Digestive System

Anatomy of the Digestive System

GI tract (alimentary canal) = Continuous tube running through the ventral body cavity, mouth to anus

Accessory structures, Teeth, Tongue, Salivary glands, Liver, Gallbladder, Pancreas

Digestive Process

Ingestion Movement = peristalsis Secretion ( water, HCI, buffers, enzymes)Digestion = process of breaking down large

food particles into molecules which are small enough to enter body cells

Mechanical digestion = chewing, churning, mixing with secretions

Digestive Process

Chemical digestion = series of catabolic (hydrolysis) reactions that break down large carbohydrates, lipid, & protein food particles into smaller molecules that can be used by body cells

Absorption = moving these nutrient molecules from GI tract into blood / lymph

Defecation = emptying of the rectum, to remove indigestible substances

Digestive Process

Mouth = buccal cavityUvula = muscular process which hangs from

the back of the soft palateTongue = forms the floor of the oral cavitySalivary glands

Digestive Process

Saliva = continuous secreted into the mouth; increased amount of saliva secreted with presence of food in mouth / nervous stimulation, Lubricates; keeps oral and pharyngeal membranes moist, Helps to dissolve food, Starts chemical digestion of carbohydrates (contains the enzyme amylase)

3 pairs of major salivary glands: parotid, submandibular, sublingual

Esophagus

Esophagus = muscular tube behind the trachea; connects pharynx to stomach Moves the bolus by peristalsis; NO chemical digestion Esophagus contains upper and lower esophageal

sphincters

Stomach

Shaped like a “J” = stomach is just a wide place in the GI tract

4 main regions:1. Cardia = Right uppermost; just past the lower

esophageal sphincter2. Fundus = Left uppermost3. Body = middle, curved portion of stomach4. Pylorus = lower portion; attaches to the duodenum

Lining of stomach contains folds (rugae), similar to bladder lining

Stomach

Gastric glands; located in gastric pits: HCl, mucus (protective),other enzymes

Only a few substances are absorbed thru the stomach wall: some water Electrolytes certain drugs (aspirin) alcohol

Pancreas

Posterior to lower stomach Pancreas is connected to duodenum by 2 ducts

(pancreatic & accessory)Tiny patches of cells (1%) = Secrete

hormones, 99% of pancreas cells = Secrete pancreatic juice: Pancreatic amylase → breaks down carbs Trypsin, chymotrypsin, carboxypeptidase → digest

proteins Pancreatic lipase → digests fats Ribonuclease & deoxyribonuclease → digest nucleic

acids

Liver

Liver = 2nd largest organ of the bodyLarge right lobe + small left lobe (positioned behind

lower sternum), Produce bile → through a duct system to gallbladder for storage, Gallbladder then secretes bile when stimulated by nervess / hormones

Functions of the Liver Carb metabolism Lipid metabolism Protein metabolism Also convert one amino acid to another, as needed by the body Liver removes & detoxifies certain drugs & hormones from the

blood Liver stores vitamins (A, B12, D, E, K) and minerals (ferritin, Cu,

etc.)

Gallbladder

Gallbladder stores & concentrates the bile

Small Intestines

Small Intestines, Duodenum = top end; connected to pyloric sphincter, Jejunum, Ileum = lower end; connected to large intestine at ileocecal sphincter

Small intestine is highly adapted for digestion & absorption, Large surface area for absorption

Absorption = passage of end products of digestion from GI tract into blood or lymph (90% of absorption occurs in the small intestine)

Large Intestines

Large Intestine = Colon, Cecum = a blind pouch about 2.5” long; hangs below the ileocecal sphincter, Vermiform appendix = coiled tube attached to the cecum; 3” long, Colon (4 parts)

Rectum = anterior to the sacrum & coccyx; about 8” long, Anus = outer opening of the large intestine Internal anal sphincter = smooth muscle (involuntary) External anal sphincter = skeletal muscle (voluntary)

More water gets absorbed in the Colon (liquid chyme → solid/semisolid feces)

