151 terms

muscle quiz #1 - anatomy

the study of muscles
nervous and endocrine
muscles are controlled by these two systems
skeletal, cardiac, smooth
muscles classified under three types
voluntary, striated
skeletal muscle....
-voluntary or involuntary
-striated or not
involuntary, striated
cardiac muscle...
-voluntary or involuntary
-striated or not
involuntary, not striated
smooth muscle...
-voluntary or involuntary
-striated or not
smooth muscle
lines organs and sphincters
producing body movements, stabilizing body positions, storing and moving substances within the body, generating heat
four functions of muscle tissue
producing body movements
integrated functioning of bones, joins, and skeletal muscles causes all movement
(function of muscle tissue)
stabilizing body positions
skeletal muscle contractions stabilize joints and help maintain body positions, such as standing or sitting
(function of muscle tissue)
storing and moving substances within the body
cardiac muscle, smooth muscle, skeletal muscles all move substances and store them
(function of muscle tissue)
generating heat
as muscle tissue contracts, it produces heat, a process known as thermogenesis
(function of muscle tissue)
measure or length
electrical excitability, contractility, extensibility, elasticity
four properties of muscle tissue
electrical excitability
property of both muscle and nerve cells, the ability to respond to certain stimuli by producing electrical signals such as action potentials
(property of muscle tissue)
the ability of a muscle tissue to contract forcefully when stimulated by an action potential
(property of muscle tissue)
the ability of muscle to stretch without being damaged
(property of muscle tissue)
the ability of muscle tissue to return to its original length and shape after contraction or extension
(property of muscle tissue)
principle action of the muscle
relative shape of the muscle
origin and insertion
site where muscle inserts and originates
number of origins
number of tendons of origin
structure near which a muscle is found
direction of fibers
orientation of muscle fascicles relative to the body's midline
relative size of the muscle
a sheet or broad band of fibrous connective tissue that supports and surrounds muscles and other organs in the body
superficial fascia
separates muscle from skin
deep fascia
dense, irregular connective tissue that lines body wall
the connective tissue wrapping that surrounds individual muscle cells (fibers)
the plasma membrane of the muscle cell
the connective tissue wrapping that surrounds each fascicle
the connective tissue wrapping that surrounds the entire muscle
bundle of muscle cells (fibers) bound together by connective tissue to form a functional unit
sheet-like tendon joining one muscle with another or with bone or with skin, muscle to bone
cord of dense fibrous connective tissue that attaches muscle to bone
cylindrical bundle of contractile filaments within the skeletal muscle cell
protein filaments that make up the myofibrils of skeletal muscle cells. 2 types
thick filaments
made up chiefly of the protein myosin
thin filaments
composed mainly of the protein actin, also has troponin and tropomyosin
protein, composes the two major portions of the thick filament. each molecule includes two heads (cross bridges) and a tail region
protein, makes up the thin filament
protein molecule that entwines around actin and blocks the myosin binding sites. In this way, tropomyosin prevents cross bridge cycling until it is moved aside by troponin. one component of the thin filament.
the region of the myofibril's striation that has the darker appearance; also called the dark band. alternates with the light region, corresponds to the length of the thick filaments
Z-band (disc)
zigzag line bisecting the I band. The Z line is actually a protein disc that anchors the thin filaments and connects adjacent myofibrils
H-band (zone)
a lighter stripe in the center of the dark (A) band, corresponding to the region between thin filaments. width varies depending on the degree of muscle contraction. widest when muscle is related and stretched.
the light region of the myofibril's striation that alternates with dark (A) bands; contains only thin filaments. the I band's width is the distance between adjacent thick filaments. gets narrower during muscle contraction
M line
a line in the center of the H zone consisting of protein fibers that connect neighboring myosin filaments
-compartment that contains the filaments in each myofibril
-the contractile unit of that extends from one Z line to the next; includes the entire A band and half of the I band (to the Z line) on each side of the A band
a three-unit group consisting of one T tubule lying between 2 adjacent terminal cisternae
sarcoplasmic reticulum (SR)
the endoplasmic reticulum of the muscle cell. Its interconnecting tubules surround each myofibril like the sleeve of a loosely knit sweater
terminal cisterns
the sac-like regions of the sarcoplasmic reticulum lying adjacent to the T tubules; serve as specialized reservoirs of calcium ions
T-(transverse) tubules
an invagination of the sarcolemma that projects deep into the muscle cell's interior
to make a synaptic connection with an effector organ
neuromuscular junction
synapse between a motor neuron and skeletal muscle fiber. the muscle cell and motor neruron do not actually touch, but are separated by the synaptic cleft
synaptic cleft
the space between the axon terminal and the membrane of the target cell
acetylcholine (ACh)
neurotransmitter released by neurons that simulate skeletal muscles, some neurons of autonomic nervous system, and some neurons in the brain
red pigment protein similar to hemoglobin that stores oxygen in skeletal muscle
The cytoplasm of striated muscle cells.
giant protein that functions as a molecular spring which is responsible for the passive elasticity of muscle
actin, tropomyosin, troponin
thin filament composed of... (3)
Z line
where is actin connected to?
neuromuscular junction
functional site of communication between the motor neuron and muscle fiber
blood capillaries
bring in oxygen and nutrients and remove heat and waste products of muscle metabolism
lactic acid
buildup causes muscle soreness
sum of all chemical reactions that take place, both building up and breaking down
-requires a ton of ATP at a rapid pace
creatine phosphate, anaerobic cellular respiration, cellular respiration
ways to produce ATP (3)
muscle fatigue
inability of a muscle to contract forcefully after prolonged activity
-results from changes within muscle fibers but don't know actual cause
growth of skeletal muscles after birth is mainly due to...
