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.
We do not share your email address with others. It is only used to allow you to reset your password. For details read 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.
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

Ch.6 muscles

muscle cells muscle fibers
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 original resting length after they have been stretched
each skeletal muscle is surrounded by a connective tissue sheath called the ____ epimysium
____ is another connective tissue located outside the epimysium fascia
muscle fasciculi are surrounded by loose connective tissue called the ____ perimysium
each fiber is surrounded by a connective tissue sheath called the ____ endomysium
the cytoplasm of each fiber is filled with ___ myofibrils
thin myofilaments (pearls twisted) actin myofilaments
thick myofilaments (golf balls) myosin myofilaments
joined end to end to form the myofibril sarcomeres
the charge difference across the membrane resting membrane potential
the brief reversal back of the charge action potential
nerve cells that carry action potentials to skeletal muscle fibers motor neurons
Each branch that connects to the muscle forms a _____ _____, or _____ near the center of the cell. neuromusclular junction ; synapse
a single motor neuron motor unit
enlarged nerve terminal presynaptic terminal
the space between the presynaptic terminal and the muscle cell synaptic cleft
postsynaptic terminal muscle fiber
secrete a neurotransmitter synaptic vesicles
neurotransmitter acetylcholine
enzyme that breaks down muscle cells acetylcholinesterase
the sliding of actin myofilaments past myosin myofilaments during contraction sliding filament mechanism
___ ___ is a contraction of an entire muscle in response to a stimulus that causes the action potential in one or more muscle fibers muscle twitch
a muscle fiber will not respond to stimulus until that stimulus reaches a level called ____ threshold
the time between application of a stimulus to a motor neuron and the beginning of a contraction lag phase
the time of contraction contraction phase
the time during which the muscle relaxes relaxation phase
where the muscle remains contracted without relaxing tetany
the increase in number of motor units being activated recruitment
ATP is produced in the _______ mitochondria
adenosine triphosphate ATP
adenosine diphosphate ADP
high-energy molecule ATP stores creatine phosphate
without oxygen anaerobic respiration
with oxygen (more efficient) aerobic respiration
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 oxygen debt
results when ATP is used during muscle contraction faster than it can be produced in the muscle cells muscle fatigue
the length of the muscle does not change, but the amount of tension increases during the contraction process isometric muscle contraction
the amount of tension produced by the muscle is constant during contraction, but the length of the muscle changes isotonic muscle contraction
Muscle tone refers to constant tension produced by muscles of the body for long periods of time. Keeps head up and back straight muscle tone
contract quickly and fatigue quickly fast twitch fibers
contract more slowly and are more resistant to fatigue slow twitch fibers
At these attachment points the muscle is connected to the bone by ____ a tendon
the most stationary end of the muscle origin
the end of the muscle undergoing the greatest movement insertion
the portion of the muscle between the origin and the insertion the belly
muscles that work together to accomplish specific movements synergists
muscles that work in opposition to one another antagonists
if one muscle plays the major role in accomplishing the desired movement it is the _____ prime mover
Occipitofrontalis raises the eyebrows
Orbicularis oculi closes the eyelids
Orbicularis oris puckers lips
Buccinator flattens 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
Erector spinae group of muscles on each side of the back. Responsible for keeping the back straight and the body erect
muscles that move the thorax thoracic muscles
elevate the ribs during inspiration External intercostals
contract during forced expiration Internal intercostals
accomplishes quiet breathing diaphragm
tendinous area of the abdominal wall linea alba
On each side of the linea alba is the ____ rectus abdominis muscle
______ cross the rectus abdominis at three or more locations, causing the abdominal wall of a well-muscled person to appear segmented Tendinous inscriptions
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, and is the major abductor of the upper limb
Triceps brachii extends the forearm
Created by: shelbyshepard