Exam 3

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  1. Why is nutrition important? (4 main things)
    • DNA expression
    • organ function
    • body homeostasis
    • cell physiology---> disease
  2. What is the energy balance equation?
    Energy in = energy out + stored energy
  3. Where does 'energy in' come from?
    our diet
  4. Where does 'energy out' go?
    to keeping us alive
  5. Where does 'stored energy' go?
    stored as fat
  6. Explain a positive energy storage.
    when you eat more than you need/use, you store excess energy
  7. Explain a negative energy storage.
    When you expend more energy than you take in, you deplete your energy stores
  8. Every gram of carbohydrates provides how many kJ of energy?
  9. Every gram of protein provides how many kJ of energy?
  10. Every gram of fat provides how many kJ of energy?
  11. Every gram of alcohol provides how many kJ of energy?
  12. What is the energy ratio for a balanced diet?
    • 55% carbs
    • 30% fats
    • 15% protein
  13. What is the best source of expendible energy?
  14. Energy 'out' goes to what 3 main things?
    • RMR (resting metabolic rate)
    • thermic effect of feeding
    • physical activity
  15. What is RMR?
    the minimum amount of energy required to do unconscious things
  16. ______ is relatively constant for the same individual?
  17. ________ is highly variable among individuals?
  18. What 4 variables is RMR based on?
    • fat free mass
    • age
    • gender
    • physical activity
  19. What is thermic effect of feeding?
    • 10% of energy that we ingest is used to digest what we ate
    • effect of heat can last up to 5 hours
    • higher for proteins and carbs rather than fats because they have to be broken down
  20. ______ is a multiple of RMR?
    MET (metabolic equivalent)
  21. What is physical activity measured in?
    • metabolic equivalent (MET)
    • the higher the MET, the more energy is being expended
  22. What is PAL (physical activity level)?
    the ratio of total energy expenditure to RMR
  23. What is the average person's total daily energy expenditure?
    10 MJ
  24. What is the average person's PAL? And how do you get that?
    • 1.6
    • total daily energy expenditure divided by RMR (10/6)=1.6
  25. What are the typical amounts of energy a person burns per day in all 3 categories of RMR, thermic effect of feeding and physical activity?
    • RMR= 6 MJ/day
    • thermic effect= 2 MJ/day
    • physical activity (no exercise)= 2 MJ/day
  26. How do we maintain body mass homeostasis?
    when energy in= energy out
  27. What are the 3 types of carbohydrates?
    • sugars (mono and disaccharides)
    • oligosaccharides
    • polysaccharides
  28. What are all the different types of sugars (carbs)?
    • glucose
    • sucrose
    • lactose
    • maltose
    • fructose
    • galactose
  29. What are oligosaccharides?
    • chains of 3-9 sugars (carbohydrate)
    • ex: maltodextrins (a glucose polymer produced from corn and potatoes)
  30. What are polysaccharides?
    • many sugars in a chain (carbs)
    • ex: starch, cellulose
  31. _______ is a long polymer of alpha-glucose?
  32. ______ is a long polymer of beta-glucose?
  33. ________ are an excellent source of energy and you don't have large stores, so eating them is critical for energy homeostasis?
  34. The avg. adult needs to eat about _____ g/kg body mass per day of _______?
    • 4
    • carbs
  35. How many days does the average person have worth of stored carbs?
    1.5 days (not very much)
  36. Where are most of the stored carbs found in our bodies?
    as glycogen in the liver
  37. What are the 4 main reasons why we need carbs in our diet?
    • energy homeostasis
    • they form the carbon skeletons of amino acids like DNA and RNA
    • they form glycoproteins (mucins, antibodies, clotting factors)
    • they form proteoglycans (the junk b/w our cells)
  38. What is glycemic index?
    it tells us how quickly a food enters the blood in the form of glucose
  39. What can be caused by a problem with carb homeostasis?
    • diabetes mellitus
    • hypoglycemia
  40. White bread, potatoes and rice cakes have a ____ glycemic index?
  41. What are the different ways that carbs are stored in our bodies?
    • in the liver as glycogen
    • in the muscle as glycogen
    • in the body fluids and blood as glucose
  42. ______ have the highest energy content of the macronutrients, so are excellent for long-term energy storage?
  43. _____ are critical for the formation of hormones?
