Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
24 Cards in this Set
- Front
- Back
|
· Basis of Chemical Messengers i.e. Autocrines vs. paracrines |
• Autocrines: chemicals that exert effects on the samecells that secrete them • Paracrines: locally acting chemicals that affect cellsother than those that secrete them• Autocrines and paracrines are local chemicalmessengers and will not be considered part of the endocrine system |
|
|
· Two Main Chemical Classes of Hormones Including their mechanisms of action(water soluble vs. lipid soluble) |
• Two main classes1. Aminoacid-based hormones • Amines, thyroxine, peptides, and proteins2. Steroids• Synthesized from cholesterol• Gonadal and adrenocortical hormones |
|
|
Mechanisms of Hormone Action 5. |
1. Alter plasma membrane permeability of membranepotential by opening or closing ion channels 2. Stimulate synthesis of proteins or regulatorymolecules 3. Activate or deactivate enzyme systems4. Induce secretory activity5. Stimulate mitosis |
|
|
1. Water-soluble hormones (all amino acid–based hormonesexcept thyroid hormone)• mechanisms. |
Cannot enter the target cells • Act on plasma membrane receptors • Coupled by G proteins to intracellular second messengers that mediate the target cell’s response |
|
|
2. Lipid-soluble hormones - name two. act on what? |
(steroid and thyroid hormones) Act on intracellular receptors that directly activategenes |
|
|
· Basics of the Second-Messenger Systemso Not specifics of either PIP2 or cAMP |
? |
|
|
Target Cell Activation • Target cell activation depends on three factors |
1. Blood levels of the hormone 2. Relative number of receptors on or in the target cell 3. Affinity of binding between receptor and hormone. |
|
|
Target Cell Specificity• Target cells must have ..... receptors to which the... binds • .... receptors are only found on certain cells of the.... cortex • ..... receptors are found on nearly all cells ofthe body |
• Target cells must have specific receptors to which thehormone binds • ACTH receptors are only found on certain cells of theadrenal cortex • Thyroxin receptors are found on nearly all cells ofthe body |
|
|
· Control of Hormone releaseo Humoral vs. Neural vs. HormonalStimulis |
Humoral Stimuli• Changing blood levels of ions and nutrients directlystimulates secretion of hormones Neural Stimuli• Nerve fibers stimulate hormone release Hormonal Stimuli• Hormones stimulate other endocrine organs to releasetheir hormones |
|
|
Anterior Pituitary Hormones - all are ? this means? name 5. which are tropic
|
proteins. GH, TSH, ACTH, FSH, LH
TSH, ACTH, FSH, and LH are all tropic hormones(regulate the secretory action of other endocrine glands) |
|
|
Growth Hormone • Produced by .... • Stimulates most cells, but targets ... and .... muscle • Promotes .... synthesis and encourages use of .... for fuel • Most effects are mediated .... by ........ (IGFs) • GH release is regulated by • ..... (GHRH) • ....... (GHIH)(somatostatin) |
Produced by somatotrophs • Stimulates most cells, but targets bone and skeletalmuscle • Promotes protein synthesis and encourages use of fatsfor fuel • Most effects are mediated indirectly by insulin-likegrowth factors (IGFs) • GH release is regulated by• Growth hormone–releasing hormone (GHRH) • Growth hormone–inhibiting hormone (GHIH)(somatostatin) |
|
|
o Posterior Pituitary Hormones... |
oxytocin and ADH |
|
|
· Thyroid Gland • Consists of two lateral lobes connected by a medianmass called the .... • Composed of follicles that produce the ..... thyroglobulin • Colloid (.... + ....) fills the .... ofthe follicles and is the precursor of ...... hormone • Parafollicular cells produce the hormone ..... |
• Consists of two lateral lobes connected by a medianmass called the isthmus • Composed of follicles that produce the glycoproteinthyroglobulin • Colloid (thyroglobulin + iodine) fills the lumen ofthe follicles and is the precursor of thyroid hormone • Parafollicular cells produce the hormone calcitonin |
|
|
Parathyroid Gland Parathyroid Hormone and its function • Stimulates ...... to digest bone matrix • Enhances reabsorption of .....+ and secretion of phosphate by the .... • Promotes activation of vitamin D (by the kidneys); increases absorption of Ca2+ by intestinal mucosa • ..... feedback control: rising Ca2+ in the blood inhibits ... release |
• Stimulates osteoclasts to digest bone matrix • Enhances reabsorption of Ca2+ and secretionof phosphate by the kidneys • Promotes activation of vitamin D (by the kidneys);increases absorption of Ca2+ by intestinal mucosa • Negative feedback control: rising Ca2+ inthe blood inhibits PTH release |
