Muscles (1) Flashcards
3 Types of muscles
Smooth
Skeletal
Cardiac
Characteristics of smooth muscle
Non striated
Spindle Shaped
Single nucleus
Characteristics of cardiac muscle
Striated
Branched and elongated
1-2 Nuclei
Characteristics of skeletal muscle
Striated
Long and cylindrical
Multinucleated
Why is the tongue good for analyzing skeletal muscle
fibers go in every direction
how far do myocytes extend
the length of a muscle
How do muscle cells become so long
Fusion
What does fusion of muscle cells result in
Multinucleated cells
Rapid information transfer
What are striations
lines that run perpendicular to the muscle fiber
What makes up striations
Z lines and bands
Sarcomeres
How do muscles contract
They shrink the long way and pull z lines together
What surrounds muscle cells
endomysium (reticular connective tissue)
A group of fibers surrounded by perimysium
Fasicle
What is perimysium
dense, irregular connective tissue
What surrounds the entire muscle
epimysium
What is epimysium
dense irregular connective tissue
Merges with deep fascia
What are tendons
Dense, regular connective tissue that doesn’t contract
What do tendons attach
Muscle to bone
What do ligaments attach
bone to bone
Internal tendons
tendons that run into the muscle for deeper connection
Tendons can not be strengthened (T/F)
False
They take longer to strengthen then muscles
Tendon Viscoelasticity
resist change in shape
Bring connections back to relaxed state
Aponeurosis
Broad, flat tendons
How are tendons protected
sesamoid cartilage or bone
Bursa
Synovial sheath
How do sesamoid cartilages or bones protect tendons
covering them (patella)
pulling them away from joints (calcaneus)
How can a bursa protect a tendon
Cushioning with fluid
What is a bursa
a fluid filled pouch between bone and tendon
What is a synovial sheath
a fluid pocket that surrounds the tendon
How can a synovial sheath protect a tendon
Fluid cushioning around the whole tendon
Skeletal muscles are under voluntary control (T/F)
True
What is the main function of skeletal muscle?
attach to and move the skeleton
What is a secondary function of skeletal muscle
preventing movement to maintain posture or achieve complex motion
Skeletal muscles can stabilize joints (T/F)
true
Minor actions of skeletal muscle
Eyeball movement
Facial expression
Respiration
Straining
Skin Wrinkling/twitching
Strap muscles
parallel fibers that don’t come together at origin or insertion
Strap muscles are strong and cause little displacement (T/F)
False they are weak and cause major displacement
Spindle muscles
parallel fibers that come together at origin and insertion
What is the power/movement combo of spindle muscles
Best of both
Some power with decent movement
Pennate muscles
Fibers do not run parallel to origin and insertion
Varying arrangements
Pennate muscles are capable of _____ strength and _____ movement
high
minimal
Muscles can attach to bony and non-bony places (T/F)
True
Non-bony attachments include to other muscles and CT
What is a muscles origin
the least movable attachment
Beginning
What is a muscles insertion
The most moveable attachment
End
The origin is closer to the joint that a muscle flexes (T/F)
False
Insertions are closer to the joint
Agonists
Primary movers
provide the most force for a particular movement
Synergists
Support the Agonist muscles
Cause the same movement as the agonist
Antagonists
Resist agonist movement
An antagonist causes movement in the same direction as an Agonist (T/F)
False
Antagonists cause movement in the opposite direction
Neutralizers
Cancel extra agonist motion
Aids movement in the correct plane
What kind of muscle prevents adverse affects of agonists
Neutralizers
Fixator muscles
Anchor agonist origins
What kind of muscle prevents a second joint from flexing when an agonist contracts
Neutralizers
Extrinsic muscles
Connect 2 things
Muscular connection of thoracic appendage
Surround shoulder
Intrinsic muscles
Cause movement of things
Limited to the limb
Synsarcosis
Links thoracic appendage to axial skeleton
Strictly muscle attachment (lacks bony link)
Actions of the extrinsic muscles of the thoracic appendage
Draw the thoracic appendage cranially, caudally, dorsally, or ventrally
If a muscle causes protraction it must…
be in front of or on the acute angle side of whatever it is moving
Protraction
extending out
Retraction
pulling in
Rotation
muscular contraction on position causes revolution from that position
Elevation
Draw dorsally
Depression
draw ventrally
Extrinsic muscles act on the thorax in what way
draw scapula towards it
support it
ab or adduct the thoracic appendage
ABduction
lateral movement
Away from main body
ADduction
medial movement
Towards the main body
Internal rotation
medial movement
External rotation
Lateral movement
Pronation
Palm down
Supination
Palm up
(internal rotation)
