KIN 292 1st Edition Lecture 15These come from the slideshows provided by the professor and include extra notes and explanations. Highlighted or bolded information are things that I believe to be information that is important to look over multiple times. The notes in red are my personal additions and quotes of Professor Starnes from the class lecture. Outline of Last LectureI. 21.1 An Overview of Whole-Body Metabolism - reviewII. 21.2 Energy Intake, Utilization, and Storage - reviewIII. 21.3 Energy BalanceIV. 21.4 Energy Metabolism During the Absorptive and PostabsorptiveStatesV. 21.5 Regulation of Absorptive and Postabsorptive MetabolismOutline of Current Lecture I. 21.6 Thermoregulation - continuedII. 21.7 Hormonal Regulation of GrowthIII. 21.8 Thyroid HormonesIV. 21.9 GlucocorticoidsCurrent Lecture21.6 Thermoregulation- Temperature Balanceo Core body temperatureo Humans: 37 Degrees C (98.6 Degrees F)- Hypothermia: decrease in body temperature- Hyperthermia: increase in body temperatureo Temperature > 41 Degrees C is dangerouso Temperature > 43 Degrees C is deadlyThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Mechanisms of Heat Transfer Between the Body and the External Environment•Radiation (heat gain or loss, + and -)•Thermal energy through electromagnetic waves•Conduction (+ and -)•Thermal energy through contact•Convection (+ and -)•Heat transfer by movement of fluid or air•Evaporation (heat loss only)•Insensible water loss•SweatingRegulation of Body Temperature•Receptors = thermo receptors (neurons)•Central: found in CNS (hypothalamus)•Peripheral: found in PNS (mainly skin)•Integrating center•Thermoregulatory center in hypothalamus•Effectors•Sweat glands•Muscles•Skeletal muscles•Smooth muscle of cutaneous (skin) blood vesselsRegulation of Body Temperature•Thermo neutral zone (TNZ) - a temperature range in which a 'standard' healthy adult can maintain normal body temperature without needing to use energy above and beyond normal basal metabolic rate•Environmental temperature range: 25–30 C (77-86 F) for a naked man, standing  upright, in still air. With clothing radiation and convection losses dramatically reduced, lowering the TNZ•Within TNZ cutaneous blood flow changes enough to regulate body temperature•Increasing body temperature → Cutaneous vasodilation•Increased blood flow to skin, causing heat loss•Decreasing body temperature → Cutaneous vasoconstriction•Decreased blood flow to skin, causing heat retention•Heat generation in a cold environment•Below the thermo neutral zone•Vasoconstriction alone cannot maintain proper core body temperature•Heat-generating mechanisms•Shivering thermogenesis – involuntary contractions of skeletal musclesuse energy and generate heat. Can raise metabolic rate as much as 5 fold! Only effective mechanism in modern humans•Non shivering thermogenesis – from brown adipose tissue found ininfants and some animals. Not so much for us adults•Piloerection – goose bumps – animals and cavemen•Heat loss in a warm environment•Above the thermo neutral zone•Vasodilation alone cannot maintain proper core body temperature•Increased production of sweat primarily from eccrine sweat glands.Much less contribution from apocrine glans located in arm pits and genital areasPower of sweating -- At rest, naked person can maintain 37 degreesC core at 54–60 degrees C (130-140 degrees F)Power of SweatingThis will be on the test. I am emphasizing this slide. He said that on the test, he will give us an equation to work out based on this.•Each 1 ml of sweat evaporation = 0.6 kcal body heat loss•At rest human heat production about 1.2 kcal/min (100W light). Counter with 2 ml sweat evaporation (2 x 0.6 = 1.2)•Maximum sweat rate is about 30 ml/min (varies considerably) or about 18 kcal heat removed/min•Heat production at maximum aerobic exercise is slightly more. What is the impact of this?Sweating – Good and Bad•Good: Primary means to dissipate heat during exercise or very hot environments.•Bad: Water loss can lead to dehydration, which adversely affects blood volume and blood flow distribution. Water for sweat comes from all compartments in the bodyWater Loss in the Heat: Dehydration: Amount of water loss directly proportional to the environmental conditionsand the length/intensity of physical activity•Consequences of Water loss (% body wt)•1-2% -- Impaired thermoregulation•3%+ -- Reduced endurance•4-6% -- possible heat cramps•>6% -- heat exhaustion, heat stroke, coma•Bottom line – stay hydrated!!•Preventing dehydration saves livesClinical Connections: Heat Exhaustion and Heat Stroke.(page10)Maintaining hydration can prevent these•Heat Exhaustion: Profuse sweating, Reduced blood volume, ↑ Blood flow to skin, ↓ blood pressure & blood flow to brain, Negative feedback, Temperature still "normal", Dizziness, fainting, Flushed and wet•Heat Stroke: No sweating, Reduced blood volume, ↑ Blood flow to skin, ↓ blood pressure & blood flow to brain, ↓ feedback – IC damage, Temperature elevated, Delirium, Flushed and dryAlterations in the Set Point for Thermoregulation: Fever•Rise in core body temperature set point•Accompanies infection•White blood cells secrete pyroxenes•Body temperature set point increases•Fever enhances immune responses•Example of the fact that set point of some regulated variables can be changed for good reasons21.7 Back to hormones.- Stanfield will be focusing on hormones affecting growth (increasing or inhibiting growth). In our test, the term growth usually refers to bodily changes accompanying increases in height.- But remember that many hormones also have a primary responsibility for glucose homeostasis. We already discussed insulin and glucagon. Table21.4 lists the other main onesNote how many hormones are involved in plasma glucose homeostasis. Insulin actions regarding plasma glucose & lipolysis are opposite all other hormones. Thyroid hormone changesmetabolic rate, which indirectly affects CBH & lipid metabolismGrowth hormone – most important one for height (bone growth)- NFL, Union Agree to New Drug Policy, HGH Testing, NEW YORK — Sep 17, 2014, 4:58 PM ET- The NFL finally will have HGH testing!- But, Growth hormone is not just for height.- Also, produces hypertrophy of