force
A push or pull upon an object resulting from the object's interaction with another objectVectorMeasured in newtons
speed
Distance/timeVector
velocity
(Displacement) /timeVector
displacement
distance from the start - finish Vector
acceleration
The rate at which an object changes its velocityVector
momentum
Mass x velocity
impulse
Mass x change in velocityChange in momentum
dendrite
links the neuron to other neurons and allows information to flow between different nerves
cell body
soma; contained within the spinal cord or in clusters just outside it
nucleus
the central part of most cells that contains genetic material and is enclosed in a membrane
axon
the main component of nerve signal transmission; similar to an electrical wire
motor end plate
The nerve fiber forms a complex of branching nerve terminals that invaginate into the surface of the muscle fiber but lie outside the muscle fiber plasma membrane;Covered by one or more Schwann cells that insulate it from the surrounding fluids
synapse
A junction between two neurons
role of acetylcholine in stimulating skeletal muscle contraction
When an electrical signal reaches the synapse, this chemical is released. This allows sodium into the cell and increases the cell's permeability. It changes the electrical state of the muscle and causes a signal called the action potential to travel along the muscle fibers.
role of cholinesterase in stimulating skeletal muscle contraction
An enzyme that breaks down acetylcholine; causes the muscle cell to repolarize and relax; released when the motor neuron initiates a resting potential through repolarization
myofibril
any of the elongated contractile threads found in striated muscle cells
myofilament
the filaments of myofibrils, constructed from proteins, principally myosin or actin
sarcomere
contractile unit of muscle
actin
part of the thin filaments; anchor
thin filaments
actin, troponin, tropomyosin
myosin
part of the thick filaments; move
H zone
A narrow and less dense zone of myosin filaments bisecting the A band in striated muscle
A band
One of the cross striations in striated muscle that contains myosin filaments and appears dark under the light microscope and light in polarized light
Z line
any of the dark thin bands across a striated muscle fiber that mark the junction of actin filaments in adjacent sarcomeres
tropomyosin
when troponin binds to calcium, this swivels off the actin and reveals the binding sites for the myosin heads; Dr. Amones
troponin
binds to calcium; when calcium binding occurs here, the tropomyosin swivels off the actin and reveals the binding sites for the myosin heads; Dr. Amones' radio
sarcoplasmic reticulum
stores calcium; surrounds myofibrils
calcium ions
binds to troponin on the tropomyosin which causes it to move and reveal the myosin binding sites on the actin
ATP
on the myosin head; hydrolyzed to form ADP + Phosphate; binds myosin head unless calcium is available
sliding filament theory
Neural impulse comes down axon terminalOpens calcium channelsCalcium floods inCauses Ach to be releasedTravels across synapseBinds to Ach channelsChannels open upNeural impulse in end plateImpulse travels along cell membraneCalcium bonds to troponinMyosin binds to actinThis causes the muscle to contractWhen nerve is no longer stimulated, acetylcholine is removed by acetylcholine esteraseCalcium goes back into the sarcoplasmic reticulumMyosin heads move back to their resting positions away from the actin
slow twitch fibers
type I; oxidative phosphorylation; endurance fibers; slower; more mitochondria; low in glycogen content depending on training status
fast twitch fibers
type IIa and IIb; glycolysis and oxidative phosphorylation; sprint fibers; faster; fewer mitochondria; high in glycogen content depending on training status
flexion
decreasing the angle at a joint
extension
increasing the angle at a joint
abduction
moving a body part away from the midline of the body
adduction
moving a body part toward the midline of the body
pronation
turning a body part downward
supination
turning a body part upward
elevation
raising a part
depression
lowering a part
rotation
turning on a single axis
circumduction
tri-planar circular motion at the hip or shoulders
dorsi flexion
flexing the foot
plantar flexion
pointing the foot
eversion
turning the sole of the foot outwards
inversion
turning the sole of the foot inwards
isotonic muscle contraction
muscle length is changing; picking up and putting down books
isometric muscle contraction
muscle length is not changing; pushing against a wall
isokinetic muscle contraction
muscle contracts and shortens at the same speed throughout the entire range of motion; hand dynamometer
concentric muscle contraction
muscle is shortened; lifting weights (biceps)
eccentric muscle contraction
muscle is lengthened; lowering weights (biceps)
agonist
mover; shortens; muscle torque is greater than any resistance torque
antagonist
acts opposite agonist; gets longer even though it is contracting
reciprocal inhibition
the agonist and antagonist cannot both be contracted at the same time
movements in relation to joint action and muscle contraction
during upward motion of a bicep curl the joint action is flexion. The bicep contracts concentrically while the tricep relaxes eccentrically.
