Busy. Please wait.
Log in with Clever

show password
Forgot Password?

Don't have an account?  Sign up 
Sign up using Clever

Username is available taken
show password

Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
Your email address is only used to allow you to reset your password. See our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Didn't know it?
click below
Knew it?
click below
Don't Know
Remaining cards (0)
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

ch.6 - muscles

Contractility The ability of skeletal muscle to shorten with force
Excitability The capacity of skeletal muscle to respond to a stimulus.
Extensibility The ability to be stretched
Elasticity Ability to recoil to their resting length after they have been stretched.
Epimysium A connective tissue sheath
Fascia A connective tissue which surrounds and separates muscles
Perimysium Loose connective tissue that surrounds the muscle fasciculi
Fibers Single muscle cells which make up the fasciculi
Muscle fasciculi Visible bundles which make up the muscle
Endomysium A connective tissue sheath which surrounds the fibers
Myofibrils A threadlike structure that extends from one end of the fiber to the other.
Actin myofilaments Thin filaments; resemble 2 minute strands of pearls twisted together
Myosin myofilaments Thick filaments; resemble bundles of minute golf clubs
Sarcomeres Highly ordered units formed by actin & myosin myofilaments; basic structural and functional unit of the muscle
Resting membrane potential The charge difference across the membrane
Action potential The brief reversal back of the charge
Motor neurons Nerve cells that carry action potentials to skeletal muscle fibers
Neuromuscular junction Each branch that connects to the muscle
Motor unit A single motor neuron and all the skeletal fibers it innervates
Presynaptic terminal The enlarged nerve terminal
Synaptic cleft The space between the presynaptic terminal and the muscle cell
Postsynaptic terminal The muscle fiber
Synaptic vessels in the postsynaptic terminal, secretes a neurotransmitter called acetylcholine
Sliding filament mechanism The sliding of actin myofilaments past myosin myofilaments during contraction
Muscle twitch A contraction of an entire muscle in response to a stimulus that causes the action potential in one or more muscle fibers
Threshold The level at which point the muscle fiber will contract maximally
Lag phase The time between application of a stimulus to a motor neuron and the beginning of a contraction
Contraction phase The time of contraction
Relaxation phase The time during which the muscle relaxes
Tetany When the muscle remains contracted without relaxing
Recruitment The increase in number of motor units being activated
ATP (adenosine triphosphate) Needed for energy for muscle contraction
Creatine phosphate A high energy molecule that ATP can store
Anaerobic respiration Without oxygen
Aerobic respiration With oxygen
Oxygen debt The amount of oxygen needed in chemical reactions to convert lactic acid to glucose and to replenish the depleted stores of creatine phosphate stores in muscle cells
Muscle fatigue Results when ATP is used during muscle contraction faster than it can be produced in the muscle cells
Isometric The length of the muscle does not change but the amount of tension increases during the contraction process
Isotonic The amount of tension produced by the muscle is constant during contraction, but the length of the muscle changes.
Muscle tone Constant tension produced by muscles of the body for long periods of time
Fast twitch fibers Contract quickly and fatigue quickly. Well adapted to perform anaerobic metabolism
Slow twitch fibers Contract more slowly and are more resistant to fatigue. They are better suited for aerobic metabolism
Origin The most stationery end of the muscle
Insertion The end of the muscle undergoing the greatest movement
Belly The portion of the muscle between the origin and insertion
Synergists Muscles that work together to accomplish specific movements
Antagonists Muscles that work in opposition to one another
Prime mover One muscle that plays a major role in accomplishing a desired movement
Occipitofrontalis Raises the eyebrows
Orbicularis oculi Closes the eyelids and causes crows feet wrinkles
Orbicularis oris Puckers the lips
Buccinator Flattens the cheeks
Zygomaticus Smiling muscle
Levator labii superioris Sneering
Depressor anguli oris Frowning
Mastication Chewing
Intrinsic Tongue Muscles Change the shape of the tongue
Extrinsic Tongue Muscles Move the tongue
Sternocleidomastoid Lateral neck muscle and prime mover
Platysma Sheetlike muscle that covers the anterolateral neck
Erector spinae Group of muscles on each side of the back
Linea alba A tendinous area of the abdominal wall
Rectus abdominis On each side of the linea alba
Trapezius Rotates scapula
Serratus anterior Pulls scapula anteriorly
Pectoralis major Adducts and flexes the arm
Latissimus dorsi Medially rotates, adducts, and powerfully extends the arm
Deltiod Attaches the humerus to the scapula and clavicle, and is the major abductor of the upper limb
Triceps brachii Extends the forearm
Biceps brachii Flexes the forearm
Flexor carpi Flexes the wrist
Extensor carpi Extends the wrist
Flexor digitorum Flexes the fingers
Extensor digitorum Extends the fingers
Quadriceps femoris Extends the leg
Created by: skfreem1
Popular Anatomy sets




Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

Pass complete!
"Know" box contains:
Time elapsed:
restart all cards