CH 45 Mastering Biology

Receptors for nonsteroid hormones are located in _____. the extracellular fluid the cytoplasm the nucleus the cytosol association with a cell's plasma membrane

Which of these is a nonsteroid hormone? estrogen testosterone both estrogen and testosterone oxytocin epinephrine and oxytocin

How do nonsteroid hormones differ from steroid hormones? nonsteroid hormones bind to a cell's DNA; steroid hormones do not bind to a cell's DNA nonsteroid hormones act via signal transduction pathways; steroid hormones do not act via signal transduction pathways the action of nonsteroid hormones never affects gene expression; the action of steroid hormones always affects gene expression nonsteroid hormones bind to cytoplasmic receptors; steroid hormones bind to plasma membrane receptors nonsteroid hormones are fat-soluble; steroid hormones are water-soluble

Which of these extracellular signal molecules could diffuse through a plasma membrane and bind to an intracellular receptor? estrogen epinephrine cellulose oxytocin starch

The primary reason steroid hormones usually act slowly is that _____. they are produced at very low concentrations acting via a signal transduction pathway makes for slower responses than does directly interacting with a cell's DNA they are too large to enter a cell and therefore must first bind to a plasma membrane receptor before having an effect on a cell target cells tend to ignore steroid hormones in favor of nonsteroid hormones they turn genes on or off and it takes time for gene products to build up or become depleted

Steroid hormone-receptor complexes act in _____. the nucleus lysosomes vesicles the cytoplasm the plasma membrane

This heating system maintains room temperature at or near a particular value, known as the _________________

You open the window, and a blast of icy air enters the room. The temperature drops to 17 degrees Celsius, which acts as a_____________ to the heating system.

The thermostat is a ________________ that detects the stimulus and triggers a response.

The heater turns on, and the temperature in the room _____________ until it returns to the original setting.

The response of the heating system reduces the stimulus. This is an example of ______________feedback.

The way this heating system maintains a stable room temperature is similar to the way an animal's body controls many aspects of its internal environment. The maintenance of a relatively constant internal environment is known as _____________________.

Each of the following phrases describes the structure, function, or regulation of either the hypothalamus, posterior pituitary, or anterior pituitary. Sort the phrases into the appropriate bins depending on whether they describe the hypothalamus, posterior pituitary, or anterior pituitary. integrates nervous and endocrine systems synthesizes oxytocin and ADH is an extension of the hypothalamus releases oxytocin and ADH regulated by hormones released into portal blood vessels synthesizes and releases PRL synthesizes and releases TSH

Which choice describes how surgical hypothyroidism would likely affect prolactin levels? Hints Thyroid hormone levels decrease, TRH levels decrease, and PRL levels decrease. Thyroid hormone levels decrease, TRH levels decrease, and PRL levels increase. Thyroid hormone levels decrease, TRH levels increase, and PRL levels decrease. Thyroid hormones levels decrease, TRH levels increase, and PRL levels increase. Thyroid hormone levels increase, TRH levels increase, and PRL levels increase. Thyroid hormone levels increase, TRH levels increase, and PRL levels decrease. Thyroid hormone levels increase, TRH levels decrease, and PRL levels increase.

Which type of hormone is lipid soluble? Hints Steroids. Polypeptides. DNA. Amino acid derivatives.

Which molecules determine the tissue specificity of hormones? Hints Receptors. Hormone-response elements. Second messengers. Agonists.

True or false? Lipid-insoluble hormones affect their target cells by binding to receptors inside the cell. Hints True False

Which of the following statements about lipid-soluble hormones is true? Hints They act by affecting the transcription of genes. They bind to DNA as soon as they enter a cell. They act by producing second messengers. They bind to receptors on the plasma membrane.

Which of the following is a structure that allows hormone-receptor complexes to bind to specific DNA sequences? Hints Promoter. Zinc finger. Enhancer. Hormone-response element (HRE).

What is the role of cAMP in the signal transduction pathway activated by epinephrine? Hints It activates adenylyl cyclase. It catalyzes the breakdown of glycogen to glucose. It binds to the receptor protein on a target cell. It binds to and activates protein kinase A, which then phosphorylates other enzymes.

True or false? For a signal transduction pathway to be activated, hormones must be present in the bloodstream at very high concentrations. Hints True False

Which of these glands secretes releasing hormones? hypothalamus adrenal cortex thymus ovaries testes

Which of these hormones are responsible for the "fight or flight" response to danger? insulin and glucagon thyroxine and calcitonin androgens and estrogens antidiuretic hormone (ADH) and oxytocin epinephrine and norepinephrine

Adrenocorticotropic hormone (ACTH) triggers the release of _____ in response to stress. melatonin insulin glucocorticoids thymosin parathyroid hormone

_____ are the main male hormones. Progesterones Mineralocorticoids Androgens Luteinizing hormones Estrogens

What hormone promotes water retention by the kidneys? follicle-stimulating hormone (FSH) prolactin antidiuretic hormone (ADH) melatonin glucagon

Which hormone opposes the action of parathyroid hormone? calcitonin insulin thyroxine thymosin glucagon

Which hormone stimulates hormone production by the ovaries and testes? progesterone testosterone glucocorticoids luteinizing hormone (LH) estrogens

Which hormone stimulates milk production? parathyroid hormone mineralocorticoids prolactin thyroid-stimulating hormone (TSH) thymosin

Which of the following is a common feature of all hormones? (Overview) Hints Hormones act as a chemical signal between cells. Hormones are produced in response to stress. Hormones enter a cell, bind to their receptor, and interact with DNA. Hormones levels are controlled by the pituitary gland. Hormones are proteins.

