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80 Cards in this Set
- Front
- Back
What are the two major anatomical subdivisions of the nervous system? |
The Central Nervous System (CNS) and the Peripheral Nervous System (PNS) |
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What does the CNS consist of? |
The brain and the spinal cord |
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What is the name of the collection of nerve cell bodies in the CNS? |
Nucleus (or Nuclei) |
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What is a tract? |
A bundle of nerve fibers (axons) connecting neighboring or distant nuclei of the CNS |
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What are the primary functions of the CNS? |
(1) Integrating and coordinating incoming and outgoing neural signals and (2) carrying out higher mental functions, such as thinking and learning. |
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One primary function of the CNS is the integration and coordination of incoming and outgoing neural signs, what is the other primary function? |
Carrying out higher mental functions, such as thinking and learning. |
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One primary function of the CNS is to carry out higher mental functions, such as thinking and learning, what is the other primary function? |
Integrating and coordinating incoming and outgoing neural signals |
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What is a nucleus? |
A collection of nerve cell bodies in the CNS |
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What connects neighboring or distant nuclei (nerve cell bodies) of the CNS? |
Tracts |
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What is a collection of nerve cell bodies called? |
A nucleus |
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What does the PNS consist of? |
Nerve fibers and cell bodies outside of the CNS |
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What do the nerve fibers and cell bodies outside of the CNS do? |
Conduct impulses to or away from the CNS |
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What is the PNS made up of? |
Nerves that connect the CNS with peripheral structures |
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What is a peripheral nerve? |
A bundle of nerve fibers (Axons) in the PNS |
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What is a peripheral nerve fibers held together by? |
A connective tissue sheath (referred to as either cranial nerves or spinal nerves) |
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What is a bundle of nerve fibers called? |
An axon |
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Where do cranial nerves come from? |
The brain |
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Where do spinal nerves come from? |
The spinal cord |
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What is a spinal ganglion? |
A collection of nerve cell bodies outside of the CNS |
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What is a collection of nerve cell bodies outside of the CNS called? |
Spinal ganglion |
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What is the difference between spinal ganglion and a nucleus? |
Spinal ganglion is a collection of nerve cell bodies outside of the CNS (found in the PNS) whereas a nucleus is a collection of nerve cell bodies found in the CNS |
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What are the subdivisions of the PNS? |
The sensory (afferent) division and the motor (efferent) division |
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What is another name for the sensory division of the PNS? |
The afferent division |
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What is another name for the motor division of the PNS? |
The efferent division |
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What are the subdivisions of the sensory (afferent) and motor (efferent) divisions? |
The sensory (afferent) and motor (efferent) division is divided into a visceral and somatic division |
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What is the function of the sensory (afferent) division of the PNS? |
It carries impulses to the CNS from sensory receptors located throughout the body |
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What division of the PNS carries impulses to the CNS from sensory receptors located in the body? |
The sensory (afferent) division |
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What are somatic afferents? |
Sensory fibers that convey impulses from the skin, skeletal muscles, and joints to the CNS |
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What are visceral afferents? |
Sensory fibers that convey impulses from the visceral organs (organs within the ventral cavity) to the CNS |
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What is the function of the motor (efferent) division of the PNS? |
It carries impulses away from the CNS to effector organs, muscles and glands |
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What are the two main subdivisions in the motor division? |
The somatic nervous system and the visceral (Autonomic) nervous system |
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The somatic nervous system and the visceral (autonomic) nervous system are subdivisions of what division? |
The motor (Efferent) division |
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What is the somatic nervous system composed of and what does it do? |
Composed of fibers that conduct impulses from the CNS to skeletal muscles |
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What is the somatic nervous system referred to as? |
The voluntary nervous system |
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Why is the somatic nervous system also called the voluntary nervous system? |
Because it allows us to consciously control our skeletal muscles |
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What does the autonomic system consist of and what does it do? |
It consists of visceral motor nerve fibers that regulate the activity of smooth muscles, cardiac muscles, and glands |
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What is another name for the autonomic nervous system? |
The involuntary nervous system |
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What are the subdivisions of the autonomic nervous system (ANS)? |
The sympathetic and parasympathetic systems |
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What do neural tissues consist of? |
Two main cells: neuroglia and neurons |
