Chapter 2 Basic Exercise Science Flashcards
Human Movement System (3 systems)
Movement through integration of three systems
Nervous system
Skeletal system
Muscular system
The 3 human movement systems are _ and produce _
kinetic
movement
All systems must _ _ to _ _ in the kinetic chain
work together
produce movement
Kinetic Chain
All components work together to manipulate human motion
If one component of the kinetic chain is not working properly, it will affect the others and ultimately affect the movement
The Muscular System
Muscles generate tension that, under the control of the nervous system, manipulates the bones of our body to move.
Skeletal Muscle Epimysium
(upon)
outer layer
surrounds the muscle belly
Skeletal Muscle Perimysium
(around)
surrounds each fasiculus
Skeletal Muscle Fasciculi
bundles of muscle fibers
Skeletal Muscle Endomysium
(under)
surrounds each individual muscle fiber
Skeletal Muscle Muscle Fiber
Bundles of sacromeres (smallest)
Tendons
attach muscle to bone
allow muscle to control movement of bone
have poor vascularity (blood supply)
susceptible to slower repair and adaption
Muscle Fibers contain what typical cell components
Sarcoplasm
Nuclei
Mitochondria
Sarcoplasm
cellular plasma
contains glycogen, fats, minerals, and oxygen binding myoglobin
Nuclei
DNA
Mitochondria
Uses O2 (oxygen and gas) to transform energy from food into energy for the cell
You can’t grow _ _
muscle cells
Myofibrils
contractile components of muscle tissue
Actin
Myosin
Sarcomere
functional unit of the muscle
it lies in the space between two z lines
Actin
thin myofilament
Myosin
thick myofilament
crossbridges (like a stick covered in barbed wire)
Tropomyosin
on the actin filament
blocks myosin bringing sites
keeps myosin from attaching to actin while the muscle is in a relaxed state
Troponin
aslo located on the actin filament
plays a role in muscle contraction
provides binding sites for both calcium and tropomyosin when a muscle needs to contract
Agonist
prime movers
gluteus maximus is an agonist for hip extension
Synergist
assist prime movers during movement
hamstring and the erector spinae are synergistic with the gluteus maximus during hip extension
Stabilizer
support or stabilize the body while the prime movers and the synergists perform the movement patterns
tranversus abdominis, internal oblique, and multifidus stabilize the low back, pelvis, and hips during hip extension
Neuron
the functional unit of the nervous system
Neurons are composed of 3 main parts:
Cell Body
Axon
Dendrites
Axon
provides communication from the brain or spinal cord to other parts of the body
Dendrites
responsible for gathering information from other structures of the body
3 Classifications of neurons determined by the direction of their nerve impulses
Sensory
Motor
Interneuron
Sensory
transmits nerve impulses from muscles or organs to the brain/spinal cord
Motor
transmits nerve impulses from brain/spinal cord to muscles or organs (contact muscle)
Interneuron
transmits nerve impulses from one neuron to another
2 types of signals that travel through the nerves
Action Potential
Neurotransmitter
Action Potential
electric nerve impulse that travels within the nerve
All or nothing response
Neurotransmitter
chemical released at the neuromuscular junction that transmits the electric signal to the receptor tissue
Acetylcholine
(ACH)
is the neurotransmitter responsible for muscle contraction
Neural activation
essential for a muscle to manipulate force for movement or stabilization
generated by the motor unit (motor neuron and its muscle fibers)
All or none law
(if a motor unit activated all muscle fibers respond. if not none will respond. joint actions)
Sliding Filament Theory
The proposed process of how muscle contraction takes place
A sacromere shortens as a result of the myosin heads attaching to the actin filament and pulling the actin across the myosin. (twists like a towel shortening in length)
A nerve impulse (_ _) is transmitted through the _ down to the _ _ (neuromuscular junction) and releases _
action potential
neuron
muscle fiber
ACH
binds to its receptor on the muscle fiber
ACH
ACH binds to its receptor on the muscle fiber which triggers…
the release of calcium (Ca2+) into the sarcoplasm (where the actin and myosin are located)
