Wednesday, October 18, 2006

Healthy digestion


The types of food you eat, the amount of exercise you get, the pace of your day and your level of stress all can affect the health of your digestive system. Good lifestyle habits can go a long way toward keeping your digestive system on track:

  • Practice good eating habits.
  • Maintain healthy weight.
  • Get regular exercise.
  • Control stress.
  • Limit alcohol and tobacco.
  • Use medications cautiously.

Large intestine


As this residue passes through the colon, your body absorbs nearly all of the water, leaving a usually soft but formed substance called stool. Muscles in the wall of your colon separate the waste into small segments that are pushed into your lower colon and rectum. As the rectal walls are stretched, they signal need for a bowel movement.

When the sphincter muscles in your anus relax, the rectal walls contract to increase pressure. Sometimes you have to use your abdominal muscles, which press on the outside of the colon and rectum. These coordinated muscle contractions expel the stool.

Tuesday, October 17, 2006

Small intestine


When bile and pancreatic digestive juices mix with other juices secreted by the wall of your small intestine, digestion shifts into high gear. What was once apple pie is propelled into the second portion of your small intestine, the jejunum. Here it's further broken down into smaller molecules of nutrients that can be absorbed. Then it slides into the final and longest portion of your small intestine — the ileum — where virtually all of the remaining nutrients are absorbed through the lining of the ileum's wall.

What remains at the end of the ileum is a combination of water, electrolytes — such as sodium and chloride — and waste products, such as plant fiber and dead cells shed from the lining of your digestive tract.

Monday, October 16, 2006

Pancreas, liver and gallbladder


In your duodenum, digestion continues, as chyme from the stomach mixes with a variety of digestive juices from your pancreas, liver and gallbladder:

  • Pancreas. The pancreas produces digestive enzymes that help break down proteins, carbohydrates, and fats. It also produces the hormones insulin and glucagon, which help regulate the level of sugar (glucose) in your blood.
  • Liver. The liver performs more than 500 functions, including storing nutrients, filtering and processing chemicals in food, and producing bile, a solution that helps digest fats and eliminate waste products.
  • Gallbladder. The gallbladder stores and concentrates bile. As fatty food enters the upper portion of your small intestine (the duodenum), the gallbladder contracts and releases bile into the small intestine through a duct.

Friday, October 13, 2006

Stomach


After entering your stomach, the pie soon becomes unrecognizable. The stomach's wall, lined with three layers of powerful muscles, begins churning and mixing it into smaller and smaller pieces. Gastric juices, rich in acid and enzymes, pour out of glands that line your stomach. The acid and enzymes help break down food into a thick, creamy fluid called chyme.

Once the concoction is well mixed, waves of muscle contractions propel it through the pyloric valve and into the first section of your small intestine (duodenum). The pyloric valve releases less than an eighth of an ounce of chyme at a time. The rest is held back for more mixing.

Thursday, October 12, 2006

Esophagus


As you swallow that last bite of pie, muscles in your mouth and throat propel it to your upper esophagus, the tube that connects your throat to your stomach. In the wall of your esophagus, muscles create synchronized waves — one after another — that propel the pie into your stomach. In this process, called peristalsis, muscles behind the bolus of pie contract, squeezing it forward, while muscles ahead of it relax, allowing it to advance without resistance.

When the bolus reaches the lower end of your esophagus, pressure from the food signals a muscular valve — the lower esophageal sphincter — to open and let it enter your stomach.

Monday, October 09, 2006

Mouth and salivary glands


After you take your first bite of pie, your salivary glands produce enough digestive juices (saliva) to begin breaking it down chemically. Besides the salivary glands in the lining of your mouth, you have three pairs of larger salivary glands — the parotid glands, sublingual glands and the submandibular glands. Together they produce 1 to 3 pints of saliva a day.
Not all of the work is chemical, though. As you savor the sweet apple tang, your teeth work to grind the pie while your tongue mixes it with saliva. This combination transforms it into a bolus — a soft, moist, rounded mass suitable for swallowing.

Wednesday, October 04, 2006

The nuts and bolts of digestion



A fresh-baked apple pie is browning in the oven. Just the sight and smell of it — and the anticipation of eating it — are enough to make you start salivating and producing stomach acids. So even before you take a bite, the digestive process has begun.

After the first steaming morsel enters your mouth, the many organs of your digestive tract kick into high gear. Here's a look at how your digestive system works, from top to bottom.

Monday, October 02, 2006

How Do I stick to a Healthy Diet? -part 3-

Make healthy choices when eating out

There are usually healthy options at every restaurant, even at fast-food places. The type of restaurant you choose can help you make healthy choices. Ethnic restaurants, such as Indian, Thai, or Japanese, have lots of healthy dishes on the menu. A vegetarian restaurant will obviously have more vegetable choices than a drive-through burger stand. However, most fast-food chains are now offering more low-fat or healthier choices on the menu.
If you eat out a lot, try the following:

  • Order a veggie pizza with a whole-wheat crust or add lots of veggies to your pepperoni.
  • Order a veggie pizza with grilled chicken instead of sausage or pepperoni. Ask for less cheese on your pizza.
  • Order a pasta with roasted vegetables, grilled chicken, or marinara sauce. Avoid cream-based sauces.
  • Order a vegetable or grilled chicken wrap.
  • Order vegetable soup if available.
  • Choose a variety of vegetables from a salad bar.
  • Order foods that are broiled or poached rather than fried or breaded.
  • Cut back on butter or margarine used on bread. Better yet: dip bread in olive oil instead.
  • Order sauces, gravies, and salad dressings on the side so you can control how much you use.
  • Share appetizers, desserts, and even entrées with your dining partner.
  • Ask for salsa with a baked potato instead of sour cream, butter, cheese, or bacon.
  • Order a child's portion or take half of your meal home.
  • Order the smallest portions at fast-food restaurants (don't be tempted to take the big meal at a reduced price); opt for salads or a broiled chicken sandwich (skip the mayonnaise and cheese).

Sunday, October 01, 2006

How Do I stick to a Healthy Diet? -part 2-

Find creative ways to add fruits and vegetables to meals
  • Add apple chunks, pineapple, and raisins to tuna salad.
  • Add lots of colorful vegetables, such as red cabbage, carrots, and spinach, to green salads.
  • Top with orange, nectarine, or grapefruit slices.
  • Add green, red, or yellow pepper strips, carrots, cucumber, and broccoli to a pasta or potato salad.
  • Add vegetables to pizza and sandwiches, and add fruits to yogurt and cereals.