Physiology- Muscular Flashcards
What is the contractile until of muscle?
sarcomere
What is the name of the organelle in the muscle cell that is high in calcium?
sarcoplasmic reticulum
What is the neurotransmitter of the neuromuscular junction?
acetylcholine
What substance fluxes through open gated channels when the action potential reaches the terminal bouton?
calcium
The depolarization of the post-synaptic membrane is known as what?
The end plate potential
Why will the end plate potential always reach threshold every time?
because it is a suprathreshold
What stops the action of acetylcholine in the synaptic cleft?
acetyl choline esterase
Adrenergic synapses use what neurotransmitter?
norepinephrine
What are the 2 contractile proteins of muscle?
Actin and myosin
Which of the contractile proteins is found in the thin filament?
actin
Which of the contractile proteins is found in the thick filament?
myosin
What are the 2 regulatory proteins that are also found on the thin filament?
troponin, tropomyosin
Which is the regulatory protein that has an inhibitory action on the formation of actin-myosin complex?
tropomyosin
What substance causes the troponin-tropomyosin complex to fall away from the active site of the actin molecule?
calcium
to which of the regulatory proteins does calcium bind?
troponin
What substance is bound to the myosin head?
ATP
What two things do we need to get the muscle to relax?
- Removal of calcium
2. ATP bound to the myosin head
Lifting and setting down contraction with muscle shortening and lengthening is known as what type of contraction?
Isotonic
Contraction with no external muscle shortening is what type of contraction?
Isometric
The force-velocity curve depicts what type of muscle contraction?
isotonic (velocity indicates movement)
The length-tension curve depicts what type of muscle contraction?
Isometric
Posture, heat generation, nerve nutrition of muscle and general circulation are all function of what?
muscle tone
What is it called when a series of action potentials reach a muscle such that it cannot relax and so force within a muscle is built to a maximum?
summation of twitches –> tetany
Accumulation of calcium in the cytoplasm is the mechanism for what?
summation of twitches