825 Flashcards
surrounds entire muscle: also known as fasica
epimysium
surrounds fasciculi
perimysium
surrounds myocytes
endomysium
muscle cell membrane; underlies the endomysium
sarcolemma
invaginations of the sarcolemma
transmit action potential into interior muscle cell
closely apposed to sarcoplasmic reticulum
transverse (T) tubules
membranous sac underlying the sarcolemma
responsible for calcium storage, release and uptake
integral to muscle contraction
sarcoplasmic reticulum
bulbous enlargements of the SR
store and release calcium
terminal cisternae
muscle cell membrane
contains sarcoplasm, cellular proteins, organelles and myofibrils
sarcolemma
divided into individual contactile units - sarcomeres thick filaments (myosin) thin filaments (actin) troponon and tropomyosin are located on actin protein
myofibrils
molecular blueprint: specifies and coordinates assembly of structural, regulatory and contractile proteins
molecular spring: links Z disk to Mline of sarcomere, maintains relative position of actin and myosin, contributes to muscle extensibility and passive force development
may also contribure to signal transduction from myofibril to nucleus and other cellular areas
Titin/ Connectin
comprises majority of thin myofilament
arranged in double helix formation
contains myosin binding sites
actin
resides in groove along length of actin protein
blocks myosin binding site under resting conditions
tropomyosin
spaced at regular intervals along length of actin protein
regulates position of tropomyosin relative to myosin binding site
troponin
slow oxidative
Type I
fast oxidative-glycolytic
Type IIa
fast glycolytic
Type IIb
recommended protein intake for sedentary adults
.8 g protein/kgBW/day
recommended protein intake for physically active adult
1 protein/kgBW/day
tendons and myocyte crossbridges
translate stretch into force
series elastic components
collagenous structures
stabilize and protect muscle
parallel elastic components
stretch creates potential energy that can enhance forces produced by contractile elements
stretch-shortening cylce
muscle tension must be developed at adequate intensity and duration
overload
training must stress the muscles, fibers, motor units that need to perform
specificity
disuse results in loss of muscle mass
reversibility
strength gains can be variable
individuality
muscle mass peaks at
25-30 years of age
velocity at which action potentials are propagated along the cell membrane is primarily determined by two factors
fiber diameter
presence of myelin
localized disturbances in post synaptic membrane potential (depolarizes or hyperpolarizes)
arise from action of ion channels
summation can occur spatially or temporally
graded amplitude, proportional to stimulus stregth
graded potentials
debolarizes membrane
all or none ampliture, stimulus strength coded by frequency
absolute and relative refractory periods
action potential
basic functional unit of skeletal muscle
motor units
contains relay pathways form cerebellum, basal ganglia, and superior colliculus to motor cortex
contributes to motor generation and self monitoring (corollary discharge)
thalamus
regulates internal environment to maintain homeostasis
temp, BP, HR, contractility, respiration, digestion, fluid balance, emotion, neuroendocrines, sleep wake, appetite, thirst
hypothalamus
receives visual and proprioceptive input
compares actual movement to motor play
generates corrective responses
this coordinates the timing and sequence of muscle activity, smoothing movement
cerebellum
autonomic regulatory centers for respiratory and cardiovascular centers
reticular system: coordinates muscle function, maintains muscle tone, contributes to selep wake cycle and consciousness, pain control
brain stem
cortiocospinal and corticobulbar tracts
innervate motor neuron in spinal cord and brainstem
involved in voluntary movement
pyramidal
primarily located in reticular formation
modulated by cortex, cerebellum, basal ganglia
involved in reflexed, postural control and coordination of movement
extrapyramidal
fight or flight
important implications for exercise due to control of HR . vasculatrue and respiration
sympathetic
feed and breed
promotes synthesis of glycogen
parasympathetic
aerobic training exercise prescription for stroke
20-60 min
3-5 days per week
low to moderate intensity (40-70% VO2 or HR)
strength trining exercise presciption for stroke
2-3 days per week
low to moderate (3 sets of 8-12 reps)
