Superheroes in Watchmen - Free Essay Example

Sample details Pages: 3 Words: 805 Downloads: 5 Date added: 2019/08/02 Category Culture Essay Level High school Tags: Superhero Essay Did you like this example? Within much of the traditional superhero genre, there is often a depiction of someone who is strong, and powerful and fights against evil to protect those they care about from injustices. Superman is one of the most iconic superheroes not only because of his super abilities but the way he uses those abilities to always fight for good. Superman has become a model of what superheroes should be because of how he is commonly being depicted, as a brave and kind-hearted hero with a strong sense of justice, and morality. Don’t waste time! Our writers will create an original "Superheroes in Watchmen" essay for you Create order In Alan Moores Watchmen we see these traditional superhero values in a different light. The novel takes place in an alternate reality where superheroes exist within the United States during the cold war when the threat of nuclear annihilation was closer than ever. The novel introduces us to six different heroes; The Comedian (Edward Blake), Dr. Manhattan (Jon Osterman), Rorschach (Walter Kovacs), Nite Owl (Daniel Dreidberg), Ozymandias (Adrian Veidt), and Silk Spectre (Laurel Jane). The novel is written through the narrative of these heroes, which makes them seem more like ordinary people that deal with problems just like the rest of us. The superheroes that exist in the world of Watchmen, exist at the mercy of contingent factors, which limit their actions . . .The superhero in Watchmen has become just another facet of society (Reynolds 10809). The way these superheroes are portrayed gives the reader a different perspective of what superheroes would actually be like during this time. The novel Watchmen shows us how the very existence of superheroes can be considered problematic and even dangerous to society. During the Cold War an atmosphere of fear enveloped many people who became convinced that nuclear war is immanent. With tensions higher than ever we are introduced to a superhero with a power greater than that of a nuclear bomb, Dr. Manhattan. Nuclear Security is often being referenced throughout the novel which makes the idea the nuclear war highly likely. Being the almighty deterrent that Dr. Manhattan has become, the novel makes it seem that he alone can prevent nuclear war; I think well give it a week, gentlemen, before bringing out our big guns   after that, humanity is in the hands of a higher authority than mine. Lets just hope hes on our side (Moore, 104). Richard Nixon discussing nuclear security and referring to Dr. Manhattan. The existence of such a powerful being causes a dangerous situation because we see the faith of humanity being put in the hands of Dr. Manhattan who is deemed a god and can easily prevent the launching of nuclear missiles, however, Watchmen asks an interesting question when putting faith in the hands of someone with the abilities like Dr. Manhattans; why would someone with such power even care about what happens to people on earth? As we see later in the novel, Dr. Manhattan becomes essentially bored with living among human beings: I am tired of this world; these people. I am tired of being caught in the tangle of their lives (Moore, 135). Putting the faith of humanity into the hands of a nihilistic Superman Traditional superhero stories lead many readers to believe that the heroes who have power are good guys and deserve that power, although in Watchmen we see that this isnt necessarily always the case. The Comedian or Edward Blake is one of the main heroes of the novel in which his murder in the beginning causes the rest of the retired heroes to come into contact with each other again. The heroes of Watchmen all begin to reveal the different sides of the Comedians personality during his funeral. As it is soon revealed the Comedian is ruthless, cynical and nihilistic, but is still considered a hero because of his involvement in the Vietnam War (Reynolds, 106). After the Keene Act was passed which made vigilantism illegal, the Comedian was exempt because of his work with the government. Rorschach or Walter Kovacs is one of the novels main characters who seems to be someone you want to see urge on, beating up bad guys, and finding out the truth, makes him seem like a real life detective who fights for justice. However, we see later in the novel that he becomes cynical and nihilistic after discovering that a young girl that was kidnapped was killed and fed to dogs, This rudderless world is not shaped by vague metaphysical forces, it is not god who kills the children. Not fate that butchers them or destiny that feeds them to the dogs. Its us. Only us. (Moore, 204). This event caused him to become more cynical in his detective work as well, Rorschach becomes obsessed with trying to find the truth which leads him to break into homes, interrogate those people, and take personal revenge on men who he deemed guilty by killing them.

