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Kine 3080 exam 3

Terms in this set (112)

Slow twitch fibers have a
slow speed of contraction and a low force production.
Fast twitch fibers have a
fast speed of contraction and a high force production.
What is hypertrophy
Increase in the size and number of myofibrils per muscle fiber which increases the size of the muscle
What is Hyperplasia
increase in the number of muscle fibers
Which muscle fibers hypertrophy the most with resistance training?
Type II (Fast Twitch)
Which muscle fibers tend to atrophy most with aging?
Type II (Fast Twitch)
The only neurotransmitter that acts upon muscles is
Acetylcholine
When acetylcholine is released and binds to a receptor (causes Na+ to enter), we get an
action potential
When ____ combines with its receptor, it causes a small change in the membrane which allows _____ ions to enter, (more negative + -86) the result is a more_____
GABA, chloride ions, negative ion.
"relaxation" occurs when ____ is pumped back into ___
Ca+, SR
Amount of force produced is inversely related to
speed (ex: high force = low speed)
I'm producing very little force, how fast am I contracting?
You don't know.
I'm producing force fast, how much force am I producing?
a little
I'm producing force slowly, how much force am I producing?
You don't know
____ fibers produce more force eccentrically
individual
The faster you go ____ produces more force
eccentrically
When force is high, velocity is
low
raise power at competition velocity by raising peak power and power at all velocities by training
at a range of velocities
shift peak to occur at competition velocity by training
at high velocities
cardiac output at rest
5 L/min = 70 bt/min × 75 ml/bt
cardiac output at max
25 (L/min) = 200 bt/min × 125 ml/bt
cardiac output at trained max
35 (L/min) = 200 bt/min × 175 ml/bt
cardiac output at trained rest
5 (L/min) = 50 bt/min × 100 ml/bt
the effect of training on the heart at rest is to increase
stroke volume
local humoral effects that cause vasodilation
heat, CO2, hydrogen ions (acidity), potassium ions
Heart rate is unchanged at max trained cardiac output, but
SV changes because the heart gets bigger and stronger
3 ways to increase muscle BF
increase cardiac output (pump more blood), redistribute O2 to muscles (send blood to muscles), and local vasodilation
Only way to increase myocardial BF
increase cardiac output, but same % is distributed to heart muscle (aerobic only)
If the heart works twice as hard, how much more energy/oxygen/blood does it need/pump?
2x as much
If the heart pumps twice as much blood flow, how does this effect myocardial BF?
2x as much
If myocardial BF goes up twice as much, how does this effect VO2?
Twice as much
The work of the heart is directly related to the
delivery of oxygen
During exercise, do arteries in the muscle dilate to in order to attract a greater percentage of Qc?
Yes
Heart rate favors
women
Stroke volume favors
men
During excise, do the arteries in the heart dilate to attract a greater percentage of Qc?
No, they always get 4%
During exercise, do the arteries in the heart dilate?
Yes, they dilate because they get more blood flowing through them
Oxygen delivery to the tissues depends
on the oxygen content of the blood, blood flow to the tissues, and local conditions
2 factors that can contribute to an increase in SV with increasing intensity of exercise are
increased venous return (preload) and increased ventricular contractility, decrease in afterload (results from a decrease in TPR)
How much blood goes through the coronary arteries?
4%
Why does cardiovascular drift result in SV decrease?
Reduction in central venous pressure
How much blood is pumped through the body at rest?
5L
Local vasodilation is caused by
heat, acidity, carbon dioxide
Effect of exercise on HR and SV
increases
What determines loss of sweat?
Core temperature
Austin is exercising and the osmolarity of his blood has gone up. Good or bad?
He is going to sweat less (a bad thing).
How we explain an increase in blood osmolarity?
You're body thinks its dehydrated , misinterpreted by Gatorade or sugary drinks.
Austin is exercising in the heat. He is dehydrated, is this going to effect his sweat rate?
Yes, he will sweat less.
If your body loses ___ of body weight, you are dehydrated
2%
Dehydration causes an _____ in hemoglobin concentration
increases content of oxygen in arterial blood
How does anemia affect the Fick Equation?
It effects the (a-v) O2 difference
What is the effect of increasing the size of the PP gradient on the flow of carbon dioxide?
It has no effect
To avoid a sudden drop of blood pressure in exercise, you
cool down
What is the value of the Bohr effect?
Shifts the curve to the right, allow you to load up 100%, but now blood holds on to less O2
Factors that determine TPR
length, viscosity, diameter
To avoid angina you should avoid
small muscle exercise
What would lower your blood pressure
lowering sympathetic activity (beta blockers)
Control of HR is
neural (rapid decline)
Control of TPR is
humoral (slow increase)
angina
Pain in the heart region caused by lack of oxygen
Increase Cardiac output by
Increase driving pressure and decrease resistance (Qc=MAP/TPR)
What makes vessels constrict?:
Cause of sympathetic activity
What causes vessel to dilate?
