CH 11 QUIZ Flashcards
(10 cards)
What is the nervous system responsible for?
The nervous system is responsible for sending, receiving, and processing nerve impulses throughout the body.
What are Schwan Cells?
Schwann cells are a type of glial cell found in the peripheral nervous system. They play a crucial role in supporting and protecting nerve cells. Schwann cells wrap around nerve fibers, forming a myelin sheath that helps to insulate and speed up the transmission of electrical signals along the nerve fibers (essential for proper nerve function).
What are nodes of ranvier
The indentations between the sections of myelin sheath.
– nerve impulses jump from node to node, which speeds up the
conduction process
– The smaller the diameter of the axon, the faster the speed of the nerve
impulse
What is the undershoot in the graph of a nervous system
The voltage-gated potassium channels stay open a little longer than needed to bring the membrane back to its resting potential. This results in a phenomenon called “undershoot,” in which the membrane potential briefly dips lower (more negative) than its resting potential.
What is the resting potential of neurons / nervous system?
The resting potential of neurons is about -70 mV.
What does -51 mv indicate?
It indicates that depolarization is occuring in the membrane has reached threshold potential. NA channels begin to open in preperation for ions moving across the membrane
What does -49 mV indicate?
Action potential has been triggered. NA channels have opened in the plasma membrane and their inward flow is changing membrane potential in a positive direction
0 mV?
At 0mV the action potential is in progress and has either not yet reached its peak or is on the way down falling reaching its peak
30 mV ?
Other voltage-gated channels are opening in the membrane. These channels are specific for the potassium ion.
Hyperpolarized membrane meaning ?
Much more negative on the inside (not a good thing)
