Lab Exam #1 Flashcards
small motor units
fine muscle control
large motor units
high force
location of cell body of motor neuron
spinal cord
why do fast twitch motor units transport signal faster than slow twitch
because of thick myelinated axon
fast twitch motor neurons
large cell bodies
thick myelinated axon
require higher level of neural stimulation to depolarize
used during max. efforts
slow twitch motor neurons
smaller cell bodies
thinner less myelinated axons
require lower level of neural stimulatiion to depolarize
get first recruited
amplitute of a EMG
increases the higher the force is
what occurs before neural fatigue
local muscle fatigue
motor units recruited at a slow speed of motion
slow- and fast twitch
who will generate greater force at slow speed of motion; sprinter or endurance, why?
a sprinter will generate greater force, since he has more FT motor units - those have higher actin-myosin binding sites
what happens to force generated when speed increases
force decreases since less ST motor units get recruited as speed increases
endurance vs. sprinter force generation as speed increases
endurance athlete will produce less force since he has more ST motor units
sprinter will experience a smaller decrease in force production since he has more FT motor units
what is the speed a muscle can contract is usually based on
thickness of axon myelination
intramascular stores of myosin ATPase
between an endurance athlete and a sprinter who can generate greater force over time when fatigue occurs
endurance, since he has a higher ST muscle contribution
how do ST motor units generate greater force over time when fatigue occurs
greater capillarization
higher intramuscular concentration of myoglobin, mitochondria and oxidative enzymes
what is the max tension a muscle can generate based on
amount of actin and myosin binding
when we increase speed of a movement, which muscle types stop working first
ST motor units
formular for work (kgm)
force (kg) x distance (meters)
what does anaerobic power measure or reflect
the development of phosphagen metabolism
highest work performed in the first 5 sec
what does Anaerobic capacity meausre or reflect
the development of phospagen anaerobic glycolytic metabolism
total work performed in first 30 sec.
what does the fatigue index measure or reflect
oxidative capacity of a muscle
percent decline in work completed (first 5 sec. and compared to last 5 sec.)
high fatigue index
low oxidative capacity of muscle tissue
low fatigue index
high oxidative capacity of muscle tissue
what does body weight determine
optimal pedalin resistance
calculation for resistance in anaerobic test
0.075 kp x body weight in kg (adjust to nearest 25)
calculation for anaerobic power
([revolutions at 5 sec of test] - [revolutions at 0 sec of test]) x workload x 6 = KGM/5sec
calculation of anaerobic capacity
([revolutions at 30 sec of test] - [revolutions at 0 sec of test]) x workload x 6 = KGM/30sec
calculation of fatigue index
- ([revolutions at 5 sec of test] - [revolutions at 0 sec of test]) x workload x 6 = KGM/first5sec
- ([revolutions at 30 sec of test] - [revolutions at 25 sec of test]) x workload x 6 = KGM/last5sec
- / 1. = percent per power (for percent x 100)
Body weight conversion into kg
lb/2.2
Calculation of Oxygen uptake rate (VO2) in L/min - conversion
VO2 ml/min / 1000
Oxygen uptake rate
VO2
Carbon dioxide production rate
VCO2
Calculation of carbon dioxide production rate in L/min - conversion
VCO2 ml/min / 1000
Respiratory exchange ratio
RER or R
Calculation of RER or R
VCO2 (L/min) / VO2 (L/min)
Calculation of kcal expended per minute
kcal/min = (kcal/liter of VO2) x VO2 L/min
Kcal used per 60 min
kcal/min x 60 min
Calculation of VO2 in ml/kg/min
(VO2 in L/min x 1000) / BW kg
Calculation of metabolic equivalence (METS)
(VO2 in ml/kg/min) / 3.5 ml/kg/min
1 resting metabolic equivalent (1MET)
3.5 ml/kg/min of VO2
What does the resting metabolic equivalent indicate
oxygen needed to maintain
body functions at rest
what does METS indicate
the rate a person works more compared to their resting metabolic rate
what is a better predictor of performance in athletes where body is supported during performance
the absolute measurement of the VO2 max in L/min or ml/min