Local humoral vasodilation (located in exercising muscles)
2 ways to increase whole body VO2
increase cardiac output (pump more blood)
widening the (a-v) O2 difference (extract more oxygen)
3 different muscle reflex receptors
joint receptors, golgi tendon organs, muscle spindles
Joint receptor stimulus, response, purpose
deformation (fast),
send specific info to respiratory (ventilation)
information about position and movement, safety, and perhaps control of ventilation in exercise
Golgi tendon stimulus, response, purpose
tension,
inhibition of motorneurons "relaxation",
info & protection. threshold for response increases with training
Muscle spindle stimulus, response, purpose
rate of stretch (can also detect length)
contraction of muscle
information, balance-posture, & involuntary control or servo-assist
3 factors in pulmonary ventilation that causes you to breathe more
increased PaCO2, decreased pH, decreased PaO2
what happens to PvO2 during exercise?
it goes down (muscles are using more oxygen)
what happens to PAO2 during exercise?
nothing
what happens to PaO2 during exercise?
stays the same, PaO2 = PAO2
voluntary hyperventilation reduces amount of
CO2 (in lung) and reduced PaCO2
determinants of Hb
sex, disease (anemia), training status
Hb is fully saturated with oxygen if PaO2 is
100 mmHg
T/F PAO2 = PaO2
True (alveolar = arteriole partial pressure)
Arterial desaturation
possibility that oxygen is not able to fill up on hemoglobin. only occurs in highly trained endurance athletes
Frank-Starling mechanism
A mechanism by which the stroke volume of the heart is increased by increasing the venous return of the heart (thus stretching the ventricular muscle).
The Frank-Starling mechanism appears to have its greatest influence at ____ exercise intensities, and improved contractile force becomes more important at _____ exercise intensities.
lower,, higher
Stroke volume is determined by four factors:
1. The volume of venous blood returned to the heart (the heart can only pump what returns)
2. Ventricular distensibility (the capacity to enlarge the ventricle, to allow maximal filling)
3. Ventricular contractility (the inherent capacity of the ventricle to contract forcefully)
4. Aortic or pulmonary artery pressure (the pressure against which the ventricles must contract)
Bradycardia is defined as a RHR lower than __ beats/min.
60
Tachycardia is defined as a resting rate greater than ____ beats/min.
100
HR increases because of:
• withdrawal of parasympathetic
• Onset of exercises & low intensities
• Increased sympathetic
What is the effect of training on the heart at rest?
To increase SV
effect of exercise on blood pressure (Q=MAP/TPR)
Cardiac output increases because MAP increases, TPR decreases
If PaO2 stays the same, ____ stays the same
CaO2
the affinity(attraction) of HB for oxygen is related to how many _______
oxygens its' holding. The more oxygens Hb is holding, the harder it holds on. To make a Hb to give up the oxygen, we have to change PP from 100 to 40.
vasovagal syncope
a common physiological response consisting of slow heart rate and low blood pressure that sometimes occurs in people with blood/illness/injury phobias
Hb CAN carry _____ oxygens per molecule or a L of blood can carry ____ mL of oxygen
4, 200
Concentration / po2 Must be higher in ____ than in ____
alveoli, blood
Concentration / pco2 Must be higher in ____ than in ____
blood, alveoli
Blood flow equation
bf = change in pressure/resistance
Henry's law
gases dissolve in liquids in proportion to their partial pressures, depending also on their solubilities in the specific fluids and on the temperature
Fick's law
rate of diffusion through a tissue such as the respiratory membrane is proportional to the surface area and the difference in the partial pressure of gas between the two sides of the tissue.
Dalton's Law
The total pressure of a mixture of gases is the sum of the individual pressures
To better respond to increased oxygen demand, hemoglobin unloading of oxygen (desaturation) is enhanced (i.e., the curve shifts to the right) when .
PO2 decreases, pH decreases, or temperature increases
\If the skin wins the competition for Qc muscles lose, less O2, so you
slow down
If the muscles win the competition for Qc skin loses, and you risk
dying of heat stroke
Conduction
The direct transfer of heat through an object or contact
Determinants rate of conduction
T gradient, area of contact/distance, material
Convection
The transfer of heat by the movement of a fluid. Open or closed system
Determinants of convection
T gradient, area of contact, distance, type & amount of fluid
Radiation
The transfer of energy by electromagnetic waves (heat coming from sun)
Determinants of radiation
T gradient, area of contact/distance, material (surface)
Skin to environment evaporation of sweat
exercise - increase sweating with increase core temp, decrease sweating with increase blood osmolarity
training - increase sweat rate
acclimatization - decrease sweat threshold
volitional - drink to maintain sweating
Sweat is _____ related to blood osmolarity
inversely
example Open system
picks up fresh air, blows it off, and carries it away
example Closed system
standing with a fan blowing, warmed up air goes around the room and comes right back. The longer the distance it has to travel, the more opportunity it has to lose heat.
Muscle to skin, skin to environment
Conduction
Most important way to transfer heat from muscle to skin
Convection
what is the main way we transfer heat from skin to environment?
evaporation of sweat
Acclimization
lowers threshold for sweating
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