exam 3

• Why are the effects of the endocrine system considered "global"

  Because the hormone travels throughout the entire body by the blood stream, anywhere there is a receptor for the hormone, the receptor will be affected.

  - This system allows for activity for organs that dont receive neural stimulation.
• What are second messengers? What's the name of the one we talked about? What's the mechanism of it's action?

  Second messengers allow a Amine/Peptide hormones to exert their effect w/o entering cell.

  
  

  cAMP: the hormone acts as a first messenger to react with the enzyme adenlyate cyclase (which is in the plasma membrane) to form the compound cAMP from ATP.

  - cAMP acts as a second messenger to active a protein kinase, which leads to the desired biological activity.
• What is the master gland? What hormones are released from here?

  The Pituitary Gland

  - Anterior Pituitary.: GH(growth hormone), TSH (Thyroid Stimulating Hormone)

  - Posterior Pituitary: ADH (anti-diuretic hormone)(sometimes called the Nerve Hormone)

  -- Posterior Pituitary is hormones released from nerve tissue.

  --Anterior Pituitary is hormones released from gland tissue
• What is the effect of ADH and how does it work?

  -released from posterior pit. (neurohormone)

  -response to dehydration (aka decreasing PV)

  -acts directly onto kidney

  **ADH causes the kidneys to hold onto water:

  - H2O Reabsorption back into blood & stimulates thirst.

  ADH is released when there is a Decrease in PV. A Decrease in PV causes an Increase in Osmolality.

  ** decreases urination
• What effect does Growth Hormone have on fat metabolism? Protein metabolism?

  GH:

  -released from anterior pit

  -has a diurnal rhythm(peaks during 1st hour of sleep)

  **makes tissue "grow"

  -Effects the Liver, causing the release of IGF1

  1. increase protein synthesis

  2. increased use of fatty acids for energy (protein synthesis)

  - also Decreases CHO use
• What's the risk of taking exogenous Growth Hormone? When is GH normally released?

  -GH makes tissues grow, taking extra increases risk for Tumor Growth (cancer).

  *because effects are GLOBAL

  -Is a diabetogenic causing type 1 diabetes.

  -Causes bone growth (i.e. the jaw, the feet);
• What's the primary effect of thyroid hormone? What does TH bind to? How does this affect metabolism?

  TSH stimulates TH release TH Primary effect:

  Regulates metabolic rate (BMR).

  It binds to mitochondria, causing ↑ O2 uptake.

  - When we exercise we increase formation of mitochondria, giving way to more TH binding sites, which helps burn more calories at rest.

  More muscle=More mitochondria.

  Exercise(any kind)=Increased Metabolic Rate

  -endurance also increases mito but smaller muscles
• How does exercise training combine with TH to affect caloric balance?

  Endurance and Resistance training causes your body to increase the number of mitochondria. You burn more calories with the help of the increased mitochondria allowing TH to bind to more mitochondria, thus greater regulation of BMR.

  ↑ BMR by ↑ Mitochondria

  - the more mitochondria, the higher BMR is at rest, because more O2 is being used (this requires more energy, so more energy is being used).
• What are catecholamines? Name them.

  -water soluble?

  -They are Amino/peptide hormones released from Adrenal glands that bind to alpha/beta receptors.

  - Epinephrine and Norepinephrine.
• What systems in the body do catecholamines affect?

  The Nervous Sys. stimulates their release into the blood stream.

  Their effects are global and are relative to exercise:

  1. Increase HR

  2. increased contractility (increase SV)

  3. Vasodilation

  4. Bronchiodilation (maintain lung diffusion gradient, ex. inhalers have epinephrine to open upper airway)

  5. Increase in Glycogenolysis (the breakdown of glycogen)

  6. Increase in Lipolysis (fat break down)
• Where are insulin and glucagon are peptide hormones released from? What stimulates their release?

  Insulin and Glucagon are released from the Pancreas.

  They maintain blood glucose (about 5mMol/L of blood)

  
  

  Insulin (water soluble)

  - Released when blood glucose is high.

  - Increases glucose uptake (i.e., removes glucose from the blood)

  -Too much Insulin (Insulin Abuse) causes an increase in AA uptake.

