Types of Muscle and Properties of Muscle
State the type of muscle located in the walls of the heart
cardiac
State the feature of a neuron that has a function to transmit signals from the cell body to the axon terminals
axon
Define isometric contractions
muscle generates force but stays the same length
Describe a 2nd class lever
the load is located between the fulcrum and effort
isotonic concentric
Outline elasticity
The ability of a muscle to return to resting length after being stretched
Identify the dominant type of muscle fiber a 50m swimmer would have in their rectus femoris
type IIx
Identify the type of contraction that occurs in the triceps brachii during the downward phase of a triceps extension
isotonic eccentric
requires less effort to move loads
provide an example of a muscle demonstrating the property of extensibility
VARIOUS - any type of stretch example
Elasticity - the ability to return to resting length after a stretch
Contractility - the ability of the muscle to generate force
Extensibility - the ability of muscle to stretch beyond resting length
Atrophy - the decrease in muscle tissue size/mass
Hypertrophy - the increase in muscle tissue size/mass
Describe a motor unit
consists of a motor neuron attached to a bundle of muscle fibers
State the agonist, antagonist, and a fixator during the extension of the knee
agonist - quadriceps (rectus femoris)
antagonist - hamstrings
fixator - rectus abdominus etc
Identify the parts of a lever in the human body during a straight legged deadlift (upwards phase)
fulcrum - hip joint
effort - gluteus maximus
load - weight/body weight
describe the advantage and disadvantage of a 3rd class lever
advantage - greater range of motion and increased speed
disadvantage - more effort required to move loads
Cardiac - contract the heart
skeletal - contract to generate movement in the body
smooth - contract to move substances through the body
Distinguish between slow twitch and fast twitch fibers (3 marks)
Slow Twitch - red in color, smallest fiber diameter, used for endurance type activities, high capillary density, high mitochondria density, low muscle glycogen stores
Fast Twitch - lighter in color, larger fiber diameter, used for more fast/powerful activities, lower capillary density, lower mitochondria count, higher muscle glycogen stores
Explain reciprocal inhibition at the ankle during dorsiflexion
the tibialis anterior (major) is the agonist and contracts. It sends an inhibitory signal to the gastrocnemius so that it relaxes. The gastrocnemius is the antagonist
Identify the parts of the lever and the class of lever when using a bat to swing in baseball
fulcrum - wrist
effort - muscles in body but attached on bat through hand
load - baseball
3rd class lever
Explain how the structure and function of fast twitch muscle fibers contributes to the performance of an Olympic shotput athlete. (3 marks)
greatest force fibers - generate a lot of power to throw as far as possible
large glycogen stores - provides quick energy needed for muscle contraction
etc