Physiology 4 (pt 2)

  1. Nutrient
    • Substance in food that is used by the body to promote normal growth, maintenance and repair
    • Large, complex molecules that function to promote living systems
  2. Major nutrients
    • Carbohydrates
    • Proteins
    • Lipids
    • Vitamins
    • Minerals
    • Water
  3. Nutrient classes that must be digested and absorbed
    • Carbohydrates
    • Proteins
    • Lipids
  4. Essential nutrients
    The ones that the body don't make or cannot convert from other molecules
  5. Carbohydrates
    • Chains of sugars
    • Provide cells with a readily available source of energy; esp when cells need energy quickly
    • Substrates for the synthesis of glycogen
  6. Monosaccharides


    Individual sugar molecules

    Pairs of sugars

    Long chains of sugars
  7. Glucose
    • Monosaccharide (simple sugar)
    • Derived from carbohydrates 
    • One of the only fuels available to the brain
  8. What does the brain use for energy exclusively?
    Glucose and ketone bodies (a class of molecules derived from fats)
  9. Examples of simple/complex carbs
    • Simple: sugars i.e fruit, honey
    • Complex: starch i.e grain, legumes
  10. Amylase
    Enzyme that digests starches into maltose
  11. Gluconeogenesis
    • Conversion of amino acids to glucose- tissue protein breakdown
    • An adult needs a minimum of 100g of carbs per day to prevent this
  12. Cellulose
    • Fiber
    • Insoluble and cannot be digested
    • Increases bulk, peristalsis and elimination
    • Amylase cannot digest
  13. Proteins
    • Chains of amino acids
    • Contain 20 different R groups to distinguish the differences
    • Formed when amino acids are linked with peptide bonds
  14. Peptide vs Proteins
    • A short chain of amino acids is a peptide
    • Longer chains are referred to as proteins
  15. Nitrogenous wastes
    • When proteins are used for energy which are excreted in the urine
    • Native proteins are metabolized for energy and dietary proteins provide amino acids can be used for synth of native proteins

    Excreted as ammonia, urea, and uric acid
  16. Essential amino acids
    9 of the 20 amino acids are refereed to this bc they must be consumed

    Isoleucine, histidine, leucine, methionine, valene, lysine, phenylalanine, tryptophan, threonine
  17. Nonessential
    Body can synth these amino acids from dietary proteins
  18. Complete proteins
    • Includes eggs, milk, meats
    • Dietary sources of protein that provide all of the essential amino acids are considered this
  19. Incomplete proteins
    • Include legumes (beans, peas), nuts, and cereals
    • Protein rich but lack one or more of the essential amino acids
  20. Amount of proteins needed
    • Depends on age, size, and metabolic rate
    • Generally, recommended intake is 0.4 grams of protein per lb of body weight per day
  21. Nitrogen balance
    • When amt of nitrogen ingested in proteins equals the amount excreted in urine and feces
    • Nitrogen content of protein is 16%
  22. Positive nitrogen balance
    • Take in more nitrogen than is lost
    • Normal for growing children and pregnant women
    • May also see after injury or tissue damage
  23. Negative nitrogen balance
    • Take in less nitrogen than is lost
    • May see during physical or emotional stress-- through energy expenditure by protein breakdown
  24. Lipids or fats
    • Long chains of carbon and hydrogen
    • Very energy dense molecules 
    • Used for long term energy storage, insulation and cushion
  25. Ketone bodies
    • One of the only fuels for the brain
    • Fats are a valuable source of this and in times of carbohydrate deficit, liver synthesizes this from fats
  26. Lipids can be used to synthesize
    • Triglycerides: storage form of fat 
    • Phospholipids: primary structural component of cell membranes
    • Fat derived hormones including prostaglandins and steroids and cholesterol
  27. Saturated fats
    • Animal products (meat, dairy)
    • Coconut
    • Fully saturated with H
    • Converted to harmful cholesterol LDL or VLDL
  28. Unsaturated fats
    • Seeds
    • Nuts
    • Most vegetable oils
    • Missing at least 1 double bond and 2 H

