Anatomy II Exam 1 Flashcards
myology
study of muscles
muscles
are made for movement of and within the body
what are the 3 types of muscle tissue
- cardiac muscle
- visceral muscle
- skeletal muscle
Visceral/ Smooth muscle
found in the viscera (organs) of the body, single nucleus, involuntary control
Skeletal muscle
this muscle is indirectly attached to the bone or skeleton, distinct striated, multinucleate, voluntary control
what are the 3 distinct parts in the skeletal muscle
- the body or belly
- origin
- insertion
Body or Belly
the bulky, fleshy part of the muscle which shortens and thickens during contraction
Origin
the relatively fixed point of attachment of the muscle
Insertion
the relatively movable point of attachment of the muscle
There are approximately _____ skeletal muscles in the body
500
The total mass of skeletal muscle tissue accounts for about ____% of the body weight
45
aponeurosis
a broad, flat tendon
Tendon
muscle attachment to bone is made indirectly, with a connective tissue structure
Action
muscles may be named for the particular type of action they produce upon contraction
Flexion
a flexor muscle decreases the angle between 2 body parts
Extension
an extensor muscle increases the angle between 2 body parts
Abduction
an abductor pulls a body part away from the median plane
Supination
a supinator turns the palm of the hand anteriorly (back into anatomical position)
Pronation
a pronator muscle turns the palm of the hand posteriorly (out of anatomical position)
Supination
a supinator turns the palm of the hand anteriorly (back into anatomical position)
Eversion
eversion implies a turning outward or inside out
inversion
inversion means to draw inward or outside in. (the feet are initially positioned in an inverted position)
Constriction
a constrictor muscle such as a sphincter muscle, narrows or binds a vessel, opening, or passageway
dilation
dilator expands an organ, vessel, or orifice
elevation
elevator muscle raise a particular body part or organ
depression
depressor be it of the tongue or otherwise, lowers a part
rotation
this muscle action has no antagonistic muscle action, but rather refers to the turning of a bone about its long axis, as when you shake your head no
circumduction
movement such that the distal end of a bone describes a circle, and the shaft describes a cone. Look for this movement by a 3rd base coach in baseball, as he waves in a runner from 2nd base to try and score a run
Sphincter muscle
circular shaped, and will constrict
Shape
names may be applied which approximately describe the shape of a muscle
Deltoid
triangular shaped muscle which gives roundness and fullness to the shoulder. Its function is to abduct the arm.
quadratus
4 sided
trapezius
trapezoid
orbicularis
sphincter muscles- circular-shaped
platysma
flat
vastus
large
rectus
straight
points of attachment
muscles may be named according to their point of origin and insertion
what are the only two muscles that are described by their points of attachment
sternocleidomastoid
occipitofrontalis
number of divisions
muscles may have prominent divisions in which fibers may be grouped into bundles that run in slightly different directions and have different points of attachment “-ceps” latin meaning “headed”
intercostal
the space between the ribs
buccinator
facial cheeks
orbicularis oris
circular-shaped muscle of the mouth
orbicularis oculi
circular-shaped muscle of the eye
superficial vs. deep
the muscles of facial expression lie superficially in relationship to the muscles of mastication, which lie deep