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What are neuroglia? |
Neuroglia are support cells |
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What are neurons? |
Neurons are nerve cells |
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What is the function of neurons (nerve cells)? |
They receive stimuli and transmit action potentials to other neurons or effectors |
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What does a nerve cell or neuron consist of? |
(1) a cell body (2) processes called dendrites (3) and axons that extend beyond the cell body, and carry impulses to and from, the cell body |
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What is another name for the cell body of a neuron? |
Soma or perikaryon |
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What is the cell body? |
(1)The metabolic and genetic center of a neuron and (2) the receptive part of the neuron as it is covered in synapses and other neuroglial cells |
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The cell bodies contain large quantities of what? |
Endoplasmic reticulum (ER) (also called Nissel bodies), mitochondria, and other neurofilaments that fill the cytoplasm |
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What is a dendrite? |
A dendrite is an extension of the cell body that receives incoming synaptic information |
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What are some characteristics of a dendrite? |
(1) They have branches (increased branching usually means a more important neuron (2) They conduct nerve impulses TOWARD the cell body |
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Structurally, the dendrite is what? |
An expansion of the cell body with the same cytoplasm as the cell body |
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A dendrite serves to aid in what? |
Nutrient absorption of the neuron by increasing surface area for nutrient exchange |
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What are axons? |
Axons are nerve fibers that are thin and thread-like |
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Axons arise from what? |
Cone shaped portion of the soma called the axon hillock |
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What is just below the axon hillock? |
An initial segment |
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The axon hillock and the initial segment are collectively called what? |
The "Trigger zone" |
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An axon is relatively un-branched until the end of one where they branch repeatedly to form what? |
The pre-synaptic terminal |
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What is the pre-synaptic terminal? |
Distal terminations of the axon that release neurotransmitters |
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What is the primary function of an axon? |
It conducts action potentials |
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An axon can transport what? |
Proteins, organelles and vesicles containing neuropeptides |
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Most cells have what? (related to axons) |
A single axon that conducts information away from the cell body |
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What are the four types of a neuron? |
(anaxonic, bipolar, pseudounipolar, and multipolar) |
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What is an anaxonic neuron? |
Small neuron, found only in the CNS, and it's hard to distinguish dendrite from axon |
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What does a bipolar neuron have? |
A single cell body with 2 axons and their dendritic extensions or 1 axon and 1 dendrite |
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What neuron is rare, unmyelinated, and found only in special sense organs? |
A bipolar neuron |
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What does a pseudopolar neuron have? |
A single axon, with dendrites on either end, with the cell body situated off to one side |
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Sensory neurons in the PNS are usually what type of neuron? |
A pseudounipolar neuron |
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What does a multipolar neuron have? |
It has several dendrites and a single axon that may or may not have multiple branches |
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What is the most common neuron? |
A multipolar neuron |
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Multipolar neurons are what? |
All motor neurons to skeletal muscles and most of the CNS neurons are multipolar |
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Most of the CNS neurons are what type of neuron? |
Multipolar |
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Neuroglia or support cells are how many times more abundant than neurons? |
Five times more abundant than neurons |
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What are the functions of neuroglia? |
They support, insulate, and nourish neurons |
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What neuroglia or support cells are found in the CNS? |
(1) Oligodendrocytes (2) Ependymal cells (3) Astrocytes (4) Microglia |
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What is the function of oligodendrocytes? |
They myelinate axons to increase functional performance of neurons. They have the ability to myelinate multiple sections on multiple axons |
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What is the function of ependymal cells? |
They produce cerebral spinal fluid |
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What are the functions of astrocytes? |
They (1) control interstitial movement within cytoplasm (2) maintain a blood-brain barrier (3) provide structural framework of CNS (4) aids in neural development and (5) inhibits regrowth of an injured axon |
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What is the function of microglia? |
they are phagocytic in nature |
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What neuroglia or support cells are in the PNS? |
(1) Satellite cells and (2) schwann cells (also known as neurolemmocytes) |
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What are the functions of satellite cells |
They help regulate nutrient and waste exchanges |
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What is the function of a Schwann cell? |
They myelinate axons to increase functional performance of neurons |
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Schwann cells can surround an axon and NOT do what? |
They can surround an axon and not myelinate them |