Nutrition 251 FINAL EXAM STUDY QUESTIONS The cumulative section of the final exam will include 25 multiple choice or true false questions based on the list of study questions and concepts below The exam will also have 50 questions on new material water major minerals trace minerals and pregnancy lactation for a total of 75 questions worth 150 points total Water and Major Minerals Chapter 12 Water 1 List the components of water intake for a typical adult In liters day and in ml kcal what is the typical water recommendation for college students who are not in sports 1 General public 1 0 1 5 liters 1000 calories 1 3 from food 2 3 from beverages Athletes 2 3 cups fluid before event 1 cup during every 15 minutes 2 Based on 2000 calorie diet you need 2 3 liters a day 8 12 cups of fluids 3 Intake Water created by metabolism 200 300ml Food 700 1 000 Water or Beverages 550 1 500 Intake 1 450 2 800 ml 2 Define obligatory water loss what is the minimum loss 1 Obligatory water loss smallest volume of waste to get rid of per day as a minimum 500ml 3 Define extracellular water and intracellular water Where is interstitial fluid Name the major electrolytes in the extracellular and intracellular compartments of the body 1 Extracellular fluid in blood vessels and interstitial fluid in the blood vessel and between the cells 2 3 4 Intracellular fluid in the cell in the cells Interstitial fluid extracellular fluid that surrounds each cell Cations Sodium potassium calcium and magnesium 5 Anion chloride bicarbonate phosphate sulfate organic acids and proteins 4 Describe the basic principle of osmosis which explains why fluids are maintained in these compartments 1 The movement of water across a membrane toward the more concentrated solutes is called osmosis 2 Water can flow both ways across the divider but has a greater tendency to move from side A to B where there is a greater concentration of solute The volume of water becomes greater on side B and the concentrations on side A and B become equal 3 Examples of solutes glucose in gut sodium in blood 4 Water can redistribute to the side of more concentration of solute 5 Describe the basic regulation of body water at the level of the nephron filtration reabsorption and excretion 1 The kidney maintains water balance with direction from the hypothalamus along with hormones which control electrolyte and water movement across kidney tubule membranes 2 Filtration blood flowing through capillaries is filtered by the glomerulus Electrolytes water and urea are filtered into the tubules of the nephron For adults about 180 liters of water are filtered each day 3 Reabsorption as needed water and electrolytes are reabsorbed back into the blood by the actions of osmosis and membrane pumps Usually 99 of water is reabsorbed Hormones regulate membrane pumps capable of electrolyte reabsorption and water reabsorption 4 Excretion excess water urea and electrolytes travel through the nephron tubules to the bladder and are excreted via urine 5 Blood to kidney enters kidney glomerulus process of filtration 1 Then nephron tubule to reabsorption depend on hormones into blood and send back or is it okay to excrete critical step 2 Then excretion 3 6 If you are very thirsty what hormone is elevated that regulates water balance Explain the hormonal regulatory process when blood sodium level is low ie could also result in low blood pressure What happens to sodium and water in the kidney tubules during this process 1 Thirst conscious desire to drink Regulated by mouth hypothalamus and nerves Hypothalamus controls water balance body temperature and appetite 2 Both the hypothalamus and pituitary gland of the brain is involved in water balance 3 Regulation of blood volume and blood pressure is dependent on fluid balance 1 Hypothalamus signals the pituitary gland to release ADH antidiuretic hormone stimulates kidneys to reabsorb 2 Renin is an enzyme released from kidneys reabsorbs Na and retains H2O also hydrolyzes a protein from the H2O liver angiotensinogen 3 Angioteninogen Angiotensin I inactive form and II constricts blood vessels signals release of aldosterone from adrenal glands signals release of ADH from pituitary glands retain more water 4 Aldosterone from adrenal gland signals kidneys to retain Na increases blood volume and excrete potassium causes vessels to constrict 4 Whenever blood volume or blood pressure falls too low or whenever the extracellular fluid becomes too concentrated the hypothalamus signals the pituitary gland to release antidiuretic hormone ADH ADH is a water conserving hormone that stimulates the kidneys to reabsorb water Consequently the more water you need the less your kidneys excrete These events also trigger thirst Drinking water and retaining fluids raise the blood volume and dilute the concentrated fluids thus helping to restore homeostasis 5 Renin cells in the kidneys respond to low blood pressure by releasing an enzyme called renin Through a complex series of events renin causes the kidneys to reabsorb sodium Sodium reabsorption in turn is always accompanied by water retention which helps to raise blood volume and blood pressure Na K 1 Besides its role in water balance what are other essential functions of sodium 1 In addition to its role as an electrolyte in maintaining water and acid base balance sodium functions in nerve impulse transmission and muscle contraction 2 Sodium is the principal cation of the extracellular fluid and the primary regulator of its volume 2 List the sodium AI UL and DV Tony is a typical American and consumes about 7 grams of sodium each day Even though you do not know his dietary practices make some suggestions as to how he may lower his intake to closer to the UL If Tony were to sprinkle teaspoon of salt on his corn on the cob how much sodium would he be adding to his meal 1 The dietary guidelines recommend a diet moderate in salt and sodium and thus recommends less than 2300 mg of sodium day UL 2 Al for sodium is 1500 mg 1 teaspoon salt 2300 mg Na DV 2400mg 3 4 5 6 teaspoon 1150mg 3 Explain what it means to be salt sensitive Lower his intake 6g 1 tsp 2300mg so he is over the mark select fresh unprocessed foods cook with little or no added salt use sodium free read labels 1 A characteristic of individuals who respond to a high salt intake with an increase in blood pressure or to a low salt intake with a decrease in blood pressure Opposite of what it normally is 4 Besides sodium what other minerals may affect blood