Muscle Physiology Flashcards
What is the area where the neuron connects with the muscle?
Muscular Junction
What channels are found on the sarcolemma by the synaptic cleft?
Chemically gated Na+ channels
What neurotransmitter is used when activating a muscle?
Acetylcholine
What happens when the Na+ channels are open on the sarcolemma?
The positive charge will spread along the membrane of the muscle through the T-tubules and activate voltage gated Ca+ channels
Whats the name of the cell membrane of muscle fibers?
Sarcolemma
What are the three parts of thin filaments?
- Troponin- Tropomyosin- Actin
What are extensions of the sarcolemma that transmit the impulse to penetrate the muscle fiber?
T-tubule
What are the structures on a muscle fiber that are used to store Ca+?
Sarcoplasmic Reticulum
When the electrical energy is traveling through the T-tubule it stimulates the release of what?
Ca+ through voltage gated Ca+ channels on the sarcoplasmic reticulum
What protein does Ca+ bind to on the thin filament?
Troponin
What happens when Ca+ is bound to troponin?
Troponin reorients itself while moving tropomyosin with it, thus exposing the active sites of actin
What is troponin attached with?
Tropomyosin
What does tropomyosin cover during rest?
Active site on actin
What protein is the thick filament made of?
Myosin
What are the golf club shaped heads called on thick filament?
Myosin Head
What is needed in order for myosin to attach to actin active sites?
ATP
What two things is ATP used for during muscle contraction?
- Move myosin head- Detach myosin head from actin active sites
How does a muscle fiber contract? Part or all of the fiber?
Maximally (the entire fiber must contract)
What is a the basic unit of striated muscle tissue?
Sarcomere
In what order is muscle organized?
- Epimysium (Muscle)- Perimysium (Fascicle)- Endomysium (Muscle Fiber)
Where are the think filaments and thin filaments attached at?
Z-lines
How is muscle attached to bone?
Tendons (CT structures)
What is another term for a muscle cell?
Muscle Fiber
What does a muscle fiber consist of?
Several myofibrils
What is responsible for the striated appearance of muscle tissue?
The thin and thick filaments (Contractile proteins) that overlap
What are the contractile proteins?
- Actin (Thin Filament)- Myosin (Thick Filament)
What are the three items necessary for muscle contraction?
- Electrical Signal- Calcium- ATP
What is the enzyme that breaks down acetylcholine (ACh)?
Acetycholinesterase
What is happening when we relax an active muscle fiber?
Ca+ comes off the troponin, where the Ca+ is pumped (Ca+ pump) back into the sarcoplasmic reticulum
What are the spring like proteins found in sarcomere?
Elastic Filament (Titin)
What is myoglobin?
Excess oxygen for the muscle to use for aerobic respiration
What is the protein that aids in the supply of oxygen to the muscle?
Myoglobin
What type of fibers are slow twitch fibers?
Type I fibers
What type of fibers are fast twitch fibers?
Type II fibers
What are the characteristics of Type I fibers?
- Small Diameter- Endurance- Red Color- Dark Spots
What are the characteristics of Type II fibers?
- Large Diameter- Fatigue Easily- Strength- Light Color
What is the term for all of the muscle fibers controlled by a single neuron?
Motor unit
What is a motor unit?
All of the muscle fibers controlled by a single neuron
What is the resting tension in a muscle called?
Muscle Tone
What is muscle tone?
The resting tension in a muscle
What does the strength of a contraction depend on?
The number of motor units recruited
What is glycogen?
polysaccharide of glucose that serves as a form of energy storage
Where is glycogen stored?
- Liver- Skeletal Muscle
What does creatine store?
Phosphates
What is the product of used ATP?
ADP
What do we do with ADP to reenergize it?
Creatine kinase can transfer a phosphate allowing ADP to become ATP and the excess is creatine
What are the properties of Muscle Cells?
- Contractility- Excitability- Conductivity- Extensibility- Elasticity
What is the plasma membrane of the muscle cell?
Sarcolemma
What is the liquid portion of the cell?
Sarcoplasma
What is significant about the sarcolemma?
It is capable of conducting electrical impulses
What are extensions of the sarcolemma that penetrate the muscle fiber?
T-Tubules
What is a globular protein with an active site on it?
Actin
What component binds calcium during contraction?
Troponin
What covers the active site on actin during periods of rest?
Tropomyosin
What are gold club shaped proteins that bind to the active sites on actin when they are exposed?
Myosin
What are the four functional groups of muscle?
- Agonist- Antagonist- Synergist- Fixator
(Function) - Agonist
Prime mover
(Function) - Antagonist
Opposes
(Function) - Synergist
Helper
(Function) - Fixator
Stabilizes a bone
What is the bone called that remains stationary during a contraction?
Origin
What is the bone called that moves during a contraction?
Insertion
