Exam 2: Objectives 30-33 Flashcards
what is another name for extrapyramidal systems?
brainstem pathways
striation appears due to numerous ____________ arranged in a __________
thick and thin filaments; myofibril
what is the net gain in ATP for aerobic respiration?
36 ATP
which kinds of muscle are striated?
skeletal and cardiac
in anaerobic glycolysis, where does glycolysis occur?
in the sarcoplasm
what splits ATP into ADP and Pi, allowing the head to bind to actin where the muscle is stimulated?
myosin head
plasma membrane covering each muscle fiber
sarcolemma
cause of muscle fatigue: due to decreased release of _______ from _________ causing decreased levels in the sarcoplasm
Ca++; SR
where do thick filaments connect? what connects them?
z lines; titin
which type of skeletal muscle fiber responds the most to training?
fast oxidative glycolytic
what is another name for the pyramidal system?
corticospinal system
assesses sensory input from vestibular and proprioceptive sensory information
romberg test
what is the most immediate way a muscle fiber can attain ATP?
creatine phosphate
tunnel-like extensions of the sarcolemma that can conduct action potentials
transverse tubules
what are possible energy sources for aerobic respiration?
glucose, fatty acids, amino acids
type of recruitment: high number of motor units
jerky contraction
which kind of muscle is responsible for vasodilation and constriction?
smooth muscle
type of skeletal muscle fiber: uses aerobic respiration
slow oxidative
which pathway to ATP can only use glucose as an energy source?
anaerobic glycolysis
what part of the brain helps initiate, terminate, and control movements, regulate muscle tone, behavior?
basal ganglia
type of recruitment: small number of motor units
smooth contraction
what are 5 causes of muscle fatigue?
- lower levels of Ca++ 2. depletion of nutrients (ex: O2, CP) 3. too much lactic acid 4. cross bridge inhibition 5. failure to reach AP
which system of motor control involves upper motor neurons?
pyramidal system
arrangement of myofibrils within a muscle cell which is the *functional unit of contraction*
sarcomere
slow, writhing movements
athetosis
what are thin filaments composed of?
actin
incoordination, wobbling gait *cerebellar deficits*
ataxia
which protein physically blocks cross bridges, thereby regulating contractions?
tropomyosin
where do thin filaments connect terminally?
z lines
sequential muscle contraction stimulations (and resulting stronger contraction)
wave summation
contains many mitochondria that mass produce ATP
sarcoplasm
which system of motor control has an indirect pathway: begins in brainstem, controls proximal musculature, lower motor neurons
extrapyramidal system
when a muscle contracts, what shortens?
sarcomeres
what is released after the power stroke?
ADP, actin
what kind of receptor is found in the motor end plate?
nicotinic
when a person exercises, oxygen is withdrawn from reserves in ________ and _________
hemoglobin and myoglobin
where does Ca+ attach after it has been released following an action potential?
to troponin
which kind of muscle has intercalated discs?
cardiac muscle
which system of motor control has a direct pathway: nerve fibers run from motor cortex to the spinal cord?
pyramidal system
where is glucose stored for glycolysis?
blood and within muscle fiber
what do intercalated discs allow?
for the muscle to be autorhythmic
what produces the power stroke that pulls the thin filament toward the center?
release of Pi cocks the myosin head
which ion is released when muscle cells are stimulated by an action potential?
Ca+
sudden, irregular, jerky movements without purpose
chorea
what does the sarcoplasmic reticulum store?
