Biological eletricity Flashcards
What is biological electricity?
Biological electricity refers to the electrical phenomena that occur in excitable tissues like nerve, muscle, and heart cells, which enable rapid communication and function in the body.
What is the role of excitable tissue in animals?
xcitable tissues allow animals to respond rapidly to environmental changes and maintain homeostasis by transmitting electrical signals.
What are the properties of biological materials as electrical conductors?
Biological materials are poor electrical conductors, meaning electrical signals dissipate quickly due to high resistance.
What is the resting potential of a nerve cell?
The resting potential is the electrical charge difference across the nerve cell membrane, typically around -70mV, with the inside of the cell being negative.
What factors contribute to the resting potential?
1) Electrolytes in body fluids, 2) large negatively charged proteins inside the cell, 3) selective permeability of the membrane, 4) Na+/K+ pump maintaining ion gradients.
How is the resting potential calculated in nerve cells?
The resting potential is influenced mainly by the concentration of K+ ions inside and outside the cell, calculated using the Nernst equation.
What is the function of the Na+/K+ pump?
The Na+/K+ pump actively transports Na+ out of the cell and K+ into the cell, helping maintain the ion gradients that are essential for resting potential and action potential generation.
What is an action potential?
An action potential is a rapid, self-regenerating electrical impulse that travels along nerve axons, allowing nerve cells to communicate.
What causes depolarization during an action potential?
Depolarization occurs when voltage-gated Na+ channels open, allowing Na+ ions to rush into the cell, making the inside momentarily positive.
What is repolarization?
Repolarization is the process where K+ ions exit the cell, restoring the negative charge inside the cell and returning it to its resting potential.
How does an action potential propagate along a nerve axon?
The action potential propagates as a wave of depolarization and repolarization along the axon, with signals jumping between Nodes of Ranvier in myelinated axons.
What are voltage-gated ion channels?
Voltage-gated ion channels are proteins in the cell membrane that open or close in response to changes in the electrical field, allowing specific ions like Na+ and K+ to pass through.
How fast do electrical signals travel in nerve fibers compared to metal wires or light?
Signals in nerve fibers travel at about 288 mph, much slower than the speed of electrical signals in copper cables (20 million mph) or light (670 million mph).
Signals in nerve fibers travel at about 288 mph, much slower than the speed of electrical signals in copper cables (20 million mph) or light (670 million mph).
Action potentials typically occur at a frequency of about 100 Hz (signals per second), which is quite low compared to other electrical systems.
Why are nerve cells not considered simple conductors like wires?
Nerve cells actively generate electricity and use it for communication, unlike simple wires that only conduct electricity passively.
