Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Brain&Behavior ch.9
Homeostasis: active regulation of the internal environment
| Term | Definition |
|---|---|
| Homeostasis | self-regulation to maintain a stable internal environment despite changes in external environment |
| What are five things homeostasis regulates? | Temperature, Water and pH levels, Blood pressure, Glucose concentration, and Nutrition |
| Changes in the internal environment can affect _________ – process that induces or sustains a behavior | motivation |
| Temperature: There are two types of thermo regulators | endotherms, ectotherms |
| Temperature: Endotherms | GENERATE most of their own heat through INTERNAL processes |
| Temperature: Ectotherms | GET most of their heat from the ENVIRONMENT |
| Temperature: Both actively regulate body temperature, but ectotherms do so by ________ | behavior |
| Behavioral regulation of temperature occurs in three ways: | • Changing exposure of the body surface • Changing external insulation (feathers, fur, blubber, clothes) • Changing surroundings |
| Temperature: Why are behavioral methods of thermoregulation especially important to ectotherms (like iguanas)? | because they generate little heat through metabolism |
| Temperature: how does the iguana control its body temperature? | by moving toward or away from a heat source (lamp) |
| Temperature: when the iguana was injected with bacteria, how did it react? | it moved closer to the lamp to produce a “Behavioral fever” to fight infection |
| Temperature: in most endothermic animals body temperature is tightly regulated by the body's thermostat. The ____________ | hypothalamus (POA: preoptic area of hypothalamus, brain stem, and spinal chord too) |
| Temperature: these neural regions (hypothalamus/POA, brain stem, and spinal cord) initiate what? | physiological and behavioral responses to return temperature to the set zone |
| Temperature: What are some examples of behavior responses? | shivering, heat-seeking/avoiding behaviors |
| Temperature: What are some examples of physiological responses? | constriction/dilation of blood vessels, sweating, respiration, thyroid hormone secretion |
| Thermoregulation can occur at different levels of the nervous system (redundancy). Narrower set zones are at ______ levels and broader (less precise) at ______ levels | higher levels (brain) and broader (less precise) at lower levels |
| ______ studies show separate regulatory systems in the hypothalamus | Lesion |
| Anterior damage lose__________ response, but not ________; Lateral damage opposite effect | physiological, behavioral |
| what are the primary homeostatic mechanisms? | negative feedback systems |
| If a desired value, the set point, is deviated from, ____________ action begins | compensatory |
| The set zone refers to what? | the range of tolerance in a system |
| fluid regulation: Water in the Human Body Shuttles between Two Major Compartments. What are they? | Intracellular compartment and extracellular compartment |
| Most water in our body is ___cellular | intra |
| Intracellular compartment | fluid contained within cells |
| Extracellular compartment | fluid space outside cells |
| what fluids does extracellular compartment contain? (2) | interstitial fluid (between cells) and blood plasma |
| What are two forces driving water movement in our bodies? | osmosis and diffusion |
| Diffusion – molecules of a substance (_____) dissolved in another substance (______) will move until a uniform concentration is achieved | solute, solvent |
| Osmosis is the movement of water across a ____________ membrane that separates solutions of two different concentrations of a solute | semipermeable |
| Osmotic pressure | force that pushes or pulls water across the membrane |
| The extracellular fluid indicates the state of the intracellular space, and is monitored by the _______ system | nervous |
| Two states signal a need for water: Low extracellular volume from a loss of bodily fluids stimulates what? | hypovolemic thirst |
| Two states signal a need for water: High extracellular solute concentration, or very salty fluids, stimulate what? | osmotic thirst |
| Hypovolemic thirst is triggered by a loss of ______ volume | water (the saline concentration is not changed) |
| Hypovolemic thirst: ___________ in blood vessels and the heart detect the initial drop in pressure due to extracellular fluid loss | Baroreceptors |
| Hypovolemic thirst: a neural response: The brain activates responses such as _____ or salt ________ | thirst, hunger |
| Hypovolemic thirst: a neural reponse: The _________ nervous system causes arteries to constrict and several _______ systems are activated | sympathetic, hormone |
| Hypovolemic thirst: Physiological response 1: Heart decreases secretion of ______ _________ _______ | atrial natriuretic peptide (ANP) |
| Hypovolemic thirst: Physiological response 1: atrial natriuretic peptide (ANP) does what? (3)` | inhibits drinking, reduces blood pressure and promotes excretion of water and salt at the kidneys |