    Good cholesterol: HDL which cleans out the plaque
  29. Cholesterol
    The precursor to the formation of bile salts and steroid hormones
  30. Recommended daily allowance of complex carbohydrates, proteins, fats (lipids)
    • Complex carbohydrates: 45-65%
    • Proteins: 10-35%
    • Fats (lipids): 25-35% with no more than 10% in form of saturated fats
  31. Recommended fiber per day
    25-35 grams
  32. Complex and simple carbs examples
    • Complex: breads, cereal, crackers, flour, pasta
    • Simple: soft drinks, candy, fruit
  33. Fat soluble vitamins
    Vitamin A, D, E, K
  34. Vitamin A
    • Retinol
    • Photosensitive chemicals within the retina
    • Important to cell differentiation and is an antioxidant

    Deficiencies can cause night blindness and poor growth in children
  35. Antioxidants
    Protect biological molecules from the damaging effects of highly reactive oxidizing chemicals
  36. Vitamin D
    Required for the absorption of calcium from the intestines

    Deficiencies of this can produce rickets or osteomalacia
  37. Rickets
    • Caused from vitamin D deficiency
    • Poorly calcified weak bones in a child
  38. Osteomalacia
    • Vitamin D deficiency
    • Poorly calcified, weak bones in an adult
  39. Vitamin E
    • Antioxidant that protects cell membranes from oxidative chemicals
    • Role is very similar to that of the mineral selenium

    Deficiencies are rare, but can cause damage to RBC and neurons
  40. Vitamin K
    Important in the production of several biological molecules within the blood clotting pathways

    Deficiencies can lead to uncontrolled bleeding
  41. Normal intestinal flora can supply which vitamin?
    Vitamin K

    • Individuals that have lost their normal flora bc of antibiotic consumption are at a greater risk for vitamin K deficiency
    • Typically supplemented for newborn children
  42. Water soluble vitamins
    • B vitamins: folic acid and vitamin B12
    • Vitamin C
  43. Folic acid
    Needed for the production of DNA and RNA as well as the metabolism of certain amino acids

    Deficiencies have a significant impact on rapidly growing tissues; producing anemia and diarrhea and inflammation of the tongue
  44. Deficiency of folic acid during pregnancy
    • Can cause poor growth and neural tube defects for developing fetus
    • Certain contraceptives significantly reduce these levels and often takes several months after discontinued use before levels return to normal
  45. Vitamin B12
    • Involved in energy metabolism as well as amino acid synthesis
    • A deficiency in this can induce a folic acid deficiency
  46. Vitamin B12 deficiency
    Can cause anemia as well as degradation of the myelin sheath that surrounds neural axons
  47. Pernicious anemia
    Refers to vitamin B12 deficiency that results from a lack of intrinsic factor
  48. Biotin
    • Required for synthesis of glucose and fatty acids, as well as the metabolism of certain amino acids
    • Deficiency can result in nausea, dermatitis, hair loss, and lethargy
  49. Vitamin C (ascorbic acid)
    • Collection of biosynthetic rxns including the synth of collagen
    • Involved in immune function and has antioxidant effects
  50. Collagen
    Extracellular connective tissue fiber
  51. Scurvy
    • Deficiency of vitamin C 
    • Characterized by swollen joints, delayed wound healing, and bleeding gums
  52. Sodium
    • Primary extracellular electrolyte within the body
    • Imp to the production of AP by excitable cells and its profound osmotic effect
  53. Sodium deficits
    Alter the ability of neurons to produce AP leading to nervous system disturbances like lethargy, confusion, and coma
  54. Excess of sodium
    Lead to inappropriate distribution of water throughout the body causing dry mucus membranes, pulmonary edema, and convulsions
  55. Potassium
    • Primary intracellular electrolyte within the body
    • Like sodium, it is imp to the activity of excitable cells
  56. Potassium excesses and deficits
    Create disturbances in cardiac function by altering resting potential and action potential activity of the cardiac cells
  57. Calcium
    • Primary constituent of the inorganic component (calcium phosphate) of the bone
    • Responsible for giving bones rigidity and hardness
    • Used to regulate muscle cell contraction and secretion of many neurotransmitters and hormones
  58. Calcium deficits? excess?
    Can lead to over excitability of neuron and muscle cells

    Lead to lethargy, kidney stones, and deposits of calcium within soft tissue
  59. Iron
    Component of oxygen binding molecules such as hemoglobin (transports oxygen) and myoglobin (draws oxygen into the tissues)
  60. Iron deficiencies? excess?
    • Result in anemia
    • Children are at risk of iron deficiency during periods of exceptionally rapid growth bc of increased iron demand associated w/expanding blood volume
    • Menstruation also increases risk