Ca2+ binds to the protein _, forcing the protein _ to move away from the myosin binding site and allowing for _ to attach to _
troponin
tropomyosin
myosin
actin
_ attaches to _, creating a pull of the filaments across each other (sliding filament theory) and causing muscle to shorten (contract)
myosin
actin
Once the neural impulse for contraction subsides (you put the weight down)
calcium in the sarcoplasm decreases, forcing myosin to unbind with the actin, ending the muscle contraction
Muscle Fiber Types
Type I slow twitch
Type IIx fast twitch
Type IIa fast twitch
Type I slow twitch
higher capillaries, mitochondria, and myoglobin
increased oxygen delivery
smaller in size
produce less force
slow to fatigue
long term contractions (stabilization)
Type IIx fast twitch
lower in capillaries, mitochondria, and myoglobin
decreased oxygen delivery
larger in size
produce more force
quick to fatigue
short term contractions (force and power)
Type IIa fast twitch
intermediate in capillaries, mitochondria, and myoglobin
can be used in aerobic or anaerobic work
moderate in size
produce moderate force
fatigue quicker than I slower than IIx
not as powerful nor as much endurance
Can any of the muscle fiber types turn into each other
type IIa can turn into type IIx
that is the only one and it is not reversible
Muscle Fiber Types cans and can’ts
You are born with ALL the muscle fibers you will ever get
You cannot add muscle fibers to the body
Genetics determines the distribution of each fiber throughout the body
You CAN enhance existing fibers
2 main components of the nervous system
Central Nervous System (CNS)
Peripheral Nervous System (PNS)
CNS
The central nervous system is composed of the brain and spinal cord
PNS
The peripheral nervous system is the nerves that communicate with the CNS
Subdivisions of the PNS include
somatic nervous system
autonomic nervous system
somatic nervous system
responsible for the voluntary control of movement
autonomic nervous system
responsible for the involuntary systems of the body
The autonomic is divided into…
sympathetic nervous system
parasympathetic nervous system
Sympathetic nervous system
fight or flight
parasympathetic nervous system
crash/ relax
Sensory
The ability of the nervous system to sense changes in either the internal or external environment
pre-loading (picking up a weight)
Integrative
The ability of the nervous system to analyze and interpret the sensory information to allow for proper decision making, producing the appropriate response
Brain take inventory of muscle tone and force potential
Motor
The neuromuscular response to the sensory information
able to lift weight or must put it down
Sensory Receptors
Mechanoreceptors
Nociceptors
Chemoreceptors
Photoreceptors
what responds to mechanical forces (touch and pressure)
Mechanoreceptors
Mechanoreceptors
Muscle spindle
Golgi tendon organ
Joint receptors
Muscle spindle
sensitive to tone, change in length and rate of length change in muscle
Golgi tendon organ
sensitive to changes in muscular tension and rate of tension change
joint receptors
respond to pressure, acceleration, and deceleration of the joint.
Muscle Spindle and golgi tendon organ help with…
Proprioception
Proprioception
The body’s ability to sense the relative position of the parts of the body.
Training the body’s proprioceptive abilities will improve…
balance, coordination, and posture and enable the body to adapt to its surroundings without consciously thinking about movement
It becomes important to train the nervous system efficiently to ensure proper movement patterns, which enhances performance and decreases the risk of injury.
The nervous system purpose (3 points)
Movement is a response to our sensory information and is, therefore, dictated by the nervous system.
This reflects the importance of training in a multi sensory environment.
The most effective way to create positive long term results in a client is to directly affect (properly train) his or her nervous system. (moving away from the “bodybuilding” mentality.
Physical Activity and the Nervous system (2 points)
Early stage improvements to physical activity are largely due to changes in the way the CNS and PNS coordinate movement.
Unsuccessful activity can be modified with sensory input to improve performance.