"Motivation is defined as a process that arouses directs and maintain behavior".
The following part of the brain are involved in motivation.


This part of brain is known to be a critical importance in the system of eating, drinking, sleeping, sexual and emotional behavior. The general location of this part is between midbrain and diencephalon and is physically at the base of cerebellum, lying above the optic chiasm and is adjacent to the pituitary gland.
It is consisted on 3 major Zones carried 14 major nuclei. The zones are anterior hypothalamus, the lateral hypothalamus and the ventro medial hypothalamus. The nuclei are interconnected in a very complex form and controlled different aspects of body e.g gustatory and somatosensory, olfactory, sensory system and lower portion or regions and the most anterior of the body.


The part of limbic system the covered sea horse shaped brain structure of mostly gray matter. It runs from the dorsal part to the Corpus Callusum. It has primary function in the mediation of olfactory and visceral process. As a part of limbic system it is also considered a major region of motivation. The lesion in this region may become the disability of motivation.
Amygadala and Almond shaped neural structure comprises the part of the temporal lobe. It is involved in the regulation of Homeostasis which means the process in which the body's substances and characteristics such as temprature, glucose level and maintain required level.

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"Thirst an internal physiological state that results from water dispiration".

The body contain four major fluid compartments, one is Intra Cellular the other three are Extra Cellular fluid compartments. The compartments which is found within the cell is called Intra Cellular. The fluid portion of the cytoplasm of the cell or the fluid contained within the cell.
The rest of fluid is known to be Extra Cellular fluid or the fluid outside the cell. It is divided into three major compartments.

I) Inter Stitial Fluid.
It means that baths. The cell filling the space between the cells of the body.
II) Blood Plasma/ Intra Vascular Fluid.
This fluid is found within the Vessels.
III) Cerebro Spinal Fluid.
It is similar to blood plasma that is found in the ventricular system of the brain and the subarchnoid space surrounding the brain and spinal cord.

The intra cellular fluid is controlled by the concentrations of Solutes in the inter stitial fluid.


A solid compound that is desorption in liquid or solution normally inter-stitial fluid is "Isotomic" which means equal to osmotic pressure to the contents of the cell. A cell placed in isotomic solution neither loses nor gain water, due to this aspect water does not move into or outside the cell, while the inter-stitial loses water. The losing of water is known to be "hypertonic" and another hand if the inter-stitial fluid gains water is called "hypotonic".


Reduction in the volume of the intra vascular fluid. Litrarily ,earns low volume of blood. Due to this problem Heart can no longer pump the blood and Heart failure can occur. In other words there are two important characteristics of the body fluid which maintain the body system.
1) The solute concentration of intra cellular compartments.
2) Volume of blood.
Water regulates with above methods.

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Types of Thirst

Thirst means a sensation that people say that they are dehydrated or tendency to suck water and to ingest it. There are two kinds of thirst.

1. Osmomatric Thirst

The term means to the fact that three detectors or actually responding to change in the concentration of the inter-stitial fluid that surrounds them. Osmosis means the movement of water through semipermeable membrane from a region of low solute concentration to one of high solute concentration.
Semipermeable membrane -- A membrane that allows some but not all molecules to pass through osmomatric thirst produce by an increase in the osmomatric pressure of the inter-stitial fluid relative to intra-cellular, thus produce cellular dehydration.
Osmosis receptors -- Neurons that detect in the solute concentration of the intra-stitial fluid that surrounds in and are responsible of osmomatric thirst and located in the region of the anterior of hypothalamus.
Thirst osmomatric -- Thirst produce by increase in the relative osmatic pressure of extra cellular fluid which results from loss of cellular fluid.
Thirst volumetric -- Thirst produce by decrease amount of extra cellular fluid in the body.

