Muscular System Flashcards
What is striated muscle?
that tissue attached to the skeleton that is under voluntary or conscious control.
Muscle is stimulated to contract when:
it receives a nerve impulse from the central nervous system.
Muscles undergo two types of contraction:
isometric and isotonic
When a muscle becomes smaller as a result of lack of use it is said to be:
atrophied
the more a muscle is used the larger it will become, it is said to be:
hypertrophied
A muscle is attached to a bone at 2 points. Its starting point is called its:
origin, and moves least during contraction.
the opposite end where the muscle inserts on the bone is called the:
insertion
Describe intrinsic muscles
lie completely within one region of the body where they have their origin and insertion. they act on the joints of that part only.
describe extrinsic muscles
Run from one region of the body to another and alter the position of the whole part in relation to the other.
What are the four muscles of mastication?
Digastricus (opens the jaw), Masseter (closes the jaw), temporalis (also closes the jaw), medial and lateral pterygoids (aid in closing the jaw).
what 2 muscles keep the jaw closed when not in use?
masseter and temporalis
the extrinsic muscles of the eye, also called:
extraocular muscles
what are the FOUR RECTUS muscles of the eye?
- dorsal rectus
- ventral rectus
- medial rectus
- lateral rectus
What are the actions of the four rectus muscles?
the names reflect their actions; the dorsal muscles turns the eye upwards, the medial turns the eye inwards etc.
what are the TWO OBLIQUE muscles of the eye?
- dorsal oblique
- ventral oblique
