Chapter 11 Fundamentals of the Nervous System
The nervous system is know as?
the master controlling and communicating system of the body
What are the 2 main divisions of the nervous system?
Central and peripheral
What are the 3 overlapping functions of the nervous system?
The central nervous system consists of?
brain, spinal chord
The peripheral nervous system consists of?
nerves tha extend from the brain and spinal cord to portion of the nervous system outside the CNS
What are the 2 functional divisions of the PNS?
sensory (afferent) "carry towards"
Motor (efferent) "carry away"
In the PNS, the sensory (afferent) division is made up of what 2 types of fibers?
somatic (skin, muscle, joints) and viceral (organs)
In the PNS, what are the 2 subdivisions of the motor (efferent) division?
somatic (voluntary, conscious control)
autonomic (involuntary, unconscious)
In the PNS, what are the 2 divisions of the autonomic system?
parasympathetic (conserves energy "rest or digest")
sympathetic (mobilizes body system during activity "fight or flight")
What are the 2 cells of nervous tissue?
What are the 6 types of neuralgia/glia cells (AS SOME)?
What are considered the structural units of the nervous system?
What are star-shaped CNS neuroglia that assists in exchanges between blood capillaries and neurons.
What are small, ovoid CNS neuroglia with long, spiny processes that can transform into a phagocyte in area of neural damage or inflammation.
What are often ciliated CNS neuroglia that lines the central cavities of the brain and spinal cord. Their cilia circulate the cerebrospinal fluid.
What are CNS neuroglia that composes myelin sheaths.
What are PNS neuroglia that surrounds the neuron cell bodies and is thought to assist in exchanges between blood capillaries and neurons?
What are PNS neuroglia that surrounds the nerve fibers an forms myelin sheaths?
What does the neuron cell body consist of?
rough endoplasmic reticulum (chromatophilic substance)
What are the 2 different types of neuron processes?
What are the functions of dendrites?
lmain input region
convey messages toward cell body as garden potentials (short distance signals)
colect information with dendritic spines
What is the axon hillock?
there is one per axon, it is the cone shaped area of a cell body where the axon arises from
What are long axons called?
What are the distal endings on axons called?
axon terminals or terminal boutons
What are the main functions of the axon?
conducting region of neurons
generate nerve impulses and transmits them along the neuron cell membrane
Neurotransmitter are known as?
the language of the nervous system
In regard to movement of molecules and organelles along the axon, what is anterograde?
movement away from the cell body (good organelles)
In regard to movement of molecules and organelles along the axon, what is retrograde?
movement toward the cell body (bad organelles)
What is the white, fatty, protection of myelinated fibers that protects and electrically insulates axons and increases speed of nerve impulses?
What its dense myelinated fibers with fast moving impulses?
What is non-myelinated fibers with slow moving impulses?
What is the most abundant structural class of neurons in the human body?
Where are bipolar neuron structures found?
sensory organs (eye, ear, etc.)
Where are unipolar neuron structures found?
mostly in the PNS, dorsal root ganglia of the spinal cord and sensory ganglia of cranial nerves
99 % of the body's neurons are what functional classification?
What functional classification of neurons carry impulses from the CNS to effectors?
What classification of neurons transmit impulses from sensory receptors towards the CNS?
What connects neurons functionally and mediates information transfer through neurons?
What are the 2 main types of synapse classification?
axosomatic (soma means cell body)
A _________ neuron conducts impulses towards synapse and a ________ neuron transmits electrical signals away from synapse.
What is saltatory conduction?
transmission of an action potential along a myelinated fiber in which the nerve impulse appears to leap from gap to gap.
What is temporal summation?
the process when one or more presynaptic neurons transmit impulses in a rapid-fire order, and bursts of neurotransmitter are released in quick succession.
What is spatial summation?
the process when many presynaptic neurons transmit impulses to one postsynaptic neuron. Excitatory postsynaptic potentials summate and dramatically enhance depolarization.
What are the nodes of Ranvier?
the myelin sheath gaps between Schwann cells on the axon of PNS neuron.