Muscles Flashcards
Thousands of parallel _____ join together to form a muscle cell
Myofibril
Muscle cells are also known as
Muscle fibers
The cellular membrane of a muscle cells is known as
Sarcolemma
Muscle fibers join together to form
Fascicles
The muscle organ is formed from what smaller subunit?
Fasicles
Sheath of fibrous elastic tissue surrounding the muscle?
Sheath of connective tissue surrounding a bundle of muscle fibers?
Delicate network of connective tissue which surronds individual muscle fibers.
Epimysium
Perimysium
Endomysium
Myofibrils are divided lengthwise into
Sarcomeres
2 types of myofilament in a sarcomere
Actin & myosin
Which myofilament is thin
Which is thick
Actin is thin
Myosin is thick
Z - lines do what
Seperate sarcomere
This model describes:
During contraction the 2 ends of a sarcomere come closer and the thin filaments slide past the thick ones so actin and myosin overlap more
Sliding filament model
Muscles cells endoplasmic reticlum is called
Sarcoplasmic reticlum
Myosin uses _____ to crawl along actin to produce_____
ATP
Mechanical energy
How many strands is myosin
What kinda enzyme is myosin
2
ATPase
ATP binds to which myosin or actin
Myosin
A motor unit is comprised of
Lower motor neuron
Neuromuscular Junction
Skeletal muscle cell
Fasciculations
Twitches
What is the tone of a muscle?
What is hypotonia
Tone is how much the muscle is contracted when one tries to relax it
Decreased tone in a muscle
When a muscle contracts the bone that moves is called the _________
The bone that doesn’t move is called
Insertion point
Origin
4 functional groups of Skeletal Muscles
Prime Movers
Antagonist
Synergists
Fixators
Muscles mainly responsible for a movement are called
Prime mover
Muscles that move in reverse of a particular movement
Antagonist
Help prime mover muscles by lending a little extra oomph stabilizing joints against dislocation
Synergists
Group of muscle fibers that all get their signals from the same, single motor neuron
Motor unit
3 phases of a muscle twitch
Latent period
Period of contraction
Relaxation Period