Ca+ ions and myoglobin (oxygen)
how does the creatine phosphate reaction provide ATP for the muscle fiber?
phosphate group is moved from CP to ADP
part of a striation: found in the center of each A band; helps hold down thick filaments *middle of a sarcomere*
M line
which type of myofilament has the proteins tropomyosin and troponin?
thin filaments
type of skeletal muscle fiber: uses both aerobic and anaerobic respiration, many mitochondria, resistant to fatigue
fast oxidative glycolytic (FOG/IIA)
part of a striation: the center of the A band with no thin filament overlap
H zone
a motor neuron plus the muscle fibers it innervates
motor unit
what are the byproducts of anaerobic glycolysis?
pyruvic acid and lactic acid
part of a striation: contains all of the thick filament and some thin filament overlap
A band
which kind of muscle is the only type that can contract without a motor neuron?
cardiac muscle
upper or lower motor neuron lesion: stiff, exaggerated reflexes, loss of inhibition?
upper
what part of the brain coordinates sensory inputs from muscles, joints, eyes, ears?
cerebellum
how does the cell return to rest after a contraction?
ATP required to pump Ca+ back into SR
where do cross bridges form?
between myosin and actin
where are most neuromuscular junctions located?
near the middle of the muscle fiber
what are the 2 binding sites on myosin?
actin and ATP binding sites
cylindrical structures that extend the entire length of the muscle fiber
myofibrils
what are the 3 types of skeletal muscle fibers?
slow oxidative, fast oxidative glycolytic, fast glycolytic
what are the 3 ways a muscle fiber can form ATP for contractions?
creatine phosphate, anaerobic glycolysis, aerobic respiration
type of skeletal muscle fiber: few mitochondria, mainly anaerobic respiration, fatigue quickly, rapid and powerful
fast glycolytic
about 90 stimulations per second resulting in a sustained contraction
fused tetanus
what is the primary role of the pyramidal system?
voluntary motor movements: fine, isolated
during a muscle contraction, which type of band shortens and which does not?
I bands shorten; A bands do not
which pathway to ATP happens after creatine phosphate?
anaerobic glycolysis
upper or lower motor neuron lesion: soft, absence of reflexes
lower
what is a muscle twitch?
a single action potential
what are thick filaments composed of?
myosin
what part of the brain maintains movements initiated by the primary motor cortex?
cerebellum
what is the effect of Ca+ binding to troponin after an AP?
it moves tropomyosin: myosin can access actin to form cross bridges: muscle contraction is possible
what does the action potential provide for the muscle cell?
increased Ca+ in the sarcoplasm
period between excitation and development of force in a skeletal muscle that includes the time needed for the AP to travel down the sarcolemma, T tubules, to release Ca+ from SR, move tropomyosin, and cycle the cross bridges
latent period
which protein prevents myosin from binding at rest?
tropomyosin
these are symptoms of lesions where? resting tremor, chorea, athetosis
basal ganglia
part of a striation: found in the center of each I band *end of a sarcomere*
Z line
where is the premotor cortex located?
frontal lobe
what is the net gain in ATP of anaerobic glycolysis?
2 ATP
which part of the brain initiates movement?
primary motor cortex
formation of glucose from non-carbohydrate sources
gluconeogenesis
Order these steps to stimulating a muscle fiber: a. end plate potentials are produced (EPSPs) b. Ach is released from the motor neuron c. voltage-gated Ca+ channels open and cause Ca+ channels in SR to open d. Ach binds to nicotinic cholinergic receptors on motor end plate of skeletal muscle e. calcium is released and can bind to troponin f. APs are generated along sarcolemma and travel down T tubules
b, d, a, f, c, e
where is the primary motor cortex located?
precentral sulcus
primary role of which system of motor control: posture, upright movement, balance, walking *involuntary movements*
extrapyramidal system
part of a striation: contains only thin filaments
I band
processing and storage center for a muscle cell
sarcoplasmic reticulum
what is the formula for aerobic respiration?
glucose + O2 > CO2 + H20 + ATP
where does aerobic respiration take place?
mitochondria
protein that anchors thick filaments to z lines and allows elastic recoil
titin
multiple stimulations to muscle resulting in increasing but wavering contractions
unfused tetanus
what determines the force produced by a single muscle fiber?
frequency and the # contracting in unison
these are symptoms of lesions where? ataxia, intention tremor
cerebellum
type of skeletal muscle fiber: small diameter, contains most myoglobin, many mitochondria, resistant to fatigue, found in postural muscles
slow oxidative (SO/IA)