A Rose For Emily And Gothic Literature - 1212 Words

Have you ever read a story filled with horror, death, and a little romance? In literature, stories with these characteristics are classified as gothic literature. For example A Rose For Emily by Emily Faulkner is Southern gothic literature as the setting is specific to the south while The Cast of Amontillado by Edgar Allen Poe is gothic literature. In A Rose for Emily, Emily and the community are stuck in the old ways of the South as they attempt to avoid the inevitable changes happening around them. In the end, Emily dies and the community is shocked to find her lovers body laying in her room. On the other hand, The Cast of Amontillado focuses on the protagonist revenge plot and death of the antagonist. An analysis of Poe s and†¦show more content†¦Emily s house represents old southern ideas because it sits on an plantation which as her family were once prominet slave owners. Although both stories involve creepy old structures, the setting in Faulkner s story is specific to the South. Additionally, the death and decay of a character represents the instability of the protagonist while creating suspense. In A Rose for Emily, Emily experienced death twice as her father dies of unstated causes and she kills her lover, Homer Barron. The death of Homer Barron creates suspense as the last sighting of Homer is going inside Emily s but is never seen or heard from again. In the end, the townspeople go in Emily s room after her funeral and find Homer s decaying body laying in her bed. Moreover, a long piece of gray hair and indention in a pillow is found on an pillow laying next to Homer. Thus, Emily was sleeping next to his rotting body every night until her own death. Moreover, decay is representative of Emily s life from an well respected figure in her community to a drown woman with an bloated pale figure left to long in the water (Faulkner ). Faulkner, illustrates how Emily was once of high status but now times in the old South have shifted causing her heal th to decline. Emily s reluctancy to part ways with the old south causes her to become alone and isolated for the majority of her life. Hence, the reason she unmarried as her father drove awayShow MoreRelatedGothic Literature: A Rose for Emily by William Faulkner1267 Words   |  6 Pages William Faulkner’s story â€Å"A Rose for Emily† is an example of gothic literature. Faulkner shows sadness for the love that is not returned and a drive that Emily uses to get what she wishes for. He has a gloomy and mysterious tone. One of the themes of the story is that people should let go of their past, move on with the present so that they can focus on welcoming their future. Emily was the evidence of a person who always lived in the shadow of her past, because she was afraid of changing forRead MoreGothic Literature: A Rose For Emily, The Tell Tale Heart, and Daddy976 Words   |  4 PagesIn William Faulkner’s, â€Å"A Rose for Emily, Edgar Allan Poe’s †Å"The Tell Tale Heart,† and Sylvia Plath’s â€Å"Daddy†, are endowed with many features that contribute to their gothic form and success. Faulkner’s,† A Rose for Emily† is characterized by a powerful imagery, plot and setting which are interwoven to create a gothic feeling. The story unfolds in Jefferson, the living fragments of a land that is plagued with civil war. Among the remains of Jefferson is Emily’s house which appears to be the summaryRead MoreA Rose for Emily and the Feather Pillow1375 Words   |  6 PagesDamian Oronoz Mr. Lpez English 11 17 May 2010 A Rose for Emily The Fetter Pillow Essay Hocus pocus in a dark castle, black cats over the graveyards, and two men writing gothic literature. Characteristics of gothic literature include ruined sinister buildings, dungeons, underground passages, crypts, and catacombs which in modern houses become spooky basements or attics. In â€Å"A Rose for Emily† by William Faulkner and â€Å"The Feather Pillow† by Horacio Quiroga, the authors use spooky setting,Read MoreUses of the Conventions of the Gothic Story in The Yellow Wallpaper and A Rose for Emily1467 Words   |  6 Pages In the eighteenth century, Gothic story was an extremely popular form of literature, and it has been a major genre since then. The Yellow Wallpaper by Charlotte Perkins Gilman and A Rose for Emily by William Faulkner are both Gothic horror stories consisting madness and suspense. The Gothic horror story carries particular conventions in its setting, theme, point of view, and characterisation. Both Gilman and Faulkner follow the conventions o f the Gothic horror story to create feelings of gloomRead MoreAmerican Gothic Compare and Contrast Essay 930 Words   |  4 Pagesof