Muscular System Flashcards
3 basic muscle types
Skeletal, Cardiac, & Smooth
Contraction and shortening of muscles are due to the?
movement of microfilaments
Actin and myosin
When muscle contracts,
z-line is closer together
myo- and mys-
muscle
3 connective tissues that is a supportive sheaths to the muscle
Endomysium, Perimysium, Epimysium
sarco-
flesh
responsible for all types of body movement
Muscles
wraps around a fascicle (bundle) of muscle fibers
surrounded by fascicle (muscle fibers)
Perimysium
No striations; Involuntary
Contractions are slow and sustained
Smooth Muscle
How many muscles in the body?
640
encloses a single muscle fiber
inner most layer
Endomysium
Smooth Muscle
No striations; Involuntary
uninucleate
covers the entire skeletal muscle; made from dense connective tissue
Epimysium
Cardiac Muscle
Striations; Involuntary
uninucleate
Striations; Involuntary
Contracts at a steady rate set by pacemaker
Cardiac Muscle
striated; voluntary
multinucleate
Skeletal Muscle
on the outside of the epimysium
Fascia
surrounded by connective tissues
Skeletal Muscle
when myofibrils divide it becomes
sarcomere
thick filament
myosin
sarcomere will divide into
microfilaments (actin and myosin)
thin filament
actin
Muscle protein that blocked actin and myosin
tropomyosin and troponin
sarcomere is separated by a line
Z-line
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
Muscle cells version of an endoplasmic reticulum
Its walls are loaded with calcium pumps which use ATP to save up a bunch of calcium ions
Sarcoplasmic Reticulum
guards can be bought off with
ATP and calcium
ATP is converted into motion. What kind of motion?
mechanical energy
contains chemical energy
produce by mitochondria
ATP (Adenosine Triphosphate)
____ sends an ____ along the motor neuron until it
____ with a muscle cell in arm
What can you find in your muscle cells that will receive the signals _____
This channels open up, action potential will go to _____ which contain t-tubules it will triggered the voltage-sensitive protein that are linked to calcium channels. In ______ it will allowed stored calcium to go to rest of _____ then it will activate ____ then it will bind with _____, since it binds, _____ will be pull way then _______
Brain / action potential / synapses / receptors/sodium channels / sarcolemma.
Calcium channels / muscle cell / myosin / troponin / tropomyosin / myosin with bind with actin
For relaxation/unbinding
___ will become ___and then ___ will go back to its original place
ATP / ADP / phosphate
troponin and tropomyosin
light band
Contains only thin filaments
I band
long organelles inside muscle cell
Myofibrils
Structural and functional unit of skeletal muscle
contractile unit of a muscle fiber
Sarcomere
specialized plasma membrane
Sarcolemma
dark band
Contains thick filaments
A band
ability to receive and respond to a stimulus
Irritability
ability to forcibly shorten when an adequate stimulus is received
Contractility
ability of muscle cells to be stretched
Extensibility
ability to recoil and resume resting length after stretching
Elasticity
sartorius in your upper thigh
Longest
gluteus maximus in your butt
Tiniest
stapedius in your middle ear
Biggest
Longest muscle
sartorius
Tiniest muscle
gluteus
Biggest muscle
stapedius
Muscles never ___. They always ___.
push/pull
That movement is always a pull with the ___ bone being drawn toward the ___ bone
insertion / origin
muscle brings the insertion closer to the bone that doesn’t move or at least moves less
Origin
when a muscle contracts, the bone that moves
Insertion point
Whatever one muscle does, another muscle can ___.
undo
producing a movement
Prime movers or agonists
moves it away from the body
Abduction
brings a limb toward the body; place back from the side
Adduction
Antagonist – deltoids
Primer movers – pecs and lats
Adduction
Antagonist – pecs and lats
Prime mover – deltoids
Abduction
staying relaxed, or stretching, or contracting
keep prime movers from over-extending
Antagonists
Helps the prime movers and stabilizing joints
infraspinatus and teres minor
Synergists
If synergist immobilizes the muscles’ origin bone so that the prime mover can be more effective, then the synergist muscle
Fixators
group of muscle fibers that all get their signals from the same, single motor neuron
Motor unit
Number of muscle fiber in a neuron
What is bigger than the other
Innervation
When a motor unit responds to a single action potential, those fibers quickly contract and release
Twitch
3 distinct phases of twitch
Latent Period, Period of Contraction, Relaxation Period
The stimulus has arrived, but no force is being produced.
Start of the action
Latent Period
When the myosin and actin is binding
Muscle fibers contract
Period of Contraction
Calcium goes back into sarcoplasmic reticulum
actin and myosin stop the binding cycle
muscle relaxes
Relaxation Period
all those twitches blend together until they feel like one gigantic contraction; nasa taas lang
Tetanus
twitches end up adding to each other as they get closer together in time; pababa
Temporal summation
Generally affected by both the frequency and strength with which they’re stimulated
Graded muscle responses
Muscle force is a product of how many ____ in each sarcomere
many myosin are bound to actin
More ___ = more available binding sites
calcium
More frequent ___ means ever more calcium
activation
numbness
Paresthesia
Change in length
Isotonic movement
no change in length
Isometric contractions
site of axon terminal of the motor neuron and sarcolemma of a muscle
Neuromuscular junction
Chemical released by nerve upon arrival of nerve impulse in the axon terminal
Neurotransmitter
Myofilaments are able to slide past each other during contractions
Isotonic movement
Muscle filaments are trying to slide, but the muscle is pitted against an immovable object
Isometric contractions
the neurotransmitter that stimulates skeletal muscle
Acetylcholine (ACh)
Gap between nerve and muscle filled with interstitial fluid
Synaptic cleft
When stimulations become more frequent, muscle contractions get ___ and ___
stronger and smoother
Only energy source that can be used to directly power muscle contraction
Stored in muscle fibers in small amounts that are quickly used up
ATP
N
N
Decreases the angle of the joint
Brings two bones closer together
Flexion
increases muscle size and strength
Resistance exercise
Increases angle between two bones
Straightening the elbow or knee
Extension
results in stronger, more flexible muscles with greater resistance to fatigue
Aerobic exercise
Movement of a bone around its longitudinal axis
Rotation
Combination of flexion, extension, abduction, and adduction
Circumduction
Movement of a limb away from the midline
Abduction
Movement of a limb toward the midline
Adduction
Turning sole of foot laterally
Eversion
Forearm rotates laterally so palm faces anteriorly
Radius and ulna are parallel
Supination
Forearm rotates medially so palm faces posteriorly
Radius and ulna cross each other like an X
Pronation
Moving the thumb to touch the tips of other fingers on the same hand
Opposition
Lifting the foot so that the superior surface approaches the shin (toward the dorsum)
Dorsiflexion
Pointing the toes away from the head
Plantar flexion
Turning sole of foot medially
Inversion