  44. How are lipids transported through the body?
    by lipoproteins
  45. What is a lipoprotein?
    • a clump of lipids with apolipoproteins embedded
    • carries lipids through the body
  46. How are lipoproteins classified?
    by their density and the type of apolipoprotein
  47. what are the 4 types of lipoproteins? ordered from lowest density to highest
    • chylomicrons
    • VLDL (very low density)
    • LDL (low density)
    • HDL (high density)
  48. T/F: chylomicrons have the highest density of all the lipoproteins.
    false; lowest
  49. What type of lipoprotein is made in the intestine?
  50. _______ are short lived lipoproteins in the blood (15-30 minutes)?
  51. ______ are critical for transporting vit A, D, E and K to the liver?
  52. ________ transport lipids from food to the blood and liver?
  53. _____ are lipoproteins made in the liver?
  54. _________ transport fatty acids from the liver to heart, muscle and adipose tissue?
  55. ______ are primarily composed of cholesterol?
  56. ______ transport cholesterol to the liver and other tissues?
  57. What is the "worst" type of lipoprotein to have a lot of?
  58. ___________ are made in the intestine and liver?
  59. _______ transport cholesterol from the tissues back to the liver where it is stored?
  60. Which are worse, LDLs or HDLs?
  61. What are the 4 different kinds of fatty acids?
    • polyunsaturated
    • monounsaturated
    • saturated
    • trans-fats
  62. Which type of fatty acid has no double bonds?
  63. Which type of fatty acid has 1 double bond?
  64. Which type of fatty acid has 2 or more double bonds?
  65. Which type of fatty acid is unsaturated but behaves like a saturated fat?
  66. Which type of fatty acid is manufactured by hydrogenation?
  67. Which fatty acids cause an increase in risk for coronary heart disease?
    trans-fats = bad!
  68. T/F: Non-essential fatty acids cannot be made by the body.
    false; can be made by the body
  69. T/F: Non-essential fatty acids are not essential.
  70. T/F: essential fatty acids cannot be made by the body.
  71. What are some good sources of essential fatty acids?
    • omega 6 (linoleic acid)
    • omega 3 (alpha linoleic acid)
  72. Where can we get omega 6 fatty acids in our diet?
    vegetable oil
  73. Where can we get omega 3 fatty acids in our diet?
    • salmon
    • flax
  74. Which fatty acid is stimulated by insulin?
    non-essential (ones that are made in the body)
  75. How are non-essential fatty acids made in the body?
    by lipogenesis in the liver
  76. What do the 3 and the 6 in omega 3 and omega 6 tell us about the molecule?
    where the double bond is located
  77. T/F: saturated fats cause an increase in both HDL and LDL.
  78. Which are better, cis or trans monounsaturated fats?
    • cis
    • cause a slight decrease in LDL and increase HDLs
  79. Which 2 types of fat cause a huge increase in LDLs and also increase obesity?
    • saturated fats
    • trans monounsaturated fats
  80. Most of our fat intake should come from _______ fats?
  81. ______ should make up about 30% of our total daily energy intake?
  82. Why do we need lipids in our diet?
    • energy storage
    • membrane fluidity
    • to build other molecules like hormones, cholesterol, vitamin E, vitamin D
  83. How much of our protein is found in muscle?
  84. How much of our protein is found in our skin?
  85. How much or our protein is found in the blood?
  86. ~50% of all the protein mass in our body comes from what 4 proteins?
    • collagen
    • actin
    • myosin
    • hemoglobin
  87. How much ATP is consumed just by turning over protein daily?
  88. How much protein do we break down and synthesize in a day?
    ~500 g
  89. What is cereal a good source of?
  90. T/F: animal product is a good source of methionine, lysine, threonine, and tryptophan.
  91. T/F: Legumes are a good source of methionine.
  92. T/F: Cereals are a good source of lysine.
  93. T/F: Cereals are a good source of tryptophan.
  94. T/F: cereals are a good source of threonine.
  95. When do body fat % and BMI tell you different things?
    if you have a lot of muscle mass, you could weigh a lot but not be overweight/have a high BMI
  96. What is BMI?
    • body mass index
    • weight/height2
  97. What BMI tells us that you might be overweight?
    > than 25
  98. T/F: in general, women have higher essential fat and total fat contents.
  99. What is the typical essential fat % for women and the total fat % for women?
    • essential fat= 10-12%
    • total fat= less than 30%
  100. what is the typical essential fat % for men and the total fat % for men?
