Absorption and GI disease

Question 1

Three main processes of nutrients absorption

Answer 1

1) Passive diffusion
2) Facilitated diffusion
3) Active transport

Question 2

Passive diffusion

Answer 2

• Movement of molecules through the cell membrane without the expenditure of energy, by way of special protein channels or intermolecular gaps in the cell membrane.

• Concentration gradients drive passive diffusion.

Question 3

Facilitated diffusion

Answer 3

• Special channel protein channels help substances cross the cell membrane.

Question 4

Active transport

Answer 4

Substances that usually require active transport across some cells membranes include many minerals, several sugars, and most amino acids.

Question 5

Circulation of nutrients

Answer 5

1) Vascular system
2) Lymphatic system

Question 6

Vascular system:

Answer 6

• Or also known as blood circulatory system, is a network of veins and arteries through which the blood carries nutrients.

• Heart pump the blood to circulate through the body.

• Water soluble nutrients are absorbed directly from intestinal cells into tiny capillary to the liver before they are dispersed throughout the body.

• Once the destination cells have used the oxygen and nutrients, carbon dioxide and waste products are picked up by the blood and transported to the lungs and kidneys, respectively for excretion.

Question 7

Lymphatic system

Answer 7

1) A network of vessels that drain lymph, a clear fluid formed between cells.

2) Lymph moves through these vessels and empties into the bloodstream near the neck.Carries fat-soluble nutrients.

3) After a fatty meal, lymph can contain 1 to 2 percent fat.

4) Nutrients absorbed into the lymphatic system bypass the liver before entering the bloodstream.

5) Has no pumping organ but contains one-way valves.

6) Smooth muscles in the vessel walls contract to pump lymph forward when vessels are filled.

7) Skeletal muscle contractions also help move lymph by squeezing the vessels.

8) Performs an important cleanup function by carrying proteins and large particles from tissue spaces, which can not be absorbed directly into blood capillaries.

Question 8

Nutrition and GI disorders

Answer 8

1) Constipation

2) Diarrhea

3) Heartburn and Gastro-Esophageal Reflux Disease (GERD)

4) Irritable Bowel Syndrome

5) Irritable Bowel Disease

6) Colorectal cancer

7) Gas
8) Ulcer

Question 9

Constipation

Answer 9

• Defined as having a bowel movement fewer than three times per week.

• Is a symptom, not a disease.

• Stools are hard, dry,small in size, and difficult to eliminate.

• People who are constipated may find it painful to have a bowel movement and often experience straining, bloating, and the sensation of a full bowel.

• High-fiber diets and plenty of liquids prevent dehydration.

• Regular exercise helps keep body’s muscles healthy, including the GI tract muscles, and will help promote regularity.

Question 10

Diarrhea

Answer 10

• Loose, watery stools that occur more than three times in one day.

• Is a symptom of many disorders that cause increased peristalsis.

• Culprits include stress, intestinal irritation or damage, side effects of medications, and intolerance to gluten (a protein in wheat), fat or lactose.

Question 11

Heartburn and Gastro-Esophageal Reflux Disease (GERD):

Answer 11

• Occurs when the sphincter between the esophagus and stomach relaxes inappropriately, allowing the stomach’s content to flow back into the esophagus.

• Unlike stomach, the esophagus has no protective mucous lining, so acid can damage it quickly and cause pain.

• Many people experience occasional heartburn.

• Chronic heartburn lead to GERD.

Question 12

How to avoid GERD

Answer 12

• Avoid foods and beverages that can weaken the esophageal sphincter (chocolate, peppermint, fatty foods, coffee, and alcoholic drinks).

• Avoid food and beverages that can irritate a damaged esophageal lining (citrus fruits and juices, tomato products, and pepper).

• Eating meals at least two to three hours before bedtime.

• Smoking weakensthe esophageal sphincter.

Question 13

Irritable Bowel Syndrome:

Answer 13

• Poorly understood condition that causes abdominal pain, altered bowel habits (diarrhea and constipation), and cramps.

• Beans, chocolate, milk products, and large amounts of alcohol are frequent offenders.

• Factors aggravate IBS:
i) Fat
ii) Caffeine
iii) Menstrual period

• IBS does not shorten life span or progress to more serious illness.

