Exam 2 Ex Phys

152 flashcards · Other · by Emma Yarbrough

1. What does the cardiovascular system transport?

   water oxygen carbon dioxide fuels for energy production electrolytes hormones metabolic products

2. 2 main parts of the cardiovascular system:

   muscular pump = the heart network of blood vessels

3. Horses cardiovascular systems are specifically designed for...

   the transport of oxygen from lungs to body tissues

4. What is the function of the heart?

   To pump enough blood to maintain blood pressure and oxygen flow to tissues

5. What does the left atrium do?

   receives oxygenated blood from the lungs blood empties into the left ventricle

6. What does the left ventricle do?

   pumps blood into the aorta blood is sent to the body via arteries

7. What does the right atrium do?

   receives the blood returning to the heart after systemic circulation

8. What does the right ventricle do?

   sends low-in-oxygen blood to the lungs

9. Heart/Blood path:

   lungs -> left atrium -> left ventricle -> arteries/body -> right atrium -> right ventricle -> lungs

10. How does a horse's heart rate act during exercise?

    HR increases quickly at the onset of exercise HR reaches a steady state in 2-3 minutes most likely due to sympathetic nerve activity or catecholamine release

11. What does the sympathetic nervous system do?

    fight-or-flight response

12. What does the parasympathetic nervous system do?

    rest and digest functions

13. What is the importance of warming up?

    without warm-up, there may be an overshoot of max HR oxygen consumption also increases more rapidly at the beginning of exercise if there has not been a warm-up

14. What is cardiovascular drift?

    when, after 30 minutes of constant-load exercise, mean HR increases from 154 to 173 bpm

15. Cardiovascular drift doesn't always happen but may be dependent on some factors:

    exercise type environmental conditions animal fitness

16. What is maximal heart rate?

    the highest heart rate measured for a specific horse at a specific training level loss of linearity -- if no plateau, then it's peak heart rate

17. What is peak heart rate?

    The highest heart rate measured of the training session

18. Importance of max heart rate:

    very repeatable to measure in an individual horse not an important measure of fitness not affected by training despite increases in VO2 max more important to look at the speed at which HRmax was reached

19. Heart rate recovery after exercise:

    rapid during the first minute after exercise cessation decreases more gradually toward normal resting values

20. In an endurance race, a heart rate greater than 65-70 bpm after 30 minutes of recovery often leads to...

    the development of dehydration and exhaustion if allowed to continue

21. Oxygen pulse:

    ratio of oxygen consumption to heart rate reflects the maximal aerobic capacity in humans... and probably horses

22. The oxygen pulse of horses _____ as heart rate increases

    increases

23. Cardiac output =

    heart rate x stroke volume the volume of blood ejected from the left or right ventricle each minute

24. Increasing cardiac output is principal means of

    increasing oxygen uptake during exercise

25. cardiac output increases linearly with

    increases in workload, mostly due to increased heart rate

26. stroke volume =

    the volume of blood ejected from each cardiac ventricle with each contraction

27. systole:

    contraction

28. disastole:

    relaxation

29. blood pressure:

    systole/diastole

30. blood volume consists of

    the plasma and the cells in the blood

31. Blood volume is _____% of a resting horses body weight.

    ~9

32. ____% of blood volume is in pulmonary circulation.

    20

33. ___% of blood volume is in systemic circulation.

    80

34. __% of blood volume is in veins and venules

    60

35. __% of blood volume is in arteries

    15

36. Contraction of spleen during excitement and exercise:

    adds red blood cells to circulation increases hematocrit values from 35-45% at rest to 50-70% after exercise

37. In untrained TBs, blood volume is approximately

    53L

38. Increase in blood volume depends on:

    work intensity age sex training state of the horse

39. Plasma volume:

    resting: 16-31 L usually decreases with exercise (water movement --> sweat)

40. Resting plasma volume has been found to _____ with training.

    increase may be important in thermoregulation, allowing increased blood flow to the skin

41. Horses fed one large meal a day had decreased plasma volume by _____ for at least 1 hour.

    10-15%

42. Total red blood cell volume is determined as the

    volume of RBCs in circulation after exercise or an injection of epinephrine

43. We don't frequently evaluate total red blood cell volume because we

    don't know the relevance to performance and relationship to VO2 max

44. Distribution of cardiac output during exercise:

    blood flow will be redirected to the working muscles without compromising blood flow to the CNS

45. During exercise, there is ________ in skeletal muscles and skin.

    vasodilation

46. During exercise, there is _________ in nonworking muscles, like the GI organs and the spleen.

    vasoconstriction

47. During exercise, blood flow to the _______ _______ is more than doubled

    adrenal glands

48. What 2 things maintain internal body temperature?

    peripheral thermoreceptors hypothalamus

49. Peripheral thermoreceptors:

    responsible for detecting a disturbance skin, skeletal muscle, abdomen, regions of spinal cord, medulla oblongata

50. Hypothalamus:

    interpretive center signals to end organs, which results in reduction of stimulation

51. Mechanisms of heat transfer:

    radiation convection conduction evaporation

52. Radiation:

    movement of heat between objects without direct physical contact via electromagnetic radiation

