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.

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

A&P:I:Muscles part 2

Parallel Muscles Fibers parallel to the long axis of muscle e.g., biceps brachii The center or body of the muscle thickens when parallel muscle contracts Parallel muscles contract about 30%
Convergent Muscles A broad area converges on attachment site (tendon, aponeurosis, or raphe) Muscle fibers pull in different directions, depending on stimulation e.g., pectoralis muscles
Pennate Muscles: Unipennate fibers on 1 side of tendon e.g., extensor digitorum
Pennate Muscles: bipennate fibers on both sides of tendon e.g., rectus femoris
Pennate Muscles: multipennate Multipennate: tendon branches within muscle e.g., deltoid
Pennate Muscles Form angle with tendon Don’t move as far as parallel muscles Contain more myofibrils than parallel muscles Develop more tension than parallel muscles
Circular Muscles Also called sphincters Open and close to guard entrances of body e.g., obicularis oris
What do muscles provide and required to overcome? -Applied force -resistance
What is lever's function? direction of an AF distance & speed of movement produced by an AF effective strength of an AF
What are the three types of classes dependent on? force fulcrum and resistance
Each bone is a ___ and each joint is a ____ Lever fulcrum
First-Class Levers Seesaw is an example Center fulcrum between applied force and resistance Force and resistance are balanced
Second–Class Levers Wheelbarrow is an example Center resistance between applied force & fulcrum A small force moves a large weight
Third-Class Levers Most common levers in the body Center applied force between resistance & fulcrum Greater force moves smaller resistance Maximizes speed and distance traveled
Origin Muscles have 1 fixed point of attachment (origin
Insertion 1 moving point of attachment (insertion)
Action Movements produced by muscle contraction Body movements e.g., flexion, extension, adduction, etc. Described in terms of bone, joint, or region
agonist produces a particular movement
Antagonist opposes movement of a particular agonist
What works in pairs? agonist and antagonist
How do agonist and antagonist work in paris together? when 1 contracts, the other stretches i.e., flexors–extensors, abductors–adductors, etc.
Synergist a smaller muscle that assists a larger agonist and helps start motion or stabilize origin of agonist (fixator)
sternocleidomastoid from clavicle and sternum to mastoid Origin: Sternal head-manubrium of sternum Clavicle head-medial rd of clavicle Insertion=Mastoid
Oblique muscles -compress underlying structures -rotate vertebral column
Diaphragmatic muscle or diaphragm -divides thoracic and abdominal cavities -preforms respiration Origin=xiphoid process of sternum and costal cartilages and adjacent ribs 7-12 Insertion: central tendon
supraspinatus abduction at the shoulder Origin: spuraspinous fossa of scapula insertion:greater tubercle of humerus
Gracilis flexion at knee adduction and medial rotation at hip origin: body and inferior ramus of pubis insertion:medial surface of tibia
sartorius flexion at knee flexion and lateral rotation at hip Origin: anterior superior illiac spine Insertion: medial surface of body of tibia
Gastrocnemius extension (Plantar flexion) at ankle inversion of foot flexion at knee Origin- lateral and medial condyles of femur and capsule of kneee Insertion;calcaneus by way of calcaneal tendon
why do muscles interact with one another? Muscles work in groups to maximize efficiency
___ muscles reach maximum tension first, followed by ____,____ muscles smaller larger, primary
6 ways that muscles are named 1)location 2)origin and insertion 3)fascicle organization 4) Relative position 5) Structural character 6) Action look in powerpoint for in depth
Effects of Aging on the Muscular System Skeletal muscle fibers become smaller in diameter Skeletal muscles become less elastic: develop increasing amounts of fibrous tissue (fibrosis) Decreased tolerance for exercise Decreased ability to recover from muscular injuries
Internal Oblique Origin: Anterior iliac crest, lateral half of inguinal ligament , and thoracolumbar fascia Insertion: Costal cartilage of ribs 8-12, abdominal aponeurosis to linea alba Actions: Flexes vertebral column, rotates vertebral column, laterally flexes
External Oblique Origin: External surfaces of ribs 5-12 Insertion: Anterior iliac crest and abdominal neurosis to linea alba Actions: Flexes vertebral column, rotates vertebral column, and laterally flexes vertebral column
Created by: talennna