The Muscular System Flashcards
Skeletal muscle
Individual muscle fibers
Voluntary muscle
“Muscle” = multiple bundles of muscle fibers held together by connective tissue.
One of 3 major types of muscles: also cardiac and smooth muscle
Muscular system
Series of muscles that moves the skeleton.
“Movers and stabilizers”
Epimysium
A layer of connective tissue that is underneath the fascia and surrounds the muscle
Bundles of muscle fibers
Broken down into layers from outer to innermost layer.
First bundle = actual muscle itself wrapped by putter layer of connective tissue called fascia
Fascia
Outer layer or connective tissue that wraps the actual muscle itself
Fascia & emipysium connected to bone to help form muscles tendon
Perimysium
The connective tissue that surrounds the fascicles
Fascicle
Comes after the epimysium.
Wrapped by the perimysium
Endomysium
The deepest layer of connective tissue that surrounds individual muscle fibers
Connective tissue
Play vital role in movement
Allow forces generated by the muscle to be transmitted from the contractile components of muscle to bones.
Each layer of connective tissue extends the length of the muscle helping from the tendon
Tendons
Connective tissues that attach muscle to a bone and proved an anchors for muscles to produce force.
Poor vascularity, slower repair and adaptation
Sacrolemma
Plasma membrane that encases muscle fibers
Muscle fibers & their contractile elements
Encased by sarcolemma & contain cell components such as cellular plasma (sacroplasma), nuclei, & mitochondria.
Have myofibrils that contain myofilaments - the actual contractile comments of muscle tissue. -> actin (thin filaments) & myosin (thick filaments)
Sarcomere
The functional unit of the muscle, lies b/w two Z lines, that produces contraction (muscle contraction) containing actin and myosin
Tropomyosin
Located on the actin filament and blocks myosin binding sites located on the actin filament, keeping myosin from starching to actin while the muscle is in a relaxed state
Troponin
Located on the actin filament, provides binding sites for calcium and tropomyosin when muscle needs to contract
Neural activation
Contraction of a muscle generated by neural stimulation
Communication link b/w the nervous and muscular system
Motor unit
A motor neuron and all of the muscle fibers it connects with
Muscles divided into motor units
Either contract maximally or not at all
Neurotransmitters
Chemical messengers that cross the neuromuscular junction (synapse) to transmit electrical pulses from
The nerve the the muscle.
Once released, they link with receptor sites on muscle fiber.
Once attatched, ACh stimulates the muscle fibers to initiate muscle contractions
Neuromuscular junction
The point at which the motor neuron meets and individual muscle fiber.
This junction is actually a small gap b/w the nerve and muscle is called a “Synapse”
Acetylcholine (ACh)
The neurotransmitter used by the neuromuscular system.