    • essential = 2-4%
    • total fat = less than 20%
  101. What are the 5 different classifications of fats?
    • sterols
    • triglycerides
    • non-essential fa
    • essential fa
    • phospholipids
  102. _________ are lipids combined with proteins (to make them miscible in water) that transport fats through the body?
  103. What 3 amino acids can everyone make in their body (dispensable)?
    • glutamic acid
    • alanine
    • aspartic acid
  104. What does indespensable mean?
    our bodies cannot make, we need to get from our diet
  105. What are the main indespensable amino acids that Dillon wanted us to focus on?
    • threonine
    • methionine
    • tryptophan
    • lysine
  106. Rank foods in terms of their quality of indespensable amino acids.
    animal protein > legumes > cereals > tubers
  107. Where do we find methionine?
    • cereals
    • also high in sesame seeds
  108. Where would you not find methionine?
  109. For mice on unrestricted diets, methionine ________ lifespan?
  110. For flies on restricted diets, methionine _________ lifespan without reducing reproduction?
  111. Reducing ______ without compromising ______ increases lifespan in yeast, worms, flies, rodents, and maybe primates?
    calories; nutritional content
  112. What are some reasons why a caloric restriction might increase lifespan?
    • possible low level of stress on the body
    • efficiency of metabolism and free radicals
    • reproduction vs. survival tradeoff
  113. What is found in red wine that might be a life extender?
  114. __________ alone restores fecudity without reducing lifespan?
  115. Where would you find high amounts of lysine?
    • legumes
    • L= L
  116. Where would you not find lysine?
    essentially absent from cereals, rice, wheat, corn
  117. Where would you find threonine?
    • cottage cheese
    • animal products
    • legumes
    • sesame seeds
  118. Where would you not find threonine?
  119. Where would you not find tryptophan?
  120. Where would you find tryptophan?
    • cottage cheese
    • animal products
    • legumes
    • sesame seeds
  121. Which indespensable amino acid is a precursor for serotonin- melatonin synthesis?
  122. Why are worldly cuisines generally protein complete?
    • they have legumes and cereals together in one dish
    • (rice + beans) even if there is no meat
  123. What is marasmus?
    • severe energy deficiency
    • not enough protein overall
  124. What do peole with marasmus look like?
    emaciated and wasted
  125. Where do people with marasmus generally live?
    • in countries where there is little or no animal protein
    • ex: India, Zimbabwe, Nigeria
  126. What is Kwashiorkor?
    wasting with edema (swelling)
  127. T/F: In Kwashiorkor, the person gets plenty of protein, but it is not the right kind.
  128. What causes the edema seen in Kwashiorkor?
    • Aflatoxins
    • they are found in warm, humid tropical environments and are produced by molds
    • these aflatoxins cause liver damage, which causes low albumin levels, which keeps water in your blood, which causes edema (water leakage into tissues)
  129. ______was originally thought to be caused only by a deficiency or protein, but now it is thought to be related to alflatoxins/molds also?
  130. After water, what is the major constituent of our body?
  131. What part of our body is made of myosin and actin?
  132. What part of our body is made up of collagen?
    skin, hair, nails
  133. What part of our body is made of hemoglobin?
  134. What are the 2 main causes of Kwashiorkor?
    • micronutrients
    • aflatoxins
  135. What is a maladaptive diet syndrome?
    • a
    • disease of nutritional excess

    1. What are some examples of maladaptive diet syndromes?

        • obesity
        • (too much fat, sugar)

        • Coronary
        • heart disease (CHD) (too much fat, salt)

        • type
        • 2 diabetes (too much sugar, fat)

        • hypertension
        • (too much salt, fat)

        • alcoholism
        • (too much alcohol)

  136. Where does vitamin A come from?
    plants and animal foods
  137. ____ ______ is a precursor for vitamin A?
