molecules is lipid soluble and acts on target cells at distant locations from where it is released?
cortizol
Which of the following statements about polypeptides is true?
some function as growth factors
Which of the following are properties of steroid hormones?
Steroid hormones regulate gene transcription by binding to intracellular receptor proteins.
Tadpoles undergo metamorphosis in their development. The changes include reabsorption of the tail, growth of limbs, and the development of lungs. Amazingly, all of these changes are induced by thyroxine. Which of the following best explains the diverse effects of thyroxine?
Different tissues have thyroxine receptors that activate different signal transduction pathways.
Which of the following organs includes endocrine and exocrine tissues
the pancreas
Which of the following are the two main systems for communication and control in most animals?
nervous and endocrine
Molecules that act quickly over short distances are types of ________
local regulators
Which of the following correctly describes the target cells in autocrine signalin
They secrete autocrine signals.
Which of the following statements is true?
neurohormones diffuse into the bloodstream
A new type of pesticide sprayed onto fields of corn interferes with the ability of nematodes to find potential mates. This new pesticide most likely interferes with _______
pheromones
A new type of pesticide sprayed onto fields of corn interferes with the ability of nematodes to find potential mates. This new pesticide most likely interferes with _______
nitric oxide
Which of the following is a steroid hormone that coordinates molting in arthropods?
ecdysteroid
Which one of the following statements is true?
Hormones often regulate homeostasis through antagonistic functions
The mammary glands secrete milk in response to circulating oxytocin. A suckling baby feeding on this milk stimulates additional oxytocin release. These related events are an example of ________.
positive feedback
Which of the following pairs correctly describes an example of antagonistic hormones that regulate homeostasis?
insulin and glucagon regulate blood glucose levels
The insect hormones ecdysteroid and PTTH __
reflect the coordinated responses of the endocrine and nervous systems
Which of the following is the source of the hormones secreted by the posterior pituitary gland?
hypothalamus
Which of the following functions would most likely be disrupted by an injury to the hypothalamus?
regulation of water balance
Which of the following is an example of a simple endocrine pathway?
release of secretin by cells of the duodenum after exposure to low pH
Which of the following contain capillary beds connected by portal blood vessels?
hypothalamus and anterior pituitary
Which of the following organs is directly affected by antidiuretic hormone (ADH)?
kidney
Diabetes insipidus is a disorder that results in the kidneys not being able to conserve water during urine production. Which hormone most likely plays a role in diabetes insipidus?
ADH
which two hormones in a lactating mammal promote milk synthesis and milk release respectively
prolactin and oxytocin
Oxytocin and antidiuretic hormone (ADH) are synthesized in the ________ and are released from the ________
hypothalamus and posterior pituitary
Which of the following is the most likely cause of a goiter?
low levels of iodine in the diet
When a person drinks alcohol, the rate of urination increases. Which of the following best explains the increase in urination above normal rates?
Alcohol inhibits the release of ADH.
Which of the following glands produces hormones that affect osmoregulation, reproduction, and metabolism
anterior pituitary
Which of the following is the most likely outcome of a reduction of blood flow in the portal system connecting the hypothalamus and the pituitary gland?
reduced levels of growth hormone in the blood
Which of the following is a function of glucocorticoids
increasing blood glucose levels
Which of the following correctly pairs a gland with its impact on the fight-or-flight reaction?
adrenal medulla, leads to increased secretion of epinephrine
Certain diseases of the adrenal glands result in increased secretion of adrenal hormones. The symptoms include high blood pressure, increased heart rate, and elevated body temperature. Which of the following hormones is secreted by the adrenal glands and most likely contributes to these symptoms
epinephrine
Which one of the following is a type of catecholamine?
epinephrine
Which of the following occurs under stressful conditions that include shock, low blood pressure, and low blood sugar levels?
ACTH stimulates the release of corticosteroids.
In response to stress, the adrenal gland promotes the synthesis of glucose from noncarbohydrate substrates via the action of the steroid hormone ________
cortisol
Which of the following best explains how epinephrine produces different effects in different target cells
The target cells differ in their types of receptors.
Which of the following is affected by exposure to diethylstilbestrol (DES)
reproduction and development
Which of the following events will be initiated by the fight-or-flight response following a stressful stimulus?
liver cells convert glycogen into glucose
Which of the following hormones is vital to maintaining a pregnancy in a mammal?
progesterone
Which of the following is the most likely effect of a drug that increases adrenocorticotropic hormone (ACTH) synthesis?
increased release of glucocorticoids
Which of the following contributes to poor health when people experience chronic stress?
high levels of glucocorticoids suppress the immune response
Thyroxine can trigger growth, temperature tolerance, or osmoregulation depending on the organism in which it is produced. Which is the most likely mechanism for such diverse responses in different organisms?
The function of thyroxine in a particular tissue is determined by the genes that are transcribed by the activated thyroxine receptor.
Which hormone contributes to calcium homeostasis in fishes and rodents by opposing the effects of parathyroid hormone
calcitonin
Which hormone regulates skin color in fishes, amphibians, and reptiles?
melanocyte-stimulating hormone
Which of the following best describes sex hormones in male and female vertebrates?
Androgens, estrogens, and progesterone are found in males and females, but in different proportions.
Which statement is accurate
Hormones are often regulated through feedback loops.
The hypothalamus ______
regulates both reproduction and body temperature
Growth factors are local regulators that _____
bind to cell-surface receptors and stimulate growth and -development of target cells
Which hormone is correctly paired with its action?
oxytocin–stimulates uterine contractions during childbirth
What do steroid and peptide hormones typically have in common?
their requirement for travel through the bloodstream
Which of the following is the most likely explanation for hypothyroidism in a patient whose iodine level is normal
hyposecretion of TSH
The relationship between the insect hormones ecdysteroid and PTTH is an example of ________
an interaction of the endocrine and nervous systems