“Hunger” from a Scientific Biopsychological Perspective

The term â€Å"bio† means life and â€Å"logos† means study. The word biology can thus be defined as the study of life. The study of physiological bases of behavior is known as Biological psychology. Biological psychology is the study in three ways namely the comparative method, Physiology and Investigation of inheritance. In the comparative method a number of different species are studied and then the results are compared and are related in order to understand the human behavior. Physiology basically focuses on how the brain functions, how the nervous system and hormones work and how their functions affect human behavior. The Investigation of inheritances focuses on how the mechanism of inheritance works. This paper will shed light on hunger from a scientific biopsychological perspective. When level of glycogen in the liver fall below a certain point, a feeling is experienced by an animal which is known as hunger. The organ responsible for originating this unpleasant feeling is the hypothalamus part of the brain. The hypothalamus alarms the liver and the stomach through the sense receptors. Animals can basically be divided into three major categories namely the carnivores, the herbivores and the omnivores. Though they all belong to same parent class but there eating habits are pretty different. Carnivores are basically meat eaters. They generally live on live foods. The biological reason behind this is because they have large mouth and very sharp teeth. This allows them to easily get a hold on their prey and tear off the huge pieces of flesh. The short intestinal tract and the huge stomach is perfect for them to hold even an entire big fish. Carnivores prefer to eat meat because there digestive system basically lacks the ability to digest vegetable matter. Even if they try to live on vegetable they won’t be able to survive for long because there body won’t be absorbing any nutrients. As carnivores have a huge stomach. They don’t have to eat food very frequently as there serving size is usually very huge. A lion is an example of carnivore. Herbivores on the other hand are totally opposite to carnivores. The proper diet for herbivores consists of plants, algae and fruits. They have adaptive themselves according to the biology of their body. There specialized intestines makes their body capable of breaking down matter. They have flat teeth through which they grind food before swallowing. The herbivores must have to eat frequently because their stomach lacks the ability to hold large volumes of food. They need to take meals several times a day and there serving size is usually very small. An example of a herbivore is a zebra. Omnivores can eat almost anything. They can vegetables and meat. Their teeth and digestive are made in such a way that they can adapt themselves to have the properties of both the omnivore and the herbivore. An example of an omnivores are humans. The part of the brain responsible for stimulating hunger is the hypothalamus. The hypothalamus can be divided into areas namely the lateral hypothalamus and the ventro hypothalamus. The lateral hypothalamus is the part that makes you feel hungry where as the ventromedial hypothalamus is the part that make you feel full and satisfied. When a person is eating a big meal and believes he no more has the capacity to eat more, the ventromedial hypothalamus is doing the job to indicate you. Signal impulses are generated by the hypothalamus at appropriate times in order to indicate that when to eat and when to stop. The hypothalamus is trained to maintain a certain optimal body weight. If the body weight falls below the marginal line, the hypothalamus lowers the metabolic rate and when we eat it tells the body to stop eating and increases the metabolic rate to burn excess foods. The neurotransmitter also effects are eating habits. The neurotransmitters that have relation with hunger is serotonin and dopamine. The serotonin is basically a neurotransmitter that keeps us happy. When we feel good, our body suppresses hunger. People who are usually depressed tend to put on weight because they feel hungry all the time. Dopamine neurotransmitter is also dependant on amino acids in the body. Dopamine levels can affect your body weight. A low dopamine level means that you’re less likely to consume amino acids in the body. As a result, there is more intake of carbohydrates and other fats and then you put on weight because you feel hungry. The processed or packaged food has certain chemical in them that effect your neurotransmitters levels in the body and thus you get hunger pangs. The hormones that affect our appetite and hunger is Ghrelin. Ghrelin levels increase before meals and lower down after meals. Gherlin has been discovered as the first hunger circulating hormone. www. soc. ucsb. edu) Obesity is a disease in which body consumes a lot of fat and chronic imbalances takes place. Science has proved that genes do play a role in obesity. Genes that are related to obesity can effect the metabolic rate. They could also affect human behavior, changing our lifestyles and increasing the risk of being obese. Science has proved that some genes control appetie. Such genes make us less able to sense when a feeling full where are as some genes make our bodies more responsive to food by affecting our sense of taste, smell or sight of food. Some genes make us feel lazy and less active and as result people put on weight. Epigenetic is a birth given to a new science. Epigenetic basically involve the study of gene activity in which though they do not involve alterations to the genetic code but can still be passed down to at least one successive generation. The cellular material for expressing these gene patterns is known as epigenome. (www. britannica. com) Both nature and nurture have affects on our diet and body size. The evolutionary factors that basically shape the genetics that we inherit from our parents and ancestors is known as Nature. Things that influence us since we were born is nurture. The range of human potential is basically determined by nature where as the ways in which the human potential is actualized is determined by nurture. Your diet and body size is affected both by the nature and the nurture. Parents that are usually tall are mostly likely to have kids that are going to be tall. This is genetic and thus nature has it roles. However, parents who are short does not necessarily mean will have kids that will be short too. If kids are given proper food, they exercise well and they remain active so they can affect their body size. Thus nurture has its role as well. (Sharpe) As for diet, your appetite is affected both by nature and nurture. In some families, they love to eat so their kids are mostly likely to eat as well. People who generally have tendencies to put on weight usually have low metabolic rate and their genes can be passed on to children. Hence nature plays it role but if the kids control their appetite, exercise well they can adapt their body and bring changes. This is where nurture plays its role. (www. answers. com)