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38 Cards in this Set

  • Front
  • Back
Central Nervous System (CNS)
brain and spinal cord, coordinates and integrates info received from sensory receptors and intiates and transmits impulses to neurons, muscles, or glandsto maintain homeostasis.
Peripheral Nervous System (PNS)
nerves and ganglia outside the CNS
Afferent (toward the CNS) Division
sensory receptors and nerves, transmit impulses to the CNS.
Sensory Receptor
detect changes in the environment and transmit the impulse along sensory (afferent) nerves to the CNS.
Efferent (away from CNS) Division
motor nerves that tranmsit impulses from the CNS toward effertors (neurons or glands).
cells that conduct AP and are the basic structural and functional units of nervous tissue.
cells of nervous tissue that support , protect, supply nutrients, and facilitate neuron transmission. Cell are smaller and more abundant, six basic types
A) Astrocytes
found in CNS, star shaped appearance, perivascular feet wrap around neurons and blood vessels to keep neurons in place and guide neurons during development.
Blood-Brain Barrier
formed by astrocytes, surrounds and protects the brain (neurons) from unwanted substances.
B) Oligodendrocytes
found in the CNS, support neurons by wrapping myelin sheaths aorund axons, increase the speed of transmission of impulses.
C) Microglia
found in the CNS, phagocytic cells that engulf debris and pathogens.
D) Ependymal Cells
ciliated cells that line the 4 ventricals of the brain , central canal of the spinal cord, producing and moving cerebral spinal fluid (CSF.
E) Schwann Cells
found in the PNS, flattened cells wrap and form a myelin sheath around axons, increase transmission speed and aid in regeneration of PNS axons.
F) Satellite Cells
found in the PNS, flattened supportin cells that wrap around cell bodies of neurons in PNS ganglia.
Structure of Neurons
B)Cell Body
1. Axon Hillock
C) Axon
1. Trigger Zone
2. Axon Collaterals
3. Axon Terminals
receives impulses, many short processes extending from the cell body, may generate a grade potential.
Cell Body
contains the nucleus and organelles needed to maintain the neuron.
Axon Hillock
triangular shaped are that joins th cell body to the axon.
single, long process that carries impulses away from the cell body towards the effector.
Trigger Zone
1st part of axon where AP arise.
Axon Collaterals
side branches of the axon.
Axon Terminals
fine processes found at the ends of axon and axon collaterals. Neurotransmitters are released from axon terminals to transmit an impulse across a synapse toward an effector or another neuron.
Structural Classifications of Neurons
A. Multipolar Neurons
B. Bipolar Neurons
C. Unipolar Neurons
Multipolar Neurons
many dendrites and 1axon , most neurons of the CNS are mulitpolar
Bipolar Neurons
1 dendrite and 1 axon, found in special senses (ear, eye, olfactory).
Unipolar Neurons
1 process, an axon, dendrites are attached to the axon, sensroy neurons of the skin, muscles, and organs, carrying info to the CNS.
Functional Classification of Neurons
A) Sensory (afferent) Neurons
B) Interneuron (assosciation nueron)
B) Motor (efferent) Neurons
Sensory (afferent) Neurons
transmit environmental changes detected bt receptors (stimulus) from receptors to the CNS, general sensory neurons are unipolar.
Interneurons (assosciation neurons)
90% of the neurons in the CNS, connects sensory neurons to other interneurons and/or motor neurons. unmyelinated multipolar.
Motor (efferent) neurons
carry impulses from the CNS towards effectors, multipolar.
Myelin Sheath
insulated wrappings around axon produced by oligodendrocytes (CNS), and schwann cells (PNS). layers are similar to plasma membranes (80% lipid, 20% protein). Provides protection, insulation, increase speed of impulse transmission, helps generate damaged PNS axons.
outer layer of the myelin sheath of a schwann cell where most of the cytoplasm annd nuclei is located.
Nodes of Ranvier
"gaps" b/w myelin sheath on axons allowing impulses to be conducted quickly, more neurons in the PNS.
Myelinated Fibers
myelinated axons
Unmyelinated Fibers
axons that are not myelinated , but only have thin coating of ogligodendrocyte or schwann cell plasma membrane covering the axon, slower conduction rate.
White Matter
groups of myelinated axons in the CNS that form tracts and have a white color.
Gray Matter
neuron cell bodies, dendrites, unmyelinated axons, and neuroglia (integration)
clusters of neurons (gray matter) in the brain with a common function.