EXAM IV Fill-In-The-Blank Flashcards
That part of the nervous system that is voluntary and conducts impulses from the CNS to the skeletal muscles is the ________ nervous system.
somatic
________ are found in the CNS and bind axons and blood vessels to each other.
Astrocytes
A gap between Schwann cells in the peripheral system is called a(n) ________.
The node of Ranvier
What mechanism is responsible for axonal transport?
ATP-dependent “motor” proteins such as kinesin, dynein, and myosin are responsible. They propel cellular components along microtubules.
The synapse more common in embryonic nervous tissue than in adults is the ________.
electrical synapse
When information is delivered within the CNS simultaneously by different parts of the neural pathway, the process is called ________ processing.
parallel
________ potentials are short-lived, local changes in membrane potential that can be either depolarized or hyperpolarized.
Graded
________ is a disease that gradually destroys the myelin sheaths of neurons in the CNS, particularly in young adults.
Multiple sclerosis (MS)
When one or more presynaptic neurons fire in rapid order it produces a much greater depolarization of the postsynaptic membrane then would result from a single EPSP; this event is called ________ summation.
temporal
What is the role of microglial cells and why are they so important in the CNS?
In the presence of invading microbes, microglial cells become macrophages to phagocytize the microbes and neuronal debris. This protective role is important because cells of
Define neurotransmitter. Name two amino acid neurotransmitters, two catecholamines, and two peptides.
Neurotransmitters are chemical signals used as a means of communication. GABA and glycine are amino acid neurotransmitters; dopamine and norepinephrine are catecholamines; and endorphin and enkephalin are peptide transmitters.
What function is served by the increased axon diameter at the nodes of Ranvier?
Increased diameter results in increased surface area on the membrane for sodium channels. This results in increased speed of impulse propagation.