    In high doses can damage the intestines and acid-base imbalances
  61. Iodine
    Essential component of the thyroid hormones
  62. Hypothyroidism
    Results from an iodine deficient diet that creates an abnormally low metabolic rate (causing lethargy and weight gain) and enlargement of thyroid (goiter)
  63. Basal Metabolic Rate
    • Amount of calories the body burns to stay alive
    • Measured by total heat produced by all work
    • Measured in kilocalories per sq. meter of body surface per hour (larger person burns more calories)
  64. How is BMR measured?
    Person lies in bed for 12 hours in a room set at 20 degrees C without stress
  65. Average BMR
    At 154 lbs= 60-72 Kcal/hr
  66. Factors that affect BMR
    • Age: younger person, higher BMR; older=lower bc muscle atrophy
    • Sex: metabolic rate is disproportionately higher in males; more muscles
    • Body surface area: larger=higher bc more heat loss 
    • Thyroxine levels: Higher TH=more heat created and energy burnt
  67. Factors that affect metabolic rate
    • Body temperature: lower body temp=lower MR
    • Activity: increase activity=increase MR
    • Stress: increase stress=increases MR
    • Thyroxine abnormalities: hyperthyroidism results in excess MR
  68. Ideal body weight
    • Doesn't exist
    • The avg weight given in insurance tables for person of a given height and sex
  69. Body mass index
    Estimates if you are a healthy weight bc overweight puts strain on heart and can lead to type 2 diabetes, hypertension, sleep apnea
  70. Hunger
    Physiological need to eat, decreased glucose, fat, amino acid in blood plasma
  71. Appetite
    Desire for food, a phycological phenomenon dependent on memory and associations
  72. Pica
    • Craving and eating substances not normally considered nutrients (clay)
    • Pregnant women experience this bc the body needs a nutrient causing a hormone imblance
  73. Hunger vs Appetite
    • Hunger:
    • builds gradually several hours after meal
    • goes away when full with feeling of satisfaction

    • Appetite: 
    • develops suddenly and is unrelated tot time
    • specific cravings with feelings of guilt
  74. Hypothalamus in food intake
    • Regulate hunger and satiety
    • Use negative feedback signals to regulate feeding behavior and hunger including: 
    • Thermoreceptors (more heat, more energy being used and replacement calories are needed)
    • Chemoreceptors (glucose, insulin)
  75. Regulation of food intake is based on
    Blood chemistry: plasma levels of glucose, amino acids, fatty acids provide info to adjust energy intake to energy output
  76. Blood levels of hormones
    Regulate plasma nutrient levels 

    • Include: 
    • Insulin
    • Glucagon
    • Epinephrine
    • Cholecystokinin (CCK)
    • Serotonin
    • Leptin
    • Ghrelin
  77. Insulin
    Released during food absorption, known to depress hunger and is a satiety signal (feel full or satisfied)
  78. Glucagon
    Levels rise during fasting and stimulate hunger bc blood sugar is low
  79. Epinephrine
    Triggers hunger (released during fasting) or low blood sugar
  80. Cholecystokinin (CCK)
    Intestinal hormone secreted during food digestion that depresses hunger
  81. Serotonin
    • Neurotransmitter that also delivers satiety signals
    • Excepts large amounts may signal hunger
  82. Leptin
    • Acts on the hypothalamus to cause a reduction in food intake, inhibits neuropeptide Y which makes you want to eat
    • Stimulates MR
  83. Ghrelin
    Peptide hormone synthesized and released by stomach

    • Functions:
    • Increase growth hormone release
    • Increase hunger

    Why kids eat more when they are growing bc GH is released at night
  84. Body temperature
    Colder climate = hungrier
  85. Neural factors that contribute to food intake
    • Gastric contractions
    • Oral cavity monitoring
    • Limbic system
    • Serotinin
    • NPY
  86. Gastric contractions that monitor food intake
    • Contractions of the stomach emptying activate hunger 
    • If stomach is full, you won't eat
  87. Oral cavity monitoring for food intake
    • Act of chewing/tasting activates the satiety centers
    • Eating is suppose to suppress eating
  88. Limbic system on eating
    Cultural factors, the environment, stress, and past experiences relative to the sight, smell and taste of food also effect food intake