Disorders and procedures of the digestive system

Parotitis – mumps, swollen parotid salivary glands, bacterial

Heartburn – chyme pushed up esophagus due to incomplete closure of the esophageal sphincter

Vomiting – noxious chemicals, disease, motionGall stones – cholesterol crystals formed in gall

bladderColon cancer – rectal bleeding, anemiaAppendicitis – inflammation, peritonitis, shock,

caused by bacterial infection or fecolith Diarrhea – speed bowel up

Disorders and procedures of the digestive system

Constipation – slow bowel down Stomach ulcers – lack of mucous bacteria or

Nsaids drugs creates a holeCeliac disease – autoimmune, chronic diarrhea,

fatigue, failure to thrive in childrenCystic fibrosis – recessive genetic disease,

chloride channel not transported across membrane, malabsorption in gut cannot exchange water, pancreas does not make enzymes well

Appendectomy – cut off appendixCholecystectomy – cut off gall bladder

Disorders and procedures of the digestive system

Endoscopy – sending fiber optic camera into esophagus to evaluate and band bleeding vessels

Colonoscopy – sending fiber optic camera into colon to evaluate and take biopsy

Short gut syndrome – genetic abnormality short small intestinal tract

Comb procedure – zipper cut the intestines to increase length, fix short gut

Whipple – surgical removal of pancreatic cancer, attach remaining pancreas to duodenum, attach stomach to jejunum, duodenum become duct for pancreatic and liver secretions

Crazy surgical options: 100lbs overweight, bmi of 40

Lap band – plastic band around stomach that can be tightened, removable surgically

Gastric bypass – any rearranging or skipping of the stomach or small intestines

Roux-en-y – cut off most of stomach, attaches small egg sized portion to the jejunum, caused malabsorption

Healthy Diet

A healthy diet is one that helps maintain or improve general health. It is important for lowering many chronic health risks, such as obesity, heart disease, diabetes, hypertension and cancer. A healthy diet involves consuming appropriate amounts of all essential nutrients and an adequate amount of water.

Healthy Diet-

Nutrients can be obtained from many different foods, so there are numerous diets that may be considered healthy. A healthy diet needs to have a balance of macronutrients (fats, proteins, and carbohydrates), calories to support energy needs, and micronutrients to meet the needs for human nutrition without inducing toxicity or excessive weight gain from consuming excessive amounts.

Diet types gluten free, vegetarian, vegan, diabetes, Atkins, south beach, lactose intolerant

Gluten Free

A gluten-free diet is a diet that excludes foods containing gluten. Gluten is a protein found in wheat (including kamut and spelt), barley, rye, malts and triticale. It is used as a food additive in the form of a flavoring, stabilizing or thickening agent, often as "dextrin". A gluten-free diet is the only medically accepted treatment for celiac disease, the related condition dermatitis herpetiformis, and wheat allergy.

Gluten Free

Additionally, a gluten-free diet may exclude oats. Medical practitioners are divided on whether oats are an allergen to celiac disease(chronic diarrhea and failure to thrive) sufferers or if they are cross-contaminated in milling facilities by other allergens.

Gluten Free

The term gluten-free is generally used to indicate a supposed harmless level of gluten rather than a complete absence. The exact level at which gluten is harmless is uncertain and controversial. A recent systematic review tentatively concluded that consumption of less than 10 mg of gluten per day is unlikely to cause histological abnormalities, although it noted that few reliable studies had been done.

Gluten Free

Regulation of the label gluten-free varies widely by country. In the United States, the FDA issued regulations in 2007 limiting the use of "gluten-free" in food products to those with less than 20 ppm of gluten.

Vegetarian and Vegan

Vegetarianism encompasses the practice of following plant-based diets (fruits, vegetables, etc.), with or without the inclusion of dairy products or eggs, and with the exclusion of meat (red meat, poultry, and seafood). Abstention from by-products of animal slaughter, such as animal-derived rennet and gelatin, may also be practiced.

Vegetarianism can be adopted for different reasons: In addition to ethical reasons, motivations for vegetarianism include health, religious, political, environmental, cultural, aesthetic or economic.