-enlargement of existing cells
increase in number of fibers
replacement of muscle fibers by fibrous scar tissue
breaking down
anabolism and catabolism
together, they make up metabolism (2)
oxygen debt
added oxygen, over and above the resting oxygen consumption, that is taken into the body after exercise
muscular atrophy
a wasting away of muscles, individual muscle fibers decrease in size bc of progressive loss of myofibrils
disuse atrophy
atrophy that occurs when muscles are not used
-ex: bedridden individuals and people with casts
denervation atrophy
nerve supply to a muscle is disrupted or cut
above or excessive
muscular hypertrophy
the enlargement of existing muscle cells, increase in the diameter of muscle fibers owing to the production of more myofibrils, mitochondria, etc. results from very forceful repetitive muscle activity
increase in the number of fibers
increased muscle tone, either rigidity (muscle stiffness) or spasticity (muscle stiffness associated with an increase in tendon reflexes)
decreased or lost muscle tone, usually due to damage to somatic motor neurons
below or deficient
painful condition
painful, nonarticular rheumatic disorder that usually appears between the ages of 25 and 50
known as muscle strain; tearing of a muscle bc of forceful impact and causes bleeding and severe pain
muscular dystrophy
group of inherited muscle-destroying diseases that cause progressive degeneration of skeletal muscle fibers
duchenne muscular dystrophy (DMD)
most common form of muscular dystrophy and strikes boys almost exclusively
inflammation of muscle fibers (cells)
inflammation of
pain in or associated with muscles
myastenia gravis
autoimmune disease that causes chronic, progressive damage of the neuromuscular junction
a tumor consisting of muscle tissue
a sudden involuntary contraction of a single muscle in a large group of muscles
a painful spasmodic contraction
rhythmic, involuntary, purposeless contraction that produces a quivering or shaking movement
an involuntary, brief twitch of an entire motor unit that is visible under the skin
spontaneous contraction of a single muscle fiber that is not visible under the skin but can be recorded by electromyography. May signal destruction of motor neurons.
spasmodic twitching made involuntarily by muscles that are ordinarily under voluntary control
shortening of a muscle
rigor mortis
muscles are in a state of rigidity
exercise induced muscle damage
torn sarcolemmas in muscle fibers, damaged myofibrils, disrupted z discs, increases in blood levels or proteins, such as myoglobin and the enzyme creatine kinsae (normally confined within muscle fibers)
creatine supplementation
small, amino acid-like molecule that is both synthesized in the body's own synthesis of creatine and it's not known whether natural synthesis recovers after long term creatine supplementation
pain relief
the site of a muscle's attachment to the more stationary bone
the site of a muscle's attachment to the more moveable bone
-usually moves toward origin as muscle contracts
a rigid structure that can move around a fixed point
a fixed point
causes movement
opposes movement
effort and load
two forces
mechanical advantage
when a smaller effort can move a heavier load, effort must move a greater distance and faster than the load
mechanical disadvantage
when a larger effort moves a lighter load, effort must move a shorter distance and slower than the load
first class lever
-the fulcrum is between the effort and the load
-can produce either a mechanical advantage or disadvantage
-ex: scissors and seesaws and head on vertebral column
E---F-L : mechanical advantage
E-F---L : mechanical disadvantage
second class lever
-the load is between the fulcrum and the effort
-always produces a mechanical advantage
-no second class levers in the body
-ex: wheelbarrows
F-L---E : makes mechanical advantage
third class lever
-the effort is between the fulcrum and the load
-always produces a mechanical disadvantage
-most common levers in the body
-ex: forceps, elbow joint, bones of the arm and forearms, the biceps brachii muscle
F-E---L : makes mechanical disadvantage
first class lever
second class lever
third class lever
the fleshy part of the muscle between the tendons of the origin and insertion
originate on outside and insert
originate and insert on inside
increase angle
decrease angle
moves away from midline
moves towards midline
palm backwards/down
palm foreward/up
turn soles outward
move soles inward
revolve around axis
distal part moves in a circle
prime movers/agonist
muscle that contracts to cause an action
stretches and yields to the effects of the prime mover
-muscles that contract and stabilize the intermediate joints
-aids movement of prime mover and helps prevent unwanted movements
improved physical performance, decreased risk of injury, reduced muscle stress, improved posture
benefits of stretching (4)
sternocleidomastoid muscle (sternomastoid)
side of neck, large, from clavicle/sternum to mastoid
trapezius muscle
largest muscle on outside of back, goes down and outward and then down and inward
levator scapulae muscle
back side of neck, medial to scalenus muscle
scalenus muscle
three muscles on side of neck, lateral to levator scapulae muscle
subclavius muscle
muscle right below clavicle
deltoid muscle
shoulder muscle, largest on shoulder
pectoralis major muscle
pecs, larger, superficial
pectoralis minor muscle
pecs, deep