    Seeing birthday cake=wanting to eat it
  89. Serotonin on hunger
    Neurotransmitter depresses hunger; except in high levels
  90. NPY in hunger
    Hypothalmic neurotransmitter that stimulates eating, released during exercise, fasting
  91. GI tract
    • Continuous, muscular digestive tube that extends from mouth to anus
    • Function: digest food chemically into its individual components (monomers) and then to absorb this components across the GI wall into the blood stream
  92. GI tract organs
    • Mouth
    • Pharynx
    • Esophagus
    • Stomach
    • Small and large intestine
  93. Accessory digestive organs
    Not part of the main tube, are essential for the digestion and absorption of nutrients from the GI tract
  94. Organs of the accessory digestive organs
    • Teeth
    • Liver
    • Salivary glands
    • Gallbladder
    • Tongue
    • Pancreas
  95. Oral cavity
    • Physical and chemical digestion (only carbs)
    • Taste, swallowing, and speech
  96. Mastication
    • Teeth bite off chunks of food and grind these chunks into smaller pieces in mastication (chewing)
    • Physical Digestion
  97. Salivary glands
    • Presence of food in mouth, smell of appealing food, or thinking about it can stimulate the parasympathetic salivary reflex to the salivary glands
    • Major glands are located outside the mouth (extrinsic salivary glands)
  98. Extrinsic salivary glands
    • Parotid, submandibular, and sublingual salivary glands
    • Contain salivary amylase
    • Avg production is 1000-1500 ml of saliva per day
  99. Salivary amylase
    Begins chemical digestion of carbohydrates into simplest form called monosaccharide and includes sucrose and glucose
  100. Bolus
    Ground up, lubricated food ball which is swallowed
  101. Deglutition
    Complicated process that involves the coordinated activity of the tongue, soft palate, pharynx, esophagus, etc
  102. 2 phases of swallowing
    • Voluntary: buccal phase (located in mouth)
    • Involuntary: pharyngeal and esophageal phase
  103. Voluntary buccal
    • When tongue pushes a bolus into the oropharynx 
    • Contraction of the tongue
  104. Involuntary pharyngeal/esophageal
    Controlled by the swallowing center located in the medulla and lower portion of the pons
  105. Two requirements that must be present to swallow
    • Presence of food in the oropharynx
    • Oropharynx has to be moist
  106. What happens when the requirements to swallow are met?
    • Peristalsis (wavelike contractions)
    • Uvula folds upwards to seal off the nasopharynx
    • Epiglottis folds downwards to seal off the opening into the larynx; prevents aspiration
    • Peristalsis pushes the bolus towards the stomach
    • Gastro-esophageal sphincter relaxes to allow food to enter the stomach
  107. Entire time for solid food passage3
    • 4-8 seconds
    • Fluids are 1-2 secs
  108. Gag reflex
    • Autonomic reflex from the medulla following the irritation of the uvula and posterior-most aspect of the tongue
    • Causes sudden but not prolonged reverse peristalsis
  109. Stomach
    • Large, multi-fold sac between two small diameter tubes, esophagus and small intestine
    • Stores food and imitates the chemical digestion of protein
    • Major digestive role of the stomach to store, mix and liquefy food
  110. Goblet cells
    Within the lining of the stomach to secrete mucus
  111. Gastric pits
    Leads into gastric glands which collective produce the stomach secretion called gastric juice
  112. Mucous neck cells
    Produce the mucus that protects the lining of the stomach from HCL and the development of an ulcer
  113. Ulcer
    Damage to the underlying tissues due to a breach to the mucosal barrier
  114. Parietal cells
    • Produce HCL and intrinsic factor
    • HCL activates pepsinogen to pepsin (which digests proteins)
    • HCL lowers the pH within the stomach preventing most microorganisms from living and growing in the stomach (kills bacteria ingested with food)
