muscular system Flashcards
what is the role of a fixator muscle during exercise?
- stabilises the origin so working muscles can contract
what is isometric contraction+example?
-length of muscle doesn’t change or angle at joint
- muscle holds a static position but still produces tension
E.G: plank
agonist and antagonist in knee flexion
agonist-hamstrings
antagonist-quadriceps
fixator and synergist in knee flexion
fixator-glutes
synergist-gastrocnemius
agonist and antagonist in elbow flexion
agonist- biceps
antagonist- triceps
what is an agonist
agonist: muscle that contracts to produce movement
what is an antagonist
muscle that relaxes
what is a synergist
muscle that assists the agonist
what is the fixator
muscle that assists the agonist by stabilising the origin so the muscle can contract
insertion
- the end of the muscle that moves
- normally crossed over a joint to allow movement when the muscle shortens
origin
- fixed end of the muscle that remains stationary
how does increased muscle pliability affect an athlete?
-muscles working more therefore need energy so temperature increases
-makes muscles more flexible
-allowing greater range of movement
-preventing injury
describe responses of muscular system
-blood supply increases cause there’s a greater demand for oxygen. the oxygen is used for energy. blood vessels vasodilate so greater blood flow reaches working muscle
-micro tears: tiny tears in fibres when muscles are under stress
-lactate production, anaerobic exercise rapid fatigue/burning+heaviness in muscles
how does increased myoglobin stores help athletes
-increased myoglobin stores: responsible for binding and storing oxygen, means increased oxygen transported to mitochondria
-more energy is available
adaptations of muscular system
-increased storage of glycogen
-hypertrophy
-increased storage of fat
-increased tolerance to lactate
additional factors affecting muscular system?
age: get older muscle mass decreases , decrease in muscle strength and power
cramp: involuntary contraction of muscles, tightening or muscle fibres.
how does dehydration cause cramp?
-results in inadequate supply of blood to the muscles, reducing the supply of oxygen and essential minerals
what causes muscle temperature to increase during exercise?
-temperature increases as muscles need energy
-fats and carbohydrates are broken down to satisfy this
-produces heat as a waste product
-higher energy demands= greater breakdown of fuel sources=more heat in muscle
what is the all or none law
- a muscle must receive a nerve impulse to contract
-the stimulus must be sufficient enough to activate at least one motor neuron and the attached muscle fibres
-if stimulus isn’t large enough to stimulate motor unit no contraction will take place
-all muscle fibres must be activated or no contraction will occur
what does a motor unit consist of?
a neuron and a muscle fibre
characteristics of type 1 muscle fibres
-exert smaller forces at slower speeds
-suited to long duration events as they have high aerobic capacity
-high mitochondria counts- provides more opportunities for aerobic respiration to occur
-dense capillary networks: increase
blood supply
-long distance
characteristics of type 2a muscle fibres
-exert greater forces at higher speeds
-fatigue quicker: limited aerobic capabilities
-less efficiency blood supply
-less reliant on oxygen have good aerobic capabilities
-large glycogen stores: allow high intensity work
-400m run, speed activitues
characteristics of type 2x muscle fibres
-highest contraction force and speed
-large pc stores allow explosive and high intensity movements
-limited blood supply and mitochondria: reduce aerobic capabilities
-100m sprint, football runs
skeletal muscle type characteristics
-attached to bone
-voluntary control
-complete sporting movements
cardiac muscle type characteristics
-surrounds the heart
-ejects blood at high pressures around the body
-involuntary control
smooth muscle type characteristics
-in digestive tract and blood vessel walls
-contract to assist follow of fluids through the body
-involuntary control
what is doms?
-response to exercise
-significant tears during exercise can remain inhaled for 2-3 days leading to prolonged discomfort