when you hear the words American Gothic? If you thought of death, heartbreak, loneliness, then you are correct. The writing period of American Gothic was one that people decided to write about the other side of the happy endings. the heart breaks and the funerals and the thought of being lonely forever. They tell you about the reality of things and what the truth is, how things really happened and it doesn’t sugar coat anything. In â€Å"A Rose for Emily† Emily becomes a sad and depressed person whoRead MoreA Rose for Emily731 Words   |  3 Pagesthe Gothic elements of â€Å"A Rose for Emily† Gothic can be defined as â€Å"literature dealing with the strange, mysterious, and supernatural designed to invoke suspense and terror in the reader.† (Pickering, 2004, p. 1425) Gothic literature generally presents the same themes and motifs: love lost, hidden secrets, love and death hand in hand, beauty, youth, grotesque characters, macabre eroticism, etc. Gothic literature also explores taboo subjects such as murder, suicide and incest. â€Å"A Rose forRead MoreAnalysis Of The Poem Southern Gothic 1566 Words   |  7 PagesEnglish 1102 17 April 2016 Southern Gothic Literature In the 19th century, the Southern Gothic genre quickly became popular after Edgar Allen Poe poems in the 18th century. Most writings were formed around the Civil War era, which plays an enormous part in the tone and setting in Southern Gothic writing styles. (O’Connell 63) Southern Gothic writing elements consist of â€Å"horror, romance and psychological and domestic dramas† (63). The setting of Southern Gothic was always dingy and dark which explainsRead MoreCharacteristics Of Southern Gothic Literature1694 Words   |  7 PagesJordan Cole English 1102 Professor Myszkowski 1 December 2017 Southern Gothic Literature Throughout the course of history, literature has gone through considerable changes. Dating back to its humble beginnings in folklore, fables, and storytelling all the way up to the scientific books and dramatic novels of today. Literature is arguably the centerpiece of all mankind. It is useful for record keeping, education, and bringing cultures and societies together. It has allowed us to expand our mindsRead MoreGothic Literature : The Southern Gothic Fiction1476 Words   |  6 Pagesmorbidly dark and eccentric characters combined with southern charm and the ever-present gender divide to tell stories that represent a writing style known as southern gothic literature. â€Å"Southern Gothic is a subgenre of Gothic fiction unique to American literature that takes place exclusively in the American South. Elements of a Gothic treatment of the South were apparent in the 19th century, ante- and post-bellum, in the grotesques of Henry Clay Lewis and the de-idealized visions of Mark Twa in.[3]Read MoreA Rose for Emily by William Faulkner Essay1064 Words   |  5 Pagesâ€Å"A Rose for Emily† opens with a line that immediately tells the audience that the main character, Emily Grierson, lived a life that was on display; â€Å"When Emily Grierson died, our whole town went to her funeral† (Faulkner 119). The voyeurism that is evident throughout the story, following the life of the main character through the perspective of her watchful community, is introduced by the very first line. In Donaldson’s essay, she explains that many classic southern gothic tales â€Å"bring attention

Motivation Evaluation Free Essays

Motivation can help and hinder the choices an individual makes, sometimes simultaneously. People act and behave various ways and some people may never be understood or why may never be pinpointed. However, every action or behavior is an impulse of an experience or the potential of that individual. We will write a custom essay sample on Motivation Evaluation or any similar topic only for you Order Now Whether it is to achieve a goal, better themselves, or gain success people will act or behave certain ways through their specific form of motivation. Miley Cyrus’s actions evaluated Most people that surf the Internet, watch MTV, or music television, have witnessed or seen the controversy over Miley Cyrus’s latest performance on MTV’s Music Video Awards (The Huffington Post, 2013). There were many controversies over her lyrics, clothing, and actions that pertained to her overall behavior during the performance (The Huffington Post). From her clothing of the bare essentials to her obscene gestures, she was obviously motivated by one thing or another. The psychoanalytic view Assuming Miley was motivated by the psychoanalytic view of motivation, would suggest her decision to behave that way was of little or no control of her own (John Wiley Sons Inc. , 2009). It would also