Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
89 Cards in this Set
- Front
- Back
The PNS (Peripheral Nervous System) has two functional subdivisions, the __________ and the __________. |
Sensory (or afferent) and motor (or efferent). |
|
Afferent means |
carrying toward |
|
efferent means |
carrying away |
|
The afferent division conveys impulses _________ the CNS, and the efferent division conveys impulses _________ the CNS. |
To, away from. |
|
The sensory (afferent) division consists of nerve fibers (axons) that convey impulses ________ the CNS _______ sensory receptors located throughout the body. |
To, from. |
|
Somatic sensory fibers convey impulses from the ______, ____________, and _________. |
Skin, skeletal muscles, and joints |
|
Visceral sensory fibers transmit impulses from the _____________. |
Visceral organs (organs within the ventral body cavity) |
|
The somatic nervous system is composed of somatic _____________ that conduct impulses ________ the CNS _________ skeletal muscles. |
motor nerve fibers, from, to. |
|
The autonomic nervous system (ANS) consists of visceral motor nerve fibers that regulate the activity of ________, _________, and _________. |
smooth muscles, cardiac muscles, and glands |
|
The ANS is also called the ________________. |
Involuntary nervous system. |
|
The 3 overlapping functions of the nervous system are: |
1. Sensory input 2. Integration 3. Motor output |
|
The 2 functional subdivisions of the ANS are: |
1. Sympathetic division 2. Parasympathetic division |
|
The ______________ and the ______________ typically work in opposition to each other. Whatever one stimulates, the other inhibits. |
sympathetic division and parasympathetic division. |
|
Nervous tissue is made up of just two principal types of cells: |
1. Neuroglia (supporting cells) 2. Neurons (excitable nerve cells) |
|
The ____________ are small cells that surround and wrap the more delicate neurons. |
Neuroglia |
|
______________ are excitable (responsive to stimuli) and transmit electrical signals. |
Neurons |
|
The four types of neuroglia of the CNS are: |
1. Astrocytes 2. Mircoglial cells 3. Ependymal cells 4. Oligodendrocytes |
|
Neuroglial cells can be distinguished by their __________ size and ___________ nuclei. |
Smaller, darker-staining. |
|
Neuroglia outnumber neurons ___ to ___, and make up about _____ of the brain. |
10 to 1, half. |
|
Astrocytes are the most ___________ and __________ glial cells. |
Abundant and versatile |
|
Astrocytes __________ and __________ the neurons and anchor them to their nutrient supply lines. |
support and brace |
|
Astrocytes play a role in making exchanges between ___________ and __________. |
capillaries and neurons |
|
Astrocytes guide the __________ of young neurons and formations of __________ between neurons. |
migration, synapses |
|
Astrocytes control the ___________ environment around neurons. |
chemical |
|
Astrocytes are connected by _____________ |
gap junctions |
|
Astrocytes signal each other by taking in _____________, creating slow-paced intracellular _________ pulses, and by releasing extracellular ________________. |
calcium, calcium pulses, chemical messengers. |
|
MIcroglial cells are ________ and __________ with relatively long __________ processes. |
small, ovoid, thorny |
|
Microglial cells monitor neurons' __________. |
Health |
|
"ependymal" means |
"wrapping garment" |
|
Ependymal cells range in shape from _______ to _______, and many are ________. |
squamous to columnar, ciliated. |
|
Ependymial cells line the ______________ of the brain and the spinal cord, wher ethey form a fairly ___________ barrier between the ___________ fluid that fills those cavities and the tissue fluid bathing the cells of the ___________. |
central cavities, permeable, cerebrospinal, CNS. |
|
The beating of ependymal cells' _______ helps to circulate the cerebrospinal fluid that cushions the brain and spinal cord. |
cilia |
|
Oligodendrocytes have ________ processes than astrocytes. |
fewer |
|
Oligodendrocytes line up along the thicker ________________ in the CNS and wrap their processes tightly around the fibers, producing an ____________ covering called a ______________-. |
nerve fibers, insulating, myelin sheath |
|
The two kinds of PNS neuroglia are called: |
1. satellite cells 2. Schwann cells |
|
Satellite and Schwann cells differ mainly in: |
location |
|
Satellite cells surround ____________________ located in the peripheral nervous system |
neuron cell bodies |
|
Satellite cells are thought to have many of the same functions in the PNS as _____________ do in the CNS. |
astrocytes |
|
Schwann cells are also called: |
neurolemmocytes |
|
Schwann cells surround all ___________ in the PNS and form ______________ around the ___________ nerve fibers. |
nerve fibers, myelin sheath, thicker. |
|
Schwann cells are vital to regeneration of damaged ___________ nerve fibers. |
Peripheral |
|
Neurons are also called |
nerve cells
|
|
Neurons are the: |
structural units of the nervous system |
|
Neurons have ___________ longevity. Given good nutrition, they can function optimally for over _________ years. |
extreme, 100 |
|
AS neurons assume their roles as communicating links of the nervous system, they lose their ability to __________. In other words, they are __________. |
divide, amitotic |
|
Neurons have an exceptionally high _____________ and require continuous and abundant supplies of ___________ and ___________. |
metabolic rate, oxygen and glucose |
|
The ________________ consists of a spherical nucleus with a conspicuous nucleolus surrounded by __________. |
neuron cell body, cytoplasm |
|
The neuron cell body is also called the _____________ or _____________. |
Perikaryon, soma |
|
The cell body is the major __________ center of a neuron. |
biosynthetic |
|
The neuron cell body's ER (endoplasmic reticulum) is also called the ___________.
