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NEUROMUSCULAR SYSTEM
MUSCULAR SYSTEM
Anterior Posterior
Smooth Muscle
Cardiac Muscle
MUSCULAR SYSTEM
Skeletal Muscle
Smooth Muscle
Found in the digestive, circulatory, urinary and reproductive systems
Controlled by the autonomic nervous system
Smooth in appearance
Involuntary controlled
MUSCULAR SYSTEM
MUSCULAR SYSTEM
Cardiac Muscle
Found in the heart
Contraction of the heart is controlled by the sinoatrial node (SAN)
Striated in appearance
Involuntary controlled
MUSCULAR SYSTEM
Skeletal Muscle
All attached either directly or indirectly to the skeleton
Controlled by the somatic nervous system
Striated in appearance
Voluntary controlled
SKELETAL MUSCLE ANATOMY
myofibrilmuscle filament
fasciasurrounds the muscle
connected to periosteum (bone)
Epimysiumthe outer layer
perimysiumaround each bundle of fibres
muscle fibre
endomysiumaround each muscle fibre
SLIDING FILAMENT THEORY
actin
myosin
myosin cross-bridges attach to the actin filaments
actin is pulled together and sarcomere length is reduced
NEUROLOGICAL SYSTEM
The nervous system consists of two primary
divisions, the central nervous system (CNS) and the peripheral nervous system (PNS)
NEUROLOGICAL SYSTEM
The Central Nervous System
The Brain and Spinal Cord
The PeripheralNervous System
THE REFLEX ARC
Central Nervous SystemSensory Receptor
Sensory Nerve
Motor Nerve
Muscle responds to nerve impulses
MUSCLE FIBRE RECRUITMENT
Motor units and muscle fibre recruitment:
A motor unit consists of a motor neuron and all the fibres it innervates
‘All or none law’
The more muscle units that are recruited for a task, the greater the force will be developed
ROLES OF MUSCLES
Agonist- A muscle that carries out a voluntary movement
Antagonist- The opposing muscle that relaxes in order to allow the movement to occur
Synergist- A muscle that assists the agonist in producing movement
Fixator- A muscle that stabilises a body part whilst the agonist is contracting
Muscular Contractions
TYPES OF MUSCLE CONTRACTION
Concentric (positive); the muscle contracts and shortens to overcome a resistance
Eccentric (negative); the muscle contracts and
lengthens to control a resistance
Isometric (static); the muscle contracts toovercome a resistance but without any change in length
MUSCLE FIBRE TYPES
Slow-twitch or Type 1
MUSCLE FIBRE TYPE
STRUCTURAL FEATURES
Smaller diameter fibre Large myoglobin content Many mitochondria Many capillaries Red in colour
MUSCLE FIBRE TYPE
FUNCTIONAL FEATURES
Increased oxygen delivery Produce less force Long-term contractions Resistant to fatigue
MUSCLE FIBRE TYPE
ACTIVITIES-
Maintaining posture Endurance-based activities
MUSCLE FIBRE TYPE
Fast-twitch or Type ll
MUSCLE FIBRE TYPE
STRUCTURAL FEATURES
Larger diameter fibre Smaller myoglobin content Fewer mitochondria Fewer capillaries White (pale) in colour
MUSCLE FIBRE TYPE
FUNCTIONAL FEATURES
Decreased oxygen delivery Produce more force Short term contractions Less resistant to fatigue
MUSCLE FIBRE TYPE
ACTIVITIES-
Rapid, intense movements
NEUROMUSCULAR SYSTEM
Responses of the neuromuscular system to exercise
Short term response:
Vasodilation (diversion of blood) to the muscles
NEUROMUSCULAR SYSTEM
Responses of the neuromuscular system to exercise
Long term adaptations to aerobic exercise:
Increase in the number and size of mitochondria in the muscle fibres
Increase in the number of capillaries surrounding these fibres
Increase in the number of aerobic enzymes, stored glycogen and triglycerides (fats)
NEUROMUSCULAR SYSTEM
Responses of the neuromuscular system to exercise
Long term adaptations to strength training:
Decrease nervous inhibition (increased nervous stimulation!)
Increase in the diameter of the recruited fibres Increase in work performed under anaerobic
conditions or high stress conditions
Principles of Training
PRINCIPLES OF TRAINING
OVERLOAD
In order to challenge the muscle you need to work outside of your comfort zone. The degree of extra challenge depends upon the aims and fitness level of the individual
PRINCIPLES OF TRAINING
SPECIFICITY
Training that is relevant to the desired outcome
PRINCIPLES OF TRAINING
REVERSIBILITY
You cannot store fitness – if you don’t use it you will lose it!
Muscles which are not regularly stimulated will suffer muscle wastage or “atrophy”
PRINCIPLES OF TRAINING
PROGRESSION
As you adapt to a workload and can complete it without feeling challenged, the next step is to increase the workload in order to progress
PRINCIPLES OF TRAINING
ADAPTATION
An anatomical or physiological change that occurs in the body, such as getting stronger, losing fat or increasing muscle size.
The body will adapt to any new stresses by protecting and strengthening the area.
PRINCIPLES OF TRAINING
HYPERTROPHY
An increase in cross-sectional diameter of trained muscle fibres
PRINCIPLES OF TRAINING
ATROPHY
An decrease in cross-sectional diameter of muscle fibres due to lack of use