  115. Helicobactor pylori (H. pylori)
    • Acid-resistant bacteria which attaches to the epithelium and destroys the protective mucosal layer
    • Use antibiotics, traditional antiulcer drugs and busmuth or peptobismol to treat
  116. Intrinsic factor
    • Produced by parietal cells
    • Only stomach function essential to life
    • Needed for absorption of vitamin B12 in small intestine
    • Lack of this results in pernicious anemia
  117. Chief cells
    • These cells produce an inactive protease or enzyme called pepsinogen
    • Pepsinogen is activated to pepsin by HCL
    • Role of pepsin is to digest larger protein molecules into smaller ones to allow protein digestion in the stomach
  118. Regulation of gastric secretion/motility is controlled by:
    • Cephalic phase
    • Gastric phase
  119. Cephalic phase/Neural control
    • Achieved by both parasympathetic and sympathetic divisions
    • Initiated when receptors in the head are stimulated by sight, smell, taste, and chewing
    • Emotions can also initiate this
  120. Parasympathetic activation of the cephalic phase
    Stimulates gastric secretions and peristalsis and relaxes the pyloric sphincter for stomach emptying i.e receptive relaxation
  121. Receptive relaxation
    • The stomach is very small; 50ml when empty
    • But before the arrival of food, the stomach relaxes to allow as much as 1.5 liters of volume
  122. Sympathetic stimulation of the cephalic phase
    • Stimulation of the stomach causes a decrease in gastric secretion, peristalsis and motility
    • No digestion during exercise
  123. Gastric phase/Chemical or hormonal control
    • 4 types of stimuli in the stomach initiate the reflexes that constitute this regulation: 
    • Distension, acidity, amino acids and peptides formed during the digestion of ingested proteins
    • Hormone control of gastric activity is done by enterendocrine cells
  124. Hormones produced by enteroendocrine cells in the stomach
    • Gastrin
    • Somatostatin
    • Histamine
  125. Gastrin
    • Stimulates gastric secretions/peristalsis
    • Most pronounced effect is on HCL secretion
  126. Somatostatin
    Decreases gastric secretions/peristalsis
  127. Histamine
    • Produced in the wall of the stomach
    • Binds to the H2 receptors and stimulates gastric secretions
  128. Hormones produced by enteroendocrine cells in the intestine
    • Secretin: decrease gastric secretions
    • GIP (gastric inhibitory peptide): decrease peristalsis, decrease gastric secretions
    • CCK (cholecystokinin): decrease peristalsis, decrease gastric secretions
  129. Time for the stomach to empty
    • Empties completely within four hours after a meal (6 hours after a meal high in fats)
    • Larger the meal, the more liquefied the contents, the faster the stomach empties
  130. Pancreas
    • Accessory digestive organ
    • Produces broad spectrum of enzymes and secretions that breakdown all categories of food stuffs
    • Secretions are delivered to the small intestine for digestion (breakdown); proteins, carbs, fats digested by this
  131. Pancreatic juice
    Secretions are rich in bicarbonate and potassium ions
  132. Bicarbonate ions
    • Neutralize the hydrochloric acid in the chyme from the stomach
    • Severe diarrhea can cause metabolic acidosis due to the loss of this or hypokalemia due to the loss of potassium and dehydration due to the loss of water
  133. Pancreatic amylase
    • Does much of the starch digestion
    • Takes 10 mins after entering intestine to digest completely in maltose, then to monosaccharides
  134. Pancreatic Lipase
    • Does most of the fat digestion, breaking fat into its simplest components: fatty acids and glycerol 
    • Pancreas is the main source of fat digesting lipases
  135. Three different proteases or proteolytic enzymes
    • That digest proteins into amino acids:
    • Trypsinogen to trypsin
    • Chymotrypsinogen to chymotrypsin 
    • Procarboxypeptidase to carboxypeptidase

