Chapter 2 - Basic Exercise Science - The Muscular System Flashcards
Muscular System
The full collection of all of the muscles in the human body.
Epimysium
This is the layer of muscular connective tissue on the outside.
Perimysium
This is the muscular connective tissue in the middle that encompasses the muscle fascicle.
Endomysium
The deepest layer of the muscular connective tissue that covers muscle fibers.
Tendons
Connect skeletal muscles to the bone with a band of white, inelastic, dense and tough band of tissue.
Sarcomere
The smallest contractile unit of a muscle fiber.
It is comprised of actin and myosin. This is the repeating section of a muscle.
Neural Activation
This is the process of nervous system activation of a muscle fiber by the means of the neuromuscular junction
Motor unit
The motor neuron as well as all of the muscle fiber that it innervates.
Neurotransmitters
These are small chemical messengers that are able to cross the neuromuscular synapse (junction) in order to transmit these and electrical impulses from the nerve to the muscle.
Muscle Fiber Type 1 (slow twitch)
These are also known as endurance fibers. They are smaller, produce less power, receive more oxygen and are more mitochondrial dense.
Muscle Fiber Type II (fast twitch)
These do not have as much endurance, have less oxygen delivery, have short-term contractions, can produce more force and power and are larger than type I fibers.
Muscle Fiber Type IIx
These have a low oxidative capacity and or quick to fatigue.
Muscle Fiber Type IIa
These have a higher oxidative capacity and will fatigue slower than type IIx. Another name for these is intermediate fast twitch muscle fibers.
Excitation-contraction coupling
This is the process where the nervous system stimulates a muscle in the body to contract. Also know as siding filament theory.
5 step process - Excitation - contraction coupling (sliding filament theory)
States that actin filaments at each end of the sarcomere slide inward on myosin filaments, pulling z lines toward the center of the sarcomere and thus shortening the muscle fiber
