Exam #1 Flashcards
Skeletal muscular system
Framework for muscles to act
Cardiovascular and respiratory systems
Nutrients carried to cells (O2) and removal of wastes (CO2)
Skin
Maintenance of body temp - sweating
Urinary system
Fluid and electrolyte balance (sodium, potassium)
Nervous system
Coordinate signals of all systems (brain to muscles)
Ligament
bone to bone
Tendon
Bone to muscle
Exercise physiology
studies body functions, adaptations, and changes as
the result of stress of exercise and training
5 properties of muscle
- Stimulated by Nerve Impulses
o Capable of receiving stimulation from nerves and responding - Contractible
o After receiving stimulation, they contract & produce force - Extensible
o Can be stretched during the application of force - Elastic
o Muscle can return to its original shape after contracting or lengthening - Adaptable
o Muscle can be changed or altered (Hypertrophy or Atrophy)
5 types of muscle movements
- Adduction
o Moving of a body part toward the midline of the body - Abduction
o Moving of a body part away from the body - Flexion
o Bending a joint to decrease the angle of the joint - Extension
o Straightening a joint to increase the angle of the joint - Rotation
o Moving a body part around an axis
3 types of muscle
- Smooth
o Involuntary muscle (not under conscious control)
o In walls of blood vessels and organs (digestive or respiratory system) - Cardiac
o Found only in the heart (controls itself) - Skeletal *
o Voluntary – conscious effort or decision to make them move
o Attached to and move the skeleton (muscle to bone via ‘tendons’)
Human body contains over ___ muscles
600
Outer tissue =
Epimysium
Inner tissue =
Fascicles
Inside fascicles =
Muscle fiber
Each fibre has a ____ ____ ____
Single motor nerve
____ _____ ____ _____ to the muscle fibres
Motor nerves send signals
Motor nerve impulses come from the _____ _ ____ ____
Brain or spinal cord
When an impulse arrives, ____ _____ ______ _____
Nerve endings secrete a chemical
An ____ _____ is transmitted down the muscle fibre
Electrical charge
Muscle fibres are made up of hundreds or thousands of _____
Myofibrils
When sarcomeres contract… muscle contracts producing force
Myofibrils are divided into ______
Sarcomeres
Sacromeres are made up of ___ ________… _____ & ______
Two filaments
Actin and myosin
Muscles need ___ in order to contract?
ATP - adenosine tri-phosphate
Myosin stands grab ATP, which does what?
Breaks down ADP and a phosphate
Hardest on muscles is what type of training?
Eccentric
2 types of muscle fibres
- Slow Twitch
o Take 110 miliseconds to reach peak tension - Fast Twitch
o Take 50 miliseconds to reach peak tension
What happens when ST neurons are fired?
far LESS muscle fibers are activated
ST fibers produce less force (sub-maximal movements)
Aerobic exercise… walking, jogging, biking, swimming
What happens when FT neurons are fired?
far MORE muscle fibers are activated
FT fibers produce more force (explosive movements)
Anaerobic exercise… jumping, sprinting, throwing
Muscles are __% FT and __% ST fibers
50 and 50
ST and FT msucles fibers are determined by?
Genes
We tend to specialize in one more than the other
Example of FT and ST muscle fibres in athletes:
World class sprinters = 75% Ft fibers in lower leg muscles
World Class Endurance Runners = 95% ST fibers in lower leg muscles
Our bodies prime movers are?
The agonists - produce the force
Biceps
Our bodies opposing movers are?
The Antagonists ( protective role... the brakes) Triceps
Our bodies muscles that assist the prime movers:
Synergists
Brachioradiallis
What are the three types of muscle actions?
Eccentric - lengthening
Isomentric - static or still
Concentric - shortening
Size of the muscle number and type of motor units activated (ST & FT)
Larger generally means more fibres = more capability
More FT = more force
What is the optimal joint angle?
Optimal angle of a joint for force production is 100 degrees
Muscles length when activated
A ‘stretched’ muscle… think of an elastic band… generates more force than a relaxed one
Maximal force for concentric and eccentric movement
Maximal force for ‘concentric’ movements is slower (squat or bench press)
Maximal force for ‘eccentric’ movements requires speed (plyometrics)
