Busy. Please wait.
or

show password
Forgot Password?

Don't have an account?  Sign up 
or

Username is available taken
show password

why


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.

Remove Ads
Don't know
Know
remaining cards
Save
0:01
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:
Retries:
restart all cards




share
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

Muscular system Ch

Chapter 9 definitions

TermDefinition
Muscle fiber A skeletal muscle cell
Endomysium Delicate connective tissue that covers each muscle fiber
Fascicles Bundles of muscle fibers
Perimysium Sheath of tougher connective tissue that encase the fascicles
Epimysium Surrounds the muscle as a whole and binds all the muscle fibers together
Fascia Connective tissue surrounding the muscle outside the epimysium
Deep fascia Connective tissue that lies between muscles
Superficial fascia Hypodermis that resides just under the skin
Direct attachment Muscle fibers merge with the periosteum of the bone, forming a strong attachment
Indirect attachment The epimysium extends past the muscle as a tendon. The tendon then merges with the periosteum
Aponeurosis Broad tendon that attaches muscle to muscle
Sarcolemma Plasma membrane surrounding each muscle fiber
Sarcoplasm Cytoplasm of the cell
Myofibrils Long protein bundles that fill the sarcoplasm and store glycogen and oxygen
Sarcoplasmic reticulum (SR) Smooth endoplasmic reticulum of a muscle fiber that surrounds each myfibril and where calcium ions are stored
Transverse (T) tubules System of tubules that extends across the sarcoplasm formed from inward projections of the sarcolemma; allow electrical impulses to travel deep into the cell
Myofilaments Finer fibers within myofibrils; can be thick or thin; gives skeletal muscles its striated appearance
Thick myofilaments Made of the protein myosin
Thin myofilaments Made of the protein actin
Z-disc Also called a Z-line; serves as an anchor point for thin myofilaments
Sarcomere Section between the Z-discs where muscle contraction occurs
Cross bridge When the myosin heads latch onto the actin myofilaments
Motor neuron Nerve that stimulates a skeletal muscle to cause contraction
Neuromuscular junction Connection between a motor neuron and a muscle fiber
Muscle tone Continuous state of partial contraction
Motor unit The neuron and all the fibers it stimulates
Twitch Single, brief contraction
Threshold Minimum voltage needed to cause a muscle fiber to contract
Treppe Successive twitches contract more forcefully than the previous one; staircase phenomenon
Incomplete tetanus Rapid contraction with only partial relaxation
Complete tetanus Rarely occuring, twitches merge into one prolonged contraction
Recruitment The process by which an increasing number of motor units are called into action
Isometric contractions The tension within a muscle increases while its length remains the same
Isotonic contractions The muscle changes length and moves a load, while the tension within the muscle remains the same
Aerobic With oxygen
Anaerobic Without oxygen
Origin End of a muscle that attaches to the more stationary bone
Belly Thick mid-section of a muscle
Insertion End of a muscle that attaches to the more movable bone
Prime mover Main muscle triggering the movement
Synergists Muscles that assist the prime mover
Antagonists Oppose the action of the prime mover, therefore balancing the movement
Hypertrophy Muscle enlargement due to strength training
Atrophy Muscle shrinkage due to lack of use
Flexors Muscles that flex the wrist, located on the anterior of the forearm
Extensors Muscles that extend the wrist, located on the posterior of the forearm
Frontalis Muscle of the head and neck that raises eyebrows and shows expressions of surprise
Orbicularis oculi Muscle of the head and neck that closes the eye
Zygomaticus Muscle of the head and neck that makes laughing possible
Orbicularis oris Muscle of the head and neck that draws lips together
Buccinator Muscle of the head and neck that makes smiling and blowing possible
Temporalis Muscle of the head and neck that closes the jaw
Masseter Muscle of the head and neck that closes the jaw
Sternocleidomastoid Muscle of the head and neck that flexes the head; "prayer muscle"
Trapezius Muscle of the head and neck that extends the head (looking up), flexes the head to one side, and elevates the shoulder
External intercostals Muscles of the truck that elevate the ribs
Internal intercostals Muscles of the trunk that depress the ribs
Diaphragm Muscle of the trunk that enlarges the thorax to trigger inspiration
Rectus abdominis Muscle of the trunk that flexes lumbar region to allow bending forward
Transverse abdominal Muscle of the trunk that compresses contents of the abdomen
Internal oblique Muscle of the trunk that stabilizes the spine to maintain posture and permits rotation at the waist
External oblique Muscle of the trunk that stabilizes the spine
Deltoid Muscle of the shoulder and upper arm that abducts, flexes and rotates the arm
Pectoralis major Muscle of the shoulder and upper arm that flexes and adducts the upper arm
Serratus anterior Muscle of the shoulder and upper arm that pulls the shoulder down and forward
Trapezius Muscle of the shoulder and upper arm that raises or lowers shoulders
Latissimus dorsi Muscle of the shoulder and upper arm that adducts and extends the arm backward
Rotator cuff Muscle of the shoulder and upper arm that rotates and adducts the arm; consists of 4 muscles - supraspinatus, infraspinatus, teres minor, and subscapularis
Brachialis Muscle that flexes the forearm
Biceps brachii Muscle that flexes the forearm
Triceps brachii Muscle that extends the forearm
Brachioradialis Muscle that helps flex the forearm
Pronator muscles Pronates the forearm
Supinator Supinates the forearm
Iliacus Muscle acting on the hip and thigh that flexes the thigh
Psoas major Muscle that acts on the hip and thigh that flexes the thigh
Sartorius Muscle that acts on the hip and thigh that adducts and flexes the leg; permits sitting "cross-legged"
Adductor muscles Muscles that acts on the hip and thigh that adducts the thigh; consists of 4 muscles - adductor magnus, adductor brevis, adductor longus, and gracilis
Quadriceps femoris Muscles that act on the hip and thigh that flex the thigh and extend the leg; consists of 4 muscles - rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius
Gluteus medius Muscle acting on the hip and thigh that abducts and rotates the thigh outward
Gluteus maximus Muscle acting on the hip and thigh that extends and rotates the thigh outward
Gluteus minimus Muscle acting on the hip and thigh that abducts and rotates the thigh
Hamstring group Muscles that act on the hip and thigh that extend the thigh; consists of 3 muscles - biceps femoris, semitendinosus, semimembranosus
Gastrocnemius Muscle acting on the foot that causes plantar flexion of the foot
Soleus Muscle acting on the foot that causes plantar flexion of the foot
Tibialis anterior Muscle acting on the foot that causes dorsiflexion of the foot
Extensor digitorum longus Muscle acting on the foot that causes dorsiflexion of the foot
Created by: cbooher16