Question 14

Irritable Bowel Disease

Answer 14

Inflammatory bowel disease (IBD) is a broad term that refers to chronic swelling (inflammation) of the intestines.

Question 15

Some types of IBD include:

Answer 15

• Crohn’s disease
• ulcerative colitis
• indeterminate colitis

Question 16

Colorectal cancer:

Answer 16

• Third leading cause of cancer-related deaths in the United States.

• Risk increased with high intakes of meat and fat.

• Risk decreased with high intakes of fruits and vegetables.

• Fiber in fruits and vegetables are thought to:
i) Dilute the carcinogensin stool.
ii) Rapid transit of carcinogensthrough the GI tract.
iii) Lower colon pH due to bacterial fermentation of fiber.

• However, humans and animals studies fail to support these theories.

Question 17

Gas:

Answer 17

• Flatulence has an unpleasant odor because bacteria in release small amounts of gases that contain sulfur.

• Commonly caused by swallowing air.

• Flatus (lower intestinal gas) composition depends to a great extent on carbohydrate intake and the activity of the colon’s bacterial population.

• One-third of people release methane.

Question 18

Ulcer

Answer 18

• Burning pain in the upper abdomen.

• Cause nausea, vomiting, loss of appetite, and weight loss.

• Peptic ulcer is a sore that forms in the duodenum or the lining of the stomach.

• Previous thought to be related to stress and spicy food.

• Research confirmed infection by H. pylori caused most ulcers.

• These bact. weaken the protective mucous coating.

• Both bact. and acid irritate the lining and cause a sore or ulcer.

• NSAIDs cause ulcer by interfering the GI tract’s ability to protect itself from acidic stomach juices.

• Fortunately, NSAID-induced ulcers usually heal once the person stops taking the medication.

Question 19

Risk factors for peptic ulcers:

Answer 19

1. Infection with H. pylori
2. NSAIDs
3. Alcohol consumption
4. Genetics
5. Smoking
6. Emotional stress
7. Excess acid production

Question 20

Functional dyspepsia

Answer 20

• Refer to chronic pain in the upper abdomen that has no obvious physical cause (such as inflammation of esophagus, peptic ulcer, or gallstones).

• Cause unknown.

• Stress-reduction techniques, such as meditation and biofeedback, can often relieve the symptoms of functional dyspepsia.

Question 21

Diverticulosis:

Answer 21

• Condition of having diverticula in the colon, which are outpocketings of the colonic mucosa and submucosa through weaknesses of muscle layers in the colon wall.

• Common in the sigmoid colon, which is a common place for increased pressure.

• This is uncommon before the age of 40 and increases in incidence after that age.

Question 22

Risk factors for diverticulosis:

Answer 22

1. A diet which is low in fiber content or high in fat
2. High intake of meat and red meat
3. Increasing age
4. Constipating conditions
5. Connective tissue disorders which may cause
   weakness in the colon wall

Question 23

Symptoms of Diverticulosis

Answer 23

• Often this disorder has no symptoms.

• The most common is
1) Bleeding (variable amounts)
2) Bloating
3) Abdominal pain/cramping after meals or otherwise often in the left lower abdomen
4) Changes in bowel movements (diarrhea or constipation).

Question 24

Symptoms of Indigestion

Answer 24

• Pain, fullness, or discomfort in the upper part of the abdomen or chest

• Heartburn

• Loss of appetite

• Feeling sick

• Flatulence

Question 25

Some of the following can trigger symptoms of indigestion:

Answer 25

• Drinking excess alcohol

• Smoking

• Stress and anxiety

• Medicinessuch as aspirin and anti-inflammatory
medicines used to treat arthritis

• Not eating regular meal -> acid levels can build up if meals are missed

Question 26

Appendicitis

Answer 26

• Inflammation of the appendix is termed appendicitis.

• It is characterized by high fever, elevated WBC count, and a neutrophil count higher than 75%.

• Subsequent infection can produce edema and ischemia.

• An appendicitis typically begins with referred pain to the umbilical region of the abdomen, followed by
nausea, and vomiting.

• After several hours, pain localizes in the right lower quadrant.