    beta carotene
  138. What precursor for vitamin A comes from plants?
    beta carotene
  139. What precursors of vitamin A come from animal foods?
    • retinol
    • retinoic acid
    • retinal
  140. What vitamin is stored in the liver then transported by albumin to our tissues?
    vitamin A
  141. Liver is a good source of vitamin ____?
  142. Which molecule is converted to retinal and retinoic acid?
  143. T/F: retinal can be converted back to retinol.
  144. T/F: Beta carotene can be converted to either retinoic acid or retinol.
  145. T/F: retinoic acid can be converted back to retinol.
  146. Vitamin A is stored in the liver as ____ ______?
    retinyl palmitate (retinol + palmitic acid)
  147. About how much of a supply of retinol do you have in your liver?
    1 year's supply
  148. T/F: our body can use retinal and retinoic acid.
  149. What is retinoic acid important for in our bodies?
    • critical cofactor for DNA transcription
    • needed for fast growth tissues like epithelial tissue and HOX genes
  150. ______ is a critical regulator of gene expression?
    retinoic acid (vit A)
  151. Low _______ causes cells to secrete keratin instead of mucous?
    retinoic acid (vit A)
  152. What can low retinoic acid levels cause?
    • intestinal problems
    • respiratory problems
    • dry eye (xeropthalmia)
  153. Which ones need the most vitamin A, rods or cones?
    • rods need more
    • rod= rhodopsin= retinal
  154. What is rhodopsin made of?
    opsin + 11-cis retinal
  155. 11-cis retinal + light = ?
    all trans retinal
  156. all-trans retinal + enzymes = ?
    11-cis retinal
  157. What will happen if you don't have enough 11-cis retinal (and precursor of vit A)?
    you won't have night vision
  158. A deficiency in Vitamin A will cause what 3 major problems?
    • night blindness (reduced retinal = reduced turnover of rhodopsin)
    • keratinization (reduced retinoic acid)
    • -respiratory infections, xerophthalmia (dry eye)
    • cell-differentiation problems (fertility and developmental problems)
  159. Why do we need Vitamin D?
    to keep our blood Calcium levels up
  160. What is Ricket's?
    • a lack of vitamin D growing up
    • affects children
    • reduced calcification of growing bones
  161. What is osteomalacia?
    • in adults
    • a reduction in bone density
    • not absorbing enough calcium from diet
  162. The receptors for what vitamin are found in immune cells?
    vitamin D
  163. Vitamin D actively upregulates what system?
    immune system
  164. There is a link between vitamin D deficiency and what disease?
  165. Why might flu season be in winter months?
    because we don't get enough vitamin D in the winter and vitamin D upregulates our immune system
  166. What is another name for vitamin E?
  167. What is a good source of Vitamin E?
    nuts and oils
  168. What value is vitamin E mostly known for?
    its an antioxidant!
  169. Vitamin __ is a fat-soluble antioxidant found mostly in cell membranes?
  170. What 2 vitamins are good at getting rid of free radicals?
    vitamin C and E
  171. What does Vitamin E do to free radicals that are attached to fatty acids from our cell membranes?
    it binds with free radicals making the free fatty acid
  172. T/F: after vitamin E attaches to a free radical, the free radical cannot leave and continue damage.
  173. How do you remove a free radical from vitamin E?
    with vitamin C
  174. T/F: vitamin E can attach 2 free radicals at once.
  175. What vitamin do you need in order to make Gla (gamma carboxylic acid)?
  176. What 2 things do you need to convert glutamic acid to gamma carboxylic acid (Glu --> Gla) ?
    • vitamin K
    • carboxylase
  177. In general, what is vitamin K most important for?
  178. _____ is critical for clotting factors, allowing them to bind phospholipids in the presence of calcium?
    Gla (gamma carboxylic acid) which comes from vitamin K
  179. Where do we find vitamin K in our diet?
    • kale
    • green vegetables
  180. What vitamin can also be synthesized by bacteria in the large intestine?
  181. T/F: vitamin K can be stored in our bodies.
    false; not stored!
  182. Which vitamin deficiency is apparent within 48 hours?
    vitamin K
  183. If a newborn doesn't receive a vitamin K shot following birth, what could happen?
    profuse bleeding because no clotting factors
  184. What vitamin do newborns need a shot of immediately following birth and why?
    • vitamin K
    • because it is fat soluble and cannot cross the placenta in utero
  185. What vitamin might be linked to osteoporosis (not vitamin D)?
    vitamin K
  186. What is the only B vitamin that can be stored?
  187. T/F: B vitamins are fat-soluble.
    false; water-soluble!