suggest her actions were driven by either her unconscious instincts of life and sexuality or her unconscious instincts of death and aggression (John Wiley Sons Inc.). More specifically her unconscious need of an outlet for aggression or her unconscious need for sexual satisfaction (John Wiley Sons Inc. ). For example: Miley behaved that way because she was upset about losing a boyfriend, and unconsciously let out her aggression through dancing seductively on another man (The Huffington Post, 2013). The humanistic view Assuming Miley was motivated by the humanistic view of motivation, would suggest her decision to behave that way could be because of a specific need, such as self-actualization or achievement that she consciously needed to fulfill (John Wiley Sons Inc. , 2009). It would also suggest she was driven by her goals of fulfilling her full personal potential (John Wiley Sons Inc. , 2009). (John Wiley Sons Inc. ). For example: Miley was tired of her well-known Disney roles in entertainment that subdued her true self, therefore her behavior was an attempt to move toward her new goals of achievement and self-actualization. The diversity view Assuming Miley was motivated by the diversity view of motivation, would suggest her decision to behave that way could be because of her individual goals and personal incentives (John Wiley Sons Inc. , 2009). It would also suggest she behaved that particular way to fulfill a psychogenic need, or combination of the various needs simultaneously to fulfill her personal goal (John Wiley Sons Inc. ). For example: Her behavior was an attempt to fulfill her needs of achievement to increase self-regard, affiliation of being an adult instead of a child, and sentience to enjoy sensuous impressions (John Wiley Sons Inc. ). To better explain: The diversity view of motivation by Henry Murray is the theory of needs. This theory states human lives have to be understood in the context of time, because people live in response to the past and their anticipation of the future (John Wiley and Sons Inc. , 2009). Therefore, people organize their lives and bind their time through direct and select forces that resides within the person and their environment (John Wiley Sons Inc. ). The direct forces are needs, specifically physiological (viscerogenic) needs and psychogenic needs (John Wiley Sons Inc. , 2009). The physiological needs are basic human needs, such as air, sleep, and water (John Wiley Sons Inc. ). The psychogenic needs are categorized into 20 basic needs, such as dominance, sex, order, and 17 others (John Wiley Sons Inc.). According to Henry Murray (John Wiley Sons Inc. ), human behavior is organized by a single need or a combination of needs simultaneously, to fulfill a personal goal (John Wiley Sons Inc. ). However, â€Å"The full dynamics of human behavior are revealed in the interaction of needs and press, producing a thema (John Wiley Sons Inc. , 2009, p. 281). Therefore, when a need is built up overtime, it causes tension, which is released through thoughts and behavior by the individual (John Wiley Sons Inc. ). Conclusion There is a purpose behind every person’s behavior, whether it follows the psychoanalytic, humanistic, or diversity view of motivation, it can be analyzed or evaluated through certain processes and theories to see the purpose (John Wiley Sons Inc. , 2009). One thing stands to be true, all people are unique, but behave similarly and differently for various reasons. Whether it is to achieve a goal, better themselves, or gain success people will act or behave certain ways through their specific form of motivation. How to cite Motivation Evaluation, Papers

Osmometric Thirst free essay sample

Thirst  is the craving for liquids, resulting in the basic  instinct  of humans or animals to  drink. It is an essential mechanism involved in  fluid balance. It arises from a lack of fluids and/or an increase in the concentration of certain osmolites  such as  salt. If the water volume of the body falls below a certain threshold, or the osmolite concentration becomes too high, the  brain  signals thirst. Continuous  dehydration  can cause a myriad of problems, but is most often associated with neurological problems such as seizures, and renal problems. Excessive thirst, known as  polydipsia, along with excessive urination, known as  polyuria, may be an indication ofdiabetes. Thirst produced by an increase in the osmotic pressure of the interstitial fluid relative to the intracellular fluid thus producing cellular dehydration fluid, Intracellular fluid, fluid contained within cells. Osmometric thirst occurs when the osmotic balance between the amount of water in the cells amp; the