Ex. Phys Quiz 3

86 flashcards · Other · by Emma Yarbrough

1. What is the main function of the cardiovascular system?

   To transport

2. What does the cardiovascular system transport?

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

3. 2 main parts of the cardiovascular system:

   muscular pump = the heart network of blood vessels

4. Horses are specifically designed for transport of...

   oxygen from lungs to body tissues

5. Function of heart:

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

6. mass of horse heart:

   4-5kg (1% BW)

7. Increase in heart mass seems to happen _____ in training.

   early

8. Left Atrium:

   Receives oxygenated blood from the lungs Blood empties into the left ventricle

9. Left ventricle:

   Pumps blood into the aorta Blood is sent to the body via arteries thick-walled

10. Right atrium:

    blood returns to heart after systemic circulation

11. Right ventricle:

    sends low-in-oxygen blood to the lungs

12. Heart Path:

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

13. Resting heart rate of a horse:

    25-40 bpm

14. Heart rate during exercise:

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

15. Sympathetic nervous system:

    fight-or-flight responsd

16. Parasympathetic nervous system:

    rest and digest functions

17. Warm-up importance:

    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

18. Cardiovascular drift:

    30 minutes of constant load exercise (no increase of decrease) mean HR increases from 154 to 173 bpm

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

    exercise type environmental conditions animal fitness

20. Maximal Heart Rate:

    Loss of linearity HRmax = highest heart rate measured, which results in a plateu of HR If no plateau, then it is peak heart rate

21. What's the difference between peak heart rate and maximal heart rate?

    Peak heart rate is the highest heart rate of the training session, while maximal heart rate is the highest heart rate of the horse at that fitness level.

22. Maximal Heart Rate importance:

    very repeatable to measure in an individual horse not an important measure of fitness not affected by training, despite increases in VO2max More important to look at the speed at which HRmax was reached

23. Heart rate recovery after exercise:

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

24. Heart rate recovery rates can be susceptible to rapid increases because of excitement:

    crowd, photographers, other horses, handlers, etc. in research, needs to be in a "controlled" environment

25. In an endurance race, a heart rate greater than 65-708 bpm after 30 minutes of recovery...

    often leads to the development of dehydration and exhaustion if allowed to continue

26. Heart rate: training

    many studies have found that HR during submaximal exercise to be lower after horses have undergone a training regime HR during submaximal exercise may be a means of monitory adaptation of cardiovascular system to training -- often the decrease is 10-20 bpm. Decreasing HR during submaximal exercise may be confounded by environmental factors -- acclimating to a new environment, testing procedures, etc.

27. Oxygen Pulse:

    ratio of oxygen consumption to heart rate expresses the volume of oxygen ejected from the ventricles with each cardiac contraction reflects the maximal aerobic capacity in humans...and probably horses

28. Oxygen pulse of horses _____ as heart rate increases.

    increases

29. cardiac output =

    heart rate x stroke volume, therefore... cardiac output = the volume of blood ejected from the left or right ventricle each minute (L/min or mL/kg/min)

30. Increasing cardiac output is principal means of...

    increasing oxygen uptake during exercise

31. cardiac output increases linearly with....

    increases in workload, mostly due to increased HR

32. stroke volume =

    volume of blood ejected from each cardiac ventricle with each contraction 800-900mL or 2-2.5 mL/kg increases by 20-50% from rest to submaximal exercise does not change as exercise intensity increases from 40-100% VO2max

33. Blood pressure and vascular resistance:

    product of cardiac output and total peripheral resistance

34. total peripheral reistance

    dependent on diameter of arterioles influenced by blood viscosity

35. Blood pressure: training

    mean systolic and diastolic aortic blood pressures have been found to be lower during exercise after treadmill training

36. systole:

    contraction

37. diastole:

    relaxation

38. blood pressure:

    systole/diastole

39. vascular resistance: training

    in humans, training is associated with a fall in peripheral vascular resistance reduction in total peripheral resistance in arterial circulation after training is reported in horses

40. Blood volume:

    consists of the plasma and the cells in the blood

41. Blood volume is ___ of a resting horses body weight:

    ~9%

42. ____ of blood volume is in pulmonary circulation

    20%

43. ___ of blood volume is in systemic circulation

    80%

44. ___ of blood volume is in veins and venules

    60%

45. ___ of blood volume is in arteries

    15%

46. Contraction of spleen during excitement and exercise:

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

47. In untrained TBs, blood volume is approximately

    53L

48. Increase in blood volume depends on:

    work intensity age sex training state of the horse

49. Plasma volume:

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

50. Resting plasma volume has been found to ______ with training.

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

51. Horses fed one large meal a day had decreased plasma volume by _________ for at least 1 an hour.

    10-15%

52. Total red blood cell volume:

    determined as the volume of RBCs in circulation after exercise or an injection of epinephrine we don't frequently evaluate, as we don't know the relevance to performance and relationship to VO2max

53. distribution of cardiac output:

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

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

    vasodilation

55. During exercise, there is _____________ in nonworking muscles, like the GI organs and the spleen.

    vasoconstriction

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

    adrenal glands

57. Maintenance of internal body temperature:

    peripheral thermoreceptors Hypothalamus

58. Peripheral thermoreceptors:

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

59. Hypothalamus:

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

60. Mechanisms of heat transfer:

    radiation convection conduction evaporation

61. Radiation:

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

62. short-wave (solar) radiation:

    received from the sun by any object exposed to sunlight

63. long-wave radiation:

    heat interchanges between an animal and its surroundings

64. 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

65. Free convection:

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

66. Forced convection:

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

67. Conduction:

    direct transfer of heat between surfaces that are in contact

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

    directed away from extremities

69. Due to conduction, at high temps, blood is...

    directed toward extremities through vasodilation

70. Extremities have...

    high surface area to mass area.

71. Evaporation:

    homeotherms lose heat by panting, sweating, or insensible perspriation

72. Sweating:

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

73. Respiratory heat loss =

    initial heat transfer to the inspired air - subsequent transfer back to the mucosa

74. Equine Sweat:

    hypertonic relative to plasma = higher concentration of electrolytes in sweat than in plasma high intensity exercise produces more dilute sweat than low-intensity prolonged exercise

75. Latherin:

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

76. 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

77. 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

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

    1*C per minute

79. Muscle temps of ____ have been reported

    45*C (113*F)

80. Muscle blood flow is _________ during exercise.

    increased

81. Heat flows down the....

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

82. Core blood is heated with...

    heat storage exceeding heat dissipation

83. Storage of heat...

    reduces the amount that must be dissipated

84. Moderate elevation of muscle temp...

    improves performance

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

    falls slightly increased convection resulting from the motion of the subject

86. Convection and radiation are most effective when...

    environmental temperature is low