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What Part Of The Brain Controls Thirst And Hunger

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Brain Areas Involved In Hunger And Thirst

Hypothalamus – Human Brain Series – Part 17

You may think that hunger is all in your stomach and that dieting is all in your head. But nutrition experts know that hunger is regulated by a complex system of chemicals that send signals between your brain and your body.

The cells in the hypothalamus communicate with cells in other parts of the brain to coordinate the release and uptake of chemicals that help regulate how much and what you eat. Food triggers the brain to turn the desire to eat into the act of eating. How a food smells, what it looks like, and how you remember it tasting excite chemicals within your brain.

The breakdown products of foods – aminoacids from protein, fattyacids from fat, and glucose fromcarbohydrates– regulate hormones such as insulin, which affect the process at a cellular level. They send messages to the brain telling it that fuel is needed.

When the body needs nourishment, neurotransmitters are released. One neurotransmitter called Neuropeptide Y is important in sending messages to various parts of the brain.

Scientists have recently identified two chemicals – ghrelin and leptin – circulating in the blood that communicate with NPY.

In addition, these processes are at work:

The Hypothalamus And Hunger

While leptin and ghrelin are hormones produced by the body to signal hunger as well as satiation, the hypothalamus has receptors for these hormones. There are three regions within the hypothalamus itself that are associated with hunger and satiety.

Lateral Hypothalamus Known for hunger recognition

Ventromedial Hypothalamus Recognizes the feeling of fullness

Paraventricular Hypothalamus Regulates hunger

What Controls Our Hunger

The hypothalamus houses the hunger and satiety centers. Several neural centers in the hypothalamus are involved in the control of food intake. The lateral nuclei of the hypothalamus act as the feeding center, because when stimulated they excite a voracious appetite .

In contrast, the destruction of the lateral hypothalamus cancels the desire for food and leads to progressive starvation, a state characterized by noticeable weight loss, muscle weakness, and reduced metabolism.

The lateral hypothalamic feeding center emits motor impulses for foraging. Rather, the ventromedial nuclei of the hypothalamus serve as an important satiety center and are believed to confer a sense of nutritional pleasure that inhibits the eating center.

Electrical stimulation of this region can induce complete satiety and, in fact, when very appetizing foods are offered, the animal rejects them .

On the contrary, the destruction of the ventromedial nuclei motivates a voracious and continuous feeding until the animal reaches extreme obesity, sometimes quadrupling its weight.

The paraventricular, dorsomedial, and arcuate nuclei of the hypothalamus are also believed to be instrumental in regulating food intake.

For example, lesions of the paraventricular nuclei usually lead to overeating, while those of the dorsomedial nuclei generally reduce eating behavior.

The hypothalamus receives:

  • Signals from hormones released by adipose tissue,
  • Signals from the cerebral cortex that modify eating behavior.

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How Do These Various Areas Of The Brain Know When To Stimulate Hunger

It turns out that the brain monitors the levels of glucose , fat, carbohydrates, and insulin in the blood. Changes in the levels of these substances in the blood signal the need for food. The presence of a particular hormone, leptin, also influences our desire to eat.

The fat cells in our body produce leptin, which travels in the bloodstream and is detected by the hypothalamus. High levels of leptin signal the brain to reduce appetite or increase the rate at which fat is burned.

The brain also monitors the amount and type of food a person eats. Receptors in the stomach detect not only how much food the stomach contains but also how many calories that food contains.

The signals from these receptors travel to the brain. When food enters the small intestine, a hormone is released into the bloodstream and carried to the brain, where it serves as an additional source of information about the bodys nutritional needs.

But, as we noted earlier, a biological need for food does not always lead to hunger. The feeling of hunger is the product not only of the things that happen in the body, but also of those that happen outside.

Brain Areas And Their Functions

1 physiology of feedimg, appetite &  hunger

The brain is divided into areas which are each responsible for different areas of functioning.

The brain can be divided into three basic units: the forebrain, the midbrain and the hindbrain.

These areas are: Occipital lobe, Temporal lobe, Parietal lobe, Frontal lobe.Cerebral cortex, Cerebellum, Hypothalamus,Thalamus,Pituitary gland, Pineal gland, Amygdala, Hippocampas and the Mid- brain.

The image below indicates where the areas are.

Occipital lobe: This is found in the back of the brain. The area is involved with the brain’s ability to recognise objects. It is responsible for our vision.

Temporal lobe: The temporal lobes are found on either side of the brain and just above the ears. The temporal lobes are responsible for hearing, memory, meaning, and language. They also play a role in emotion and learning. The temporal lobes are concerned with interpreting and processing auditory stimuli.

Parietal lobe: The parietal lobes are found behind the frontal lobes, above the temporal lobes, and at the top back of the brain. They are connected with the processing of nerve impulses related to the senses, such as touch, pain, taste, pressure, and temperature. They also have language functions.

Frontal lobe:It is concerned with emotions, reasoning, planning, movement, and parts of speech. It is also involved in purposeful acts such as creativity, judgment, and problem solving, and planning

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Hormones Of The Hypothalamus

To maintain homeostasis, the hypothalamus is responsible for creating or controlling many hormones in the body. The hypothalamus works with the pituitary gland, which makes and sends other important hormones around the body.

