Test 3- Muscle Tissue Flashcards
Striated and voluntary
Skeletal tissue
Striated and involuntary
Cardiac tissue
Non-striated and involuntary
Smooth tissue
the ability of a muscle to shorten
Contractility
The ability of a muscle to respond to a stimulus
Excitability
One motor neuron and the muscle fiber that it innervates
Motor unit
Individual muscle fibers contract as hard as they can or there is no contraction
All or None Law
The ability of a muscle to be stretched
Extensibility
The ability of a muscle to return to its resting length
Elasticity
What are the functions of muscle tissue
movement
opening/closing passageways
maintaining posture
heat generation
connective tissue that surrounds the muscle
Epimysium
Connective tissue that surrounds fascicles
Perimysium
Connective tissue that surrounds each individual fiber
Endomysium
The attachment of the muscle on the less movable bone
Origin
The attachment of the muscle on the movable bone
Insertion
Bundles of thick and thin filaments that serve as the contractile elements of muscle fiber
Myofibrils
Thick filaments in myofibrils
Myosin
Thin filaments in myofibrils
Actin
Boundaries at each end of a sarcomere
Z Lines
Myofilaments attached to the Z lines
Thin filaments/ Actin
Myofilaments in the center of the sarcomeres and the ends have myosin heads
Thick filaments/ Myosin
Springlike molecule that resists overstretching
Titin
Dark bands from the presence of thick filaments
A bands
Central part of the A bands where there are no thin filaments present
H zone
Contains rods that hold the thick filaments together
M line
Light bands because they contain only thin filaments
I bands
What is the main protein component of thick filaments?
Myosin
What is on the myosin heads?
Actin Binding sight
ATP Binding sight
Contractile protein
Actin
What are the regulatory proteins
Tropomyosin
Troponin
Lies alongside the groove of actin and covers myosin binding sites
Tropomyosin
What 3 units make up troponin
Binds to tropomyosin
Binds to actin
Binds to Ca2+
Muscle contracts, but does not shorten
Isometric contraction
Muscle shortens and does work
Concentric contraction
Muscle generates force as it lengthens
Eccentric contraction
Muscle contraction that acts as a brake as you run down hill or land from a jump
Eccentric contraction
What chemicals are needed for contraction
ATP
Calcium
O2
Acetylcholine
Allows coin and myosin to slide over each other
Calcium
Allows for cellular respiration for ATP production
O2
Space between the neuron and muscular fiber at the neuromuscular junction
Cleft
Stimulus from this neurotransmitter causes calcium to be released from the sarcoplasmic reticulum
Acetylcholine
Sliding filament mechanism of contraction
All sarcomeres throughout muscle fiber’s length shorten simultaneously
Contraction is accomplished by thin filaments from opposite side of each sarcomere sliding closer together between thick filaments
First step of Sliding filament theory of muscle contraction
Troponin molecules hold the actin and myosin in place (muscle is relaxed)
Second step of sliding filament theory of muscle contraction
A nerve impulse (action potential) travels down a motor neuron to the muscle causing the release of acetylcholine into the space between the neuron and the muscle fiber
Third Step of sliding filament theory of muscle contraction
Acetylcholine stimulated receptors on the muscle fiber, which initiates an impulse that travels along the sarcolemma (muscle cell membrane) to the sarcoplasmic reticulum
Fourth step of sliding filament theory of muscle contraction
Calcium is released from the sarcoplasmic reticulum into the sarcoplasm
Fifth step of sliding filament theory of muscle contraction
Calcium binds with troponin on the actin
Sixth step of sliding filament theory of muscle contraction
Binding causes tropomyosin to change shape, moving it away from blocking position- undercover binding sites on actin for myosin cross bridges
Seventh step of sliding filament theory of muscle contraction
Myosin cross bridges attach to actin on the exposed binding sites
Eighth step of sliding filament theory of muscle contraction
Binding causes cross bridge to bend, resulting in a power stroke fueled by ATP
Ninth step of sliding filament theory of muscle contraction
Cross bridge unbinds, if calcium is still present, returns to step 7
Tenth step of sliding filament theory of muscle contraction
Contraction stops
If the oxygen cannot be supplied fast enough, the individual suffers from shortness of breath
Oxygen debt
Muscle that does most of the work
Prime mover
Assisting muscles
Synergists
Muscle working in the opposite direction
Antagonists
How do you increase the strength of a muscle contraction?
Increase the amount of muscle fibers contracting
or
Each muscle fiber contracts more often
Maximal sustained contraction
Tetany
The tension of muscle adding up until a maximal contraction is sustained
summation
Unexplained chronic muscle pain
Fibromyalgia
Inherited disease characterized by progressive deterioration of muscle tissue
Muscular dystrophy
Results in atrophy of the affected muscle and muscle fibers are replaced by fibrous connective and fatty tissue
Muscular dystrophy
Poisoning caused be eaten contaminated food where bacteria in food produces a neurotoxin
Botulism
Symptoms include drooping eyes, double vision, dry mouth and difficulty swallowing
Botulism
Neurodegenerative disease affecting various motor neurons
Amyotrophic Lateral Sclerosis (ALS)
Loss of function leads to muscle weakness, atrophy, and spastic paralysis
ALS
Autoimmune disease in which antibodies are produced that attach to the acetylcholine receptors on the sarcolemma, thus blocking or reducing the stimulatory effect of the neurotransmitter
Myasthenia gravis
Sudden involuntary contractions of muscle or groups of muscles
Spasms
Involuntary painful, sustained contractions of a muscle
Cramps
Disease caused by bacteria commonly found in soil that affects motor neurons in the spinal cord, resulting in continuous stimulation and contraction of muscles
Tetanus