  188. T/F: B vitamins must be eaten daily.
  189. Which vitamins are known as cofactors and coenzymes?
    B-complexes (B1, B3, B6, B12, folic acid)
  190. What are some good sources of vitamin B complex?
    • cereal
    • animal products
  191. Which vitamin is a constituent of FAD (a critical electron donor/acceptor)?
    • vitamin B2 (riboflavin)
    • F= riboFlavin
  192. What is another name for vitamin B2?
  193. What will a deficiency in riboflavin (B2) look like?
    • it will affect fast-growing tissues (skin and mouth)
    • will affect DNA transcription and replication
  194. Where can you find riboflavin (B2)?
    • animal products
    • green, leafy veggies
  195. too much of what vitamin can cause you to be flushed?
    niacin (B3)
  196. About how much niacin (B3) do you need per day?
    ~20 mg
  197. Which vitamin can be made from tryptophan in the presence of vitamin B6?
    niacin (B3)
  198. What is another name for vitamin B3?
  199. Which vitamin is a constituent of NAD (ATP production)?
    • niacin (B3)
    • N=Niacin
  200. High corn diets are associated with what disease and what deficiency?
    • pellagra
    • low niacin, deficiency in tryptophan
  201. How do you treat pellagra?
    with vitamin supplements (niacin)
  202. what is pellagra?
    • diarrhea
    • dermatitis
    • dementia
    • associated with low B3 (niacin) and deficiency in tryptophan
  203. Pellagra is associated with high _____ diets?
  204. Which vitamin is a cofactor necessary for heme, neurotransmitters, and niacin?
    vitamin B6
  205. What is another name for vitamin B6?
    trick! no other name given in notes :0
  206. A deficiency in vitamin ___ might cause depression or anxiety?
  207. A deficiency in vitamin ___ might cause anemia?
  208. A deficiency in vitamin ___ might cause pellagra?
    B6 (or technically B3 too)
  209. What vitamin is a necessary cofactor for carb metabolism?
    vitamin B1 (thiamine)
  210. What are the 2 main bad results coming from a deficiency in B1 (thiamine)?
    • cardiac problems
    • nervous system problems
  211. What are the 3 diseases associated with a deficiency in B1 (thiamine)?
    • Wernicke's-Korsakoff's syndrome
    • Dry beriberi
    • Wet beriberi
  212. What disease is marked by a buildup of metabolism byproducts, encephalopathy, high carbs, and poor nutrition?
  213. What disease is marked by extensive sensory and motor neural deficits due to damage of peripheral nerves?
    Dry beriberi
  214. A person needs crutches, has wrist and ankle drop and a loss of sensation due to nervous system damage. What disease do they have and what are they deficient in?
    • dry beriberi
    • deficient in B1 (thiamine)
  215. What is another name for vitamin B1?
  216. A person has an increased heart rate, increased cardiac output, reduced peripheral resistance, and peripheral edema caused by heart failure. What disease do they have and what are they deficient in?
    • Wet beriberi (wet = heart or wet= edema)
    • B1 (thiamine)
  217. What are the signs of wet beriberi?
    • reduced ATP available for heart function
    • peripheral edema caused by heart failure
    • increased CO and HR
  218. Even if you get enough of this vitamin in your diet, if you damage your stomach you will have a deficiency. What vitamin?
  219. T/F: folic acid is stored in our bodies.
  220. T/F: Vitamin B12 is stored in our bodies.
  221. Where is B12 stored in our bodies and how long will our store last us?
    • liver
    • 3 year supply
  222. What cofactor in the stomach is required to absorb vitamin B12?
    IF (intrinsic factor)
  223. What two vitamins are critical for the synthesis of nucleotides and tend to effect rapidly dividing tissues (like in pregnancy)?
    • B12
    • folic acid
  224. Which B vitamin is key for myelin synthesis?
  225. Deficiencies in what 2 vitamins can cause spinal cord degeneration and macrocytic anemia (reduced stem cell division)?