Together, the hypothalamus and pituitary gland control many of the glands that produce hormones of the body, called the endocrine system. This includes the adrenal cortex, gonads, and thyroid.

Hormones secreted by the hypothalamus include:

  • antidiuretic hormone, which increases how much water is absorbed into the blood by the kidneys
  • corticotropin-releasing hormone, which helps regulate metabolism and immune response by working with the pituitary gland and adrenal gland to release certain steroids
  • gonadotropin-releasing hormone, which instructs the pituitary gland to release more hormones that keep the sexual organs working
  • oxytocin, a hormone involved in several processes, including the release of a mothers breast milk, moderating body temperature, and regulating sleep cycles
  • prolactin-controlling hormones, which tell the pituitary gland to either start or stop breast milk production in lactating mothers
  • thyrotropin-releasing hormone activates the thyroid, which releases the hormones that regulate metabolism, energy levels, and developmental growth

In these cases, there are some hormone tests that doctors might prescribe to get to the root of the disorder.

What Part Of The Brain Controls Rage And Hunger

The part of our brains associated with hunger, fear, anxiety and anger is called the limbic system. It starts automatic responses we have before they even come to consciousness in the higher brain area, which takes information from the limbic system and the environment and then modulates these primitive responses.

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What Part Of The Brain Controls Love

Emotions, like fear and love, are carried out by the limbic system, which is located in the temporal lobe. While the limbic system is made up of multiple parts of the brain, the center of emotional processing is the amygdala, which receives input from other brain functions, like memory and attention.

What Makes Us Thirsty

Internal Regulation: Thirst

When your body starts to run low on water, a number of changes take place: for one, the volume of your blood decreases, causing a change in blood pressure. Because the amount of salt and other minerals in your body is staying constant as the volume of liquids decreases, their relative concentration increases . This concentration of particles in bodily fluids relative to the total amount of liquid is known as osmolality, and it needs to be kept in a narrow range to keep the cells in your body functioning properly. Your body also needs a steady supply of fluids to transport nutrients, eliminate waste, and lubricate and cushion joints. To some extent, the body can compensate for water depletion by altering heart rate and blood pressure and by tweaking kidney function to retain more water. For you, though, the most noticeable indication that your body is running low on fluids is likely the feeling of thirst, as you increasingly feel like you need to drink some water.

Figure 1: Brain regions controlling thirst.Figure 2: Thirst signals and their effects.

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Windows Between The Brain And Blood

As mentioned, the bloodstream acts like a postman, collecting and delivering chemical messages to and from the brain. However, there is a major obstacle in the postmans path. The blood vessels of the brain are sealed tightly by a special safeguard, called the blood-brain barrier . The cells that build the blood vessel walls are connected tightly to one another, similar to bricks glued together by cement, so almost nothing can pass through . The main purpose of this barrier is to protect the brain from infection. When the BBB is loosened as a result of disease or injury, bacteria might enter the brain and cause severe damage or even death.

  • Figure 3 – To BBB or not to BBB?
  • There are two types of capillaries in the brain. On the top, you can see fenestrated capillaries lacking the BBB. The wide-open windows in the capillary wall allow passage of molecules to and from the bloodstream. On the bottom, you can see a tightly sealed BBB capillary, which restricts entry of molecules to keep brain cells safe.
  • v

What Are The Parts Of The Nervous System

The nervous system is made up of the central nervous system and the peripheral nervous system:

  • The brain and the spinal cord are the central nervous system.
  • The nerves that go through the whole body make up the peripheral nervous system.

The human brain is incredibly compact, weighing just 3 pounds. It has many folds and grooves, though. These give it the added surface area needed for storing the body’s important information.

The spinal cord is a long bundle of nerve tissue about 18 inches long and 1/2-inch thick. It extends from the lower part of the brain down through spine. Along the way, nerves branch out to the entire body.

The brain and the spinal cord are protected by bone: the brain by the bones of the skull, and the spinal cord by a set of ring-shaped bones called vertebrae. They’re both cushioned by layers of membranes called meninges and a special fluid called cerebrospinal fluid. This fluid helps protect the nerve tissue, keep it healthy, and remove waste products.

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The Hypothalamus: The Brains Center Of Homeostasis

So far, we have described how the brain collects information from the body and decides which commands to send in order to maintain homeostasis. The specific region of the brain where most of this activity takes place is called the hypothalamus, which means under the inner chamber in Greek . The hypothalamus controls many important body functions, such as sleep, blood pressure, temperature, hunger, thirst, and energy consumption and storage. Much like a computer microprocessor, the hypothalamus runs an algorithm that computes the information by following a set of rules. Then, the hypothalamus makes a decision about whether or not to send commands to the body. This type of computation occurs in brain cells called neurons. The neurons in the hypothalamus can receive feedback both from inside the body and from the external environment. They can also produce various hormones.

  • Figure 2 – The meeting point between hypothalamic neurons and pituitary capillaries.
  • On the right, the hypothalamus is highlighted in green and the pituitary in blue. On the left, you can see that commands from the hypothalamus travel along the neurons to the pituitary gland. The pituitary then releases commands in the form of hormones into the bloodstream, via the fenestrated capillaries.

