exercise🤸♀️ Flashcards
what are long fibres in skeletal muscle good for
rapid movement
what are short fibres in skeletal muscle good for
large forces
what are the 3 fibre types
type 1 -slow
type 2a -fast
type 2b -fast
features of slow twitch type 1 muscle fibres
oxidative
red
prolonged endurance activity
features of fast twitch type 2a muscle fibres
red
either endurance or rapid force
quickly fatigue
features of fast twitch type 2b muscle fibres
white - low myoglobin
rapid force production
quickly fatigue
glycolytic metabolism
what do the 3 diff fiber types look like on a microscope
type 1 = dark
type 2a = light
type 2b = medium
what are two types of muscle contraction
isometric
isotonic
what is isometric muscle contraction
contraction against resistance where length of muscle remains the same
eg holding a weight in your hand with arm outstretched
what is isotonic muscle contraction + the two types?
contraction against resistance where length of muscle changes
concentric = in direction of contraction eccentric - opposite to direction of contraction
what is the result of endurance exercise training
increased mitochondrial function
hypoxia inducible factors (HIFs) involved in gene control of red muscle cell production and regulation of glycolytic enzymes
increased haemoglobin conc
how is creatine phosphate made
resting muscle =ATP + creatine -> Creatine phosphate + ADP -> creatine phosphate -> creatine + atp in active muscle
what small molecules are produced in the cirtic acid cycle
1x ATP
3X NADH
1X FADH2
brief pathway of how pyruvate forms ATP in aerobic krebs cycle
pyruvate -> acetyl CoA -> mitochondria -> ATP
brief pathway of how pyruvate forms ATP in anaerobic pathway
pyruvate -> lactic acid -> liver -> ATP
what is gluconeogenesis
synthesis of new glucose from noncarbohydrate precursor
what is energy changes in intense short term exercise, 10-15sec, up to 2 min, several mins
10-15 sec
-creatine phosphate
-ATP
up to 2 mins
-glycogen to glucose-6-phosphate
several minutes
-lactic acid build up
-oxygen debt
-about 2L of oxygen required to replenish ATP and creatine phosphate
what are the energy changes in longer less intense exercise?
glycogen from circulation
glucose from plasma
hepatic glucose production increases
-short term glycogenolysis
-longer term gluconeogenesis
-muscle proteolysis
-glucagon and insulin
-fatty acid release
what happens during the recovery phase of exercise +what are the 2 components
-fast component
->resting levels of ATP and CP restores
-slow component
->lactic acid converted to glucose in liver
->lactic acid converted to pyruvic acid
what is the role of the respiratory system during exercise and how does it change to reflect this
to meet the increased oxygen demand
-increase in ventilation rate
-increased in tidal volume
what 8 things control respiration
psychological
cns
co2
h+ ion level
O2 level
pulmonary stretch receptors
peripheral joint receptors
body temperature
what happens to blood gas levels in arteries and veins during respiration and exercise
not much.
-arterial O2 and venous CO2 do not change significantly during exercise
because:
- respiratory system can provide adequate aeration
what changes happen to oxygen consumption during exercise?
oxygen consumption increases
similar rate for first few seconds
reaches steady state where lactate acid accumulation is minimal
VO2max = when steady state oxygen consumption does not increase with work intensity
when can u exercise past VO2 max?
when u produce an increased lactic acid accumulation
-age - decreases after 25
-sex - lower for females
-activity - improves with activity
what happens in the lungs themselves
o2 and co2 diffusion capacity increases with exercise
what changes happen to the heart during exercise
increase cardiac output
-increase stroke volume
-increase heart rate
how is cardiac output controlled
increased activity to sympathetic nervous system increases stroke volume in ventricular myocardium
decreased activity to parasympathetic nervous system increases heart rate via SA node
increase cardiac output
what is stroke volume - what is CVS and TPR
the amount of blood expelled by the heart in each beat
CVS= central venous pressure changes diastolic filling pressure therefore more blood available to fill heart
TPR = total peripheral resistance changes ability to expel blood into arterial system
how is stroke volume controlled?
-increased venous return, increases end-diastolic volume
-increase sympathetic activity/epinephrine - increase contractility
-decrease arterial pressure
- increase stroke volume
what is starling’s law
the more full the heart is the harder it will contract increasing the stroke volume (ventricular performance)
force of contraction related to how stretched the cardiac muscle is
how does control of heart shift during exercise change
during exercise, heart control shifts from parasympathetic (cPNA) to sympathetic (cSNA)
during recovery shifts back to cPNA
what are the benefits of exercise
reduced BP
increased circulating HDL and reduced triglycerides
changes in arterial wall homeostasis reducing atherosclerotic disease
improved aortic valve function and reduction in calcification
increased ventricular chamber wall thickness
increased red cells
changes in cardiac vasculature to increase o2 availability
how does exercising affect depression
moderate clinical effect in a decline in depression
long term follow up on mood found in favour of exercise
no more effective than psychological or pharmacological treatments
important for those who do not want pharmacological treatments
how may exercise affect RA
2/3 RA patients may suffer from muscle wastage
higher risk of low bone density from RA - high intensity weight bearing exercise mitigates this
joint health - resistance training can increase tendon stiffness + strengthen connective tissues
cyclic loading enhances cartilage integrity and joint lubrication
mobility exercise to increase range of motion