  - AA uptake helps with muscle repair.

  -- sugar also stimulates the uptake of AA by stimulating the release of Insulin! This is a good thing.

  IMPORTANT:

  1. glyconegensis (resynthesizes CHO stores)

  2. muscle repair(uptake amino acid & signal for protein synthesis)

  
  

  Glucagon

  - Released when blood glucose declines

  - Stimulates gluconeogenesis; takes A.A and lactate to make glucose
• What is Glut4?


  Glut4 is a transport protein released by Insulin (and by exercise), and is used to transport glucose into the cell.

  - more glucose transport with less insulin
• How does exercise affect glucose transport? How is this significant for diabetics?

  Exercise causes an Insulin-like effect, that translocates GLUT4 from inside the muscle to the cell membrane.

  GLUT 4 is activated during exercise by the release of Calcium in the muscle cells, which causes an increase in insulin sensitivity.

  
  

  - Exercise is recommend because, exercise causes the activation of GLUT 4 (GLUT 4 can stay active in the body after exercise from 12-48hrs), without the need of insulin. This is why exercise is good for Type II Diabetes (a resistance to insulin) and Type I (the body does not produce insulin)
• How is an elevated glucagon beneficial to the exercise response?

  glucagon released in response to low blood glucose (so if low insulin then high glucagon)

  -increases breakdown of liver glycogen to maintain blood glucose

  -increases gluconeogenesis (AA & lactate)

  EXERCISE RESPONSE:

  1. increase glucagon

  2. decreased insulin
• What duration and intensity intervals will best increase VO2max in athletes? How much rest should accompany these intervals?

  In Athletes we see

  - Hi-intensity exercise (at 90% to reach VO2max)

  - Short rest intervals; 1:1 ratio

  - target the Oxidative system (3-7mins of exercise)
• What duration intervals promote increases in glycolytic capacity? What is the optimal work to rest ratio for glycolytic intervals?

  Duration: 1-2 minutes

  - Recovery is 2:1, so its twice as long as the exercise.
• How can you improve the phosphagen energy system?

  Duration: Less than 1 minute.

  - Recovery 3:1, 3x longer, or 3-5 minute

  - Intense exercise.
• What are the two primary training principles discussed?

  Overload Principal

  - Brings about adaptation = muscular growth and endurance growth

  (push yourself)

  
  

  Specificity

  -Genes; very little difference between the Strength and Endurance training, only 27 genes are diff
• What effect does HIIE have on VO2max? Which is more effect is increasing VO2max: HIIE, or steady exercise?

  HIIE increases VO2max.

  HIIE is more effective than steady state (SS) exercise

  Benefits of HIIE: larger increase and shorter time period
• Which burns more calories HIIE or steady exercise?

  Steady State burns more calories

  than HIIE
• 40. How does this complicate our understanding of dosing exercise?

  because the standard had been you need to burn at least 1000kcal to get effects of exercise but HIIE burns less and burns more fat!!
• 41. Given this difference would you expect HIIE do have an effect on weight loss?

  Yes.

  - Greater than SSE

  - Decreases appetite
• Which is likely most effective in targeting abdominal fat losses HIIE or steady

  exercise?

  HIIE
• What effect does HIIE have on mitochondrial biogenesis? How can "anaerobic intervals" stimulate this? What stimuli could effect this mechanism?

  -increases

  -unclear

  - AMP signal turns on PFK: AMPk is an energy sensor that increases mito. (HIIE increase AMP)

  -glycogen levels drop and AMP levels increase
• What is muscular strength? How can we use weight training to increase it? How can we induce muscular hypertrophy using weight training?

  Muscular strength is tension developed in muscle (more tension= more strength)

  ***strength doesn't equal size of muscle

  Heavy weight: high tension with few reps (5sets of 3 ~90% 1RM)

  RM= the greatest weight a person can do for 1 rep

  -To increase strength with weight training, the key is VOLUME: Volume=weight x reps

  -Hypertrophy "get swole" (muscle growth) tends to happen after 12 weeks

  ***Recommended to train @ 75% of 1RM, 3x10 to get most hypertrophy/muscle growth

  
  

  EX: 1Rm= 200lb (91kg)

  high volume

  3 x10 reps at 75% 1RM

  30150lbs=4500lbs**BEST

  high strength

  5x3 reps @ 90% 1RM

  15 * 180lbs= 2700lbs
• Summary

  Training VO2max.

