Chapter 6 Flashcards
primary function of cardiovascular system
deliver oxygen and nutrients
remove waste and metabolites
cardiac output
blood pumped measured in L/min
cardiac output = stroke volume x heart rate
stroke volume
blood ejected with each beat
measured in milliliters
cardiac output acute response to aerobic exercise
relative & absolute values
4x increase
from 5L/min to 20-22L/min
what VO2 max does stroke volume plateau
40% - 50%
maximal stroke volume for men - sedentary vs trained
100-120ml avg sedentary
150-160ml avg trained
2 physiological factors responsible for regulating stroke volume
- end diastolic volume
- epinephrines producing a more forceful contraction
end diastolic volume
the volume of blood available to be pumped by left ventricle at end of diastole
venous return
the amount of blood returning to the heart (important for increase in stroke volume and end diastolic volume)
3 mechanisms contributing to increased venous return
venoconstriction, skeletal muscle pump, respiratory pump
Frank Starling mechanism
the more a muscle is stretched, the greater the force of contraction
ejection fraction
& what increases it
the fraction of end diastolic volume ejected from heart
stronger contractions from Frank Starling mechanism
how to measure maximal heart rate
220 - age
+/- 10-12
heart rate vs intensity graphic relationship
linear increase
oxygen uptake
the amount of oxygen consumed by the body’s tissues
3 components of oxygen demand
mass of exercising muscle, metabolic efficiency, exercise intensity
maximal oxygen uptake
&significance
the greatest amount of oxygen that can be used at the cellular level for the entire body
the most widely accepted measure of cardio respiratory fitness
2 factors of capacity to use oxygen
- the ability of heart and body to transport O2
- the ability of body tissues to use it
1MET (metabolic equivalent)
& amount
resting oxygen uptake
3.5ml of O2 per kg of body weight per minute
max O2 uptake range (METs)
7.1 - 22.9 METs
Fick equation
VO2 = Q (cardiac output) x a-vO2 difference
systolic blood pressure
blood pressure against arterial walls when blood is ejected
systole
ventricular contraction
diastolic blood pressure
pressure against arterial walls when no contraction
diastole
ventricular relaxation
resting avg systolic vs diastolic BP
110-139mmHg - systolic
60-89mmHg - diastolic
mean arterial pressure
average blood pressure throughout cardiac cycle
max systolic BP during exercise
220-260mmHg
2 mechanisms for regulating regional blood flow
vasoconstriction
vasodilation
% blood flow to skeletal muscle at rest vs during exercise
15%-20% at rest
up to 90% during exercise
minute ventilation
the volume of air breathed per minute
factors of minute ventilation
depth of breathing, frequency of breathing
breathing frequency at rest vs during exercise
12-15 per minute at rest
35-45 per minute during exercise
tidal volume
the amount of air inhaled and exhaled with each breath
tidal volume at rest vs during exercise
.4L to 1L at rest
3L+ during exercise
minute ventilation increase at rest vs during exercise
RELATIVE
15x-25x
ventilatory equivalent
the ratio of minute ventilation to oxygen uptake
2 metabolic causes of ventilation increase
increased oxygen uptake
increased CO2 production
alveoli
unit of pulmonary system where gas exchange occurs
anatomical dead space
areas of respiratory system not functional for gas exchange (nose, mouth, trachea, bronchi, bronchioles)
physiological dead space
alveoli with impairments
diffusion
the movement of CO2 and O2 across a cell membrane
cause of diffusion
pressure gradients of gases between blood and tissue
hemoglobin content and oxygen content in 100ml of blood
15g-16g hemoglobin
20ml oxygen
process of blood removal of CO2
CO2 + H2O –> bicarbonate
bicarbonate is carried to the lungs by blood plasma
blood removal of lactic acid
cori cycle
chronic cardiovascular adaptations to aerobic training
increases and decreases
increase: max cardiac output, stroke volume, muscle fiber capillary density
reduce: HR at rest & during exercise
primary mechanism for increasing O2 uptake
increasing cardiac output
aerobic endurance training effect on SA node discharge rate
slows due to increase in parasympathetic tone
most significant change in cardiovascular function with long-term aerobic endurance training
increase in max cardio output via improved stroke volume
chronic respiratory system adaptations to aerobic exercise
increased tidal volume
chronic neural adaptations to aerobic exercise
- increased efficiency
- rotation of neural activity in synergists and motor units
chronic muscular adaptations to aerobic exercise
- higher maximal aerobic power and greater % intensity sustentation
- OBLA delay to 80%-90% of VO2 max
- increased aerobic capacity of type I & II
- reduction of type II fiber size (if low intensity)
- mitochondria increase size & number
myoglobin
protein that transports oxygen within a cell
mitochondria
organelles that produce ATP
causes of greater % intensity sustentation
glycogen sparing & increased fat utilization
causes of OBLA shift
- reduced production of lactate
- changes in hormone release
- faster lactate removal
key to stimulating new bone formation through aerobic exercise
intensity significantly higher than normal daily activities
strategies to stimulate new bone formation and connective tissue growth through aerobic exercise
- increase rate of limb movement
- weight bearing activity on cartilage
- moderate running program (1hr/day, 5days)
endocrine adaptions to aerobic exercise
increases in circulation, receptor changes, increase in absolute secretion rates
more physiological adaptations to endurance training
- increase in max cardio output
- increase in max oxygen consumption
- increased running economy
- lower blood lactate concentration
hyperventilation
increase in pulmonary ventilation
two important acute responses to high altitude
- hyperventilation
- increase in cardiac output via increase in heart rate
long-term cardiovascular altitude adaptations
increases & decreases
- decreased: stroke volume, max HR, max cardiac output
- increased: capillary density
long-term hematologic altitude adaptations
- increased: red cell production (30%-50%), hemoglobin production (5%-15%)
hyperoxic breathing
breathing oxygen enriched gas mixtures during rest or after exercise
effects of smoking
- airway resistance
- cilia paralysis
- carboxyhemoglobin formation
blood doping
artificially increasing red blood cell mass
erythropoietin (EPO)
stimulates red blood cell production
benefits of blood doping
- 11% increase VO2 max
- decreased blood lactate
- diminishes impact of environmental conditions
most common cause of OTS
continued intensified training without adequate rest
overtraining effect on cardiovascular system
- decreased OR increased heart rate
- max HR decrease
aerobic overtraining effect on endocrine system
decrease & increase
- decrease: (30% or more) in test, cortisol, GH secretion, dopamine levels
- increase: epinephrine &norepinephrine levels
tapering
planned reduction of volume (duration, frequency) of training before competition or recovery microcycle
effect of detraining on VO2 max
short term & long term
short term: 4% - 14%
long term: 6% - 20%
factors of detraining VO2 max reduction
- decreased blood volume
- decreased stroke volume
- decreased max cardiac output
- increased submax heart rate