better predictor of performance in athletes where athletes have to carry their own body weight
relative measurement of the VO2 max in L/min or ml/min
methods to measure and monitor heart rate
palpation (tasten) of radial or carotid artery (multiply 10 sec by 6 for beats per minute (b/min)
use heart rate monitor – record an ECG
range of normal resting heart rate
60 – 100 b/min
resting heart rate greater than 100 b/min
trachycardia
resting heart rate less than 60 b/min
bradychardia
what is the age predicted max heart rate for land sport
220 – age in years
how accurate is the age predicted max heart rate
+/- 10 b/min
only for 68% of population
age predicted max heart rate for land-based arm exercise
207 – age in years
age predicted max heart rate for water based exercise
208 – age in years
effects of training on max heart rate
no difference following training, but resting – and submax is lower
blood pressure
force that moves blood through the circulatory system
direction of blood flow
from location of high blood pressure to low pressure
systolic blood pressure
highest pressure
pressure in the arteries during contraction of the ventricle
normal healthy range for systolic pressure
100 – 140 mmHg
systolic pressure greater than 160 mmHg
major coronary heart disease risk factor
resting systolic blood pressure between 140 – 160 mmHg
mild hypertension
what can mild hypertension develop to
coronary artery disease
what is equivalent to weight control
burning of kcal
what kind of training help controlling weight
high intensity
relative contraindication to exercise testing
resting symbolic blood pressure greater than 200 mmHG
what indicates stopping of an exercise test (systolic blood pressure
systolic blood pressure values greater than 250 mmHg
a sudden drop (20 mmHg or more) in systolic blood pressure
failure of systolic blood pressure to increase with increasing workload
diastolic blood pressure
pressure in arteries during relaxation of the ventricles
normal healthy range for diastolic blood pressure
60 – 89 mmHg
diastolic blood pressure equal or greater than 90 mmHg
major coronary heart disease risk factor
diastolic indicator to stop exercise test
diastolic blood pressure greater than 120 mmHg
effects of training on resting blood pressure
low and high amount of training – high blood pressure
moderate training – low blood pressure
what does and ECG/EKG measure
electrical impulses of the heart during various stages if cardiac stimulation
what works as the pacemaker of the heart
SA node
P-wave of ECG/EKG
contraction/depolarization of the atria
QRS complex on an ECG/EKG
electrical activity of ventricular contraction
T-wave of an ECG/EKG
repolarization of ventricles
What else occurs during the QRS complex
repolarization of the atria
One cardia cycle
combination of P-wave, QRS complex and T-wave
Positive deflections in a normal ECG/EKG
P, R, T
Negative deflection in a normal ECG/EKG
Q, S
6 Limb leads of an ECG
3 Bipolar Leads
3 Unipolar leads
3 Bipolar leads
Lead I – III
Site of positive electrode of Lead I and direction of QRS
Left Arm (Right Arm negative) Positive/negative
Site of positive electrode of Lead II and direction of QRS
Left Foot (right arm negative) Positive
Site of positive electrode of lead III and direction of QRS
Left Foot (left arm negative) Positive
3 unipolar leads
augmented voltage right (AVR)
Augmented voltage left (AVL)
Augmented voltage foot (AVF)
Site of positive electrode of AVR and direction of QRS
right arm
Negative
Site of positive electrode of AVL and direction of QRS
left arm
negative
6 chest leads
V1 – V6
Site of positive electrode of V1 and direction of QRS
right sternal border, 4th intercostal space
Negative
Site of positive electrode of V2 and direction of QRS
left sternal border, 4th intercostal space
Negative
Site of positive electrode of V3 and direction of QRS
Equally spaced between V2 and V4
Negative or positive
Site of positive electrode of V4 and direction of QRS
midclavicular line, 5th intercostal space
Positive
Site of positive electrode of V5 and direction of QRS
anterior axillary line, 5th intercostal space
Positive
Site of positive electrode of V6 and direction of QRS
midaxillary line, 5th intercostal space
Positive
