Questions and Answers
Steroid hormones exert their action by:
The second-messenger mechanism of hormone action operates by:
The stimuli causing endocrine glands to secrete their hormones in direct response to changing blood levels of certain critical ions and nutrients are called:
Virtually all of the protein or amino acid-based hormones exert their effects through intracellular:
Signup and view all the answers
Which of the following is not a category of endocrine gland stimulus?
Signup and view all the answers
Which of the following is NOT a property of endocrine glands?
Signup and view all the answers
Chemical substances secreted by cells into the extracellular fluids and that regulate the metabolic function of other cells in the body are called:
Signup and view all the answers
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?
Signup and view all the answers
Hormones that regulate the secretory action of other endocrine glands are called:
Signup and view all the answers
Which of the following hormones stimulates the adrenal cortex to release glucocorticoids that help the body to resist stressors?
Signup and view all the answers
Which of the following hormones mainly serves to stimulate milk production by the breasts?
Signup and view all the answers
Which of the following is not a type of hormone interaction?
Signup and view all the answers
The ability of a specific tissue or organ to respond to the presence of a hormone is dependent on:
Signup and view all the answers
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:
Signup and view all the answers
Thyroid hormone (a small iodinated amine) enters target cells in a manner similar to:
Signup and view all the answers
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:
Signup and view all the answers
Thyroxine is a peptide hormone, but its mechanism is different from other peptide hormones. Which of the following statements is true concerning this difference?
Signup and view all the answers
Direct gene activation involves a second-messenger system.
Signup and view all the answers
What type of hormones bind to receptors located on the cell membrane?
Signup and view all the answers
Which intracellular substance degrades cAMP, thus inactivating the response to a hormone?
Signup and view all the answers
Growth factor hormones, such as insulin, bind to which type of receptor?
Signup and view all the answers
Which is the correct order of events for hormones activating Gs proteins?
Signup and view all the answers
Which second messenger causes the release of calcium from the endoplasmic reticulum?
Signup and view all the answers
Which of the following hormones has intracellular receptors?
Signup and view all the answers
What is the mechanism of action of lipid-soluble hormones?
Signup and view all the answers
After a lipid-soluble hormone is bound to its intracellular receptor, what does the hormone complex do?
Signup and view all the answers
Which hormone's receptor is always bound to DNA, even when the receptor is empty?
Signup and view all the answers
What keeps intracellular receptors from binding to DNA before a hormone binds to the receptor?
Signup and view all the answers
What tropic hormone stimulates cortisol from the adrenal gland?
Signup and view all the answers
What is the function of the ventral hypothalamic neurons?
Signup and view all the answers
Insulin-like growth factors (IGFs) are intermediary hormones stimulated by which of the following hormones?
Signup and view all the answers
Which of the following hormones is regulated by a neuroendocrine ('letdown') reflex?
Signup and view all the answers
Where is antidiuretic hormone (ADH), also known as vasopressin, synthesized?
Signup and view all the answers
What is the most important regulatory factor controlling the circulating levels of thyroid hormone?
Signup and view all the answers
Hypersecretion of what hormone can produce the effects of gigantism?
Signup and view all the answers
What hormone released into the blood by the posterior pituitary inhibits or prevents urine formation?
Signup and view all the answers
What gland secretes growth hormone?
Signup and view all the answers
Which hypothalamic hormone stimulates the release of growth hormone from the anterior pituitary (lobe)?
Signup and view all the answers
Acromegaly may be caused by all EXCEPT which of the following?
Signup and view all the answers
Which of the following is NOT a change that may be caused by hormonal stimulus?
Signup and view all the answers
Which of the following is NOT a major type of stimulus that triggers endocrine glands to manufacture and release hormones?
Signup and view all the answers
_____ is the situation when one hormone cannot exert its full effects without another hormone being present.
Signup and view all the answers
What is the primary function of hormones?
Signup and view all the answers
Which of the following is not a steroid-based hormone?
Signup and view all the answers
Which of the following is NOT a change typically produced by a hormonal stimulus?
Signup and view all the answers
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?
Signup and view all the answers
Study Notes
Hormone Mechanisms and Types
- Steroid hormones enter the nucleus and alter gene expression.
- Second-messenger mechanisms bind to specific receptors using G proteins and cAMP to initiate cellular responses.
- Hormones are chemical substances that regulate metabolic functions in the body; they affect other cells by binding to their receptors.
Types of Stimulus for Hormone Secretion
- Humoral stimuli trigger endocrine glands to secrete hormones in response to blood levels of ions and nutrients.
- Types of endocrine gland stimuli include humoral, neural, and hormonal; enzymatic stimuli are not included.
Hormonal Interactions and Effects
- Synergism occurs when multiple hormones enhance each other's effects on target cells.
- Tropins are hormones that regulate the secretory actions of other endocrine glands.
Specific Hormones and Their Functions
- Adrenocorticotropic hormone (ACTH) stimulates the adrenal cortex to release glucocorticoids.
- Prolactin primarily stimulates milk production in the breasts.
- Growth hormone (GH) plays a crucial role in growth and regulation of other hormones.
Responses of Target Cells
- Target cell responsiveness to hormones depends on the presence of specific receptors.
- Up-regulation occurs when more receptors are synthesized in response to prolonged hormone exposure.
Mechanisms of Lipid-Soluble and Water-Soluble Hormones
- Water-soluble hormones bind to cell membrane receptors, while lipid-soluble hormones diffuse through the membrane to their intracellular receptors.
- Activation of genes by lipid-soluble hormones increases protein synthesis by acting as transcription factors.
Hormonal Regulation and Feedback Mechanisms
- Negative feedback is the primary regulatory mechanism for circulating thyroid hormone levels.
- Oxytocin operates via a neuroendocrine reflex, impacting processes like childbirth and lactation.
Hormone Production and Synthesis
- Antidiuretic hormone (ADH) is synthesized in the hypothalamus and inhibits urine formation.
- Growth hormone is produced in the anterior pituitary gland and regulated by growth hormone-releasing hormone (GHRH) and growth hormone-inhibiting hormone (GHIH).
Distinctions in Hormone Types and Interactions
- Cortisol is a steroid hormone with intracellular receptors, while insulin is a water-soluble hormone that binds to membrane receptors.
- Feedback mechanisms include feedback interactions, but feedback itself is not categorized as a type of hormone interaction.
Hormonal Disorders and Effects
- Acromegaly is linked to hypersecretion of GH; it may result from several factors except for positive feedback on the pituitary.
- Gigantism is also a result of excess growth hormone.
Endocrine System Overview
- The endocrine system utilizes various hormones to alter cell activity and metabolic processes.
- Hormonal stimuli lead to changes in cellular activities, but they do not directly control the nervous system.
Noteworthy Hormonal Categories
- Steroid hormones include cortisone, aldosterone, and estrogen; epinephrine is a non-steroid hormone.
- One hormone may require the presence of another to exert its full effect, known as permissiveness.
Overview of Hormonal Functions
- Hormones primarily influence metabolic activity by altering the activity of target cells rather than activating external enzymes directly.
- Intracellular substances like phosphodiesterase degrade second messengers like cAMP to inactivate hormone responses.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Prepare for your Anatomy and Physiology exam with this set of flashcards focused on Chapter 16, covering the Endocrine System. Test your knowledge on key concepts such as steroid hormones and their mechanisms of action. Perfect for students looking to reinforce their understanding of endocrinology.