    • B12
    • folic acid
  226. Which vitamin has the most broad scale effects?
    vitamin C
  227. T/F: humans can make vitamin C.
  228. A deficiency in what vitamin will cause scurvy?
  229. What is scurvy?
    • reduced synthesis of collagen and elastin
    • bone fractures
    • edema
    • infections
    • poor wound healing
  230. T/F: all animals except guinea pigs, elephants, and primates can make vitamin C.
  231. Why can we not make vitamin C?
    we lack glucose oxidase enzyme
  232. Which vitamin is a reducing agent (electron donor) and reactivates numerous enzymes?
  233. T/F: vitamin C is an electron donor.
  234. T/F: free iron is toxic.
  235. T/F: iron is a potent generator of free radicals.
  236. What molecule moves iron molecules around the body?
  237. T/F: apoferritin is attached to iron.
  238. _____ lacks iron?
  239. T/F: ferritin does not contain iron
  240. What do you get when iron attaches to apoferritin?
  241. T/F: ferritin transports iron throughout our body.
    false; transferrin
  242. T/F: women are often colder than men.
  243. T/F: in general, everyone is warmer in the morning and colder in the afternoon.
    false; colder in the a.m., warmer in the p.m.
  244. T/F: women in the follicular phase and men are usually colder than women in the luteal phase or on contraceptives.
  245. T/F: early birds tend to have a warmer overall temperature.
  246. T/F: night owls tend to have a warmer overall temperature.
  247. Maintenance of ____ ______ within a ______ range is critical for the functions of proteins in the body?
    • body temperatures
    • narrow
  248. What variables are our body temperatures dependent on?
    • gender
    • time of day
    • reproductive cycle
    • night owl vs. early bird
  249. What are the two temps that if we fall below or above will cause serious damage or be fatal?
    • below 25 C
    • above 41 C
  250. What one thing do we gain heat by?
  251. What one thing do we lose heat by?
  252. What three things can we either lose or gain heat by?
    • conduction
    • convection
    • radiation
  253. How efficient are we at heat exchange regarding metabolism?
    only 20%
  254. How much of the energy that burn is converted to heat that is lost?
    80% (inefficient)
  255. While at rest, where does most of our heat production come from?
    our trunk viscera
  256. While exercising, where does most of our heat production come from?
    muscle and skin
  257. T/F: RMR is greater for males than females.
  258. T/F: As you age, your RMR decreases.
  259. T/F: At birth, you have a very low RMR.
    false; very high
  260. T/F: thermic effect of feeding causes a 20% increase in metabolic rate.
    false; 10%
  261. T/F: a male cyclist has a much higher sustained metabolic rate than a female scientist.
  262. What is shivering thermogenesis?
    activating our muscles to generate heat
  263. About how long can we continue shivering?
    ~2 hours
  264. How much can shivering thermogenesis increase our RMR?
    about 3-10 times normal RMR (a lot, but only for short periods)
  265. What is nonshivering thermogenesis?
    • aka futile cycling
    • use of uncoupling proteins to generate heat in the cells
  266. T/F: fatty acids and glucose can be used by UCP to generate heat.
  267. Uncoupling proteins are an alternate route for ______?
    H+ ions
  268. Instead of generating ____, UCPs generate heat.
  269. ____ ____ allow protons to 'leak' from the intermembrane space to the mitochondrial matrix, releasing the energy stored in the gradient as heat?
    Uncoupling proteins
  270. Where is the only place that UCP1 is found?
    BAT (brown adipose tissue)
  271. How many different UCPs do we know of ?
  272. Where is UCP2 found?
    • BAT
    • WAT
    • heart
    • skeletal muscle
    • beta cells
  273. T/F: higher UCP2 expression in beta cells causes an increase in insulin release.
    false; a decrease
  274. In a beta cell, UCP2 is upregulated by what?
    reactive oxygen species
  275. In a beta cell, instead of creating lots of ATP to trigger insulin release, the cell instead makes lots of ROS, which leads to a risk for?
