Biology Chapter 5: Endocrine System (3 Stars) Flashcards
_________ are signaling molecules that are secreted directly into the bloodstream to travel to a distant target tissue.
Hormones
What secrete hormones?
Glands
What are 3 types of hormones?
Hormones can be peptides, steroids, or amino acid derivatives.
Endocrine signaling involves the secretion of hormones directly into the bloodstream. The hormones travel to distant target tissues, where they ____ to receptors and induce a change in gene expression or cell function.
Bind
_______ are composed of amino acids and are derived from larger precursor proteins that are cleaved during posttranslational modification.
Peptide hormones
Peptide hormones are ____ and ____ pass through the plasma membrane.
polar
cannot
These hormones bind to _______ receptors, where they trigger the transmission of a second messenger.
extracellular
Each step of the signaling cascade can demonstrate _______ of the signal.
amplification
Peptide hormones usually have rapid onset but are ________
short-lived.
________ hormones travel freely in the bloodstream and do not require a special carrier.
Peptide hormones
Peptide hormones have surface receptors and act via _____ messenger systems. ______ hormones bind to intracellular receptors and function by binding to DNA to alter gene transcription.
second
Steroid
Steroid hormones are derived from _________
cholesterol
Steroid hormones are minimally polar and _____ pass through the plasma membrane.
can
_____ hormones bind to and promote a conformational change of intraellular or intranuclear receptors; the hormone–receptor complex binds to DNA, affecting the transcription of a particular gene.
Steriods
Steroid hormones usually have slow onset but are ________
long-lived.
Steriod hormones ______ dissolve in the bloodstream and must be carried by specific proteins.
cannot
___________ hormones are modified amino acids.
Amino acid-derivative
____________ chemistry shares some features with peptide hormones and some features with steroid hormones; different __________ hormones share different features with these other hormone classes.
Amino acid-derivative
Common examples are epinephrine, norepinephrine, triiodothyronine, and thyroxine.
______ hormones have major effects in other endocrine tissues.
Usually originate in the brain and anterior pituitary gland, as these structures are involved in coordination of multiple processes within the body
Tropic
__________ hormones have major effects in non-endocrine tissues.
Direct
The hypothalamus is the bridge between the ______ and endocrine systems.
nervous
The release of hormones from the hypothalamus is mediated by a number of factors, including projections from other parts of the brain, chemo- and baroreceptors in the blood vessels, and ________ feedback from other hormones.
negative
In negative feedback, the final hormone (or product) of a pathway ______ hormones (or enzymes) earlier in the pathway, maintaining homeostasis.
inhibits
The hypothalamus stimulates the anterior pituitary gland through paracrine release of hormones into the ________ portal system, which directly connects the two organs.
hypophyseal
___________ promotes the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
Gonadotropin-releasing hormone (GnRH)
Growth hormone-releasing hormone (GHRH) promotes the release of ________ hormone.
growth hormone.
____________ promotes the release of thyroidstimulating hormone (TSH).
Thyroid-releasing hormone (TRH)
Corticotropin-releasing factor (CRF) promotes the release of ____________
adrenocorticotropic hormone (ACTH).
Prolactin-inhibiting factor (PIF or dopamine) inhibits the release of _________
prolactin
Interactions with the _______ occur via the axons of nerves in the hypothalamus. Antidiuretic hormone (ADH or vasopressin) and oxytocin are synthesized in the hypothalamus and then travel down these axons to the _________, where they are released into the bloodstream.
posterior pituitary
The anterior pituitary synthesizes and secretes #____ different products.
seven
The ___________ releases hormones in response to stimulation from the hypothalamus. Four of these (FSH, LH, ACTH, and TSH) are tropic hormones, while three (prolactin, endorphins, and growth hormone) are direct hormones.
anterior pituitary
__________ promotes the development of ovarian follicles in females and spermatogenesis in males.
Follicle-stimulating hormone (FSH)
____________ promotes synthesis and release of glucocorticoids from the adrenal cortex.
Adrenocorticotropic hormone (ACTH)
________ promotes milk production.
Prolactin
__________decrease perception of pain and can cause euphoria.
Endorphins
_________ promotes ovulation in females and testosterone production in males.
Luteinizing hormone (LH)
____________ promotes synthesis and release of triodothyronine and thyroxine from the thyroid.
Thyroid-stimulating hormone (TSH)
___________ promotes growth of bone and muscle and shunts glucose to these tissues. It raises blood glucose concentrations.
Growth hormone (GH)
Name the missing items
The bones most commonly affected are those in the hands, feet, and head _____________
acromegaly
The posterior pituitary releases #_____ hormones produced in the hypothalamus.
two
_________ is secreted in response to low blood volume or increased blood osmolarity and increases reabsorption of water in the collecting duct of the nephron, increasing blood volume and decreasing blood osmolarity.
