Chapter 8 Flashcards
What are muscles
an organ that contracts for movement
what are 3 things muscles can do
muscle tone, distribute heat, generate heartbeat
List the 3 types of muscles
smooth, skeletal, cardiac
define epimysium
connective tissue that closely surrounds the muscle
define perimysium
separates the muscle tissue into small compartments
define fascicles
bundles of skeletal muscle fibers
what do fascicles do
allows the parts of the muscle to move somewhat independently
what is tendinitis
painful inflammation of repeated stress on a tendon
define muscle fiber
single cell that contracts in response to stimulation
define myofibrils
threadlike fibers important in contraction
list and describe the two types of protein fibers
myosin- thick
actin- thin
what do muscle fibers connect to
an axon
what is a motor neuron
a nerve cell for movement
why are mitochondria abundant
muscle cells need a lot of ATP
what happens when a motor neuron transmits an impulse
all muscle fibers linked will contract together
what is muscle contraction
a shortening of muscle fibers that pull its attachments
what is ATPase
an enzyme that catalyzes ATP into ADP that releases energy and puts the myosin cross bridge into a ready position
when do skeletal fibers contract
when the neurotransmitter acetylcholine stimulates it
what is a neurotransmitter for
contraction of skeletal fibers
true or false: when nerve impulses cease, 2 events lead to muscle relaxation
true
what are the 2 events that lead to muscle relaxation
1st acetylcholine is rapidly decomposed by the enzyme acetylcholinesterase
2nd calcium is transported back into the sarcoplasmic
what is botulism
food poisoning that paralyzes muscles
what does creatine phosphate contain
high-energy phosphate bonds
what do RBC’s do
carry oxygen needed on hemoglobin