    type 2 diabetes
  276. What are the possible functions of UCP3, 4 and 5?
    • obesity
    • ROS removal
    • temp regulation
    • neuronal function
    • regulates glucose vs. fatty acid oxidation
  277. Our metabolic contribution to heat production depends on what 5 things?
    • non-shivering thermogenesis
    • shivering thermogenesis
    • RMR (size, gender, age, time of day, repro cycle, early bird vs. night owl)
    • thermic effect of feeding
    • physical activity
  278. What unit do we express metabolic rate as?
    • "B" in the equation
    • (W/m2)
  279. What is the equation for metabolic heat production?
    • 0.8*B*S
    • (1-efficiency * metabolic rate in W/m2 * surface area in m2)
  280. Our change in body temp depends on what 5 processes?
    • metabolism
    • evaporation
    • conduction
    • convection
    • radiation
  281. Where can you find brown adipose tissue (BAT)?
    • babies
    • hibernating animals
  282. Evaporative heat loss (sweat) depends only on the difference in ___ ____ ____ between the skin and the surrounding air?
    water vapor pressure
  283. Evaporative heat loss is proportional to? (equation)
  284. If water vapor pressure is ____ at the skin, then water will evaporate to the surrounding air?
  285. If water vapor pressure is lower at the skin, then water will ______ on the skin?
  286. If water vapor pressure is ______ at the skin, then water will condense on the skin.
  287. If water vapor pressure is higher at the skin, then water will _______.
  288. T/F: when talking about evaporative heat loss, temperature does not matter and does not play into the equation.
  289. T/F: the more exposed skin you have, the more evaporative hat loss there will be.
  290. Evaporative heat loss depends on what 3 things?
    • air speed
    • wetted surface area (exposed skin)
    • difference in WVP between skin and air
  291. What is the equation for evaporative heat loss?
  292. What is the symbol for heat loss depending on wind speed?
  293. ______ is heat transfer by the movement of fluid molecules?
  294. Convection depends on what 3 things?
    • surface area of exposed skin
    • convective heat transfer coefficient
    • temp difference between air close to the skin and surrounding air
  295. What is the equation for convective heat exchange?
  296. What is the symbol for heat transfer depending on convection?
  297. T/F: in high winds, you will cool more quickly and lose more heat.
  298. T/F: convective heat loss depends on the size of the organism.
  299. Larger animals have larger ____ ____ and therefore have reduced convective heat exchange?
    boundary layers
  300. What makes a larger animal have lowered convective heat exchange?
    they have larger pockets of air surrounding them (boundary layer)
  301. ______ is the exchange of heat between surfaces in contact?
  302. What 3 things does conductive heat exchange depend on?
    • temp difference between the skin and the surface
    • surface area of skin touching the surface
    • the conductive heat transfer coefficient
  303. What is the symbol used for conductive heat transfer?
  304. What is the equation for conductive heat exchange?
  305. Surfaces with low thermal conductivity vaues are usually _____ insulators?
  306. T/F: insulation and conductivity are inversely related.
  307. What units do we use to measure conductivity?
  308. What two types of radiation can effect heat exchange?
    • solar radiation
    • terrestrial radiation
  309. What type of radiation is short wavelength?
  310. What type of radiation is long wavelength?
  311. The amount of radiation we absorb depends on what two things?
    • how "strong" the radiation is
    • how much skin is exposed
  312. What is the equation for solar heat gain/radiation?
    solar heat gain= RsolarSw
  313. What is the equation for terrestrial radiation?
  314. What 3 things determine how much radiation we gain or lose by terrestrial radiation?
    • surface area of skin exposed to surroundings
    • radiative coefficient
    • difference between temp of our skin and the temp or our surroundings
  315. ___ ____ = deposits - withdrawals
    total heat (W=J/s)
  316. The effect of the total heat on your body temperature depends on what 2 things?
    • body mass (kg)
    • specific heat capacity cp (J/gC)
  317. The larger the specific heat capacity, the _____ the temperature change?
  318. The larger the mass, the _______ the temperature change?
  319. What is the equation for change in temperature? (C/s)
    total heat (J/s)///mass(kg)*cp(J/gC)
  320. T/F: we can lose quite a bit of heat when we breathe.
  321. Body tissues have _____ thermal conductivity, so heat flow is dominated by convection (blood flow).
  322. Temperature is detected in the dermis and epidermis by what two types of fibers?
    • A delta fibers-myelinated, large, faster
    • C fibers- unmyelinated, small, slower
  323. A delta and C fibers relay info about skin temperatures via the _____ _____?
    reticular formation
  324. T/F: Cold fibers respond to cold temperatures with greater frequency than warm fibers respond to warm temperatures.
    false; warm fibers respond more intensely because hot temps on the skin are more harmful than cold
  325. What are TRP channels?
    • transient receptor potential channels
    • large, diverse family of cation channels
  326. What is another name for the TRPV1 receptor?
    vanilloid receptor 1
  327. What does TRPV1 detect?
    painfully hot temps (>43 C)
  328. What cells in our skin might play a role in temp and pain sensation?
  329. _____ secrete neurotrophins, ATP, beta-endorphin and interleukins that help with sensation?
