PHARMACY TECHNICIAN CHAPTER TWENTY THREE

Main Organs of the Digestive System Mouth Esophagus Pharynx Stomach Small intestine Large intestine Teeth Tongue Salivary glands Liver Gallbladder Pancreas

Physiology of the Digestive System A series of hollow organs connected in a long tube Extends from the mouth to the anus Lined with protective mucosa that prevents acid from causing sores or ulcers In the mouth, stomach, and small intestine, the mucosa also contains tiny glands that produce the liquid digestive juices that help digest food Other organs, such as the liver and pancreas, also produce products that aid in digestion

Three Categories of Nutrients Macronutrients—nutrients that the body requires in larger quantities Carbohydrates Proteins Fats (lipids) Micronutrients—nutrients that the body requires in small quantities Vitamins Minerals Water—an indispensable component of the body

Carbohydrates and Proteins Break down into monosaccharides during digestion Provide immediate energy Most readily available sources of food energy AMDR for carbohydrates—45 to 65 percent of daily caloric intake Proteins Break down into amino acids during digestion The body uses amino acids to make and repair: Body cells Tissues Muscle AMDR for protein—10 to 35 percent of daily caloric intake

Fats (Lipids) Break down into fatty acids and glycerol The body uses fats or lipids to: Provide lubrication Store fat as an energy reserve Store fat as insulation to provide warmth Provide a cushion that act as a shock absorber to protect vital organs Help metabolize carbohydrates and proteins more efficiently Carry fat-soluble vitamins A, D, E, K AMDR for fats—20 to 35 percent of daily caloric intake Not more than 10 percent of calorie intake should be saturated fat

Amino Acids The body can produce 11 types of amino acids, referred to as nonessential There are 9 types of amino acids that the body requires, but cannot produce These are referred to as essential amino acids (See table 23.9) Essential amino acids have to be derived from food intake

Vitamin A (Retinol) Helps with eyesight and epithelial cells and tissues (skin cells) Deficiencies in vitamin A may cause: Night blindness Xerosis (dryness) of the conjunctiva and cornea Xerophthalmia and keratomalacia Keratinization of lung, GI tract, and urinary tract Increased susceptibility to infections DRI is 900 µg/day for males and 700 µg/day for females

Vitamin D Helps with the absorption of calcium from the intestine to make stronger bones and teeth Deficiency causes metabolic bone softening: Called rickets in children Called osteomalacia in adults DRI is 5 µg/day (ages 19–50) for both males and females DRI is 10 µg/day (ages 51–70) for both males and females

Vitamin E A strong antioxidant for lipids Deficiency is generally caused by malabsorption rather than lack of ingestion Vitamin E deficiency may cause: Disorders of the reproductive system Abnormalities of muscle, liver, and bone marrow Hemolysis of RBCs Defective embryo genesis Brain dysfunction A disorder of capillary permeability DRI is 15 mg/day for both males and females

Vitamin K Necessary for blood coagulation Controls formation of coagulation factors II, VII, IX, and X in the liver Also needed for calcium uptake in bones Can be used as an antidote for coumadin overdoses Deficiency is rare DRI is 120 µg/day for males and 90 µg/day for females

Vitamin B1 (thiamine) Necessary for carbohydrate metabolism Deficiency causes the disease beriberi Affects the peripheral neurologic, cerebral, cardiovascular, and GI systems DRI is 1.2 mg/day for males and 1.1 mg/day for females

Vitamin B2 (riboflavin) Necessary for the health of the mucous membranes in the digestive tract Aids absorption of iron and vitamin B6 Deficiency leads to: Oral, eye, skin, and genital lesions - Dizziness Hair loss - Insomnia Light sensitivity - Poor digestion Retarded growth - Slow mental responses Burning feet

Vitamin B3 (niacin) Important in oxidation-reduction reactions Vital in protein metabolism Deficiency leads to the disease pellagra: Affects skin, mucous membranes, GI, and brain/CNS systems Causes photosensitive rash, scarlet stomatitis, glossitis, diarrhea, and mental aberrations Deficiency found in diets high in corn DRI is 16 mg/day for males and 14 mg/day for females

Vitamin B5 (pantothenic acid) Important for secretion of hormones such as cortisone Important for maintenance of healthy skin, muscles, and nerves B5 deficiency extremely rare Symptoms of B5 deficiency include: Insomnia Depression Nausea Headache Muscle spasm

Vitamin B6 (pyridoxine) Needed for: Red blood cell formation - Antibody production Cell respiration - Cell growth Conversion of tryptophan to niacin Helps convert stored carbohydrate to glucose to maintain normal blood sugar levels Synthesis of neurotransmitters such as serotonin and dopamine Deficiency can cause: Anemia similar to iron-deficiency anemia Decreased antibody production Suppressed immune response Symptoms such as dermatitis, a sore tongue, depression, confusion, and convulsions

Vitamin B9 (folic acid) Important for: Energy production -Formation of red blood cells Strengthening immune system Promoting healthy cell division and replication Protein metabolism Preventing depression and anxiety Deficiency can be serious and may result in: Anemia - Apathy Digestive disturbances - Fatigue Growth impairment - Insomnia Labored breathing - Memory problems Paranoia - Weakness

Vitamin B12 (cyanocobalamin) Needed for healthy nerve cells, to make DNA, and for the formation of RBCs Deficiency leads to irreversible nerve damage Signs and symptoms include: Fatigue - weakness Nausea - constipation Flatulence - loss of appetite weight loss - depression Confusion - poor memory

Vitamin C (ascorbic acid) Antioxidant Essential for collagen formation Maintains integrity of connective tissue, bone, and teeth Important for wound healing and recovery from burns Helps the absorption of iron Severe deficiency results in scurvy: Characterized by general weakness, bleeding gums, anemia, and skin bleeding The DRI is 90 mg/day for males and 75 mg/day for females

Water 60% of an adult’s body weight is water Forms a major portion of every tissue Provides the medium in which most of the body’s activities are conducted Facilitates many of the metabolic reactions that occur in the body Helps transport vital materials to the cells Vehicle in which glycogen is transported into muscle cells