-
smooth muscle may be found in the
digestive tract
-
the only location for cardiac muscle in the human body is the
heart
-
for every muscle that acts in one direction there is another muscle that is
antagonistic
-
the skeletal muscles of hte body are under
voluntary control
-
the two proteins of the myofibrils are
actin and myosin
-
the Z line, I band, and H zone are all anatomical parts of the
sarcomere
-
the amount of space between the Z lines shortens during
contractions
-
the functional units of skeletal muscle are
sarcomeres
-
the energy for muscle contraction is supplied by
ATP
-
muscle contraction occurs when
the myosin filaments slide over the actin filaments
-
the myoglobin of red muscle is important becasue it
supplies oxygen for muscle contraction
-
the presence of myoglobin in red muscle permits the muscle to
resist fatigue
-
In a muscle at rest, the myosin heads are prevented from binding to actin
by the protein tropomyosin
-
for the successful completion of a muscle contraction, the sarcoplasmic reticulum releases
calcium ions that trigger muscle contractions
-
in order for a muscle contraction to occur
a nerve impulse must stimulate the muscle fiber
-
during muscle contractions, calcium ions bind to sites
on troponin molecules
-
muscle cells that lack a supply of ATP
remain contracted
-
the fact that a muscle fiber contracts completely or not at all is known as the
all-or-none response
-
the number of contracting muscle cells in a particular muscle represents the
graded response
-
the state of sustained maximum contraction by a muscle
is known as tetanus
-
creatine phosphate is utilized in muscle cells as an
energy reserve for ATP
-
the amount of ATP produced during anaerobic reactions in a muscle cell
is much less than is produced in aerobic reactions
-
smooth muscle differs from skeletal muscle does not have
as many actin filaments
-
the ends of cardiac muscle cells are connected through
intercalated disks
-
cardiac muscle is
striated and involuntary
-
the structural unit of muscle tissue is the muscle cell, also known as the
muscle fiber
-
the three types of muscles are
smooth, skeletal, and cardiac
-
the skeletal muscles of the body are under __________ control
voluntary
-
the cytoplasm of the muscle cell is referred to as
sarcoplasm
-
the thick filaments of the muscle fiber are composed of the protein
myosin
-
the line at the ends of sarcomeres is known as the
Z line
-
the major energy source for the contraction of muscle is the molecule
ATP
-
the second but most important ion for triggering muscle contraction is
calcium
-
the contraction observed in a muscle fiber is referred to as a
twitch
-
the state of maximum contraction observed in a muscle is referred to as
tetanus
-
the state in which a muscle is kept partially contracted over a long period of time is called
tonus
-
when a person breathes deeply after strenuous muscle exercise, the oxygen brought into the body helps eliminate the ________ that has built up
lactic acid
-
the type of muscle found in most visceral organs is
smooth muscle
-
intercalated disks are found only in
cardiac muscle
-
the moveable end of the muscle is referred to as the
insertion
-
connective tissue bands called aponeuroses attach to fascia of other muscles and also connect
muscles to bones
-
in the human body, muscles may serve as
- flexors
- extensors
- adductors
- abductors
-
the biceps brachii is so named becasue it has
two heads
-
the brachialis, triceps brachii, and biceps brachii are all muscle of the
upper arm
-
the muscles of the thigh include the
- sartorius
- vastus lateralis
-
the quadriceps femoris is found near the
femur and has four heads
-
the semitendinosus and semimembranosus are both considered to be
hamstring muscles
-
the largest muscle of the buttocks is the
gluteus maximus
-
when the head is flexed and extended such as in saying yes and no, the muscles permitting this movement include the
sternocleidomastoid
-
muscles are often attached to bones by connective tissue referred to as
tendons
-
the plasma membrane of a muscle cell is known as the
sarcolemma
-
___________is similar to a tendon except that they are arranged in flat sheets
aponeurosis
-
in general, skeletal muscle insertions are found
on the bone that is to be moved
-
in a skeletal muscle fiber, the sarcomere is a repetitive unit that consists of the entire region between the
Z lines
-
muscle tissue is responsible for
movement
-
muscles that are concerned with bracing actions are called
fixators
-
myofibrils are primarily composed of
actin and myosin
-
Fx of skeletal muscle
- generates heat
- maintains posture
- stabilizes joints
-
the contractions of skeletal muscle is
voluntary
-
the contractions of cardiac muscle is
involuntary
-
the contractions of smooth muscle is
involuntary
-
The location of skeletal muscle is
attached to bones or skin
-
the location of cardiac muscle is
wall of the heart
-
the location of smooth muscle is
mostly walls of hollow organs
-
five golden rules of skeletal muscle activity
- 1. all muscles cross at least one joint
- 2. bulk of muscle is proximal to the joint where it has its action
- 3. all muscles have at least two attachment sites
- 4. muscles can only pull
- 5. during contraction the insertion moves towards the origin
-
criteria used in naming skeletal muscle
- direction of fibers
- relative size
- location (associated w/ bone)
- number of origins
- location of insertion & origin
- action (extensor/flexor)
-
decrease in the angle of the joint
flexion
-
increase in the angle of the joint
extention
-
extention beyond normal position
hyper extention
-
away from the midline
abduction
-
towards the midline
adduction
-
cone shaped movement
circumduction
-
turning the bone on its own axis
rotation
-
position of palm is inferior
supination
-
position of palm is inferior
pronation
-
position of sole is medial
inversion
-
position of sole is lateral
eversion
-
toes are pointed towards the shin
dorsiflexion
-
toes are pointed away from shin
plantar flexion
-
forward movement of jaw or shoulder
protraction
-
lifting of jaw or shoulder
elevation
-
lowering of jaw or shoulder
depression
-
touching thumbs to fingertips
opposition
-
Fx of the muscular system
- produce movement
- maintain posture
- stabilize joints
- generate heat
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