    • Activated to active form in small intestine so that the pancreas does not self-digest
    • Allow for complete protein digestion
  136. Liver and gallbladder
    • The liver and gallbladder are accessory digestive organs
    • Liver's digestive role is to produce bile for export to the duodenum
    • Gallbladder is a storage place for bile
  137. Bile
    Fat emulsifier; breaks a big piece of fat up into little pieces of fat so enzymes can digest it

    • Consists of:
    • Bile salts
    • Bile pigments
    • Cholesterol
  138. Regulation of bile release
    • Bile doesn't enter the small intestine until the gallbladder contracts
    • Presence of acidic fatty chyme within the duodenum stimulates the small intestine to release cholecystokinin (CCK)
  139. CCK acts to
    • Stimulate the gallbladder to contract
    • Stimulate pancreatic secretions
    • Relaxes the hepatopancreatic sphincter
  140. Bile salts
    • Role is to decrease the surface tension that hold lipids into large droplets
    • This allows the large droplets to break apart into many small droplets
  141. Bile pigments
    • Main pigment is bilirubin
    • Bilirubin is a waste product of the heme portion of hemoglobin formed during breakdown of the worn out RBCs
    • More water soluble coating so enzymes can act on it
  142. Cholesterol
    Role is to help in the formation of micelles so we can absorb fat breakdown products
  143. Small intestine enzymes
    • Intestinal lipase
    • Intestinal disaccharases
    • Intestinal proteases
  144. Intestinal lipase
    • Not as active as pancreatic lipase but not necessary to digest fats
    • Will digest fats
  145. Intestinal disaccharases
    • Sucrase: digests disaccharide sucrose into glucose/fructose
    • Maltase: digest maltose into two glucose
    • Lactase: digests lactose into glucose and galactose (lactaid)
  146. Intestinal proteases
    Aminopeptidase/Dipeptidase: both of these speed up the process of protein digestion into amino acids
  147. Transepithelial transport
    Movement of small molecules through the epithelial cells that line the mucosa of the intestine and enter either blood capillaries or lymphatic capillaries
  148. Small intestine absorption
    • 80% of all food are absorbed, electrolytes, and water are absorbed in the small intestine
    • Completed by the ileum which reclaims some bile salts
  149. Protein and carbohydrate absorption
    Monosaccharides such as glucose/amino acids are absorbed by a combination of active transport, facilitated diffusion and diffusion into the blood capillaries
  150. Micelle
    • Needed to absorb fat
    • Collection of fatty acids, monoglycerides, bile salts, cholesterol, lecithin (phospholipid found in bile and fat soluble vitamins (A, D, E, K) clustered together in such a way that the hydrophilic ends face the water and phobic portions form the micelle core so it doesn't reform into a large droplet
    • Can diffuse into the cell rather than "ride the wave" out of the body
  151. Triglycerides
    • Most American caloric intake is in this form
    • Molecule consisting of a monoglyceride + two fatty acids
    • Commonly stored in fat cells
  152. Chylomicrons
    Triglycerides combined w/phospholipids and cholesterol and coated with a "skin" of proteins to form this water soluble lipoprotein
  153. What happens when chylomicrons leave the cell by exocytosis?
    • Enter the lymphatic capillaries (lacteals)
    • Transported to the liver via blood stream
    • Converted to various lipoproteins that are transported in the blood including HDL and LDL cholesterol
  154. HDL
    • High density lipoprotein
    • Transports cholesterol from the peripheral tissues to the liver where it is broken down and made into bile 
    • Good fats from nuts and seeds
  155. LDL
    • Low density lipoprotein
    • Leads to cholesterol plaques and coronary artery disease 
    • Bad cholesterol
  156. Major function of the large intestine
    Eliminate indigestible food and absorb water
  157. Entering large intestine
    • Material that was not absorbed in the small intestine pass through the ileocecal sphincter
    • Materials contain few nutrients, still has 12-24 hours to spend there 
    • No further breakdown occurs in the large intestine
  158. Gastrocolic reflex
    • Movement of food into the stomach stimulates mass peristalsis in the colon
    • This pushes the contents of the colon toward the rectum

    Bulk or fiber, in the diet increases the strength of colon contractions and softens the stool
  159. Defecation reflex
    • Rectum is generally empty, but when feces are forced into it by mass movements stretching of the rectal wall initiates the defecation reflex
    • Spinal cord mediated parasympathetic reflex that causes the walls of the sigmoid colon and the rectum to contract
    • Causes relaxation of the inner and external anal sphincters
  160. Inhibition of defecation reflex
    If defecation is delayed, the reflex contractions end within a few seconds and rectal walls relax
  161. Facilitation of defecation reflex
    • During defecation, the muscles of the rectum contract to expel the feces
    • Relax external anal sphincter
    • Valsalvas maneuver involved
  162. Valsalvas maneuver
    • Aid defecation by voluntarily closing the glottis and contracting diaphragm and abdominal wall muscles to increase the intra-abdominal pressure
    • Levator ani muscle also contracts and pulls the anal canal superiorly, leaving feces below the anus and outside of the body
  163. Function of large intestine
    • Absorb water and electrolytes
    • Vitamin K and B complex vitamins synthesized by the bacterial flora in the GI tract
    • Releases some potassium as well
  164. Feces
    • After absorption and secretion, the material remaining within the lumen of the colon 
    • Of the 500 ml of the food entering in the cecum daily, 150 ml becomes feces
  165. Normal color of feces
    Due to the metabolite of bilirubin called urobilinogen (brown) bile pigment which is waste product of heme
Card Set
Physiology 4 (pt 2)