Homeostasis
And the Digestive System
Fun Facts about Homeostasis and the Digestive System
The oncept of homeostasis is widely used, in Life Science, to identify what seems to be a general attribute of living organisms: the tendency to maintain and restore certain steady states or conditions of the organism. An obvious example is that of body temperature, which in the human tends to fluctuate only in a narrow range about the value 98.6° F. When the temperature rises above the normal range, corrective reflexes (perspiration, reduced metabolism, etc.) go into action to restore the steady state. Persistent deviation may initiate other actions (moving into the shade, plunging into water, etc.). If body temperature drops, other corrective actions are observed.
Many bodily steady states follow this pattern. Blood glucose level, blood pH, and osmotic pressure are examples. The key concepts are: an observable steady state that persists over time with minor changes; thresholds above and below this normal range; a sensory input that reports changes in the steady state; and effector mechanisms for restoring the steady state.
When a deviation goes beyond either the upper or the lower threshold, energy is mobilized to restore the steady state to its optimal value.
The Circulatory System
The systems of the human body must work together for the body to function properly. For example, humans require oxygen to survive. Your lungs take in oxygen and release carbon dioxide. The cells in your body use oxygen to help process the energy in nutrients into energy that cells can use. Oxygen helps the body obtain energy from nutrients by performing cellular respiration. As discussed next, various organ systems work together and help the body take in oxygen and move it through the body. Oxygen enters the body through the respiratory system. When you inhale, the respiratory system works with the circulatory system and transports oxygen to all cells in the body. The muscular system also helps the respiratory system by expanding the chest so that cells in the lungs fill up with oxygen.
Recall that the circulatory system works with the small intestine and moves nutrients into the body. The circulatory system also works with the lungs and helps oxygen travel through the body, as shown in the figure above. Oxygen that is taken in by capillaries is transported to the rest of the body through larger blood vessels.
Muscular System
Food enters the body through the digestive system. There it is broken down into nutrients that can be absorbed into the body. However, the muscular system is needed to get food through the digestive system. Muscles that surround the stomach contract and move food to the small intestine. These contractions are called peristalsis (per uh STAHL sus). Muscles help the jaw move when you chew. They help you swallow. Muscles also surround the esophagus, the stomach, the small intestine, and the large intestine. These muscles help move food through the digestive system.
Skeletal System
Maintaining homeostasis keeps the internal environment in the body functioning properly. Many organ systems work together and maintain energy homeostasis. The body gets most of its energy from carbohydrates. Lipids and proteins also provide energy. The food you eat is broken down by chemical and mechanical digestion. Chemical digestion occurs when enzymes in saliva and acid in your stomach break down food. Mechanical digestion happens when you chew your food. The digestive system, the circulatory system, and the muscular system work together and process and obtain nutrients from food. The skeletal system, the endocrine system, and the lymphatic system also work with the digestive system and process those nutrients.
The Foods We Eat!
Though your children may ask for junk food because they like the taste or because their friends are eating it, you undoubtedly already know that junk food can have negative effects on them. Junk food is typically is low in nutrients and high in calories from added sugars, starches or fats.
Processed and junk food lovers beware! There are many negative repercussions to persistent junk food eating habits, not just the obvious and inevitable weight gain. Below is a short list of how junk food negatively impacts our bodies. Think about it the next time you are reaching for your second helping of cheesy nachos that accompanies the double stacked hamburger sandwich and large soda.
Weight Gain
A negative effect of junk food on children is rapid weight gain, often leading to excessive weight and sometimes obesity. This is because it often tastes good, is not very filling and is high calorie. Candy, soft drinks, French fries and other fried foods, pizza, burgers, baked goods and ice cream are examples of high-sugar or high-fat foods which provide hundreds of calories per day for the typical American youth ages 2 to 18, according to the 2010 Dietary Guidelines from the U.S. Department of Health and Human Services.
Type 2 Diabetes
Junk food puts kids at a higher risk for type 2 diabetes, according to the Centers for Disease Control and Prevention. Type 2 diabetes occurs when you are not able to properly regulate your blood sugar level. Your risk increases when you are obese and when your diet is high in high-glycemic carbohydrates, such as sugars and refined starches in sweets, white bread and potatoes. Type 2 diabetes increases your risk for kidney failure.
Nutritional Deficiencies
Junk food can lead to nutritional deficiencies when your children eat it instead of healthy foods with essential nutrients. Healthy meals and snacks should provide essential nutrients, such as B vitamins; magnesium and iron from fortified, whole-grain cereals and grains; calcium from milk or yogurt; healthy fats from nuts and dietary fiber; and vitamin A and vitamin C from fresh fruits and vegetables. Instead, children may miss out on these nutrients when settling for such things as breakfast sandwiches, potato chips, candy and soft drinks.
Cardiovascular Disease
Junk food is often high in saturated fat, which raises LDL cholesterol and may increase the risk for cardiovascular disease in children, according to the Centers for Disease Control and Prevention. Junk foods with saturated fat include pizza, ice cream, processed meats and full-fat cheese. High blood pressure is another risk factor for heart disease, and a high-sodium diet leads to high blood pressure. Children may be at risk for high blood pressure when eating salty junk food such as potato chips, French fries, pretzel
Obesity
Junk food enthusiasts are prone to put on weight, especially when they eat this kind of food very often. The fat and processed flour only make people fatter and unhealthier, as does the oil and grease that are used for fries, chips, donuts and other deep-fried foods. Statistics even show people who eat junk food tend to accompany it with sodas and alcohol, which are either laden with sugar or empty calories and both increase a person’s tendency to put on weight.