Vegetarian and Vegan

There are varieties of the diet as well: an ovo-vegetarian diet includes eggs but not dairy products, a lacto-vegetarian diet includes dairy products but not eggs, and an ovo-lacto vegetarian diet includes both eggs and dairy products. A vegan diet excludes all animal products, including eggs, dairy, and honey.

Diabetic Diet

The basics to diabetic diet meal planning are simple once we understand the way our body breaks down food. Everything we eat is broken down into sugar eventually. Sugary foods such as sweets or fruit hit the bloodstream almost immediately, followed by the slower starches (carbohydrates, or carbs), which take an hour or two to break down depending on their complexity.

Diabetic Diet

Proteins are next, taking about four hours, then between six and eight hours the fats finally break down. If strict attention is paid to diet and exercise, many diabetics can control their blood sugar with minimal dependence on medication.

Atkin’s Diet

The Atkins diet involves limited consumption of carbohydrates to switch the body's metabolism from metabolizing glucose as energy over to converting stored body fat to energy. This process, called ketosis, begins when insulin levels are low; in normal humans, insulin is lowest when blood glucose levels are low (mostly before eating).

Atkin’s Diet

Ketosis lipolysis occurs when some of the lipid stored in fat cells are transferred to the blood and are thereby used for energy. On the other hand, caloric carbohydrates (for example, glucose or starch, the latter made of chains of glucose) impact the body by increasing blood sugar after consumption. (In the treatment of diabetes, blood sugar levels are used to determine a patient's daily insulin requirements.) Fiber, because of its low digestibility, provides little or no food energy and does not significantly impact glucose and insulin levels.

Atkin’s Diet

The Atkins Diet restricts "net carbs" (digestible carbohydrates that impact blood sugar). One effect is a tendency to decrease the onset of hunger, perhaps because of longer duration of digestion (fats and proteins take longer to digest than carbohydrates). Atkins states in his 2002 book New Diet Revolution that hunger is the number one reason why low-fat diets fail and that the Atkins diet is easier because you are allowed to eat as much as you want

South Beach Diet

According to Agatston, hunger cycles are triggered not by carbohydrates in general, but by carbohydrate-rich foods that the body digests quickly, creating a spike in blood sugar. Such foods include the heavily refined sugars and grains that make up a large part of the typical Western diet. The South Beach Diet eliminates these carbohydrate sources in favor of relatively unprocessed foods such as vegetables, beans, and whole grains. Carbohydrate sources are considered "good" only if they have a low glycemic index.

South Beach Diet

Given that South Beach Diet was designed by a cardiologist, it should be no surprise that it eliminates trans-fats and discourages saturated fats. Although foods rich in these "bad fats" do not contribute to the hunger cycle, they do contribute to LDL cholesterol and heart disease. The South Beach Diet replaces them with foods rich in unsaturated fats and omega-3 fatty acid which contribute to HDL cholesterol and provide other health benefits. Specifically, the diet excludes the fatty portions of red meat and poultry, replacing them with lean meats, nuts, and oily fish.

South Beach Diet

Agatston divides the South Beach Diet into three phases, each progressively becoming more liberal. "Phase 1" lasts for the first two weeks of the diet. It eliminates all sugars, processed carbohydrates, fruits, and some higher-glycemic vegetables as well. Its purpose is to eliminate the hunger cycle and is expected to result in significant weight loss. "Phase 2" continues as long as the dieter wishes to lose weight. It re-introduces most fruits and vegetables and some whole grains as well. "Phase 3" is the maintenance phase and lasts for life. There is no specific list of permitted and prohibited foods. Instead, the dieter is expected to understand the basic principles of the diet and live by the principles

Lactose Intolerant

Lactose intolerance, also called lactase deficiency or hypolactasia, is the inability to digest and metabolize lactose, a sugar found in milk. It is caused by a lack of lactase, the enzyme required to break down lactose in the digestive system, and results in symptoms including abdominal pain, bloating, flatulence, diarrhea, nausea and acid reflux.