Which one of the following statements is correct? (Concept 45.1) Hints The series of changes in cellular proteins that convert the extracellular signal to a specific intracellular response is called signal transduction. Receptors for steroid hormones are located inside target cells. Many hormones elicit more than one type of response in the body. Local regulators are signals that link neighboring cells. All of the above statements are true.

Which one of the following statements about hormones or the endocrine system is correct? (Concept 45.1) Hints Hormones result in quick, short responses, compared with nervous system responses. Hormones are distributed only to specific cells having the appropriate membrane receptors. Hormones are secreted onto a surface of the body. Endocrine organs are sometimes derived from nervous tissue. None of the choices is correct.

The action of a local regulator is illustrated when _____. (Concept 45.1) Hints prostaglandins released from the placenta alter the excitability of the muscle of the uterus there is relaxation of arterial smooth muscle caused by nitric oxide cytokines play a role in immune responses growth factor stimulates the growth of embryonic cells All of the choices are correct.

In their mechanism of action, a difference between lipid-soluble and water-soluble hormones is that _____. (Concept 45.1) Hints water-soluble hormones cross the plasma membrane more readily than do lipid-soluble hormones lipid-soluble hormones bind to an intracellular receptor and this hormone-receptor complex binds to DNA lipid-soluble hormones use a "second messenger" water-soluble hormones bind reversibly to DNA None of the choices is correct.

Which one of the following statements about the endocrine functions of the pancreas is correct? (Concept 45.2) Hints Diabetes mellitus is caused by a deficiency of glucagon. Alpha cells make insulin. Insulin triggers the uptake of glucose from the blood. Beta cells make glucagon. None of the choices is correct.

Which of the following is an exocrine gland? (Concept 45.3) Hints pituitary gland adrenal gland islets of Langerhans salivary gland None of the choices is an exocrine gland.

Which statement about the lobes of the pituitary is correct? (Concept 45.3) Hints The posterior lobe of the pituitary is glandular tissue closely associated with the brain. The hypothalamus sends hormones to the anterior pituitary. The posterior pituitary produces oxytocin and antidiuretic hormone. The anterior pituitary receives hypothalamic hormones from brain cells. The anterior lobe of the pituitary is nervous tissue that connects directly to the brain.

Which function below is not influenced by thyroid hormones? (Concept 45.4) Hints rate of cellular respiration fight-or-flight response growth rate blood pressure maintenance muscle tone

Jet lag occurs when a person moves rapidly from one time zone to another, causing conflict between the body's biological rhythm and the new cycle of light and dark. Some scientists suspect that jet lag may result from disruption of a daily hormone cycle known as _____. (Concept 45.4) Hints epinephrine melatonin estrogen insulin prolactin

Epinephrine is an example of _____. a glucocorticoid an androgen a catecholamine an estrogen

What is the function of endocrine glands? Hints They release enzymes into the bloodstream through ducts. They release hormones into a space other than the circulatory system by means of ducts. They are the targets of hormones. They release hormones into the bloodstream for distribution around the body.

True or false? The homeostatic system for blood calcium concentration is maintained by the hormones calcitonin and parathyroid hormone. Hints True False

Which of the following statements about the pituitary gland is false? Hints The anterior pituitary is connected to the hypothalamus by blood vessels Neurosecretory cells produce hormones that are stored in the anterior pituitary. It produces hormones that control the menstrual cycle. The posterior portion is an extension of the hypothalamus.

True or false? The pancreas is responsible for producing hormones that maintain the homeostatic levels of glucose in the blood. Hints True False

How is the production of hormones such as thyroxine and estrogen regulated? Hints Hormones produced in the hypothalamus act on the thyroid gland and ovaries to stimulate or inhibit the production of these hormones. The hypothalamus directs the posterior pituitary to produce hormones that then stimulate or inhibit the production of these hormones. The anterior pituitary directs the hypothalamus to produce hormones that then stimulate or inhibit the production of these hormones. The hypothalamus directs the anterior pituitary to produce hormones that then stimulate or inhibit the production of these hormones.

Which of the following statements about endocrine glands and the hormones they produce is true? Hints Antidiuretic hormone (ADH) produced by the anterior pituitary controls the body's metabolic rate. Aldosterone produced by the adrenal glands controls the reabsorption of sodium ions by the kidneys. Prolactin produced by the posterior pituitary triggers contractions in the uterus during labor. Erythropoietin (EPO) produced by the kidneys increases blood calcium levels.

Gigantism, a condition characterized by exceptionally rapid growth, is sometimes caused by a tumor that induces the gland in which it develops to overproduce a certain hormone. Where would such a tumor be expected to grow? Hints Adrenal glands. Thyroid gland. Pituitary gland. Pancreas.

The hypothalamus __________. regulates both reproduction and body temperature influences the function of only one lobe of the pituitary gland synthesizes all of the hormones produced by the pituitary gland produces only inhibitory hormones

Vertebrates have two major communication and control systems: the endocrine system and the nervous system. Choose the correct statement describing the coordination of these systems. Epinephrine functions as a hormone in the endocrine system and as a neurotransmitter in the nervous system. The parathryroid gland is a fused endocrine and neuroendocrine gland. The adrenal cortex secretes hormones in response to nervous stimulation.

Select the correct statement about feedback regulation in endocrine systems. Some homeostatic control systems rely on pairs of negatively regulated hormone pathways, each counterbalancing the other. All hormones are regulated by negative feedback loops. A hormone cascade pathway involves the hypothalamus, posterior pituitary, and endocrine gland.