| Hypovolemic thirst: Physiological response 2: Posterior pituitary releases ________ | vasopressin |
| Hypovolemic thirst: Physiological response 2: What does vasopressin do? (1) | Acts on kidneys to slow urine productions |
| Hypovolemic thirst: Physiological response 3: Kidneys trigger production of __________ __ | angiotensin II (AII) |
| AII has several water-conserving actions: Conserves water by constricting ______ _________, in turn increasing blood pressure | blood vessels |
| AII has several water-conserving actions: Stimulates release of v__________ and a___________ | vasopressin and aldosterone |
| AII has several water-conserving actions: we already know that vasopressin acts on kidneys to slow urine productions. What does aldosterone do? | promotes conservation of sodium by the kidneys |
| AII has several water-conserving actions: AII acts directly on the brain, at the _______ area, and areas called ___________ organs to stimulate drinking behavior | preoptic area (POA, circumventricular organs (CV organs) |
| AII has several water-conserving actions: CV organs in wall of ventricular system can directly monitor salt in the _______ | blood |
| Osmotic thirst occurs when the extracellular fluid becomes too _______ | salty (water loss or salt increase) |
| osmotic thirst: Water is pulled out of the cells through osmosis. Volume ________ and solute concentration ________ | decreases, increases |
| osmotic thirst: _________ neurons in the hypothalamus specifically monitor changes in concentration of the extracellular fluid | Osmosensory |
| osmotic thirst: These neurons are also found in the ____ (abr), a circumventricular organ | OVLT |
| osmotic thirst: Too much extracellular salt triggers osmosis into or out of the cell? | out of the cell |
| The amount of water that the body can retained depends on the number of ____ ions in the body. | Na+ |
| When water is scarce Na+ ions must be conserved: Angiotensin II also stimulates adrenal glands to release a_________ | aldosterone |
| aldosterone is a steroid hormone that stimulates the ________ to conserve Na+, aiding water retention | kidneys |
| Drinks that are slightly salinated can quench thirst faster, because of why? | they add Na+ ions back into the extracellular fluid |
| Too much salt in your drink (drinking seawater) would only cause more _______ thirst. | osmotic |
| The regulation of eating and body energy involves redundant mechanisms and complex homeostatic mechanisms.________ Regulation Helps Prepare for Future Needs | Nutrient |
| Nutrients are chemicals required for what three things? | function, maintenance, and growth of the body |
| There are _#_ amino acids (9 essential ones not synthesized by body), Fatty acids,_#_ vitamins, Minerals, and Carbohydrates | 20, 15 |
| _________ is converted glucose stored in the liver and skeletal muscles for the ____-term storage | Glycogen, short |
| This process of conversion is regulated by the pancreatic hormone _______ | insulin |
| When glucose levels drop, the hormone ________converts glycogen back into glucose | glucagon |
| For ____-term storage, lipid (fat) molecules from fats or excess sugars are stored in ______ tissue | long, adipose (fat) |
| Under prolonged food deprivation ___ can be converted into glucose and ketones, which can be used as fuel | fat |
| ______ _________ – comsumption of energy used for heat production, membrane potential maintenance, and life-sustaining processes | Basal metabolism |
| Only __-__% of food energy is used for active behavior… the majority of food energy is spent on basal metabolism. | 10-20 |
| Metabolism is under homeostatic control and can be adjusted, so dietary changes will not always produce changes in ______ | weight |
| The body needs insulin to help glucose transporters do what? | import glucose from the blood into most cells (except neurons) |
| ________ _________ results from lack of or ineffective insulin | Diabetes mellitus |
| Diabetes mellitus: In Type I (juvenile-onset) diabetes, what happens? | the pancreas stops producing insulin |
| Diabetes mellitus: Type II (adult-onset) diabetes is caused by what? | decreased sensitivity to insulin or decreased insulin production |
| Insulin release is important at mealtimes and is triggered by several mechanisms: What three phases? | cephalic phase, digestive phase, absorptive phase |
| The cephalic phase of insulin release is mediated by the brain in response to ______, _______, or _______ food | seeing, smelling, or tasting |
| In the digestive phase, insulin is released when what? | food enters the digestive tract |
| In the absorptive phase specialized liver cells called ________ signal the pancreas to release even more insulin | glucodetectors |
| The brain integrates ________ and _______ levels with other information to monitor appetite | glucose and insulin |
| The hypothalamus coordinates multiple systems that control _______ | hunger |
| Ventromedial hypothalamus (VMH) lesions caused what? | obesity—it was identified as a satiety center |