progressive loss of dopaminergic cells in basal gangla
parkinsons disease
aerobic training exercise prescription for PD
up to 60 min
3 or more days per week
low to moderage intensity (40-80% peak HR)
walking exercise prescription for PD
20-30 min per day
4-6 sessions per day
self selected pace
strength training exercise prescription for PD
3 or more times per week
low intensity
chronic, inflammatory demyelination of the CNS
disrupts neural transmission
cycles of exacerbation-remission
multiple sclerosis
aerobic training exercise prescription for MS
30 min
greater than 3 times per week
low to moderate intensity (50-60% VO2 or HR)
sympathetic nervous system catecholamines and effect on heart
epinephrine and norepinepherine
increased myocardial contractility and blood flow
VO2 max =
Q *a-vO2 difference
Q=
SV*HR
SV=
and relation to work rate
end diastolic volume- end systolic volume
increased curvilenearly with work rate until it reaches near max at about 50% or aerobic capacity
more blood in the ventricle causes a greater stretch and contract with increased force
frank starling mechanism
where is the greatest change of pressure in the vascular system
deccreases the most in the arterioles
the velocity of flow is __________ proportional to the cross sectional area of the vessel
inversely
blood flow is transiently increased following a brief period of total ischemia
reactive hyperemia
rise in CO2 disproportionate to a rise in O2
indicates the level of exercise where body has reached level in which energy can no longer be solely supplied by aerobic metabolism
anaerobic threshold
RER >1 indicates
anaerobic metabolism present
RER >1.09 indicates
maximal effort
Q at rest and exercise
5 L/min
20 L/min
normal maximal SV
100-200 ml/beat
EF=
average
SV/EDV
60%
proportion of blood pumped out of the left ventricle each beat
ejection fraction EF
karvonen formula
(training range % (max HR-resting HR)) + resting HR
tidal volume and RR both increase until
70-80% of peak exercise
after only RR increases
shortness of breath. during exercise this is most often caused by inability tor readjust the blood PCO2 and H+ due to poor conditioning of respiratory muscles
dypnea
increase in ventilation that exceeds the metabolic need for oxygen. voluntarily this reduces the ventilatory drive by increasing pH
hyperventilation
a breathing technique to trap and pressurize air in the lungs; if held for and extending period, it can reduce cardiac output. this technique is often used during heavy lifts and can be dangerous
valsalva maneuver
BP in relation to exercise
linear increase in SBP
DBP may decrease slightly or remain the same
MAP=
Q*TPR
ratio between CO2 released and oxygen consumed
Respiratory exchange ratio (RER)
all exercise prescriptions should include
warm up/stretching
conditioning
cool-down
light intensity
30-40% HR or VO2
moderate intensity
40-60% HR or VO2
vigorous intentisy
60-90% HR or VO2
exercise prescription time
30-60 min a day of mod or
20-60 min a day of vig
(3-5 days a week)
volume for exercise prescription
150 min per week
RPE for mod
12-13
RPE for vig
15-16
1 MET =
3.5 ml/(kg*min)
age associated loss of skeletal muscle mass and function
sarcopenia
increases in frequency, intensity or duration should generally be limited to
10% per week
aerobic training for AIDS
3-5 days/week
40-60% VO2 or HRR
30-60 min per day
resistance training or AIDS
2-3 days per week
2-3 sets of 10-12 reps (60% 1 RM)
level that autonomic dysreflexia appears at
T6 and above
disruption of sympathetic innervation may limit HR to
115-130 bpm
aerobic training in SCI
3-5 days per week
start at 40-60% and progress to 60-80% VO2
30-60 min total
resistance training and SCI
2-4 days per week
2-3 sets of 8-12 reps
no exercise if blood sugar
> 250 or
paradoxical closure or adduction of the vocal cords during inspiration
this causes partial to severe airflow obstruction with sensations of throat tightness, suffocation and choking
may mimic EIB
vocal cord dysfuction
stridor chest or throat tightness "cant get air in, something stuck in my throat" abrupt onset and resolution of symptoms chronic cough and harseness tingling in arms and legs feeling faint shortness of breath and breathing difficulty
vocal cord dysfunciton
four square step test interpretation
> 15 sec = fall risk
wall occiput distance interpretation
distance greater than 7 cm rules in thoracic fx
TUG interpretation
> 14 sec associated with high fall risk