2. Volumetric Thirst

This type of thirst is associated with the decrease volume of the blood or blood plasma or decrease in intra vascular volume and it occur mostly through evaporation or through loss of blood, vomiting and diarrhea.
Receptors of kidney -- These are the receptors which controlled the secretion of Angiotensin.
Angiotensin is a peptide hormone that constrict blood vessels causes the retension of sodium and water produce thirst and salt appetite.
Receptors of Heart and Blood -- These are also known as arterial baror receptors. These are associated with the volumetric thirst lie within the heart which contains sensory neurons when the blood plasma fall in the vessels. These receptors detect the change and stimulate processes.

Organum Vasculosum of the Lamina terminals (OVLT)

A circum ventricular organ located anterior portion of the third ventricle served by fenestrated capillaries and it is known to be blood brain barrier.

Sub Fornical Organ (SFO)

A small organ located in the lateral ventricle attached to the underside of the fornics contain neurons that detect the presence of angiotensin in the blood and excite neural circuits that initiate drinking.
Neural Mechanism of Thirst
1) Some part of anterior third ventricle and dorsal.
2) Hormones get signals from angiotensin.

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When we eat , we must satiation obtain adequate amount of carbohydrates, fats, amino acids, vitamins and minerals. This amount supplied us fuel and reservoirs in our body.These reservoirs are short and long term. Short term reservoirs base on carbohydrates and long term stores fats. The short term is located in the cells of liver and muscles and is field with complex insoluble carbohydrates called Glycogen. This is the conversion of glucose into glycogen in a liver functioning process. While the long term reservoirs consist of adipose tissues (fatty tissues). This is filled with fats or "triglycerides" which are the complex molecules that contain 'glycerol' or 'glycine' combined with 3 fatty acids.

1) Stearic acid.
2) Oliec acid.
3) Palmit acid.

Adipose tissue is found beneath the skin and abdominal cavity. It consists of cells absorbing nutrients from the blood, converting them into triglycerides and storing them. This is called the Metabolism of eating and the phase through all process occur is called absorptive phase.
The brain lives on glucose and the rest of the body lives on fatty acids. The brain contain detectors that monitor the availability of glucose inside the blood brain barrier (the vessels which bear blood and supplies blood to the brain) and the liver contain the detectors that monitor the availability of nutrients (glucose and fatty acids) outside the blood brain barrier.
Hypoglycemia is a potent stimulus for hunger. If a dramatic fall in the level of glucose occur due to some factors. That is known to be glucoprivation (hypoglycemia) or the deprivation of glucose in the cells which stimulate eating hunger. Hunger is also associated lipoprivation which means a fall in the level of fatty acids.

Satiety Signals

There are two sources.
Short term Satiety signals
Eyes, nose, mouth, stomach, dudemum, liver. Each part signals to brain that indicate the food has injusted and processing on the way toward absorption.
Long term Satiety signals
These signals are associated with the calories by modulating the sensitivity of brain mechanism involved in hunger.

Some Other Factors

1) Head factors
These factors refers to the several sets of receptors located in the head, eye, nose, throat and tongue.
2) Gastric factors
The stomach contain receptors that detect the presence of food.
3) Intestinal factors
Intestines contain also some detectors which are sensitive to the presence of glucose, amino acids and fatty acids. Their axons send statiey signals to the brain.
4) Liver factors
Liver receives nutrients from the intestine and send signals to the brain.

Neural Mechanism

Brain Stem
Brain stem contains neural circuits that are able to control food and satiation or physiological hunger signals such as glucose signals by means of decrease in glucose metabolism or food in the digestive system. In the brain stem the area "Posterma" and "nucleus of the solitary track" region (AP/NST) receives signals from tongue, stomach, small intestine and liver and sends information to the lateral "Para brachial nucleus" of the pones which passes the information to many regions of the brain. These signals help to control food intake.
Para Brachial Nucleus
A nucleus in the pons that receives gustatory information and informations from the liver and digestive system and relays it to the forbrain.


The two important portions of hypothalamus the lateral and ventro medial nucleus controlled hunger and satiety signals.

5-HT (NTM)

It inhibit eating especially carbohydrates.