Difference between V5 and other chest leads
V5 picks up 80% or more of all cardiac abnormalities
When does the QRS deflects negative
when the heart polarizes away from the electrode
Leads AVR, AVL, V1 and V2
Positive QRS deflection
when depolarization wave of heart move towards positive electrode
Leads II, III, AVF, V4, V5, and V6
Sound related to blood pressure
korotkoff sound
Phase I of the Korotkoff sound
first appearance of tapping, gradually increases
Phase II of Korotkoff sound
murmur, squishing quality is heard
Phase III of Korotkoff sound
sounds are crisper and increase in intensity
Phase IV of Korotkoff sound
sound is very loud, soft blowing quality
Phase V of Korotkoff sound
sounds disappear
Systolic pressure determination
point at which initial tapping sound is heard (Phase I)
Diastolic pressure determination
onset of muffling (phase IV) – preferred for exam
Disappearance of sound = intra-arterial diastolic pressure (Phase V)
Normal regular rhythm of an ECG
tight or narrow QRD with spike at the top
P-wave precedes and T-wave follows QRS complex
Premature ventricular contraction
to early and high R – wave
No P- and T – wave
Multifocal
no P – and T- wave
Every cardiac cycle looks completely different, very serious
Ischemia
inverted T-wave
ventricular flutter
nice smooth wave
no QRS
fires at 200-300/min
ventricular fibrillation
flutter turns into ventricular asytole - no cardiac activity
what does ventricular fibrillation require
cardio-pulmonary resuscitation and defibrillation
size principle
motor units with smaller cell body are recruited first, following by units with larger cell bodies (FT)
electromyogram (EMG)
recording of electrical events of muscle contraction
two recordings of an EMG
- raw recording of amlitude and frequency
2. combination of amplitude and frequency - steepness of the slope
amplitude of an EMG
represents recruited motor units
frequency of EMG
represents more frequent firing of motor units
types of ST motor units
SO - slow twitch oxidative motor units “aerobic”
types of FT motor units
FOG - Fast-twitch oxidative glycholytic motor units
FG - Fast-twitch glycholytic motor units “anaerobic”
Site of positive electrode of AVF and direction of QRS
left foot
positive
oxygen defict
beginning of exercise
VO2 is below necessary to supply all ATP
anaerobic energy systems provide additional ATP until steady state is reached
steady state exercise
oxygen supplied to working muscle = oxygen demanded
VO2 +/- 2 ml/kg/min -> normal
oxygen dept / EPOC
amount of oxygen consumed during recovering from exercise above oridinary consumed
payback of oxygen defict
two phases of oxygen debt
lactactic phase
alactacid phase
alactacid phase of oxygen debt
first 1 - 2 min
replenishment (Nachschub) of phosphagen
lactacid phase of oxygen debt
follows alactacid phase
removal of lactate by oxidation
3 reasons why oxygen debt is greater than oxygen deficit
increase oxygen demand for 2 phases and to meet oxygen transport demands
dissipation (Verteilung) of heat from muscle to skin
hormones thyroxine and catecholamines release during exercise -> they lead to an increase oxygen demand
increase in frequency of EMG recordings
increase in firing rate of motor units
what is local muscle fatigue based on
phosphagen metabolism and lactic acid
what is neural muscle fatigue based on
neurotransmitter (AcH)
relationship between force and cross section area
force is proportional to cross sectional area
Isokinetic strength
max. overload throughout an entire workload
force greater then resistance
isokinetic stress response
single effort
physiological attributes of anaerobic indices from anaerobic tests
anaerobic power
anaerobic capacity
fatigue index
relation between anerobic work indices and athletic abilities
sprinter higher results in all 3 indices -> more FT motor units
effects of body weight/composition on anaerobic work indices
BW has no effect, but body composition - more fat will lead to lower results
pacemaker rate of SA node
75 - 80 BPM
pacemaker rate of AV node
60 BPM
pacemaker rate of ventrivles
30 - 40 BPM
ST-Elevation
fresh myocardial infarction
small inverted T-wave
elevated S-wave
Q-wave infarction
wide, deep Q-wave (1/3 of QRS complex)
stay with person forever
