Cell Physiology Part 6 Flashcards
What is the Propagation of the Action Potential?
It is the movement of an action potential along the length of an axon.
In what directions can action potentials propagate?
All directions
What principle governs whether an action potential occurs or not?
The All-Or-None principle
What factors influence the velocity of action potential conduction?
Fiber diameter (larger = faster) and whether the fiber is myelinated or not
What is saltatory conduction?
The process where action potentials “jump” from one Node of Ranvier to the next in a myelinated fiber.
What are the functions of myelin?
• Faster conduction
• Reduces metabolic cost
• Saves space in the nervous system
What are the functions of myelin?
•Faster conduction
• Adds efficiency in metabolic cost
• Saves room in the nervous system
What is the significance of the refractory period?
•It separates individual action potentials
•Determines the direction of action potential propagation
What are the three main types of muscle?
•Skeletal muscle (voluntary)Striated
•Cardiac muscle (involuntary)striated
•Smooth muscle (involuntary) unstriated
What is a neuromuscular junction?
The synapse between a motor neuron and a muscle fiber.
What neurotransmitter is released at the neuromuscular junction?
Acetylcholine (ACh).
What enzyme breaks down acetylcholine in the synaptic cleft?
Acetylcholinesterase
How can neuromuscular signaling be disrupted?
•Block the release of ACh
• Occupy Ach receptors
• Inhibit ACE
What is a cross-bridge?
The temporary connection formed when the myosin head binds to the actin filament during muscle contraction.