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Eating Disoders

1. Obesity

Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems. Body mass index (BMI), a measurement which compares weight and height, defines people as overweight (pre-obese) if their BMI is between 25 kg/m2 and 30 kg/m2, and obese when it is greater than 30 kg/m2.
Obesity increases the likelihood of various diseases, particularly heart disease, type 2 diabetes, breathing difficulties during sleep, certain types of cancer, and osteoarthritis. Obesity is most commonly caused by a combination of excessive dietary calories, lack of physical activity, and genetic susceptibility, although a few cases are caused primarily by genes, endocrine disorders, medications or psychiatric illness. Evidence to support the view that some obese people eat little yet gain weight due to a slow metabolism is limited; on average obese people have a greater energy expenditure than their thin counterparts due to the energy required to maintain an increased body mass.
Dieting and physical exercise are the mainstays of treatment for obesity. Moreover, it is important to improve diet quality by reducing the consumption of energy-dense foods such as those high in fat and sugars, and by increasing the intake of dietary fiber. To supplement this, or in case of failure, anti-obesity drugs may be taken to reduce appetite or inhibit fat absorption. In severe cases, surgery is performed or an intragastric balloon is placed to reduce stomach volume and/or bowel length, leading to earlier satiation and reduced ability to absorb nutrients from food.
Obesity is a leading preventable cause of death worldwide, with increasing prevalence in adults and children, and authorities view it as one of the most serious public health problems of the 21st century. Obesity is stigmatized in much of the modern world (particularly in the Western world), though it was widely perceived as a symbol of wealth and fertility at other times in history, and still is in some parts of the world.

Childhood obesity can begin as early as 9 Months of age, Researchers Find

Everyone loves a roly-poly baby. Still, there is such a thing as an overweight infant, and obese babies -- even those as young as 9 months -- are predisposed to being obese later in life, researchers say in Friday's issue of the American Journal of Health Promotion.

Childhood obesity is a growing public health problem in the United States.  It has been linked to psychological problems, asthma, cardiovascular troubles and a greater chance of developing diabetes.

Hoping to better understand the factors associated with being obese at a very early age -- and possibly help parents and health advocates stave off its ill effects -- lead author Brian G. Moss of Wayne State University and William H. Yeaton of the University of Michigan analyzed data from the Early Childhood Longitudinal Study-Birth Cohort, a nationally representative sample of American children born in 2001.

RELATED: Obesity prevention starts early -- really, really early

The data included height, weight and demographic characteristics of 8,900 9-month-old babies and 7,500 2-year-old toddlers. Obese children were defined as those who exceeded the 95th percentile for body-mass index (as defined by the Centers for Disease Control and Prevention), and those between the 85th and 95th percentile were considered "at risk."

Moss and Yeaton found that 32% of children were either obese or at risk of obesity by the tender age of 9 months.  That figure increased to 34% by the time the munchkins reached their second birthdays.

"We weren't surprised by the prevalence rates we found in our study, but we were surprised the trend began at such a young age," Moss said in a statement.

Among the patterns that emerged:
  • Boys were more at risk than girls (this contradicted earlier research). 
  • Latinos had the highest risk.
  • Geographic location was not consistently associated with being obese or at risk.
  • The family's socioeconomic status didn't seem to make a difference at 9 months of age. But by two years, the kids in the bottom economic 20% were most likely to be obese or at risk, while those in the top 20% were least likely to be obese or at risk.
No one is suggesting that babies be put on a diet. But knowing more about the demographic characteristics of very young children who are more likely to become obese could help health officials and parents prevent later health troubles by promoting healthier eating and lifestyle choices.

