Muscular System Study Guide
ATP
(adenosine triphosphate) main energy source that cells use for most of their work
muscle acts to flex the finger joints and wrist
flexor digitorum
Motor end plate
folded area where muscle and neuron communicate
Synapse
gap between the neuron and motor end plate (synaptic cleft)
Which muscle has an action of hip extension
gluteus maximus
Myofibrils
individual parallel muscle fibers, within sarcoplasm
Sarcoplasm
inner material surrounding fibers (like cytoplasm)
Sarcolemma
muscle fiber membrane
Muscle Fatigue
muscle loses ability to contract after prolonged exercise or strain
Atrophy
muscles become small and weak due to disuse
Hypertrophy
muscles enlarge (working out or certain disorders)
Muscles whose names contain the root cervi- would be found in the
neck
Specific name for the plasma membrane of the myofiber.
sarcolemma
Perimysium
separates and surrounds fascicles
how do muscles help maintain homeostasis?
skeletal muscle contractions help maintain body temperature.
orbicularis oculi Insertion
skin around eyelids
An olympic long distance marathon winner most likely has an increase number of _______ muscle fibers.
slow
The following describes ___________ fibers. - Contains increased amount of capillary networks, providing oxygen - Contain a red pigment called myoaglobin - Contain oxygen reserves - Contain a relatively larger number of mitochondria than do fast muscle fibers
slow
A person whose genetic makeup makes him or her a better marathon runner than a sprinter probably has more __________ in his or her leg muscles.
slow fibers
Nonstriated, involuntary muscle is _________.
smooth
The muscle that inserts with the gastrocnemius to the calcaneus, via the calcaneal tendon, is the
soleus
What muscle types guard the enterance and exits of the body ?
sphincters
Which of the following acts to flex the neck?
sternocleidomastoid
Skeletal Muscle
striated and voluntary
Cardiac Muscle
striated, heart
Origin
the attachment of the muscle on the more stable bone
Action Potential
the change in electrical potential, passage of an impulse along the membrane (sarcolemma) of the muscle cell
At rest, active sites of the actin are covered by
tropomyosin
_________ moves away from the active sites.
tropomyosin
Neuromuscular junction
where a nerve and muscle fiber come together
Synaptic vesicles
where neurotransmitters are stored (these are released into the cleft and tell the muscle to contract)
Muscles dominated by fast fibers appear _________.
white
Masseter Origin
zygomatic arch
All-or-None Response
Fibers do not contract partially, they either do or don't
The orgin of the soleus is ________ and the insertion is __________
Fibula/tibia; calcaneus
________ allows for electrical stimuli sent from the brain, to reach deep into each fiber
T- tubules
threshold stimulus
The minimal strength required to cause a contraction (Motor neuron releases enough acetylcholine to reach threshold)
ATP-PC (Phosphagen System)
The most immediate system available Delivers instant energy at a high rate Dominant system in repeated, brief, maximal, high-intensity bursts Ex. weightlifting, short sprints, or throwing a ball Maxes out after around 10 seconds of all-out exertion
Motor Unit
The muscle fiber + the motor neuron
What is an effect of aging on the muscular system?
Tolerance for exercise decreases.
Which muscle inserts on the clavicle and scapula?
Trapezius
Type 2 Fibers
White in appearance Fast contraction speed "Fast twitch fibers" Used for anaerobic activity Used for short durations Fatigue easily High force production Low mitochondrial density Low oxidative capacity High Glycolytic capacity Major fuel storage: Creatine Phosphate, Glycogen
Fascia
a band or sheet of fibrous connective tissue that covers, supports, and separates muscle
Antagonist
a muscle whose action counteracts that of another specified muscle
Agonist
a muscle whose contraction moves a part of the body directly
Muscle Cramp
a sustained involuntary contraction
The deltoid acts to
abduct arm
Myofibrils are made primarily of __________.
actin and myosin
Myofilaments
actin and myosin
The striated appearance of skeletal muscle results from
actin and myosin arrangement on the sarcomere
Which of the following terms is a descriptive word for a muscle's action ?
adductor
is developed by performing frequent, brief, intense workouts
anaerobic endurance
A skeletal muscle that is not regularly stimulated by a motor neuron will become smaller and weaker; such as in those individuals that are paralyzed by spinal injuries. The term used when this occurs to the muscles is _______________.
atrophy
Insertion
attachment of the muscle to the more moveable bone.
