L1 Flashcards
The nervous system consists of which two general classes of cells?
Neurons
Neuroglia
True or False: All neurons share the same basic architecture
True
(dendrites, cell body, axons)
Which of the following contains receptor sites that receive stimulation or inhibition from outside sources?
A. Axon
B. Dendrites
C. Myelin Sheath
B. Dendrites
If electrical stimulation of cell body reaches a critical threshold, an electrical discharge known as the ____ develops
AP
True or False: Neurons do not differ greatly in their electrical properties and function as electric switchers
True
____: Site of ‘contact’ where nerve signal is transmitted from one neuron to another, or from neurons and other effector cells (muscles or glands)
Synapses
True or False: Synapses allow for structural communication
False - allow for FUNCTIONAL communication
What are the three types of synapses in the CNS?
1) Axosomatic
2) Axodendritic
3) Axoaxonic
What three features of the neuron allows for communication?
Irritability
Transmission
Conductivity
What is the PNS synapse known as?
NM Junction or Motor Endplate
True or False: Unipolar cells are found in human rods and cones of the retina while bipolar cells are found in olfactory receptors
True
Pseudounipolar cells are only found in the ____ ganglia
peripheral
____: the non-neuronal cell types of the nervous tissue
Neuroglia (glia)
True or False: Glia support and nourish neurons
True
True or False: Both satellite, schwann cells, and astrocytes are neuroglia found in the CNS
False - satellite and schwann cells are found in PNS
The brain can be subdivided into the ___, ____, and ____
brainstem, cerebellum, and cerebrum
Each cerebral hemisphere contains ___, ___, and ____
cerebral cortex, medullary white matter, and basal ganglia
True or False: Gray and white matter are found in the CNS, while peripheral nerves and ganglia are found in PNS
True
Neuronal cell bodies, dendrites, and initial portions of axons make up ___ matter
myelinated and un-myelinated axons in CNS make up ___ matter
Gray Matter = cell bodies, dendrites, initial axons
White Matter = axons (myelinated and not)
An ____ is a process arising from the neuronal perikaryon
A ____ is an axon + the glial enwrapping sheet
A ____ is a group of fibers + connective enwrapping tissue
A axon
A fiber
A nerve
_____: The capacity to react to various physical or chemical agents, which results in generation of action potential
A. Conductivity
B. Irritability
C. Transmission
B. Irritability
____: The ability to propagate these electrical signals from one location to another within the same neuron
A. Conductivity
B. Irritability
C. Transmission
A. Conductivity
Label the following:
True or False: Spinal and cranial nerves are found in the PNS
True
True or False: There are nerves in the CNS
False - there are not nerves within the CNS
Within the CNS, fibers travel organized in bundles forming ____, which are meant to carry information from one area to another area of the CNS
tracts
True or False: The ANS is made up of the parasympathetic, sympathetic, and enteric divisions
True
BELOW the cephalic flexure (inferior to the diencephalon)
Posterior = _____
Anterior = _____
Superior = ____
Inferior = _____
Compare this to ABOVE the cephalic flexure:
Posterior = Dorsal
Anterior = Ventral
Superior = Rostral
Inferior = Caudal
What are the three types of multipolar cells + where are they located?
- Motor Neuron (brain and spinal cord)
- Pyramidal Neuron (hippocampus and cerebral cortex)
- Purkinje Cell (cerebellum)
True or False: The cerebrum is composed of cerebral hemispheres and diencephalon
True
Myelinated and unmyelinated axons are often grouped together as ___ and ___
tracts; oligodendrites
Gray matter has an abundant of ____ and ___ cells
neuronal cell bodies and glial cells
_____ usually pertains to spinal cord and is synonymous with tract
A. Funiculus
B. Lemniscus
C. Fasciculus
C. Fasciculus
_____: an area the contains many tracts, pertains to the spinal cord
A. Funiculus
____: means “flat tract”, specifically used in reference to several different sensory tracts coursing to the thalamus
A. Funiculus
B. Lemniscus
C. Fasciculus
B. Lemniscus
____: the crossing of a tract over the midline
Decussation
___: refers to course/destination of a particular tract from a particular brain area
Projections
A ____ indicates the whole projection from a starting point to a final destination. It can be composed of a single tract or multiple tracts.
A ____ indicates the space between the site of the origin on the fiber and the end of the fiber.
Pathway
Tract
True or False: Peripheral nerves are bundles of nerve fibers surrounded by several layers of connective tissue
True
Within the sensory division of the PNS:
There is a ____ portion, where sensory input is perceived consciously and
There is a ____ portion, where sensory input is NOT perceived consciously
Somatic
Visceral
Within the motor division of the PNS:
There is a ____ portion, where motor output IS controlled consciously
There is also a _____ portion, where motor output is NOT controlled consciously
Somatic
Autonomic Nervous System
Within the efferent region of the PNS, there is the visceral motor (ANS) which is where the ___, ___, and ____ act
sympathetic, parasympathetic, and enteric
True or False: Neurons with similar properties can produce quite different actions due to the way they are connected with each other, forming neuronal circuits
True
True or False: Efferent neurons carry motor output while Afferent neurons carry sensory input. The interneurons, by contrast, are local neurons found in the spinal cord.
True
____: Simplest circuit made of two neurons, sensory and motor; no interneuron!
____: circuit made of three neurons: sensory, motor, and interneuron
Direct Reflex Arc
Indirect Reflex Arc
Evolutionarily speaking, the difference in size, functions, capability of the human brain vs. a chick brain is due to increased number of ___ and, of course, they way they are interconnected to each other to form neuronal circuits
interneurons
A sensory neuron can distribute the incoming information to multiple association neurons (interneurons). This phenomenon is called ____
When does this phenomenon normally occur?
Divergence
- When a stimulus carried by sensory neurons enters the CNS
____: describes information transmitted from many interneurons to one motor neuron
When does this phenomenon normally occur?
Convergence
- Occurs when output leaves the CNS
______: A neuronal pathway arranged in a circle so that impulses are recycled to cause (+) feedback or reverberation
Reverberating Circuit
______: A neuronal pathway arranged in a circle so that impulses are recycled to cause (+) feedback or reverberation
Reverberating Circuit
True or False: The brain contains at least two types of neuronal maps: one for sensory perceptions and another for motor commands
True
True or False: What makes the brain a remarkable information processing machine is not the complexity of its neurons but, rather, its many elements and the complexity of connections between them
True
How does redundancy occur in the neuronal circuitry?
Parallel processing
Why does parallel processing make sense as an evolutionary strategy for building a more powerful brain?
Increases the speed and reliability of function within the CNS
Describe the flow of information in the CNS:
Sensory input forms (ascending/descending pathway)
Sensory cortices and association (cortical)
Motor cortices (motor output forms descending pathways)
____ and ___ are areas where the integration of information and release of outputs take place
Cerebrum and Cerebellum
___ and ___ are the only areas of the CNS communicating with the periphery
Spinal Cord and Brainstem
- exception: CN1/2
When information is distributed to interneurons, this allows for ____
Divergence
Once the input reaches the __ cortices, it will be integrated with other sensory inputs
sensory cortices
The sensory and association cortices will pass information to the motor cortices, allow for ____
convergence
True or False: The nuclei of resident interneurons form different stops where information traveling through both ascending and descending pathways can be distributed and elaborated
True
Bundles of ascending and descending fibers are found in both the ____ and ___
spinal cord; brain stem
In the cerebrum and cerebellum, cortices and nuclei are interconnected among each other and are the ___ destination of ascending pathways and the origin of ___pathways
final; descending