Causes And Risk Factors

The brain

The most common causes of hypothalamic diseases are injuries to the head that impact the hypothalamus. Surgeries, radiation, and tumors can also cause disease in the hypothalamus.

Some hypothalamic diseases have a genetic link to hypothalamic disease. For instance, Kallman syndrome causes hypothalamic problems in children, most noticeably delayed or absent puberty, accompanied by an impaired sense of smell.

Hypothalamus problems also appear to have a genetic link in Prader-Willi Syndrome. This is a condition in which a missing chromosome leads to short stature and hypothalamic dysfunction.

Additional causes of hypothalamic disease can include:

  • eating disorders, such as bulimia or anorexia
  • genetic disorders that cause excess iron buildup in the body

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Diet Tips For Hypothalamus Health

As the hypothalamus plays such a vital role in the body, it is very important to keep it healthy. While a person cannot fully avoid genetic factors, they can take dietary steps towards ideal hypothalamus health on a daily basis to reduce the risk of hypothalamic disease.

The hypothalamus controls the appetite, and the foods in the diet influence the hypothalamus. Studies have shown that diets high in saturated fats can alter the way the hypothalamus regulates hunger and energy expenditure.

What Happens If You Rage Too Much

The long-term physical effects of uncontrolled anger include increased anxiety, high blood pressure and headache. Anger can be a positive and useful emotion, if it is expressed appropriately. Long-term strategies for anger management include regular exercise, learning relaxation techniques and counselling.

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What Are The Parts Of The Brain

The brain has three main sections: the forebrain, the midbrain, and the hindbrain.

The Forebrain

The forebrain is the largest and most complex part of the brain. It consists of the cerebrum the area with all the folds and grooves typically seen in pictures of the brain as well as other structures under it.

The cerebrum contains the information that essentially makes you who you are: your intelligence, memory, personality, emotion, speech, and ability to feel and move. Specific areas of the cerebrum are in charge of processing these different types of information. These are called lobes, and there are four of them: the frontal, parietal, temporal, and occipital lobes.

The cerebrum has right and left halves, called hemispheres. They’re connected in the middle by a band of nerve fibers that lets them communicate. These halves may look like mirror images of each other, but many scientists believe they have different functions:

  • The left side is considered the logical, analytical, objective side.
  • The right side is thought to be more intuitive, creative, and subjective.

So when you’re balancing your checkbook, you’re using the left side. When you’re listening to music, you’re using the right side. It’s believed that some people are more “right-brained” or “left-brained” while others are more “whole-brained,” meaning they use both halves of their brain to the same degree.

In the inner part of the forebrain sits the thalamus, hypothalamus, and :

The Midbrain

The Hindbrain

What Side Brain Controls Emotions

What is Hunger?

The neural system for emotions linked to approaching and engaging with the world like happiness, pride and anger lives in the left side of the brain, while emotions associated with avoidance like disgust and fear are housed in the right.

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How Does The Brain Work

The brain sends and receives chemical and electrical signals throughout the body. Different signals control different processes, and your brain interprets each. Some make you feel tired, for example, while others make you feel pain.

Some messages are kept within the brain, while others are relayed through the spine and across the bodys vast network of nerves to distant extremities. To do this, the central nervous system relies on billions of neurons .

How Does Our Brain Control Hunger

It begins with a low murmur that we only learn about ourselves, but soon turns into an impossible to disguise roar that catches the attention of everyone around us.

Our guts are leaving us a clear message, there is hunger and if we do not eat soon it is possible that we begin to notice other signs such as weakness and irritability.

The appetite regulating center is located in the brain. The one in charge of carrying out this process is an enzyme called AMPK and according to a study by the Institute of Science and Technology of Daegu it is possible to modify its behavior.

The way the brain perceives that we need to eat has to do with the process by which we adjust our weight, so that there can be a balance between the energy provided by the food we eat and the expenditure made by our body.

AMPK plays an important role in this process, an enzyme complex present in most organs of the body liver, muscle, adipose cells.. which is related to a cellular recycling program, autophagy, which acts as a metabolic regulator: detects cellular energy and helps the cells energy balance and calorie consumption.

When we go without food for a long time, hunger-inducing neurons set off a process called autophagy, which is a natural self-destruct mechanism through which cells recycle and discard internal structures that are no longer useful to them.

In this case, they help us understand why our character can change so much when we are hungry.

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References For Areas Of The Brain Involved In Thirst

Alvandi, E. O. . A Review on Meanings of Emotions: Steps to a Neural-Informational Notion of Semantics. Cognition, Brain, Behavior, XX, 45-63.

Britannica.com. . Sexual dimorphism. Retrieved January 29, 2017, from https://www.britannica.com/science/sexual-dimorphism

Carlson, N. R., & Birkett, M. A. . Physiology of Behavior . Boston, MA: Pearson Education.

Hayes, S. C., Strosahl, K. D., & Wilson, K. G. . Acceptance and Commitment Therapy . New York, NY: Guilford Press.

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