Lactose Intolerant

Most mammals normally become lactose intolerant when they are young but some human populations have developed lactase persistence, in which lactase production continues into adulthood. It is estimated that 75% of adults worldwide show some decrease in lactase activity during adulthood. The frequency of decreased lactase activity ranges from 5% in northern Europe through 71% for Sicily to more than 90% in some African and Asian countries.

Lactose Intolerant

Lactose is a water-soluble molecule. Therefore fat percentage and the curdling process affect tolerance of foods. After the curdling process lactose is found in the water portion (along with whey and casein) but not in the fat portion. Dairy products that are "fat reduced" or "fat free" generally have a slightly higher lactose percentage. Low fat dairy foods, additionally, often have various dairy derivatives such as milk solids added to them to enhance sweetness, increasing the lactose content

Obesity Eating Disorders

National Institute of Mental HealthEating disorders - An eating disorder is an

illness that causes serious disturbances to your everyday diet, such as eating extremely small amounts of food or severely overeating. A person with an eating disorder may have started out just eating smaller or larger amounts of food, but at some point, the urge to eat less or more spiraled out of control. Severe distress or concern about body weight or shape may also characterize an eating disorder.

Obesity Eating Disorders

Eating disorders frequently appear during the teen years or young adulthood but may also develop during childhood or later in life. Common eating disorders include anorexia nervosa, bulimia nervosa, and binge-eating disorder.

Eating disorders are real, treatable medical illnesses. They frequently coexist with other illnesses such as depression, substance abuse, or anxiety disorders.

Anorexia

Anorexia – Extreme thinness (emaciation) A relentless pursuit of thinness and

unwillingness to maintain a normal or healthy weight

Intense fear of gaining weight Distorted body image, a self-esteem that is

heavily influenced by perceptions of body weight and shape, or a denial of the seriousness of low body weight

Lack of menstruation among girls and women Extremely restricted eating.

Anorexia

Many people with anorexia nervosa see themselves as overweight, even when they are clearly underweight. Eating, food, and weight control become obsessions. People with anorexia nervosa typically weigh themselves repeatedly, portion food carefully, and eat very small quantities of only certain foods. Some people with anorexia nervosa may also engage in binge-eating followed by extreme dieting, excessive exercise, self-induced vomiting, and/or misuse of laxatives, diuretics, or enemas.

Anorexia

Some who have anorexia nervosa recover with treatment after only one episode. Others get well but have relapses. Still others have a more chronic, or long-lasting, form of anorexia nervosa, in which their health declines as they battle the illness.

Anorexia

Other symptoms may develop over time, including: Thinning of the bones (osteopenia or osteoporosis) Brittle hair and nails Dry and yellowish skin Growth of fine hair all over the body (lanugo) Mild anemia and muscle wasting and weakness Severe constipation Low blood pressure, slowed breathing and pulse Damage to the structure and function of the heart Brain damage Multiorgan failure Drop in internal body temperature, causing a person to feel cold all

the time Lethargy, sluggishness, or feeling tired all the time Infertility

Bulimia

Bulimia - Bulimia nervosa is characterized by recurrent and frequent episodes of eating unusually large amounts of food and feeling a lack of control over these episodes. This binge-eating is followed by behavior that compensates for the overeating such as forced vomiting, excessive use of laxatives or diuretics, fasting, excessive exercise, or a combination of these behaviors.

Bulimia

Unlike anorexia nervosa, people with bulimia nervosa usually maintain what is considered a healthy or normal weight, while some are slightly overweight. But like people with anorexia nervosa, they often fear gaining weight, want desperately to lose weight, and are intensely unhappy with their body size and shape. Usually, bulimic behavior is done secretly because it is often accompanied by feelings of disgust or shame. The binge-eating and purging cycle happens anywhere from several times a week to many times a day.

Bulimia

Other symptoms include: Chronically inflamed and sore throat Swollen salivary glands in the neck and jaw area Worn tooth enamel, increasingly sensitive and

decaying teeth as a result of exposure to stomach acid Acid reflux disorder and other gastrointestinal

problems Intestinal distress and irritation from laxative abuse Severe dehydration from purging of fluids Electrolyte imbalance (too low or too high levels of

sodium, calcium, potassium and other minerals) which can lead to heart attack.

