exercise physiology midterm 2 Flashcards

1
Q

satellite cells

A
  • undifferentiated cells that increase the number of nuclei in muscles which promotes growth and strengthening
  • training activated
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2
Q

synaptic cleft

A

the gap between the motor neuron and the muscle cell that the AP crosses

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3
Q

ACh

A

acetylcholine
- neurotransmitter released to be diffused across synaptic cleft

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4
Q

neuromuscular junction (NMJ)

A
  • when the nerve impulse reaches the endo f the motor nerve it comes to the synaptic cleft
  • ACh in released and diffused across the cleft to bind to the recptor site on the mtor and plate
  • opens sodium channels on the sarcolemma allowing sodium to diffuse into the muscle fiber
    -results in depolarization called the end-plate potential (EPP)
    -this is the signal to begin the contractile process
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5
Q

sliding filament thoery

A
  1. ATP binds to myosin head
  2. ATP causes cross bridges to “cock”
  3. cross bridges attach to myosin head
  4. bind to actin
  5. power stoke and slide
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6
Q

force regulations

A
  • type and number of motor units recruited
  • initial muscle length (length-tension relationship)
  • nature of the neural stimulation (simple twitch, summation, tetanus)
  • contractile history
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7
Q

size principle name

A

Henneman’s principle

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8
Q

Henneman’s size principle

A

MUs recruit from smallest to largest based on the force required
- first recruited is last to de-recruit

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9
Q

tetanus

A

sustained muscle contraction

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10
Q

what happens if previous activity is non-fatiguing

A

force production enhanced
- more sensitive to Ca
- phosphoralation of myosin light chain

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11
Q

skeletal muscle fibre types

A
  • slow oxidative (type I)
  • fast oxidative glycolytic (type IIa)
  • fast glycolytic (type IIx)
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12
Q

influences of force type distribution

A
  • genetics
    -training
  • hormone concentration
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13
Q

biochemical properties of muscle fibres

A
  1. oxidative capacity (# of cappilaries, mitochondria, amount of myoglobin)
  2. speed of ATP degragation
  3. absence of contractile proteins
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14
Q

contractile properties of muscle fibres

A
  1. maximal force produced
  2. speed of contraction
  3. maximum power output
  4. muscle fibre efficiency
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15
Q

immunohistochemical staining

A

straining of a muscle biopsy in order to see the amount of fast vs slow twitch fibres in the muscle

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16
Q

immunohistochemical staining colours

A
  • blue = type I fibres
  • green = IIa fibres
  • Black IIx fibres
  • red = dystrophin (protein in sarcolemma)
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17
Q

causes of fatigue

A
  • CV system (O2)
  • energy supply system (inadequate ATP)
  • neuromuscular system
  • thermoregulation
  • biochemical (stresses in other systems)
  • psychology
    -central governor model (prevent catastrophic failure by homeostasis)
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18
Q

central causes of fatigue

A
  • motor cortex (pain)
  • spinal cord (impaired recruitment of MN and firing frequency)
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19
Q

peripheral causes of fatigue

A
  • NMJ (impaired neuromuscular transmission)
  • impaired conduction of action potentials
  • Ca2+ (impaired release
  • imparied cross bridge cycling (myosin and actin
  • low force/power output
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20
Q

two hypothesis of peripheral fatigue

A
  • accumulation hypothesis (lactic acid, H+, Ca, Pi, etc)
  • depletion hypothesis (ACh, glycogen, BG, O2, etc)
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21
Q

accumulation of too much potassium (K)

A
  • can block nerve transmission to T-tubules
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22
Q

purpose of cardiovascular system

A
  • transport O2
  • removal of CO2
  • regulation of temp
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23
Q

two major adjustments of the CV system during exercise

A
  • increased cardiac output
  • redistribution
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24
Q

cardiac output equation

A

Q = HR x SV

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25
Q

blood flow equation

A

change in pressure / resistance

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26
Q

resting heart rate (RHR)

A
  • normal (60-8b5pm)
  • elite (28-40 bpm)
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27
Q

typical heart rate timing

A

distole - 0.5 sec
systole - 0.3 sec

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28
Q

elite heart rate timing

A

distole - 0.13 sec
systole - 0.2 sec

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29
Q

why does heart rate increase with exercise

A

initially increases abruptly with the withdrawal of PNS
- SNS kicks in and HR continues to rise

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30
Q

max heart rate equations

A

220 - age
or
208 - (0.7 x age)

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31
Q

heart rate variability

A

wide variety of HRV is considered healthy

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32
Q

stroke volume

A

(end dystolic volume - end systolic volume

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33
Q

stroke volume is determined by

A
  • end -diastolic volume
  • vascular resistance
  • contractibility
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34
Q

frank-starling law

A

the heart adjusts its stroke colume and cardiac output in response to changes in venous return and end diastolic volume

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35
Q

veinous return

A

amount of blood returned to the heart

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36
Q

three principles of EDV

A
  • venoconstriction
    -muscle pump
  • respiratory pump
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37
Q

vascular resistance

A

aortic pressure

38
Q

ejection fraction

A

portion of blood pumped out of LV each beat

39
Q

stroke volume during exercise

A

increase linearly and levels out at 40-60% VO2max
- doesnt always level out in elite athletes

