Chapter 23 The Gastrointestinal System

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The Pharmacy Technician: Foundations and PracticesMike Johnston, Karen Davis, and Jeff Gricar

The Pharmacy TechnicianFOUNDATIONS AND PRACTICES

Chapter 23The Gastrointestinal System




Figure 23.1The digestive system.




Main Organs of the Digestive System

•Mouth

•Esophagus

•Pharynx

•Stomach

•Small intestine

•Large intestine




Accessory Organs of the Digestive System

•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




Physiology of the Digestive System (cont.)

•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




Three Categories of Nutrients (cont.)

•Water—an indispensable component of the body




Carbohydrates

•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




Fats (Lipids) (cont.)

•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

•Essential amino acids have to be derived from food intake




Table 23.9

Essential and Nonessential Amino Acids




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




Vitamin A (Retinol) (cont.)

•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




Vitamin D (cont.)

•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 (cont.)

•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




Vitamin B2 (riboflavin) (cont.)

•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 B2 (riboflavin) (cont.)

•DRI is 1.3 mg/day for males and 1.1 mg/day for females




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




Vitamin B3 (niacin) (cont.)

•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




Vitamin B5 (pantothenic acid) (cont.)

•Symptoms of B5 deficiency include:– Insomnia– Depression– Nausea– Headache– Muscle spasm

•DRI is 5 mg/day for both males and females




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




Vitamin B6 (pyridoxine) (cont.)

•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 B6 (pyridoxine) (cont.)

•DRI is:– 1.3 mg/day for males and females aged 19 to

50– 1.7 mg/day males and 1.5 mg/day for females

over the age of 51




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




Vitamin B9 (folic acid) (cont.)

•Deficiency can be serious and may result in:– Anemia– Apathy– Digestive disturbances– Fatigue– Growth impairment– Insomnia




Vitamin B9 (folic acid) (cont.)

•Deficiency can be serious and may result in:– Labored breathing– Memory problems– Paranoia– Weakness

•DRI is 400 µg/day for both males and females




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:




Vitamin B12 (cyanocobalamin) (cont.)

•Signs and symptoms include:– fatigue– weakness– nausea– constipation– flatulence– loss of appetite– weight loss




Vitamin B12 (cyanocobalamin) (cont.)

•Signs and symptoms include:– difficulty in maintaining balance– depression– confusion– poor memory– soreness of the mouth or tongue

•DRI is 2.4 µg/day for both males and females




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




Vitamin C (ascorbic acid) (cont.)

•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

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Chapter 23 The Gastrointestinal System