| Lateral hypothalamus (LH) lesions caused what? | a refusal to eat and weight loss – it was identified as a hunger center |
| The dual-center hypothesis proposed... | that the two areas work in opposition |
| Later research showed that the lesioned animals did in fact experience satiety or hunger and _______, so neither center was in sole control | stabilize |
| Lesion Study: What was the hypothesis? | the hypothalamus contains discrete systems for controlling hunger and satiety |
| Lesion Study: What was the test? | place small lesions in target areas within the hypothalamus |
| Lesion Study: What happened to the lesioned animals? | lesioned animals stabilize at new body weight, return to that weight after deprivation and gain weight with rich food |
| ________ from the body drive hypothalamic appetite controller | Hormones |
| The digestive organs and fat tissue release hormonal signals about ______ balance | energy |
| A circuit within the ________ ________ of the hypothalamus is key in integrating peptide hormone signals from the body | arcuate nucleus |
| Fat cells are endocrine cells and release the hormone _____ into the blood stream | leptin |
| the release of leptin into the blood stream provides information about what to the brain? | long-term fat reserves |
| Mice deficient in leptin or with nonfunctional leptin receptors become _______ | obese; brain not triggered satiate |
| Shorter-term energy balance—presence or absence of food in the gut—is reported by hormones from the _________ organs | digestive organs |
| Two hormones important for _________ _________ are released and synthesized by endocrine cells of the stomach: | appetite control |
| G_____ reaches high levels before eating and drops off after eating. This works as an appetite _________ | stimulant |
| ______ reaches high levels after eating and works as an appetite ________ | PYY3-36, suppressant |
| How do these hormones affect the appetite control center in the hypothalamus: the ______ nucleus? | arcuate |
| 2 types of neurons with opposite effects: | NPY neuron and POMC neuron |
| NPY neurons – act as _____ neurons, stimulating appetite and reducing metabolism when activated | hunger |
| POMC neurons – act as _____neurons when activated, inhibiting appetite and increasing metabolism | satiety |
| p_______ hormones also interact with this appetite center | Peripheral |
| Visceral (gut) and somatosensory (stomach and sight, smell, taste…) information travels via what? | the vagus and spinal/facial nerves |
| ______ hormones from the gut are carried to the brain, where they help regulate appetite | Peptide |
| Leptin (and insulin) signal current state of energy store; ________ NPY and ________ POMC | inhibiting, stimulating |
| ______ and ____ have opposing effects on NPY: stimulating versus inhibiting appetite | Ghrelin and PYY |
| The peripheral hormone leptin affects arcuate neurons in opposite ways: explain | High levels of leptin activate the POMC satiety neurons but inhibit the NPY hunger neurons, working to suppress appetite |
| Ghrelin and PYY3-36 act on NPY hunger neurons in opposition: • ______ stimulates them and increases appetite • ______ inhibits them and reduces appetite | Ghrelin, PYY3-36´ |
| Orexin from the lateral hypothalamus participates in control of ______ behavior | feeding |
| Appetite signals converge on the what in the brainstem?—a common pathway for feeding behavior | nucleus of the solitary tract (NST) |
| __________ is a peptide released by the gut after feeding and acts on the vagus nerve to inhibit appetite | Cholecystokinin (CCK) |
| The ___________ system is a major regulator of appetite and feeding | endocannabinoid |
| Obesity, based on body mass index (BMI), is an epidemic in the United States: __% overweight and 1/3 obese | 61 |
| Several emerging strategies for treatment: (6) | Appetite control, Increased metabolism, Inhibition of fat tissue, Reduced absorption, Reduced reward, and Anti-obesity surgery |
| Appetite control—drugs to dampen the what? (PYY nasal spray) | hypothalamic appetite controller |
| increased metabolism—cause the body’s metabolic rate to increase and burn more ______ (thyroid) | calories |
| Inhibition of fat tissue does what? | interfere with the formation of new fat tissue |
| Reduced absorption–an obesity medication Orlistat works by doing what? | interfering with the digestion of fat |
| Reduced reward—use ____ to reduce the brain’s reward circuitry | drugs |
| Anti-obesity surgery: Liposuction | the surgical removal of fat tissue |
| Anti-obesity surgery: ______ procedures bypass part of the stomach or intestinal tract to reduce absorptive capacity | Bariatric |
| _______ _______ is a disorder in which the patients have no appetite (anorexia) and it originates in the nervous system (nervosa) | Anorexia nervosa |
| Treatments include family-based treatment (FBT), also called Maudsley therapy—focuses on “________” of the anorexic person instead of identifying causal factors | refeeding |
Created by:
cmccartney2
Popular Biology sets