water outside the cells becomes disturbed means when the concentration of salts in the interstitial fluid is greater than that inside the cells, resulting in the movement of intracellular water outside of the cell by osmosis. This is what happens when we eat salty pretzels. The Na is absorbed into the blood plasma, which disrupts the osmotic balance between the blood plasma amp; the interstitial fluid. This draws water out of the interstitial fluid and into the plasma, now upsetting the balance between the cells and the interstitial fluid. The result is water leaving the cells to restore the balance. The disruption in the interstitial solution is recognized by neurons called osmoreceptors. These osmoreceptors are located in the region of the anterior hypothalamus. These osmoreceptors send a signal that causes us to drink more water, in order to restore the osmotic balance between the cells and surrounding fluid. In the case of pretzel eating, if we do not drink more water, eventually the excess Na is simply excreted by the kidneys. The body must have water to excrete in order to rid itself of nitrogenous wastes, so the reduction in water excretion causes fluid-seeking behavior. OSMOMETRIC THIRST  is stimulated by cellular dehydration. It occurs when the tonicity of the interstitial fluid increases, which draws water out of the cells (think of water seeking to be balanced), cells then shrink in volume. The word osmosis means movement of water, through semi permeable membrane, from low solute concentration to high solute concentration. There are receptors and other systems in the body that detect a decreased volume or an increased osmolite concentration. They signal to the  central nervous system, where central processing succeeds. There are some RECEPTORS FOR OSMOMETRIC THIRST (already in the central nervous system more specifically in hypothalamus notably in two circumventrivular organs that lack an effective brain-barrier the organumvasculosum of the lamina terminalis (OVLT) and the  subfornical organ  (SFO). However, although located in the same parts of the brain, these osmoreceptors that evoke thirst are distinct from the neighboring osmoreceptors in the OVLT and SFO that evoke arginine vasopressin  release to decrease  fluid output. In addition, there are  visceral osmoreceptors. These project to the  area postrema and  nucleus tractussolitarius  in the brain), the neurons that respond to changes in the solute concentration of the interstitial fluid start firing when water is drawn out of them due to hyper tonicity; most likely located in the anteroventral tip of the third ventricle (AV3V); if activated, they send signals to neurons that control rate of vasopressin secretion So, the question will be raised such as do we want more or less vasopressin? We want more vasopressin; remember high levels of vasopressin cause kidneys to retain water, sweating causes loss of water through skin, which increases tonicity of interstitial fluid, which then draws water out of the capillaries and cells. We can lose water only from the cells, but not intravascular, by eating a salty meal in which salt is absorbed from the digestive tract into the blood, this makes the blood hypertonic (high concentration of salt), this draws water into the cell from the interstitial fluid, the loss of water from the interstitial fluid makes  it  hypertonic, now water is drawn out of the cells, as blood plasma increases in volume, kidneys excrete more water and sodium, eventually, excess sodium is excreted, along with the water that was taken from the interstitial fluid and intercellular fluid, this results in an overall loss of water from the cells, however, blood plasma volume never decreased. The damage to AV3V area can cause diabetes and lack of thirst (excessive urination, so must force self to drink) subfornical organ  (SFO) circumventricular organ whose AII receptors are the site where angiotensin acts to produce thirst; it has few neural inputs, as its job is to sense the presence of a hormone in the blood; it has many  outputs  to various parts of the brain:   endocrine   SFO axons project to neurons in the supraoptic and paraventricular nuclei that are responsible for production and secretion of the posterior pituitary hormone vasopressin   Autonomic   axons project to cells of the paraventricular nucleus and other parts of the hypothalamus, which the send axons to brain stem nuclei which control the sympathetic and parasympathetic nervous system; this system controls angiontensin’s effect on blood pressure. behavioral   axons sent to  median preoptic nucleus, an area which controls drinking and secretion of vasopressin median