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67 Cards in this Set
- Front
- Back
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What Is the CNS?
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Central Nervous System
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What makes up the CNS?
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Brain and spinal cord
Integration and command center |
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What is the PNS?
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Peripheral Nervous System
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What does the PNS do?
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Carries messages to and from teh spinal cord and brain
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What are the 2 functional PNS divisions?
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Sensory division
Motor division |
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What do sensory fibers do?
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They carry impulses from skin, skeletal muscles, and joints to the brain
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What 2 fibers make up the sensory division?
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Sensory afferent fibers
Visceral afferent fibers |
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What does the Motor division of the PNS do?
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Transmits impulses from the CNS to effector organs
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What are the 2 main parts of the motor division?
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Somatic nervous system
Autonomic nervous system |
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Somatic Nervous System
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Conscious control of skeletal muscles
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Autonomic Nervous System
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Regulates smooth muscle, cardiac muscle, and glands
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Autonomic Nervous System
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Sympathetic: fight or flight, gets body revved up and prepared to defend oneself, brain is more alert
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Autonomic Nervous System (ANS)
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Parasympathetic: rest and digest, calms heart rate
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What are the 2 cell divisions in the nervous system
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Neurons: excitable cells that transmit electrical signals
Supporting Cells: |
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What are neurons
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excitable cells that transmit electrical signals
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what are supporting cells
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cells that surround the neuron
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Neuroglia or glial cells
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supporting cells that provide a supportive framework for the nervous tissue
and segregate and insulate neurons |
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Astrocytes
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most abundant branched glial cells
star shaped |
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Functionally astrocytes:
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support and brace neurons
anchor neurons to their nutrient supplies guide migration of young neurons |
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Microglia
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small, ovoid cells with spiny processes
phagocytes that monitor the health of neurons |
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Ependymal Cells
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range in shape from squamous to columnar
they line the central cavities of the brain and spinal column |
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Oligodendrocytes
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branched cells that wrap CNS nerve fibers
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What do Schwann Cells do
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surround fibers of the PNS
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Satellite Cells
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Surround neuron cell bodies with ganglia
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What are Neurons composed of
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body, axon, and dendrites
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what does amitotic mean
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don't divide, no mitosis
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Neurons
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are long lived
have a high metabolic rate |
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What do the plasma membrane of neurons do
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electrical signaling
cell-to-cell signaling during development |
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What is the soma
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nerve cell body
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what is the major biosynthetic center
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the soma
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what is the focal point for the outgrowth of neuronal processes
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soma
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what has well-developed nissl bodies
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the soma
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what are nissl bodies
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rough ER
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what is the axon hillock
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cone-shaped area from which axons arise
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what are processes
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armlike extentions from the soma
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where are tracts
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CNS
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where are nerves
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PNS
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what are the 2 types of processes
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Axons
Dendrites |
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what is the difference between tracts and nerves
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they're pretty much the same thing, the only difference is their location
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how are the electrical signals of dendrites conveyed
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they are conveyed as graded potentials, not action potentials
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where are action potentials
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in the axons
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what are long axons called
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nerve fibers
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what are collaterals
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multiple, rare branches off of the soma
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what are the functions of axons
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they generate and transmit action potentials
secrete neurotransmitters from the axonal terminals |
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Anteograde
vs Retrograde |
toward axonal terminal
away from axonal terminal |
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What is the function of the myelin sheath
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protect axon
electically insulate fibers from one another increase the speed of nerve impulse transmission |
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What do Schwann cells form
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myelin sheath and neurilemma
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what is the neurilemma
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remaining nucleus and cytoplasm of schwann cell
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Sites where axon collaterals can emerge are called...
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nodes of ranvier
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does the CNS have myelinated and unmyelinated fibers
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yes
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what forms the myelin sheath in CNS
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oligodendrocytes
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is there neurilemma in the CNS
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NO
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CNS
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central nervous system
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PNS
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peripheral nervous system
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What is the difference between CNS and PNS
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CNS refers to the Central Nervous System whereas PNS refers to the Peripheral Nervous System.
2. The Central Nervous System comprises of the brain and the spinal cord whereas the Peripheral Nervous System comprises of the autonomic nervous system and the somatic nervous system. 3. The CNS handles involuntary information while the PNS handles voluntary information. |
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White Matter
vs Gray Matte |
Myelinated fibers
mostly soma and unmyelinated fibers |
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what are the neuron structural classification
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mulipolar: 3+ processes
bipolar: 2 processes (axon and dendrite) unipolar: single, short process |
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what are interneurons
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shuttle signals thru CNS pathways
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Passive or leakage channels
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always open
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Chemically gated channels
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open with binding of a specific neurotransmitter
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Voltage gated channels
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open and close in response to membrane potential
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Mechanically gated channels
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open and cloe in response to physical deformation of receptors
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what is the principal means of neural communication
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Action Potential
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what is the absolute refractory period
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prevents the neuron from generating an action potential
ensures that each action potential is separate enforces one way transmission of nerve impulses |
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Saltatory means:
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To jump
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what is a synaptic cleft
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fluid-filled space separating the presynaptic and postsynaptic neurons
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what are the 2 types of postsynaptic potentials
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EPSP: excitatory
ISP: inhibitory |