40
Q

cardiac output

A
  • measured in L/min
  • reflects the functional capacity of the CV system
41
Q

2 factors that drive the relaxation of capillary sphincters

A
  1. driving force of increased local BP
  2. local metabolites
42
Q

aortic blood pressure

A

systolic / diastolic (120/80)

43
Q

pulse pressure

A

systolic - diastolic
120-80
= 40

44
Q

mean arterial pressure (MAP)

A

average pressure during a cardiac cycle

45
Q

MAP equation

A

DBP + 0.33 (SBP-DBP)
- does not work for exercise

46
Q

Acute BP regulation

A

short term
- SNS
- baroreceptors (pressure sensory)
increase BP = decreased Q and TVP)

47
Q

chronic BP regulation

A

blood volume controlled by kidneys

48
Q

3 important components of CV system

A
  • heart
    -vascular network
  • blood
49
Q

blood O2 carrying capacity

A
  • 15g/100ml
  • each g binds 1.34ml O2
50
Q

redistribution of blood flow

A
  1. pump more blood
  2. re-direct blood
51
Q

double production or rate-pressure product

A

HR x SBP
- indicates the work of the heart

52
Q

central command thoery

A

changes at onset of exercise is due to centrally generated CH motor sugnals
- set general patterns of the CV response

53
Q

CV control during exercise

A
  • initial drive (central command theory - anticipates ex)
  • fine tuned by feedback
54
Q

pulmonary ventilation

A

breathing air through mouth or nose to the lungs

55
Q

external respiration

A

O2 from the lungs to the blood and CO2 from blood to lungs

56
Q

internal respiration

A

O2 from blood to cells and CO2 from cells to blood

57
Q

cellular respiration

A

O2 from cells to mitochondria and CO2 from mitochondria to O2

58
Q

respiratory zone

A

300 million alveoli
- rapid gas exchange

59
Q

boyles law

A
  • pressure of gas is inversely proportional to the volume of the container
  • increased volume = decrease pressure
60
Q

air flow

A

P1 - P2 / resistance

61
Q

pulmonary ventilation

A

amount of air moved into the lungs in a minute
- (V)

62
Q

tidal volume

A

(Vt)
- amount of air moved per breath

63
Q

breathing frequency

A

(f)
- number of breaths per minute

64
Q

pulmonary ventilations =

A

Vt x f
or
Va + Vd

65
Q

alveolar ventilation

A

(Va)
- volume of air that reaches the respiratory zone

66
Q

dead-space ventilation

A

(Vd)
- volume of air that remains in conducting airways

67
Q

minute ventilation

A

(Ve)
- air flow eahc minute
- hoe muvh air per breath and how many breaths per minute
Ve = Vt x f

68
Q

alveolar ventilation

A

(Va)
- “fresh” air per minute
Va = (Vt -Vd) x f

69
Q

ERV (expiratory reserve volume)

A

maximum volume of air expired after a normal expiration

70
Q

IRV (inspiratory reserve volume)

A

max air inspired after a normal breath

71
Q

RV

A

air left in lungs after MAXIMAL exhalation

72
Q

forced vital capacity (FVC)

A

max stroke volume of the lungs

73
Q

dynamic breathing depends on:

A
  • max stroke volume
  • speed of breathing rate
74
Q

forced expiratory volume (FEV o.1)

A

FEV0.1 / FVC
- indicates pulmonary airflow capacity

75
Q

ssex differences

A

decreased:
- lung capacity
-airway diameter
-diffusion surface
- static and dynamic function measures

76
Q

daltons law

A

each gas contributes to hte toal pressure in proportion to its number of molecules

77
Q

partial pressure

A

= total pressure x fraction of gas

78
Q

henrys law of gas exchange

A

each gas will dissolve in the liquid in proportion to its partial pressure

79
Q

partial pressure added inside alveoli

A

Ph2O = 47mmHg

80
Q

factors effecting gas exchange

A
  1. partial pressure
  2. solubility of the gas
  3. surface area and thickness
81
Q

ficks law of diffusion

A

Vgas = Q x a-vO2 difference

82
Q

ventilation -perfusion ratio

A

rate of alveolar ventilation to pulmonary BF
(high value = too much VE, too low = too much BF)

83
Q

O2 content of blood

A

97% Hgb saturation

84
Q

normal oxygen %

A

15g% - men
13g% - women

85
Q

pH shift

A

increase in pH = shift left
decrease in pH = shift right
- increase in H+ weakens O2 and Hgb bonds

86
Q

temperature shift

A

increase temp weakens O2 and Hgb bonds
- shift right

87
Q

2,3 DPG shift

A

added = shift right
none= shift left
- can bind to Hgb and reduce its affinity to O2

88
Q

myoglobin

A

facilitates O2 transfer to mitochondria

89
Q

arteriovenous O2 difference

A

describes the difference between he O2 content of arterial blood and mixed venous blood
- average = 4-5 ml O2/100ml

90
Q

CO2 transports in blood

A
  • bicarbonate (70%)
  • dissolved in plasma (10%)
  • bound to Hb (20%)
91
Q
A