preoptic nuc leus   receives information from: 1. OVLT regarding osmoreceptors 2. SFO regarding angiotensin. Baroreceptors via the nucleus of the solitary tract Lateral Hypothalamus and Zona Incerta esions of the hypothalamus disrupt osmometric and volumetric thirst, but not meal-associated drinking lesions of the zona incerta disrupt hormonal stimulus for volumetric thirst, but not the neural ones that originate in the atrial baroreceptors zona incerta sends axons to brain structures involved in movement influences drinking behavior Central processing The  area postrema  and  nucleus tractussolitarius  signal, by  5-HT, to  lateral parabrachial nucleus, which in turn signal to median preoptic nucleus. In addition, the area postrema and nucleus tractussolitarius also signal directly to subfornical organ. Thus, the median preoptic nucleus and subfornical organ receive signals of both decreased volume and increased osmolite concentration. They signal to higher integrative centers, where ultimately the conscious craving arises. However, the true  neuroscience  of this consciou s craving is not fully clear. In addition to thirst, the  organumvasculosum of the lamina terminalis  and the  subfornical organ  contribute to  fluid balance  by  vasopressin  release. Studies done†¦. Some research and study presents a theoretical model for osmotic (cellular dehydration) thirst, and evaluates several of the implications of the model. Ss were 11 male Sprague-Dawley rats. The model for osmotic thirst asserts that when a load consisting of n millimols of effective osmotic solute dissolved in v ml. of water is introduced into the extracellular compartment, the S will drink a volume of water, D (in ml. ), which is proportional to the volume of water, Diso (in ml. ), required to dilute the hypertonic load to isotonicity (ALPHA). Thus, D = k (Diso) = k-n/a-v=, where k is the constant of proportionately representing the contribution of the kidney to osmotic regulation. The experimental data show that under conditions of osmotic thirst this model accurately predicts the rats drinking behavior. Osmoregulatory thirst associated with deficits of intracellular fluid volume. Small increases of 1–2% in the effective osmotic pressure of plasma result in stimulation of thirst in mammals. It has been shown in both human subjects and other mammals that when the plasma osmolality (usually in the range of 280–295 mosmol/kgH2O) is increased experimentally as a result of increasing the concentration of solutes such as NaCl or sucrose that do not readily pass across cell membranes, thirst is stimulated. By contrast, increasing plasma osmolality by systemic infusion of concentrated solutes such as urea or  D-glucose that more readily cross nerve cell membranes is relatively ineffective at stimulating thirst (8,12,  18). In the former case, a transmembrane osmotic gradient is established and cellular dehydration results from movement of water out of cells by osmosis. Cellular dehydration does not occur with the permeating solutes in the latter case, and it is considered that specific sensor cells in the brain, termed osmoreceptors (initially in relation to vasopressin secretion), respond to cellular dehydration to initiate neural mechanisms that result in the generation of thirst (8,  18). Although there is evidence that some osmoreceptors may be situated in the liver, much evidence has accrued that localizes an important population of osmoreceptive neurons to the preoptic/hypothalamic region of the brain. The hypothalamus was implicated in the generation of thirst in the early 1950s when Bengt Andersson was able to stimulate water drinking in goats by electrical or chemical stimulation of the hypothalamus. Although he observed that drinking was induced by injection of hypertonic saline into the hypothalamus in a region between the columns of the fornix and the mamillothalamic tract, the solutions injected were grossly hypertonic, making it difficult to come to a firm conclusion that physiologically relevant osmoreceptors for thirst existed in this region. Andersson and colleagues later found evidence that more rostral tissue in the anterior wall of the third ventricle was more likely to be the site of sensors mediating osmotic thirst and proposed a role for the ambient Na+  concentration in this region of the brain in the initiation of thirst. Neural mechanisms sub serving osmotically stimulated thirst†¦ More than 25 years ago, clues emerged as to the crucial role of a region in the anterior wall of the third ventricle in thirst mechanisms when it was shown that ablation of tissue in the anteroventral third ventricle wall (AV3V region) of goats and rats