Chapter 8 Flashcards
What tissue is voluntary, striated, multinucleate, highly vascular, bony attachment for motion, posture and muscle work.?
Skeletal
What tissue is involuntary, straited, uninucleate, highly vascular, cellar branching with intercalated disks, gap junctions present and heart muscles?
Cardiac
What tissue is involuntary, nonstriated, uninucleate, spindled shaped, for viscera/blood vessels?
Smooth
What are the functions of skeletal muscles?
motion/movement, heat production, maintain posture, regulating organ volume
What characteristic shortens to produce force?
contractility
What characteristics receive and respond to stimuli, can carry an electrical signal?
excitablitity
What characteristics can stretch without damage during antagonist contraction?
extensibility
What characteristics can return to shape and form?
elasticity
Muscles that move a joint in the opposite direction of agonist, muscles can only pull bone in one direction (cannot push the bone back, so need antagonistic muscle)
Antagonist
Muscle that moves a joint in one direction
prime mover (agonist)
What is a bundle of muscle fibers?
fasicicle
What does muscle fiber =
muscle cell
What connective tissue covers the entire muscle?
Epimysium
What connective tissue covers the fascicles?
perimysium
what connective tissue covers individual muscle cells/fibers?
Endomysium
Where muscle attaches to stationary bone of a joint?
origin
Where muscles attaches to moveable bone of a joint?
insertion
What is Sarcoplasm?
muscle fiber cytoplasm
What is Sarcolemma?
muscle fiber plasma membrane
What is T-tubles?
invaginations in sarcolemma- allows electrical signal to reach into muscle fiber and trigger sarcoplasmic reticulum to release its calcium
What has network surrounding myofibrils that stores and releases calicum?
Sarcoplasmic reticulum
What has parallel cylindrical fibers that compose muscle fiber?
Myofibrils
What has repeated units that make up myofibrils?
sarcomeres
What do sarcomeres contain?
thick and thin myofilaments, extends from one z-line to the next
What are the two types of thin myofilaments
Tropomyosin and Troponin
What is troponin?
attached to tropomyosin and binds to calcium to move tropomyosin, exposing myosin binding sites on actin
What is tropomyosin?
around the actin, blocks myosin binding sites of actin
What are thick filaments made of?
Myosin protein can form cross bridges with actin and has ATP binding sites for energy to contact sarcomere.
This is a dark band of myosin with overlapping actin
A band
This band is on either side of z-lines and areas of actin only
I band
Attaches center of attachment of myosin and anchor point of myosin
M line
Areas of myosin only, on either side of the m line
H zone
Ends of sarcomeres, anchor point of actin
Z-Line
Where a neuron gets close to the muscle cells, has the ability to stimulate muscles cell, triggering contraction, muscle fibers contract in response to motor never impulses
Neuromuscular Junction (motor end plate)
also known as the synaptic bouton and terminal bouton, is the most distal portion of a neuron’s axon and is critical for neural communication.
Axon terminal
tall muscle fibers stimulated by the same neuron are known as this, all muscle fibers within this, must all contract when stimulated or are all not contracting because they are not being stimulated
Motor Unit
what is a series of changes in electrical charges?
action potential (electrical signal)
generation and propagation of an action potential
depolarization
restoration of resting membrane potential
repolarization
localized area of electrical change on the muscle cell due to binding of acetylcholine to sarcolemma
end plate potential
a single contraction that lasts only milliseconds, has three stages
muscle twitch
What are the three stages of muscle twitching?
latent period, contraction period, relaxtion period,
A time for events at neuromuscular junction leading up to contraction
latent period
when myosin and actin are interacting, and sarcomeres are actively shortening
contraction period
follows discontinuation of ACh release from neurotransmitter sarcomeres return to resting length
relaxation period
muscles changes in lengths and move load. can be concentric or eccentric
isotonic contractions
muscles shorten and does work
concentric contractions
muscles lengthens and generates force
eccentric contractions
load is greater than the maximum tension muscle can generate so muscle neither shortens or lengthens
isometric contractions
this results if two stimuli are received by a muscle in rapid succession
wave summation
increase in stimulus frequency causes muscle to progress to sustained, quivering contractions
unfused tetanus
if stimuli frequency further increases, muscle tension reaches maxium
fused tetanus