DOMS
Delayed Onset Muscle Soreness
DOMS is associate with...
structural muscle damage, inflammatory reactions in the muscle, overstretching and overtraining
DOMS results primarily from...
eccentric muscle action
DOMS is prevented by...
reducing the eccentric component of muscle actions during early training, starting training at a low intensity and gradually increasing the intensity, and warming up before exercise, cooling down after exercise
Velocity v. Time Graph: Shape
constant velocity v. changing velocitypositive velocity v. negative velocityspeeding up v. slowing down
Velocity v. Time Graph: Slope
zero- acceleration is zeropositive- acceleration is positivenegative- acceleration is negative
Distance v. Time Graph: Shape
horizontal line- object is stationarystraight line- object is moving at a steady speedsteep line- greater speed of object
Distance v. Time Graph: Slope
slope = speedspeed = distance travelled / time taken
center of mass
average of the masses factored by their distances from the reference point
change in body position during sporting activities can...
change the position of the center of mass; consider one example of an activity where the COM can remains within the body and one where the COM lies outside
first class lever
fulcrum lies between load and applied force; see-saw
second class lever
load lies between applied force and fulcrum; wheelbarrow
third class lever
applied force lies between fulcrum and load; tongs
lever: calf-ankle joint
effort: muscle forceload: body weightfulcrum: ball of toes
lever: biceps-elbow joint
effort: muscle forceload: what's in handfulcrum: elbow
Newton's first law of motion
a body at rest will remain at rest, and a body in motion will remain in motion with a constant velocity, unless acted upon by an outside force; runner stopping
Newton's second law of motion
force = mass x acceleration; baseball player uses a heavier bat or swings harder
Newton's third law of motion
for every action there is an equal and opposite reaction; swimming
angular momentum
(L); inertia (I) x angular velocity (w) about a particular axis; vector; L = I x w
momentum of inertia
(I); a measure of an object's resistance to changes in its rotation velocity
angular velocity
(w); the rate of change of angular displacement; vector
moments of inertia
how difficult a body or object is to rotate about an axis; measured in kg.m^2
non-axial
bones simply side in relation to one another; gliding joints
uniaxial
the structure of the bones at the joint restricts rotation to movement around one axis only; hinge joints and pivot joints
biaxial
two axes of rotation and bones can move in two different ways; condylar joints and saddle joints
triaxial
rotation around three axes; ball-and-socket joints
law of conservation of angular momentum
one the angular momentum has been generated, it will stay constant unless there is an interaction with another object or body which creates a torque to change it
speed of release
most important factor in determining how far the object will go
height of release
beat an opponent or maximize the range of values possible for the projection speed or angle
angle of release
important for maximum height of flight or for accuracy
Bernoulli's priciple
the relationship between air flow velocity and air pressure is an inverse one
Bernoulli's principle and golf...
the pressure difference causes the spinning golf ball to experience a force directed from the region of high air pressure to the region of low air pressure. A golf ball with backspin will experience higher air pressure on the bottom of the ball and lower air pressure on the top of the ball, causing a lift force (from high air pressure to low air pressure).
motion in the sagittal plane
flexion and extension
motion in the frontal plane
abduction and adduction
motion in the transverse plane
medial rotation and lateral rotation