Flashcards
Acute responses
Cards in this deck (39)
- 1Acuteshort-term immediate response to single bout of exercise
- 2Factors to consider when measuringenvironmental conditions - temp, humidity, light, noise, altitude
circadian variati o
time and size of last meal
menstrual cycle
ergometer - 3AUTONOMIC REFLXES AND HORMONESendocrine system controls homeostasis during exercise
- 4Anterior pituitarygrowth hormone
released in proportion to exercise
anabolic - 5Thyroid glandthyroxine
increases metabolism rate and glucose uptake - 6Adrenal glandcatecholamines
released from adrenal medulla
increase HR, BP, contractile force, muscle blood flow
dopamine also related to exercise - 7Pancreashomeostasis of blood glucose levels
insulin and glucagon - 8Receptorsfeed into brain which affects autonomic reflexes >> affect endocrine glands
baroreceptors - pressure
chemoreceptors - acidity and pp
mechanoreceptors - movement in muscle - 9CARDIOVASCULAR SYSTEMautonomic nervous system increases sympathetic stimulation
adrenaline and noradrenaline - 10Sympathetic stimulation increases:heart rate, blood pressure
blood flow to muscles
airway diameter (bronchodilation)
metabolic rate, glucose, ffa levels
mental activity - 11Redistribution of blood20% blood to muscles at rest >> ~80%
- 12Cardiac outputincrease in Q from 5l to 25l
- 13Stroke volumeincreases but begins to plateau at about 50% VO2 max
>> increase in Q after relies on HR - 14RESPIRATORY SYSTEM-
- 15Increases due to recruitment of active respiratory muscles:breathing frequency
minute ventilation
oxygen diffusion capacity
lung perfusion - 16Ventilatory breakpoint= where ventilation rises dramatically
excess ventilation due to carbon dioxide release from buffering lactic acid - 173 phases of exercise hyperpnea1
rapid increase in minute ventilation from rest
short plateau
2
slower exponential rise
~20s after onset
3
major regulatory mechanisms reach stable values - 18Hypothesised control mechanismsoscillations in arterial CO2/H+
increased chemosensitivity
skeletal muscle afferent feedback
central command
arterial potassium and/or catecholamines
cardiac afferent feedback
learned response - 19Myoglobinin muscles
similar structure to haemoglobin
greater affinity for oxygen >> helps to move oxygen from haemoglobin init muscle cell - 20Excess post-exercise oxygen consumption. (EPOC)oxygen deficit - oxygen debt
- 21a-vO2 differenceaterio-venous oxygen difference
- 22~ a-vO2 difference increases with exercise4-5ml O2 per 100ml blood at rest >> 15ml during intense aerobic exercise
muscle bed takes up more oxygen to produce ATP
bigger difference = better at taking up and using oxygen so higher VO2 max - 23Increase in H+ and VCO2 at muscle cellwith increasing intensity muscle tissue becomes more acidic
bohr effect >>
more O2 unloaded
muscle temp increase also helps unload oxygen from haemoglobin - 24METABOLISM-
- 25ATPATP >> ADP + Pi >> energy
reversible reaction
2ADPs can combine >> ATP + AMP
increasing levels AMP stimulate AMP kinase - 26AMP kinasekey cellular energy sensor - detects changes in cellular energy
maintains cellular homeostasis - glucose homeostasis in particular
alters with exercise - 27~ liverincreased lipid oxidation (breakdown)
decreased lipid and glucose production - 28~ skeletal muscleincreased glucose uptake, lipid oxidation, mitochondrial biogenesis
- 29~ adipose tissuedecreased lipolysis and lipogenesis >> decreased circulating lipids and ectopic fat deposition
- 30~ pancreasdecreased insulin secretion
- 31When fuel source changesRER > 1
anaerobic/ventilatory/lactate threshold
RPE "somewhat hard" - 32STRENGTH-
- 33Increased force and frequency of muscle contraction due to increased:stimulus via sensory receptors
(action potentials sent via alpha motor neurons to skeletal muscle)
motor unit recruitment
frequency of cross-bridge formation - 34Muscle sorenessduring and immediately after
1-2 days after = delayed onset muscle soreness - 35~ during/ immediately afterincreased H+ and local acidity
tissue oedema and acute muscle swelling - 36~ DOMSresistance exercise/ eccentric contractions major cause
inflammatory responses initiated at site of injury
increases with muscle enzymes
indirect measure of muscle damage = serum creatine kinase levels - 37Plyometric exercisemainly affects fast-twitch fibres
damages sarcolemma and sarcomere at z-disk - 38Muscle fibre damagemembrane damage to fibres disturbs Ca2+ homeostasis
activates enzymes to damage Z-disks which transmit force
need muscle damage to precede hypertrophy - 39~ under microscope
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- degree YEAR 1 (MED 123) Flashcards on Acute responses, created by Emily H on 06/04/2021.
- Created by
- Emily H · Apr 2021
- Updated
- Apr 6, 2021
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