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66 terms

Biology 2 - The Muscular System

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skeletal muscle cytoplasm is called
sarcoplasm
fascia that covers fascicle
perimysium
thin contractile fiber is called
actin
thick contractile fiber is called
myosin
a contractile unit
sarcomere
at what age do muscles begin to weaken
30
small bundle of muscled fibers
fascicle
fascia that covers myofibrils
endomysium
fascia that covers an entire muscle
epimysium
an extension of fascia that attaches a muscle to a bone
tendon
study of muscles
myology
what % of heat is generated by muscles
85%
a muscle tumor
myoma
the ability of a muscle to return to its original shape
elasticity
a painful spasmodic contraction
cramp
the membrane of a striated muscle is called
sarcolemma
sudden involuntary contraction of a muscle
spasm
another word for an impulse
action potential
hemoglobin found only in skeletal muscle that carries oxygen and provides a dark red color
myoglobin
loss of muscle tone
hypotonia
inflammation of a tendon
tendonitits
why does skeletal muscle appear striated
because of alternating strands of actin and myosin fibers
the loss of the ability to move a muscle is called
paralysis
list several nutrients needed for muscle contraction
calcium, glucose, and oxygen
explain the all or none principle
muscles will either fully contract or not contract at all. they will never partially contract.
three components of a myogram
latent period, contraction period, relaxation period
the ability to extend without damage to the muscle
extensibility
the area where the motor neuron and the muscle meet
neuromuscular junction (NMJ)
muscle stiffness due to death and how long can it last
rigor mortis, 72 hours
generation of heat by the muscle
thermogenesis
the wasting of muscle tissue due to disuse
atrophy
the skeletal muscle fiber is composed of what 2 proteins
actin and myosin
what are the 2 regulatory proteins located on the actin filament
troponin and tropomyosin
the neurotransmitter produced and secreted at the synapse
acetylcholine (ACh)
why does cardiac muscle have a long refractory period
the heart muscle needs time to recover in order to keep a normal heart beat, while skeletal muscle are constantly in use and don't need as long to recover.
place muscle components in order from simplest to most complex
actin and myson, myofibril, fascicle, muscle
what are cross bridges and where are they found
myosin heads that interlock in order to aid in muscle contraction, found on contractile units
where is calcium stored in skeletal muscles
sarcoplasmic reticulum
straited
skeletal, cardiac
voluntary
skeletal
involuntary
cardiac, smooth
thickest at center and tapering at its ends
smooth
attached to bones
skeletal
heart
cardiac
viscera
smooth
intercalated discs
cardiac
calcium binds to troponin on the actin filament exposing bridges on myosin
step 5
muscle relaxes
step 9
Acetylcholinesterase is released in the synaptic cleft and prevents another action potential
step 3
contraction
step 6
ACh diffuses across synaptic cleft and binds to receptors on motor end plate
step 2
clacium released from sarcoplasmic reticulum and floods the sarcoplasm
step 4
nerve impulse triggers release of ACh
step 1
troponin-tropomyosin complex slides back into position where binding sites are blocked
step 8
calcium ions in sarcoplasm restored to low levels by the sarcoplasmic reticulum closing
step 7
latent period
period between stimulus and initial contractions.
Ca 2+ is released from SR
contraction period
lasts from 10 to 100 milliseconds
ACh is produced
relaxation period
lasts 10 to 100 milliseconds
Ca 2+ back to SR
excitability
ability to respond to certain stimuli by producing impulses
contractility
ability to shorten and thicken
functions of muscle tissue
motion, stabilizing posture, regulating organ volume, generation of heat
anaerobic muscular activity
short periods of time, 15 seconds
aerobic muscular activity
longer periods of time, more than 30 seconds
from what do skeletal muscles develop
the mesoderm
effects of anabolic steriod use
increase muscle size, strength, and endurance
increase in breast size in men
decrease in breast size in women
what causes smooth muscles to contract
pH, alcohol, drugs, hormones, and nerve impulses