caused either temporary or permanent adipsia (1,  10). In those animals with lesions that did recover spontaneous water drinking, loss of dipsogenic responsiveness to osmotic and ANG stimuli was evident. Another clue to the location of cerebral osmoreceptors sub serving thirst came from studies in sheep suggesting that the cerebral osmoreceptors sub serving thirst and vasopressin secretion were, at least in part, located in brain regions lacking a blood-brain barrier. In subsequent years, evidence (reviewed in Ref. 14) from the study of lesions, electrophysiological recordings, and the expression of the immediate early gene c-fos  in rats have confirmed that neurons in both the organum vasculosum of the lamina terminalis (OVLT) and the subfornical organ (SFO) are most likely the sites of very sensitive osmoreceptors (Fig. 1? ). The SFO and OVLT are two circumventricular organs that lack a blood-brain barrier and that are situated in the anterior wall of the third ventricle (the lamina terminalis). In particular, the dorsal part of the OVLT and the periphery of the SFO are osmosensitive in the rat. However, the median preoptic nucleus (MnPO), which is situated in the lamina terminalis longitudinally between the two circumventricular organs and is an integral part of the AV3V region, is also strongly activated by osmotic stimuli. Lesion studies in rats have shown that the MnPO may play a crucial role in the generation of thirst in response to both osmotic and hormonal signals being relayed to this nucleus by neural inputs from the SFO and possibly the OVLT (10). Another aspect of osmoregulatory drinking is that it may be blocked pharmacologically by intracerebroventricularly injected ANG antagonists, suggesting that a central angiotensinergic pathway is involved in most mammals. The MnPO, which is rich in ANG type 1 receptors but is not amenable to circulating ANG II, is a likely site of this angiotensinergic synapse. The MnPO receives afferent neural input from neurons in both the SFO and the OVLT and may integrate neural signals coming from osmoreceptive neurons in these circumventricular organs with visceral sensory inflow from the hindbrain However, combined ablation of both the SFO and OVLT leaving a considerable part of the MnPO intact reduces but does not totally abolish osmotically induced drinking. This suggests that neurons within the MnPO may be osmoreceptive also or that they receive osmotically related input from other parts of the brain [e. g. , the area postrema (AP)] or body (e. g. , hepatic portal system). It is clear that the lamina terminalis is a region of the brain where stimuli from the circulation, such as plasma hypertonicity or hormones (e. g. , ANG II, relaxin), exert their dipsogenic action. In regard to the subsequent efferent neural pathways that may project from the lamina terminalis to other brain regions (including the cerebral cortex) to generate thirst, little is known at present. The lateral hypothalamic area, the hypothalamic paraventricular nucleus, and the periaqueductal gray are all regions that receive a strong neural input from the lamina terminalis and have been proposed as regions that may participate in the generation of thirst. However, evidence in support of such proposals is scarce. Recent studies using positron emission tomography in human volunteers identified several brain regions that became activated during an intravenous infusion of hypertonic saline that produced a strong thirst sensation in these subjects. In particular, the anterior and posterior parts of the cingulate cortex were activated, and on satiation of the thirst, these areas rapidly declined in activity. This cingulate region has been implicated in other goal-directed behaviors and probably plays a yet-to-be-specified role in the generation of human thirst. Angiotensin and thirst Classic studies by Fitzsimons and associates (see Ref. 8  for review) were the first to clearly demonstrate that renin and its effector peptide, ANG II, were highly effective as dipsogenic stimuli in the rat. Systemically administered renin or ANG II generates water intake in sated rats. As is true for osmotically stimulated drinking, ANG-induced thirst requires the structures of the lamina terminalis (i. e. SFO, MnPO, and OVLT) for sensing circulating peptides (particularly the SFO) and for initial central nervous system processing and integration of this peripherally derived information (10). The dipsogenic action of ANG is even more impressive when it is injected directly into the brain, and this has been demonstrated in several mammals (rat, goat, dog, sheep) and also in birds (duck, pigeon). This route of administration