Muscles and Movement Flashcards
What are the three types of muscles?
- Skeletal muscle
- Smooth muscle
- Cardiac muscle
What properties do muscles have besides contracting?
- Extensibility - stretch
- Elasticity - return to original length
What are the ends of the biceps and triceps connected to? What is this pair called?
- Biceps: Scapula and the radius
- Triceps: Scapula and humerus, and the ulna.
It is called antagonistic pair.
How do the antagonistic pairs function?
There are two muscles in the pair. The agonist, which causes the desired action; and the antagonist, which causes the contrary reaction.
For example; when we are flexing our arm, the bicep (agonist) is contracting and the tricep (antagonist) is relaxing. When we are extending it, the roles invert.
What are the synergists?
They are muscles that help indirectly in steadying a joint during a particular movement. They prevent unwanted movement.
For example, the muscles that attach the scapula to the axial skeleton (fixator).
Describe the structure of skeletal muscle.
Muscle cells (fibers) are arranged in bundles.
Each bundle is surrounded by connective tissue, which allows adjacent bundles to slide over one another when the muscle contracts.
Around the muscle cell, there is the plasma membrane, sarcolemma, which contains sacorplasm.
Within the sarcoplasm there are myofibrils.
Describe structure of myofibrils.
Myofibrils are composed of myofilaments, which are made of protein.
There are two types of myofilaments: thick and thin.
Thick ones are composed of protein myosin.
Thin ones are composed of protein actin.
When ATP is released, both myofilaments slide past each other to shorten the myofibril. (contract muscle)
What is muscle tone?
It is the maintenance of partial contraction of skeletal muscles. It is caused by a rotation of contraction among many different fibres.
What are the gluteal muscles in the lower limbs?
- Gluteus maximus
- Quadriceps
- Hamstrings
- Adductors
