Chapter 5: Muscle Function & Structure Flashcards
Three types of muscles that exists in the body
Smooth
Cardiac
Skeletal
Skeletal Muscle
Connects the various parts of the muscles through connective tissues called tendons
Voluntary control
Can be graded
Smooth Muscle
Located in the blood vessels, iris, respiratory tract, gastrointensitinal tract
Involuntary
Fatigue resistant
Contractions are slow and controlled
Cardiac muscles
Helps contractile activity of heart
Very fatigue resistant
Involuntary
Can be graded
Component of Skeletal Muscle
A: muscle belly
B: muscle fibre bundle
C: muscle fibre
D: myofibrils
Muscle teamwork terms
Agonist
Antagonist
Synergist
Fixators
Agonists
Producing desired activity
Antagonists
Opposing the activity
Synergistes
Muscles surrounding joint that help the movement
Fixators
Steady joints closer to the axis
Sarcomers
Contractile units within the myofibrils
Sarcomeres are made up of 2 protein filaments
Actin-thin
Myosin-thick
Myosin
Each myosin is surrounded by 6 actin filaments
Projecting from each myosin and tiny contractile myosin bridges
Cross bridge formation
Signal comes from motor nerve to motor end plate activating the fibre
Cross bridge movement
Rowing and oar like motion
Optimal cross bridge formation
Sarcomeres should be an optimal distance apart
If sarcomeres are stretched to far apart
Less force, because there will be fewer cross bridges
If sarcomeres are too close together
Less force, don’t have enough room thus interpreting with each other as there formed
Optimal muscle length & optimal joint angle
Maximum muscle occurs with optimal muscle length & at optimal joint angle
Optimal joint angle occurs at optimal muscle length
The distance between sarcomeres if dépendant on
Stretch of muscle and and the position of the joint
Genetically predetermined muscle fibre types
Slow twitch
Oxidative(type 1)
Fast twitch
Glycolitic(type 2)
Slow twitch muscle fibres
Suite for activity’s with >20-24% of force output
Low power, high endurance
Fast twitch
High power, low endurance
Muscle biopsy on the microscope
Capillaries blood vessels look like black dots
Oxidative look red
Glycolitic look white
Muscle biopsy procedure
Method used to determine muscle fibre type
Nerve-muscle interaction
Skeletal muscle is infuriated through neural activation
Our nervous systems:
Central and peripheral
Terms of function of nervous system
Sensory
And
Motor
Sensory
Collects info from sensors and takes it to the brain
Motor
Conducts signals to activate muscle
Motor unit
Group of fibres activated via the same nerve
All muscle fibres of one unit are the same kind
Muscle need to preform precise movements consist of more
Motor units and less muscle fibres
Muscles needing to preform less precise movements require
Less motor units and many fibres per unit
All or none principal
An impulse of certain magnitude or strength is required to get the fibres to contract
Intra muscle coordination
Capacity to apply motor units simultaneously
Inter muscle coordination
Interpret between agonist and antagonist muscles
Muscles adaptation to strength
Individual performance occurs through biological adaptations
Adaptations depends on activity level and athletes genetic makeup