is believed to mimic the action of this peptide at one or more periventricular brain sites. The presence of a brain renin-angiotensin system with all the components of the metabolic cascade as well as receptors being synthesized de novo in the brain has been demonstrated. It has been hypothesized that circulating ANG II acts on forebrain circumventricular organs (SFO, OVLT) in the mode of a hormone and that, either directly or indirectly, it activates angiotensinergic pathways projecting to central integrative sites when the peptide acts as a neurotransmitter (11). The systemic (renal/circulating) and the brain renin-angiotensin systems, although distinct, are functionally coupled with one another and play complementary roles in the maintenance of body fluid homeostasis. Inhibition and facilitation of thirst through hindbrain actions In addition to humoral factors acting through forebrain targets and networks to facilitate drinking, there is evidence of both stimulatory and inhibitory signals acting on or through the hindbrain. When the hypertension induced by intravenous ANG II in rats is reduced or normalized by coadministration of a systemically acting hypotensive drug, drinking responses to infusions of ANG II are enhanced (7). In rats with actions of the systemic renin-angiotensin system blocked, reducing blood pressure to below normal resting levels enhances the drinking response to intracerebroventricular ANG II infusions (11). Inhibition of thirst arises not only from arterial baroreceptors but also from volume receptors on the low-pressure side of the circulation. Distention of the region of the junction of the right atrium and vena cava or of the pulmonary vein at the entry to the left atrium by inflating balloons inhibits experimentally induced drinking. In contrast, when, in ogs, both low-pressure cardiopulmonary and high-pressure arterial baroreceptors are unloaded by reducing venous return to the heart, drinking is stimulated (9,  17). Under such conditions, Quillen and colleagues (15) found that denervation of either the cardiopulmonary or sinoaortic baroreceptors significantly attenuated thirst in the dog and that denervation of both sets of receptors completely abolished drinking even though circulating levels of ANG were high. Afferent input from the cardiopulmonary and arterial baroreceptors is carried to the brain by the IXth and Xth cranial nerves, with most of these nerves terminating in the nucleus of the solitary tract (NTS). Lesions centered on the AP, but also encroaching on the medial portions of the medial NTS (i. e. , an AP/mNTS lesion), as well as bilateral lesions centering on the medial subnucleus of the NTS proper, produce rats that overrespond to thirst-inducing treatments associated with hypovolemia (5). These effects are likely to be due to removal of inhibitory baroreceptor-derived input. However, it is possible that the AP also plays a role in the inhibitory control of thirst derived from systemic blood volume expansion or acute hypertension. As demonstrated by Antunes-Rodrigues and colleagues (2), a peptide made and released from the cardiac atria, ANP, inhibits drinking. Release of ANP in response to hypervolemia and hypertension may inhibit drinking. Its action is discussed below. Interestingly, the AP/NTS region contains cells with axons that project to the lateral parabrachial nucleus (LPBN). Electrolytic, anesthetic, and neurotoxic lesions of the LPBN produce overdrinking to mediators of extracellular dehydration in the rat (11). This is similar to the effects of AP/mNTS lesions. A significant portion of the cells that project from the AP/mNTS to the LPBN contain serotonin (5-HT), and bilateral injections of the nonselective 5-HT receptor antagonist methysergide enhance drinking as well as NaCl solution intake in response to several dipsogenic stimuli in rats (see Ref. 11  for review). The model that has been proposed is that there is a hindbrain inhibitory circuit involving the AP, NTS, and LPBN that receives and processes neural and humoral input derived from activation of cardiopulmonary and arterial baroreceptors. Ascending pathways from this inhibitory complex project to many forebrain structures, such as the structures along the lamina terminalis, the central nucleus of the amygdala, and various hypothalamic nuclei that have been implicated in thirst. In turn, many of these forebrain structures have reciprocal connections with the LPBN and NTS. It is within this visceral neural network where the input from both excitatory and inhibitory humoral and visceral afferent nerves is likely to be processed to give rise to drinking behaviors or the perception of thirst.