Please enable JavaScript.
Coggle requires JavaScript to display documents.
muscular system Alison Acuna Period 3 - Coggle Diagram
muscular system Alison Acuna Period 3
major functions of the muscular system
posture maintenance
Movement which includes both voluntary and involuntary actions
joint stabilization
heat generation through contractions
action potential in a muscle fiber
an electrical impulse that travels along the membrane of a muscle fiber, triggering muscle contraction.
depolarization- initial rising phase caused by an influx of sodium ions which triggers the muscle to contract
repolarization- follows as potassium ions exit the cell
hyperpolarization- is the period where the membrane potential is more negative than the resting period before returning to its normal state
neuromuscular junction
is the synapse where a motor neuron communicates with a skeletal muscle fiber to trigger muscle contraction
Main parts
motor neuron terminal- the end of motor neuron where synaptic vesicles filled with acytocholine are stored
synaptic cleft- the narrow gap between the mototr neuron and the muscle fiber
motor end plate- the specilaized region of the muscle fibers membrane that contains receptors for acetylcholine
All skeletal muscles
neck/trunk has the strenocleidomastoid, trapezius, deltoid, and pectoralis major
arms had the biceps brachii, triceps brachii, and the brachialis
facial- frontalis, orbicularis oculi, and sygomaticus
legs has quadriceps, hamstrings, and the gastrocnemius
muscle CT coverings
perimysium- a middle layer of CT that bundles individual muscle fibers intro groups called fascicles
endomysium- the innermost layer of loose CT that surrounds and supports each individual fiber
episymium - the outer most layer of dense CT that surrounds the entire muscle organ
3 types of muscles and their functions
skeletal are voluntary and attached to bones to move the body
cardiac is only found in the heart to pump blood
smooth are involuntary and are found in the walls of organs and blood vessels to help fluids and solids move through the body
disorders associated with the muscular system
cerebral palsy
myasthenia gravis
fibromyalgia
myositis
Muscular dystrophy
sliding filament theory of muscle contraction
Myosin: The protein that forms the thick filaments, with "heads" that bind to actin.
Sarcomere: The basic contractile unit of a muscle fiber, located between two Z-discs, which shortens during contraction.
Actin: The protein that forms the thin filaments.
ATP (Adenosine Triphosphate): Provides the energy required for the myosin heads to detach from actin and to re-cock for the next cycle.
ATP (Adenosine Triphosphate): Provides the energy required for the myosin heads to detach from actin and to re-cock for the next cycle.
): Trigger the contraction by moving tropomyosin to expose the actin binding sites.
sarcomere- a structural unit of a myofibril in striated muscle consisting of a dark band a nearer half of each adjacent band is a pale band
Function- is to shorten and contract the muscle
key components- z disc, a band, I band, M line
i- band: is the light band that only contains thin actin filaments and do not overlap
A-band: dark band that includes entire length of the thick myosin filament and part of the thin actin filament that over lap the thick part