Chapter 12- Neural Tissue Flashcards
The central nervous system consists of the…
Brain and spinal cord
The two major anatomical subdivisions of the nervous system are the…
Central nervous system and peripheral nervous system
The primary functions of the nervous system include…
- Providing sensation of the internal and external environment
- Integrating sensory information
- Regulating and controlling peripheral structures and systems
Neurons are responsible for…
Information transfer and processing in the nervous system
The region of a neuron with voltage gated sodium channels is the…
Axon
Neurons are classified on the basis of their structure as…
Anaxonic, unipolar, bipolar, and multipolar
Neurons are classified on the basis of their function as…
Motor, sensory, and autonomic
Sensory neurons are responsible for carrying impulses…
To the central nervous system
Efferent pathways consist of axons that carry impulses…
Away from the central nervous system
The two major cell types in neural tissue…
Neurons and neuroglia
The types of glial cells in the central nervous system are…
Astrocytes, oligodendrocytes, microglia, and ependymal cells
The neuroglia that play a role in structural organization by tying clusters of axons together are the…
Oligodendrocytes
Depolarization of the membrane will shift the membrane potential toward…
0 mV
The resting membrane potential of a typical neuron is…
-70 mV
If resting membrane potential is -70 mV and the threshold is -60 mV, a membrane potential of -62 mV will…
Not produce an action potential
An action potential is triggered when…
Local current reaches a voltage that opens voltage gated Na+ channels in the axon hillock
If resting membrane potential is -70 mV, a hyper polarized membrane is…
-80 mV
A node along the axon represents an area where there is…
An absence of myelin
The larger the diameter of the axon, the…
Faster an action potential will be conducted
The two most important factors that determine the rate of action potential propagation are the…
Presence or absence of a myelin sheath and the diameter of the axon
The reasons that active neurons need ATP is to support the…
- Synthesis, release, and recycling of neurotransmitter molecules
- Recovery from action potentials
- Movement of materials to and from the soma via axoplasmic flow
At an electrical synapse, the presynaptic and postsynaptic membranes are locked together at…
Gap junctions
Chemical synapses differ from electric synapses, because chemical synapses…
Involve a neurotransmitter
The effect of a neurotransmitter on the postsynaptic membrane depends on the…
Properties of the receptor
Exocytosis and the release of acetylcholine into the synaptic cleft is triggered by…
Calcium ions flooding into the axoplasm
The normal stimulus for neurotransmitter release is the depolarization of the synaptic terminal by the…
Arrival of an action potential
Compounds that alter presynaptic or postsynaptic function, thereby affecting information processing, are…
Neuromodulators
Compounds that have an indirect effect on membrane potential work through intermediaries known as…
Second messengers
An excitatory postsynaptic potential is…
A depolarization produced by the arrival of a neurotransmitter
An inhibitory postsynaptic potential is a…
Graded hyperpolarization of the postsynaptic membrane
Graded potentials that develop in the postsynaptic membrane in response to a neurotransmitter are…
Postsynaptic potentials
The addition of stimuli occurring in rapid succession is…
Temporal summation
The anatomical division of the nervous system responsible for integrating, processing, and coordinating sensory information is the…
Central nervous system
Interneurons are responsible for…
Analysis of sensory inputs and coordination of motor inputs
A long cytoplasmic process capable of propagating an action potential is the…
Axon
The type of cells that surround the nerve cell bodies on peripheral ganglia are…
Satellite cells
Schwann cells are glial cells responsible for…
Producing a myelin layer around peripheral axons
When a barrier prevents the movement of opposite charges toward one another, an…
Potential difference may exist
The membranous wrapping of electrical insulation, called myelin, around an axon is responsible for…
Increasing the speed at which an action potential travels along an axon
The simplest form of information processing in the nervous system is…
The integration of stimuli at the level of the individual cell
During the relative refractory period, a larger than normal depolarizing stimulus can…
Initiate a second action potential
Saltatory propagation conducts impulses along an axon…
Five to seven times faster than contiguous propagation
In type C fibers, action potentials are conducted at speeds of approximately…
2 mph
The larger the diameter of the axon, the…
Faster the rate of transmission
Facilitation in the neurons transmembrane potential refers to…
A shift closer to threshold
Sensory neurons that provide information about the external environment through the sense of sight, smell, hearing, and touch are called…
Exteroceptors
The main functional difference between the autonomic nervous system and the somatic nervous system is that the activities of the ANS are…
Primarily involuntary or under automatic control
EPSPs and IPSPs reflect the activation of different types of chemically gated channels, producing…
Opposing effects on the transmembrane potential
If one EPSP depolarizers the initial segment from a resting potential of -70 mV to -65 mV, and threshold is at -60 mV, an…
Action potential will not be generated
An example of presynaptic facilitation is…
Calcium channels remaining open for a longer period, due to the influence of axoaxonic synapse activity, thus increasing the amount of neurotransmitter released