Antidiuretic hormone (ADH or vasopressin)
_________ is secreted during childbirth and promotes uterine contractions. It also promotes milk ejection and may be involved in bonding behavior. It is unusual in that it has a positive feedback loop, not negative.
Oxytocin
The thyroid is located at the base of the neck in front of the trachea; it produces #____ key hormones.
3
Triiodothyronine (T3) and thyroxine (T4) are produced by follicular cells and contain _____. They _____ basal metabolic rate and alter the utilization of glucose and fatty acids.
iodine.
increase
Thyroid hormones are required for proper neurological and physical development in children.
______ is produced by parafollicular (C) cells. It decreases plasma calcium concentration by promoting calcium excretion in the kidneys, decreasing calcium absorption in the gut, and promoting calcium storage in bone.
Calcitonin
The parathyroid glands release parathyroid hormone (PTH), which _______ blood calcium concentration.
increases
PTH decreases excretion of calcium by the kidneys and increases bone resorption directly to ______ blood calcium concentration.
increase
PTH activates ________, which is necessary for calcium and phosphate absorption from the gut.
vitamin D
PTH promotes _______ of phosphate from bone and reduces reabsorption of phosphate in the kidney, but vitamin D promotes absorption of phosphate from the gut; these two effects on phosphate concentration somewhat cancel each other.
resorption
The adrenal cortex produces # ____ classes of steroid hormones.
three
_______ such as cortisol and cortisone increase blood glucose concentration, reduce protein synthesis, inhibit the immune system, and participate in the stress response. _______ release is stimulated by ACTH.
Glucocorticoids
_______ such as aldosterone promote sodium reabsorption in the distal convoluted tubule and collecting duct, thus increasing water reabsorption. ______ also increases potassium and hydrogen ion excretion
Mineralocorticoids
Aldosterone
It is regulated by the renin–angiotensin–aldosterone system
______ sex hormones include androgens (like testosterone) and estrogens in both males and females.
Cortical
The __________ is derived from the nervous system and secretes catecholamines into the bloodstream.
adrenal medulla
____________ include epinephrine and norepinephrine, which are involved in the fight-or-flight (sympathetic) response.
These hormones promote glycogenolysis, increase the basal metabolic rate, increase heart rate, dilate the bronchi, and alter blood flow.
Catecholamines
The ____________ produces hormones that regulate glucose homeostasis.
endocrine pancreas
__________is produced by α-cells and raises blood glucose levels by stimulating protein and fat degradation, glycogenolysis, and gluconeogenesis
Glucagon
_______ is produced by β-cells and lowers blood glucose levels by stimulating glucose uptake by cells and anabolic processes, like glycogen, fat, and protein synthesis.
Insulin
________ is produced by δ-cells and inhibits insulin and glucagon secretion.
Somatostatin
In excess, insulin will cause __________, which is characterized by low blood glucose concentration.
hypoglycemia
Underproduction, insufficient secretion, or insensitivity to insulin all can result in diabetes mellitus, which is clinically characterized by ________
hyperglycemia (excess glucose in the blood).
__________ is caused by autoimmune destruction of the β-cells of the pancreas; these individuals produce little to no insulin because the majority of β-cells have been destroyed. Require regular injections of insulin to prevent hyperglycemia and to permit entry of glucose into cells
Type I (insulin-dependent) diabetes mellitus
Type II (non-insulin-dependent) diabetes mellitus is the result of __________ to the effects of insulin. Type II diabetes mellitus is partially inherited and partially due to environmental factors, such as high-carbohydrate diets and obesity.
receptor-level resistance
_____ decreases plasma glucose. ______ increases plasma glucose. Growth hormone, glucocorticoids, and epinephrine are also capable of increasing ________. These hormones that raise blood glucose levels are commonly called counterregulatory hormones.
Insulin
Glucagon .
plasma glucose.
The ______ produce hormones that are involved in development and maintenance of the reproductive systems and secondary sex characteristics.
gonads
The testes secrete ________
testosterone.
The ______ secrete estrogen and progesterone.
ovaries
The ________ releases melatonin, which helps to regulate circadian rhythms.
pineal gland
Cells in the stomach and intestine produce hormones like secretin, ______, and cholecystokinin.
gastrin
The _______ secrete erythropoietin, which stimulates bone marrow to produce erythrocytes (red blood cells) in response to low oxygen levels in the blood.
kidneys
The atria of the heart secrete atrial natriuretic peptide (ANP), which promotes ______ of salt and water in the kidneys in response to stretching of the atria (high blood volume).
excretion
The _____ secretes thymosin, which is important for proper T-cell development and differentiation.
thymus