|
chromatophilic substance |
|
_____________ and ___________, which are bundles of intermediate filaments (neurofilaments), are important in maintaining cell shape and integrity. |
Microtubules and neurofibrils |
|
IN most neurons, the plasma membrane of the cell body also acts as part of the _____________ that receives information from other neurons. |
receptive region |
|
Cluster of cell bodies in the CNS are called ________, whereas those that lie along the nerves in the PNS are called ________. |
nuclei, ganglia |
|
ARmlike __________ extend from the cell body of all neurons. |
processes |
|
Bundles of neuron processes are called __________ in the CNS and __________ in the PNS. |
tracts, nerves |
|
Virtually all _________ present in the cell body also occur in dendrites. |
organelles |
|
Dendrites are the main _____________ or __________ regions. |
receptive or input |
|
Dendrites bristle with _______________ - thorny appendages having bulbous or spiky ends. |
dendritic spines |
|
The initial region of the axon arises from a cone-shaped area of the cell body called the ________________. |
axon hillock |
|
Any long axon is called a: |
nerve fiber |
|
Axon branches are called: |
axon collaterals |
|
The knoblike distal endings of the terminal branches of the axons are called : ___________ or ___________ |
axon terminals or terminal boutons |
|
The axon is the ___________ region of the neuron |
conducting |
|
The axon's plasma membrane is also called: |
axolemma |
|
The axon terminals are the ___________ region of the neuron |
secretory |
|
an axon contains the same organelles found in the dendrites and cell body with towo important exceptions: _____________ and ______________ |
Rough endoplasmic reticulum and Golgi apparatus |
|
Movement away from the cell body is ______________ movement and that in the oppostite direction is __________ movement. |
anterograde and retrograde |
|
Many nerve fibers, particularly those that are long or larege in diameter, are covered with a whitish, fatty (protein-lipoid), segmented ___________. |
Myelin sheath |
|
_______________ protects and electrically insulates fibers, and it increases the transmission speed of nerve impulses. |
Myelin |
|
_____________ conduct nerve impulses rapidly, whereas ______________ conduct impulses more slowly. |
Myelinated fibers, nonmyelinated |
|
Myelin sheaths in the PNS are formed by _______ cells. |
Schwann |
|
A characteristic that makes myelin sheaths exceptinally good alectrical insulaterors are their lack of _______ and _______ proteins. |
channel and carrier |
|
The gaps between adjacent Schwann cells are called _____________ gaps or ____ of ______. |
Myelin sheath gaps, or nodes of Ranvier |
|
In the CNS, _____________ form myelin sheaths. |
Oligodendrocytes |
|
Unlike a Schwann cell, which forms only one segment of a myelin sheath, an oligodendrocyte has multiple flat ___________ that can coil around as many as ___________ axons at the same time. |
Processes, 60 |
|
Regions of the brain and spinal cord containing dense collections of myelinated fibers are referred to as _____________ and are primarily fiber tracts. |
White matter |
|
_____________ contains mostly nerve cell bodies and nonmyelinated fibers. |
Grey matter |
|
There are three major neuron groups classified by the number of processes extending from their cell body: |
1. Multipolar 2. Bipolar 3. unipolar |
|
multipolar neurons have _____________ processes - one axon and the rest dendrites. |
three or more |
|
__________ neurons are the most common type in humans, with more than 99% of neurons belonging to this class. |
Multipolar |
|
Bipolar neurons have two processes: an _________ and a _________. |
Axon and dendrite |
|
Bipolar neurons are found in some of the special sense organs. Examples include some neurons in the _______________ and in the ___________. |
Retina of the eye and in the olfactory mucosa.
|
|
The most distal process in unipolar neurons - the ___________ process - is often associated with a ___________ receptor. |
peripheral, sensory |
|
The ____________ of a unipolar neurons enters the CNS. |
central |
|
Unipolar neurons are more accurately called _____________ neurons because they originate as bipolar neurons. |
pseudounipolar |
|
In place of "dendrites," unipolar neurons have __________ endings at the end of the peripheral process. |
receptive |
|
Based on functional classification, there are 3 types of neurons: |
1. sensory 2. motor 3. interneurons |
|
_____________, or _____________, lie between motor and sensory neurons in neurlal pathways and shuttle signals through CNS pathways where integration occurs. |
Interneurons or association neurons |
|
_____________ (based on functional classification), make up over 99% of the neurons of the body, including most of those in the CNS. |
Interneurons |