53. Short-wave (solar) radiation:

    received from the sun by any object exposed to sunlight

54. Long-wave radiation:

    heat interchanges between an animal and its surroundings

55. Convection:

    warm particles are less dense and will rise cold particles will fall takes place continuously between the surface of the body and the surrounding air

56. Free convection:

    takes place at the surface of a solid body within a fluid medium which is at a different temperature can result in significant heat losses if air temp is low

57. Forced convection:

    occurs if there are fluid movements induced by gross pressure differences wind blowing across body surface

58. Conduction:

    direct transfer of heat between surfaces that are in contact

59. Due to conduction, during low temps, blood is....

    directed away from extremities

60. Due to conduction, as high temps, blood is...

    directed toward extremities through vasodilation

61. Extremities have

    a high surface area to mass area

62. Evaporation:

    homeotherms lose heat by panting, sweating, or insensible perspiration

63. Sweating:

    evaporation of water at the surface of the body results in heat loss primary means of heat dissipation for horses

64. Equine sweat:

    hypertonic relative to plasma higher concentration of electrolytes in sweat than in plasma

65. Latherin:

    promotes spreading and evaporation of sweat and possibly aiding evaporation and cooling

66. High intensity exercise produces

    more dilute sweat than low-intensity prolonged exercise

67. Circulatory adjustments for thermoregulation:

    blood flow is a highly effective avenue for heat transfer via conduction efficiency through adjustments between peripheral vasodilation and vasoconstriction increases cardiac output redistributes cardiac output, particularly blood flow to skin

68. Thermoregulation during exercise:

    metabolic heat load is produced that is proportional to the intensity of the exercise bout heat transferred from the working muscles to the body core eventually evaporative rate will match rate of energy production

69. At onset of exercise, muscle temperature can increase at a rate of...

    1*C per minute

70. Muscle temps of _____ have been reported

    45*C (113*F)

71. Muscle blood flow is ______ during exercise.

    increased

72. Heat flows down the....

    temperature gradient primarily by convection (blood flow) a small amount by direct conduction

73. Core blood is heated with...

    heat storage exceeding heat dissipation

74. Storage of heat...

    reduces the amount that must be dissipated

75. Moderate elevation of muscle temp...

    improves performace

76. At onset of exercise, skin temperature....

    falls slightly increased convection resulting from the motion of the subject

77. Convection and radiation are more effective when...

    environmental temperature is low

78. Sweating can lead to a reduction in temp by ____ below core temperature.

    2.5*C

79. Sweating rates of horses exercising in the heat can reach...

    10 to 15 L/hr

80. Sweating will dissipate up to ___ of metabolic heat produced

    75%

81. Heat loss through sweating =

    75%

82. Heat loss through respiration =

    20%

83. Heat loss associated with warming inspired air to body temp is ___ of heat loss at rest and exercise.

    ~5%

84. Evaporative heat loss associated with humidifying respired gases _____ during exercise

    increases 10-15% of heat loss

85. Profiles of horses in training:

    housed in stables minimal/no pasture access round-pen or paddock turn-out higher-concentrate diet

86. When feeding horses, we want to be feeding no less than ____ as good quality hay.

    0.75%-1%/day body weight

87. Exercising horses may need to eat ___ BW/d

    2.5%

88. Energy:

    Expressed as calories, kilocalories, megacalories ATP is major source of readily available energy in cells

89. ATP is major source of readily available energy in cells:

    catabolism of carbohydrates, fat, protein carbs and fat under normal circumstances amino acids during starvation

90. Amino acids should go towards _____. If they are using amino acids for energy, they need____.

    making muscle higher-energy feed/better quality forage

91. In humans, cardiac output decreases during exercise in heat compared to thermoneutral environment due to:

    decreased central blood volume decreased plasma water loss of body fluid in sweat

92. When cardiac output is decreased...

    blood flow to skin must be reduced -- would impair heat loss or, reduction in blood flow to the working muscles -- would reduce metabolic performance

93. Exercise-induced heat stress is when:

    heat production during exercise exceeds dissipation body temperature reaches critical levels

94. Exercise-induced heat stress is caused by:

    exercising in adverse environmental conditions (high temp & humidity) inadequate conditioning impairment of thermoregulatory system paired with energy depletion

95. Exercise-induced heat stress symptoms:

    dehydration & exhaustion decreased skin turgor sunken eyes dry mucous membranes firm, dry feces (or none) decreased urine output increased rectal temperature respiratory rate elevated (may pant) increased heart rate diaphragmatic flutter

96. Exercise-induced heat stress treatment:

    early recognition* cold hosing, voluntary rehydration, palatable feed, electrolytes cooling: hosing with cold water continually and ventilation via breeze or fans fluid administration

97. When cold-hosing for exercise-induced heat stress, pay particular attention to:

    head, neck, and large subcutaneous vessels between hind legs blood vessels -- blood runs throughout body -- colder blood = colder body

98. Exercise-induced heat stress prevention:

    physical training heat acclimatization (2-3 weeks) electrolyte supplementation

99. Anhidrosis clinical signs:

    unable to sweat heat intolerance reduced exercise capacity elevated temp and respiratory rate dry and flakey skin, alopecia may develop the problem in the summer, but recommence sweating in the cooler months

100. Muscle is located proximally in the skeleton of the horse:

     pendulum-like effect decreases energy needed to swing the limb