|
|
· Adrenal Glandso Help us cope with..... o Glucocorticoids &Gonadocorticoids (basic function) |
stressful situations. Glucocorticoids (Cortisol)• Keep blood sugar levels relatively constant Gonadocorticoids (Sex Hormones)• Most are androgens (male sex hormones) that areconverted to testosterone in tissue cells or estrogens in females |
|
|
Pineal Gland • Small gland hanging from the roof of the .... ventricle • Pinealocytes secrete melatonin, derived from ..... • Melatonin may affect three things. |
• Small gland hanging from the roof of the thirdventricle • Pinealocytes secrete melatonin, derived from serotonin • Melatonin may affect• Timing of sexual maturation and puberty• Day/night cycles• Physiological processes that show rhythmic variations(body temperature, sleep, appetite) |
|
|
· Pancreas • Has both .. and ......cells• .... cells produce an enzyme-rich juicefor digestion • Pancreatic islets (islets of Langerhans) containendocrine cells• ..... (a) cells produce ... (a hyperglycemic hormone)• ..... (b)cells produce .... (a hypoglycemic hormone) |
• Has both exocrine and endocrine cells• Acinar cells (exocrine) produce an enzyme-rich juicefor digestion • Pancreatic islets (islets of Langerhans) containendocrine cells• Alpha (a) cells produce glucagon (a hyperglycemic hormone)• Beta (b)cells produce insulin (a hypoglycemic hormone) |
|
|
Direct action of GH • Stimulates these 4 things to produce what? • Mobilizes ...., elevates blood .... by decreasingglucose .... and encouraging glycogen breakdown (anti-insulin effect of GH) |
• Stimulates liver, skeletal muscle, bone, and cartilageto produce insulin-like growth factors • Mobilizes fats, elevates blood glucose by decreasingglucose uptake and encouraging glycogen breakdown (anti-insulin effect of GH) |
|
|
Homeostatic Imbalances of Growth Hormone • Hypersecretion • In children results in ..... • In adults results in ...... • Hyposecretion -In children results in pituitary..... |
Homeostatic Imbalances of Growth Hormone • Hypersecretion • In children results in gigantism • In adults results in acromegaly • Hyposecretion -In children results in pituitarydwarfism |
|
|
functions of oxytocin... 3 things. |
Stimulates uterine contractions during childbirth bymobilizing Ca2+ through a PIP2-Ca2+second-messenger system. Its an up regulation • Also triggers milk ejection (“letdown” reflex) inwomen producing milk. Milk letdown is positivefeedback. • Plays a role in sexual arousal and orgasm in males andfemales |
|
|
functions of Antidiuretic Hormone (ADH) –influences. If solute concentration is high... • If solute concentration is low ... |
influences body/water balance viasolute concertration. Makes kidneys hold on to morewater. • Hypothalamic osmoreceptorsrespond to changes in the solute concentration of the blood. Osmoreceptors arelike chemoreceptors. If solute concentration is high• Osmoreceptors depolarize and transmit impulses to hypothalamicneurons• ADH is synthesized and released, inhibiting urineformation If solute concentration is low• ADH is not released, allowing water loss • Alcohol inhibits ADH release and causes copious urineoutput |
|
|
Calcitonin and its function Produced by .... (C) cells • Antagonist to.... • Inhibits osteoclastactivity and release of Ca2+ from bone matrix • Stimulates Ca2+ ... and incorporationinto bone matrix • Regulated by a ..... (Ca2+ concentrationin the blood) .... feedback mechanism |
• Produced by ....parafollicular cells • Antagonist to PTH • Inhibits osteoclastactivity and release of Ca2+ from bone matrix • Stimulates Ca2+ uptake and incorporationinto bone matrix • Regulated by a humoral (Ca2+ concentrationin the blood) negative feedback mechanism |
|
|
Glucagon - made where? • Major target is the ..., where it promotes• Glycogenolysis—....... • Gluconeogenesis—synthesis of glucose from lactic acidand noncarbohydrate • end result is what? |
Alpha cells of the Islet of Langerhans • Major target is the liver, where it promotes• Glycogenolysis—breakdown of glycogen to glucose• Gluconeogenesis—synthesis of glucose from lactic acidand noncarbohydrate • Release of glucose to the blood |
|
|
Insulin made where? Effects of insulin - 4 things. |
Insulin - beta cells of the islets of Langerhans. • Lowers blood glucose levels • Enhances membrane transport of glucose into fat andmuscle cells • Participates in neuronal development and learning andmemory • Inhibits glycogenolysis and gluconeogenesis |
