A&P - Chapter 15 (Part 1) Flashcards
How many skeletal muscles are there in our body?
600
What percentage of our body weight is skeletal muscle?
40%-50%
What do muscles fill?
In the form and contour of the body
What are 3 skeletal muscle structures?
- Endomysium
- Perimysium
- Epimysium
Endomysium
Delicate connective tissue membrane that covers the skeletal muscle fibres
What another word for muscle fibres?
Muscle cells
Perimysium
Tough connective tissue membrane that binds fascicles together
Fascicles
Group of skeletal muscle fibres
Epimysium
Coarse sheath that covers the muscle as a whole
What is the result of the endomysium, perimysium and epimysium fusing together?
Tendons
Tendons
Strong, tough fibrous cords that connect muscle to bone
Aponeurosis
A broad sheet of connective tissue which is an extension of the epimysium
What characteristics do tendons and aponeurosis share?
They are very strong
- can break bones (not torn by traumas though)
Origin
Point of attachment to the bone that remains relatively fixed when movement at the joint occurs
Insertion
Point of attachment to the bone that moves when a muscle contracts
Body of muscle
Main part of the muscle
How are most body movements produced?
By the coordination action of groups of muscle
- some are relaxed while others contract
What are the 4 main muscles involved in muscle actions?
- Prime mover
- Synergist
- Antagonist
- Fixator
What is another word for prime mover?
Agonist
Prime mover
Its contraction is mainly responsibly for producing a movement
Synergist
Its contraction helps the prime mover to produce a movement
Antagonist
Its actions oppose the action of a prime mover in a movement
Fixator
Functions as a joint stabilizer
What is an example of a prime mover in the arm?
Biceps
What is an example of a synergist in the arm?
Brachialis
What is an example of an antagonist in the arm?
Triceps
What is the result of a fight between the agonist and antagonist?
Broken bone
