Loading presentation...

Present Remotely

Send the link below via email or IM


Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.


Why Do I Crave the Cookie Project

How Do I Know That I'm Hungry?

Katy Collins

on 19 March 2013

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of Why Do I Crave the Cookie Project

Digestive System Your stomach plays a major role in telling your body that it's hungry. Endocrine System Hypothalamus- gland in the brain located just above the brain stem that synthesizes and secretes hormones linked to things like hunger. Nervous System How a food smells, what it looks like, and how you remember it tasting excite chemicals in your brain.

Hunger is also triggered by learned behavior; because you have habitually eaten lunch at twelve o'clock makes you feel hungry around that time.

When the body determines that it is in need of nourishment, neurotransmitters are released.

Neuropeptide Y (NPY) is one of the most important neurotransmitters associated with sending signals to the brain.
Ghrelin and leptin are chemicals most known for communicating with NPY. "I'm Hungry" Feeling hungry is really just the tip of the iceberg. What interacts for this sensation to happen!? How Do I know That I'm Hungry? Katy Collins Disorders Feedback Mechanisms Hunger is controlled by a complex relationship between your brain and your body. Hypothalamus communicates with cells in the brain to coordinate the release and uptake of chemicals that control hunger

Chemicals released from food regulate insulin, which send messages to the brain that food is needed. Your body constantly monitors chemicals like amino acids, proteins, and glucose in your blood to determine whether or not you should eat. Your stomach rumbles or growls whether it's empty or not.
The noise comes from muscular activity in the stomach and small intestines, which originate from the peristaltic waves occurring in the gastrointestinal tract.
The sound is generally louder when the stomach is empty because there is nothing in the tract to muffle the noise.

Peristalsis is generally stronger both right after eating and after a long period of time without eating.
In the latter case, receptors in the walls of the stomach sense the absence of food, causing a reflex generation of waves in the nervous system. These waves travel along the stomach and small intestines and lead to hunger contractions.

The result of all this commotion lets the brain know that you're hungry! Positive Negative Both positive and negative feedback systems play a huge role in telling you that you're hungry. Peptides released by digestion stimulate cells in the wall of the stomach, which secrete a hormone called gastrin into the blood. Gastrin stimulates the muscles of the stomach wall and causes increased secretion - a positive feedback loop. Acids in the stomach inhibit gastrin secretion (negative feedback). If there are lots of proteins in the stomach, they react with acids and neutralize them, so gastrin keeps flowing until the protein is gone. Interactions All of these systems (and more!) interact for the simple feeling of hunger. Here we go:
Lack of nutrients circulating in the blood (circulatory) causes your hypothalamus to secrete chemicals (endocrine) that fire neurotransmitters in your brain (nervous) indicating that you're lacking essential nutrients.
The peristaltic waves occurring in your stomach and small intestine (digestive) are amplified when your gastrointestinal tract is empty, causing muscular contractions (muscular) that make "rumbling" noises.
The interaction of these systems makes you crave that cookie! Chronic overeating could lead to chemical imbalances in the brain. Studies show that obese people have fewer dopamine (chemical that causes pleasure) receptors. This could lead to binging as the body tries to stimulate the receptors. It is possible that obese people have fewer dopamine receptors because their brains are trying to compensate for having chronically high dopamine levels, which are triggered by over eating. Andrews, M. A. (2002, January 21). Why does your stomach growl when you are hungry?: Scientific American. Scientific American. Retrieved March 16, 2013, from http://www.scientificamerican.com/article.cfm?id=why-does-your-stomach-gro
Hara, T. (1997, Spring). Hunger and eating. California State University, Northrige. Retrieved March 16, 2013, from http://www.csun.edu/~vcpsy00h/students/hunger.htm
Hypothalamus. (n.d.). Encyclopedia of Science. Retrieved March 16, 2013, from http://www.daviddarling.info/encyclopedia/H/hypothalamus.html
Iliades, C., MD. (2012, September 10). Depression's effect on your appetite. EverydayHealth.com. Retrieved March 16, 2013, from http://www.everydayhealth.com/health-report/major-depression/depressions-effect-on-appetite.aspx
Kirby, J., RD. (n.d.). How your brain signals your body's need for food. For Dummies. Retrieved March 16, 2013, from http://www.dummies.com/how-to/content/how-your-brain-signals-your-bodys-need-for-food.html
Moffatt, J. D. (2005, November). How digestion is controlled. Physical Digestion. Retrieved March 16, 2013, from http://www.hsc.on.ca/moffatt/bio3a/digestive/digp7b.htm
Obesity linked to brain chemical. (2001, March 02). BBC News. Retrieved March 16, 2013, from http://news.bbc.co.uk/2/hi/health/1149876.stm
Tremer, L. (2009, February 16). Why are you hungry? Ezine @rticles. Retrieved from http://ezinearticles.com/?Why-Are-You-Hungry---Why-Do-We-Eat&id=2001564 Works Cited Review Both positive and negative feedback systems are at work in your body, helping in both hunger and digestion.

Disorders like obesity can be explained through a chemical imbalance of dopamine in the brain.
A lack of dopamine receptors requires higher quantities of dopamine in order to stimulate them, causing people to overeat to feel good.

Many body systems interact to tell your brain that you're hungry.
Nervous- The brain has neurotransmitters that communicate to tell you you're hungry. The sight, smell, or even the time of the day can excite neurotransmitters.
Digestive- The muscular stomach physically "rumbles", a noisy sign that it's been empty and probably needs nourishment
Endocrine- The lack of chemicals produced by breaking down food in the body releases chemicals from the hypothalamus that communicate with your brain that you're hungry.
Full transcript