  1. hard intervals increase Qmax

  2. Steady State (SS) training increases peripheral O2 extraction

  *need a combination of hard intervals & SS
• NSCA guidlines


  strength & power heavy weight w/ low reps (3-5reps)

  hypertrophy moderate weight 8-12 reps

  muscular endurance light weight w/ 14-20reps

  
  

  *high weight low rep builds strength

  high volume increases size
• What is the core body temperature?

  37 degrees Celsius
• Is skin temperature higher or lower than core temperature? Why is this important?


  Skin must be cooler than core temp (if not then we wouldn't be able to get rid of the heat)

  **the closer our skin gets to core temp the hotter we feel
• What mechanisms of cooling are used to maintain skin temperature?

  1. evaporation (sweat evaporates off skin)

  2. convection (air moves over body and carries heat away) (doesn't increase evaporation)

  3. conduction (transfer heat from hot body to cold surface)

  4. radiation (body radiates heat off to cooler environment)
• Why does sweating receive so much attention?

  evaporation of sweat is the only one that doesn't get effected by hot environments

  *only thing that effects sweating is humidity
• When we sweat which fluid compartment is affected the most?

  Extracellular fluid (ECF)
• What affect does this have on the cardiovascular system?

  dehydration (loss of fluid)

  decreases SV (decreases Q)

  decreases EDV

  (both effects frank starling)

  decreases ESV (increases contractility)

  **1% loss of BW decreased CV function (makes HR increases to compensate)
• How much of a fluid loss does it take to affect VO2max?

  3% loss of BW decrease in VO2max.(HR can't beat fast enough so VO2 decreases)
• 57. Why is a 6% CHO solution considered superior to water for fluid replacement?

  -6% CHO (6gCHO/100ml volume) solution is more isotonic than water(0%), so we get more intestinal absorption. Allows more fluid to be absorbed than urinated.

  -cold liquids work the best because it empties from the stomach and into the intestines faster
• What is the CHO concentration of A fluid replacement drink with 5g of CHO in 100

  mL of solution?

  5% CHO (5g/100ml)
• How can we acclimate to heat?

  To acclimate we need exposure to heat

  - Sitting in the heat

  - Training in warm-ups(clothes)

  -LOW intensity/SHORT duration exercise (~40-50% VO2max)

  -For athletes, 60-100 minutes, (regular humans 30min)

  Acclimation in 4-10 days.

  
  

  Note heat is transferred from the blood to the skin for evaporation to occur.

  - Exercise: provides the majority of heat stress (NOT the environment temp)

  High fitness= High metabolic rate( to get rid of heat)

  Increased Fitness= Increased heat tolerance
• How does our physiology change with heat acclimation?

  Increase PV

  - Increases Blood volumes

  - Increases Venous Return

  - Increased Q

  - Decrease in submax HR

  - Increase capacity to sweat

  
  

  Earlier onset of sweat (well adjusted to heat)

  - Better evaporative cooling

  
  

  Decrease sweat osmolality(not as salty sweat)

  - Sodium conservation
• Explain how altitude changes the inspired partial pressure of O2

  At higher altitudes there is lower barometric pressure, which causes a decrease in aveolar-arterial gradient, causing hypoxia.

  
  

  Higher altitude= Fewer air molecules

  ***LESS pressure not less O2

  ex: 760torr @ Sea Level

  PiO2= 760*.2093 O2

  = 159torr

  600 torr (lake tahoe)

  *.2093 O2

  PiO2= 125torr (less pressure)

  **decrease A-a gradient =less diffusion in lung
• What are the immediate responses to altitude?

  1. Hyperventilation

  2. Increased alkalinity due to loss of HCO3- ( got rid of CO2 from hyperventilating decreased H+ and shifts RBC to make Hb bind to O2)

  3. Increases Diuresis (increase urine volume, lower BV, slows down blood, allowing O2 to stick to RBCs= to try to increase blood saturation

  4. Decrease in SaO2

  5. Decrease in VO2max (because less O2 in blood)