  330. TRPV3 and TRPV4 are more detectable in ________ than in sensory neurons?
  331. TRPV1 is found in what kind of cells?
  332. ______ can trigger interleukin release in the skin.
  333. The ____ _____ integrates temp information and relays it to the hypothalamus?
    reticular formation
  334. What two types of cells are involved in sensing temperature?
    • free nerve endings
    • specialized receptor cells
  335. What part of the hypothalamus controls our core and external temp?
    pre-optic anterior hypothalamus
  336. Shivering can be suppressed by what two things?
    • attention
    • voluntary muscle activity
  337. What are 4 ways that we can lower our body temp?
    • brain- change behavior
    • sweat
    • vasodilate
    • vasoconstrict
  338. cold skin = ___ norepinephrine = _____
    increased; vasoconstriction
  339. hot skin = ______ norepinephrine = _______
    decreased; vasodilation
  340. What system controls the dilation in the skin in your limbs and trunk?
    sympathetic active vasodilator system
  341. What system controls the vasoconstriction in the skin of our feet, hands, lips, ears, nose (acral regions)?
    adrenergic vasoconstrictor system
  342. T/F: apocrine sweat glands are less important for heat loss.
  343. Which sweat glands mainly regulate our body temp?
    eccrine sweat glands
  344. Where are eccrine sweat glands most likely to be found?
    acral regions (hands, etc)
  345. T/F: sweating is controlled by sympathetic cholinergic controls and norepinephrine and epinephrine.
  346. When we are cold, normal inhibition of the _______ ______ _______ by the preoptic anterior hypothalamus is removed and we are allowed to shiver?
    dorsomedial posterior hypothalamus
  347. ___ _____ is driven by Tcore, Tskin and thermal set point?
    thermal comfort
  348. T/F: fever is a change in temperature set point.
  349. T/F: during exercise you maintain a sustained error signal.
  350. T/F: during exercise the temperature set point is changed and you have an increase in body temperature.
    false; no change in set point
  351. Why do we have a sustained error signal during exercise?
    because we can only lose so much heat by sweating
  352. T/F: sustained peripheral vasoconstriction can lead to mild ischemic injury to the gut.
    false; vasodilation
  353. What causes runner's diarrhea?
    sustained vasodilation in the skin causes blood plasma levels in the liver and stomach to go down so it can go to the brain and skin. Ischemic injury to the gut= diarrhea
  354. T/F: the POAH acts as a proportional controller of body temperature.
  355. What are the ways that we can raise our body temp?
    • behavior
    • shivering
    • non-shivering thermogenesis
  356. Skin temperature is controlled by what two systems?
    • active vasodilator
    • adrenergic vasoconstrictor
  357. _________ is the primary mechanism for controlling our body temp?
  358. The _______ sweat glands are the main source of sweat for evaporative cooling and are particularly dense in acral regions?
  359. T/F: heat-acclimated individuals can maintain a lower body temperature when challenged by sweating less.
    false; they sweat more
  360. T/F: people that are acclimated to the cold may have a higher shell conductance.
    false; lower
  361. T/F: people that are acclimated to the cold may have a lower core temperature threshold for shivering.
  362. What is the Lewis hunting response or "fishing hands"?
    • earlier cold-induced vasodilation, higher blood flow, and a rhythmic pattern of vasodilation and vasoconstriction
    • re-shunting of blood to the hands and then back to the core
  363. If you ______ more, you have increased heat tolerance and increased sweat sensitivity.
  364. T/F: as you age, you have reduced sweat sensitivity.
  365. T/F: drugs like anticholinergics and alcohol do not affect thermoregulation that much.
    false; they do
  366. Lesions to the ______ can lead to chronic hypothermia or chronic hyperthermia?
    POAH (preoptic anterior hypothalamus)
Card Set
Exam 3
Nutrition, Temperature, Exercise, High Altitude
Show Answers