RELATED: A new map of childhood obesity in the U.S.
2. Anorexia Nervousa (Loss of Peptite)

This disorder is most frequently affect young women concerned with over weight that leads to excessive dieting and often compulsive exercising can lead to starvation.
Anorexia nervosa is an eating disorder characterized by refusal to maintain a healthy body weight and an obsessive fear of gaining weight, often coupled with a distorted self image which may be maintained by various cognitive biases that alter how the affected individual evaluates and thinks about her or his body, food and eating. Persons with anorexia nervosa continue to feel hunger, but deny themselves all but very small quantities of food. The average caloric intake of a person with anorexia nervosa is 600-800 calories per day, but in extreme cases self-starvation is more extreme.It is a serious mental illness with a high incidence of comorbidity and the highest mortality rate of any psychiatric disorder.
It can affect men and women of all ages, races, socioeconomic and cultural backgrounds.Anorexia nervosa occurs in the ratio of 1:10 in males:females.
The term anorexia nervosa was established in 1873 by Sir William Gull, one of Queen Victoria's personal physicians. The term is of Greek origin: an- (ἀν-, prefix denoting negation) and orexis (ὄρεξις, "appetite"), thus meaning a lack of desire to eat.

3. Bulimia Nervousa

Bouse - (ox) Greek word
Limos - (Hunger)

Bouse of excessive hunger and eating often followed by forced vomiting or the loss of control over food intake.
Bulimia nervosa is an eating disorder characterized by restraining of food intake for a period of time followed by an over intake or binging period that results in feelings of guilt and low self-esteem. The median age of onset is 18. Sufferers attempt to overcome these feelings through a number of ways. The most common form is defensive vomiting, sometimes called purging; fasting, the use of laxatives, enemas, diuretics, and over exercising are also common. Bulimia nervosa is nine times more likely to occur in women than men (Barker 2003). Antidepressants, especially SSRIs are widely used in the treatment of bulimia nervosa. (Newell and Gournay 2000).
The word bulimia derives from the Latin (būlīmia), which originally comes from the Greek βουλιμία (boulīmia; ravenous hunger), a compound of βους (bous), ox + λιμός (līmos), hunger. Bulimia nervosa was named and first described by the British psychiatrist Gerald Russell in 1979.

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Circadian Rhythms and Zeitgebers

It is defined as a daily rhythmical change in behavior or physiological process, such rhythms are controlled by mechanism within the organism by internal clock which is a biological clock. In the brain the principal biological clock appears to be located in suprachiasmatic nuclei (SCN) -- a nucleus situated atop the optic chiasm. It contains a biological clock responsible for organizing many of the body circadian rhythms.


A stimulus that reset the biological clock responsible for circadian rhythms. In animals Pineal gland controls circadian rhythms.

Biological Basis of Behavior
Aggressive Behavior
"An emotional state consisting felling of hate and desire to inflict harm. Overt response that involves actual or intended destruction of other organisms". OR "A species typical behavior at pattern of movements, biting, striking ets".


Threat Behavior
A behavior which is consisted on postures or jestures that warm the adversely to leave or it will become the target or attack.
Defensive Behavior
A behavior that occures against the threatening situation or behavior.
Submissive Behavior
A behavior which indicate that it accepts defeat and will not challange the other one.
Predated Behavior
Behavior which is consist of an attack of one organism at an individual of another specie on which the attacking animals.

Neural Control of Aggressive Behavior

The activity of brain stem circuits appears to be controlled by hypothalmus and amygadala which have a special influence on a species typical behavior. The activity of these parts of brain is controlled by perceptual system that detect the status of environment including the presence of other behaviors while specifically. The defensive and predators is attached with the pre-aquaductal gray matter (PAG) of midbrain. While as aggressive behavior is along wth the above said part the seretonergic synapes involved in this behavior.

Aggression in Male and Female

Aggression in male and female is controlled by neural circuits that are stimulated by endrogen gland. Androginization has an organization affects. The secretion of theis gland is associated with male and female Sexual behavior. Androgin secrets a hormone testosterm and projesterm which facilitate the Sexual organ and are involved in agression behavior.

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Temperature Regulation

Human body automatically maintains a constant body temperature of 37*c or 98.6*F. This temperature may fluctuate itself according to the nature of environment. This automatically system maintain the body internal condition and it is known to be homeostasis which means a state of balance or equilibrium among internal physiological condition. When human body alterate the temperature regulation according to the alteration. This process is known to be endotherm which means any process that in response to alteration of a given condition.

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Mind Study