Binge Eating

With binge-eating disorder a person loses control over his or her eating. Unlike bulimia nervosa, periods of binge-eating are not followed by purging, excessive exercise, or fasting. As a result, people with binge-eating disorder often are over-weight or obese. People with binge-eating disorder who are obese are at higher risk for developing cardiovascular disease and high blood pressure. They also experience guilt, shame, and distress about their binge-eating, which can lead to more binge-eating.

Binge Eating

Treatment - Adequate nutrition, reducing excessive exercise, and stopping purging behaviors are the foundations of treatment. Specific forms of psychotherapy, or talk therapy, and medication are effective for many eating disorders. However, in more chronic cases, specific treatments have not yet been identified. Treatment plans often are tailored to individual needs and may include one or more of the following: Individual, group, and/or family psychotherapy Medical care and monitoring Nutritional counseling Medications.

Some patients may also need to be hospitalized to treat problems caused by mal-nutrition or to ensure they eat enough if they are very underweight.

Males

Like females who have eating disorders, males also have a distorted sense of body image. For some, their symptoms are similar to those seen in females. Others may have muscle dysmorphia, a type of disorder that is characterized by an extreme concern with becoming more muscular. Unlike girls with eating disorders, who mostly want to lose weight, some boys with muscle dysmorphia see themselves as smaller than they really are and want to gain weight or bulk up. Men and boys are more likely to use steroids or other dangerous drugs to increase muscle mass.

Males

Although males with eating disorders exhibit the same signs and symptoms as females, they are less likely to be diagnosed with what is often considered a female disorder. More research is needed to understand the unique features of these disorders among males.

Metabolism – life period, exercise quantity, genetic factors

Obesity – evolutionarily designed to hold on to calories and crave salty, sweet, greasy

Thyroidism – hypothyroidism weight gain

Calorie Equation

Recommended daily caloric intake equation:MALE: 105 lbs for first 5’, 6 lbs for every

additional inch of height, +/- 15 lbs for build = Ideal Weight

FEMALE: 100 lbs for first 5’, 5 lbs for every additional inch of height, +/- 15 lbs for build = Ideal Weight

Calorie Use

Caloric Use: average Ideal and Actual weights x 10 x 1.5 (sedentary) or 1.7 (exercise 3 days per week) or 2.0 (exercise every day) = Number of Calories you burn each day

1 lb of fat = 3,500 Cal; if you ingest 500 less Cal per day you will lose 1 lb of fat per week

Substance Abuse

Substance abuse, also known as drug abuse, refers to a maladaptive pattern of use of a substance (drug) that is not considered dependent. Substance abuse/drug abuse does is not limited to mood-altering or psycho-active drugs. Activity is also considered substance abuse when inappropriately used (as in the case of propofol and Michael Jackson's death, or steroids for performance enhancement in sports). Therefore, mood-altering and psychoactive substances are not the only drugs of abuse. Substance abuse often includes problems with impulse control and impulsivity.

Substance Abuse

The term "drug abuse" does not exclude dependency, but is otherwise used in a similar manner in nonmedical contexts. The terms have a huge range of definitions related to taking a psychoactive drug or performance enhancing drug for a non-therapeutic or non-medical effect. All of these definitions imply a negative judgment of the drug use in question (compare with the term responsible drug use for alternative views).

Substance Abuse

Some of the drugs most often associated with this term include alcohol, amphetamines, barbiturates, benzodiazepines (particularly temazepam, nimetazepam, and flunitrazepam), cocaine, methaqualone, and opioids. Use of these drugs may lead to criminal penalty in addition to possible physical, social, and psychological harm, both strongly depending on local jurisdiction. Other definitions of drug abuse fall into four main categories: public health definitions, mass communication and vernacular usage, medical definitions, and political and criminal justice definitions.

Substance Abuse

Substance abuse is a form of substance-related disorder.

Alcohol – withdrawal can killPublic health issues