Busy. Please wait.

show password
Forgot Password?

Don't have an account?  Sign up 

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.

By signing up, I agree to StudyStack's Terms of Service and Privacy Policy.

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.

Remove Ads
Don't know
remaining cards
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
restart all cards

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

Chapter 6 -Muscles


Contractility The ability of skeletal muscle to shorten with force.
Excitability The capacity of skeletal muscle to respond to a stimilus.
Extensibility The ability to be strected.
Elasticity The ability to recoil to their original resting length after they have been stretched.
Epimysium A connective tissue sheath upon the skeletal.
Fascia Connective tissue located outside the epimysium.
Muscle Fasciculi Composed of numerous visible bundles.
Perimysium Loose connective tissue.
Fibers The fasciculi are composed single muscle cells.
Myofibrils A threadlike structure tha extends from one end of the fiber to the other.
Four major functional Characteristics contractility, excitability, extensibility, and elasticity.
Myofibers consist of 2 major kinds of protein fibers actin myofilaments and myosin myofilaments
Actin myofilaments thin myofilaments; resemble 2 minute strands of pearls twisted together.
Myosin myofilaments thick myofilaments; resemble bundles of minute golf clubs
Sarcomeres Actin and myosin myofilaments form highly ordered units
Sacomere is the basic structural and functional unity of the muscle
Resting membrane potential charge difference across the membrane
Action potential brief reversal back of the charge
Motor neurons nerve cells that carry action potentials to skeletal muscle fibers
Neuromusclular junction branch that connects to the muscle near the center of the cells
Synapse neuromusclular junction
Motor Unit single motor neuron and all the skeletal muscle fibers it inntervates
Presynaptic terminal enlarged nerve terminal
Synaptic cleft the space between the presynaptic terminal and the muscle cell
Postsynaptic terminal muscle fibers
Each presynaptic terminal contains synaptic vesicles
neurotansmitter acetylcholine
Muscle twitch a contraction of an entire muscle in response to a stimulus that causes that action potential in one or more muscle fibers.
A muscle fiber will not respond to stimulus until that stimulus reaches this level threshold
tetany where the muscle remains contracted without relaxing
ATP adenosine triphosphate
ADP adenosine diphosphate
Isometric equal distance; the length of muscle does not change
Isontonic equal tension; the amount of tenison is constant during contraction
Fast-twitch fibers contract and fatigue quickly
Slow-twitch fibers contract more slowly and are more resistant to fatigue
Orgin head of muscle
Insertion undergoing the greatest movement
Belly between the orgin and the insertion
How are muscles named? location, size, orientation of fibers, shape, origin, insertion,and function
Synergists work together to accomplish specific movements
Antagonists muscles that work againist one another
Sternocleidomastoid moving neck
Frontalis raises the eyebrows
Orbicularis Oculi closes the eyelid
Orbicularis Oris puckers the lips
Buccinator flattens the checks
zygomatious smiling :)
Levator labii superioris sneering
Depressor anguli oris frowning :(
mastication chewing
extrinsic tongue muscle moves tongue
Intrinsic tongue muscle changes shape
Erector spinae muscles on each side of the back; responible for keeping straight and body erect
External intercostals elevate the ribs during inspiration
Internal intercostals contract during forced expiration
Diaphragm quiet breathing
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
Deltoid attaches the humerus to the scapula and clavicle
Triceps brachii extends forearm
Biceps brachii flexes the forearm
Brachioradialis flexes and supinates the forearm
Flextor carpi flexes the wrist
Flexor digitorum flexes the fingers
Extensor carpi extends the wrist
Flexor digitorum flexes the fingers
Extensor digitorum extends the fingers
Glueteus maximus buttocks
Gluteus medius hip muscle
Quadriceps femoris extends leg; thigh muscle
Satorius flexes thigh
Hamstring posterior thigh muscle; flexes the leg and extends the thigh
Gastrocenmius and soleus form the calf muscle
Calcaneal tendon (Achilles tendon) flexes the foot and toes
Created by: samanthav0721