Muscles Flashcards
Muscle Tissue
Made of highly specialised, elongated cell - elasticity
Motion
External and internal body part movements
Thermogenesis
Generating heat by normal contractions and by shivering
Excitability (irritability)
Ability to receive and respond to a stimulus
Contractility
Ability of muscle tissue to shorten
Elasticity
Ability to return to its original shape
Extensibility
Ability to be stretched without damage
Conductivity
Ability to conduct excitation over the length of the muscle
Primer Mover(s) / Agonists
The muscle(s) primarily responsible for the movement
Antagonist
Muscle(s) that oppose/reverse the movement caused by the prime mover
Synergist
Muscle(s) that assist the prime mover
OR
Smaller muscles that assist the primary antagonistic muscles
Fixator(s)
the muscle(s) that immobilise the origin of the prime mover
Skeletal muscle
Muscles that move bones and enable us to walk, run and carry out a wide range of voluntary physical activities
Smooth Muscle
Make up many of the internal organs, as these muscles allow for movement
Cardiac Muscle
Heart muscle
Perimysium
Sheath of connective tissue that surrounds each bundle of fasciclesso that it can function as an individual
Connective tissue
Allows adjacent bundles to slide easily over one another as they contract
Epimysium
Sheaths of connective tissue
Insertion
The tendon attached to the bone that moves
Origin
The tendon attached to the stationary bone
Ligaments vs tendons
Tendons - attach bone to muscle
Ligaments - attach bone to bone
Pennate
Feather-like muscles
Sphincter
Circular Muscles
Muscle fibre
An elongated cylinder with many nuclei
Contains: myofibrils
Sarcolemma
Thin, transparent plasma membrane that surrounds the cell
Fascicles
Bundles of muscle fibres
Sacromere
Responsible for contraction within the muscle
Myosin protein
rod-like tail with two heads.
Each head contains ATPase and an action-binding site; point to the Z line.
Tails point to the M line.
Spitting ATP releases energy which causes the head to “ratchet” and pull actin fibres.
Myofibrils
Composed of myofilaments, made of protein, these are the units that are involved in the contraction of the muscle
Thick Myofilaments
Composed mainly of the protein myosin
Thin Myofilaments
Composed mainly of the protein actin
Sarcoplasmic reticulum
A tubular network that surrounds the myofibrils
- is a storage site for calcium ions, which are released during muscle contractions
Sliding Filament Theory
suggests that when muscles contract and the sarcomeres short that is due to the actin and myosin filaments sliding over one another.
Z line in sliding filament
Protein discs in the middle of thin filaments
A band in sliding filament
The length of the thick filament (myosin)
H zone
Middle of the A band where it is light and contains only thick filaments
I band
Distance between successive thick filaments