The following describes _______ type of skeletal muscle fibers. - Produce powerful contractions - Fatigue rapidly - Few mitocondria
fast
A muscle _________ contains a sarcolemma, sacroplasm and myofibrils
fiber
Aponeruosis
A broad sheet of collagen fibers that connects muscles to each other. Similar to bones, but do not connect to a bone.
Acetylcholine
A neurotransmitter that enables learning and memory and also triggers muscle contraction
Which filiament is a thin twisted protein that contains specific active sites?
Actin
Glycolytic System
Anaerobic lactic energy system Can produce ATP Rapidly Used during activities which require bigger bursts of energy Max out in 10-90 seconds Uses carbohydrates in the form of blood glucose and stored glycogen to produce ATP Ex. 800 meter run, basketball, volleyball
Orbicularis oris Insertion
Blends into fibers of orbicularis oris
How do skeletal muscles produce movement?
By pulling on tendons that then moves bones
Tendon
Connective tissue that attach muscle to a bone
Tendon
Connects muscle to bone
After death, rigor mortis lasts until
Decomposition begins
Smooth Muscle
Involuntary muscle
Diaphragm
Muscle used for inhalation for breath
Type 1 Fibers
Red in appearance Slow contraction speed "Slow twitch fibers" Used for aerobic activity Used for long durations Very fatigue resistant Low force production High mitochondrial density High oxidative capacity Low Glycolytic capacity Major fuel storage: Triglycerides
Oxidative/Aerobic System
Requires oxygen to produce ATP, because carbohydrates and fats are only burned in the presence of oxygen Preferred one for long-duration, relatively low intensity cardiovascular activities. Used for exercise durations of 3 min + Ex. Jogging, Rowing, Cycling
What 3 muscles that make up the hamstring group ?
Semimembranosus Biceps femoris Semitendinosus
Endomysium
Surrounds each individual muscle fibers
Muscle tone
Sustained contraction of individual fibers, even when muscle is at rest
The muscle that flexes the knee
biceps femoris
Buccinator Insertion
blends into fibers of orbicularis oris
Fasicle
bundle of muscle fibers
orbicularis oculi Action
closes eye
Orbicularis oris Action
compresses and protrudes the lips
Buccinator Action
compresses cheek
The supraspinatus assists the ______________ muscle.
deltoid
Action
describes what happens when the more moveable bone is brought toward the more stable bone during muscular contraction.
describe the action of the trapezius
elevates, adducts, depresses, or rotates the scapula
A layer of collagen fibers that surrounds an entire muscle is called ________.
epimysium
Muscle Fibers
long, slender cells that make up muscles
Which of the following is a muscle that originates from the zygomatic arch and functions in elevating the mandible?
masseter
Buccinator Origin
maxillary bone and mandible
Orbicularis oris Origin
maxillary bone and mandible
orbicularis oculi Origin
medial margin of orbit
Recruitment
more and more fibers contract as the intensity of the stimulus increases
The less-movable end of a skeletal muscle is the
origin
Epimysium
outermost layer, surrounds entire muscle
Oxygen Debt
oxygen is used to create ATP, - not have enough oxygen causes Lactic Acid to accumulate in the muscles → Soreness
A sheath of connective tissue surrounding a bundle of striated muscle fibers is called __________.
perimysium
cellular respiration
process that releases energy from food in the presence of oxygen
Origin
the immovable end of the muscle
Insertion
the movable end of the muscle
Muscle origins and insertions describe the places where
the muscle attaches to the bone
sliding filament theory
theory that actin filaments slide toward each other during muscle contraction, while the myosin filaments are still
Myosin
thick filament
Actin
thin filaments
sarcoplasmic reticulum
transport