Central Nervous System
or CNS, consists of the brain and spinal cord and is responsible for integrating, processing, and coordinating sensory data and motor commands.
Includes the integration and distribution of information in the CNS.
Peripheral Nervous System
or PNS, includes all the neural tissue outside the CNS.
Motor Division of the PNS
Carries motor commands from the CNS to peripheral tissues and systems. Includes both SNS and ANS.
Somatic Nervous System
Or SNS, controls skeletal muscle contrations.
Autonomic Nervous System
Or ANS, provides automatic regulation of smooth muscle, cardiac muscle, and adipose tissue.
Sensory Division of the PNS
Brings information to the CNS from receptors in peripheral tissues and organs.
Somatic Sensory Receptors
Provide position, touch, pressure, pain, and temperature sensations.
Special Sensory Receptors
Provide sensations of smell, taste, vision, balance, and hearing.
Visceral Sensory Receptors
Monitor internal organs.
Receptors vs. Effectors
Receptors are sensory structures that detect changes in the internal or external environment, while effectors are target organs whose activities change in response to neural commands.
Receive stimuli from the environment or from other neurons.
Carry information toward other cells. Conducts nerve impulses away from the soma; there is never more than one axon per neuron.
Typical dendrites are highly branched with each branch bearing fine, long processes called dentritic spines.
The base of the axon in a multipolar neuron.
A specialized portion of the plasma membrane, surrounds the cytoplasm (axoplasm) of the axon.
Contains neurofibrils, neurotubules, small vesicles, lysosomes, mitochondria, and various enzymes.
Cell body or perikaryon
Contains organelles that provide energy and sythesize the chemical neurotransmitters that are important in cell-to-cell communication.
Similar to the intermediate filaments in other cells.
Bundles of neurofilaments that extend into the dendrites and axon, providing internal support.
The main axon trunk ends in a series of fine extensions called telodendria. End at synaptic terminals.
Where the neuron communicates with other cells.
Neuron microtubules that travel the length of the axon.
Process by which materials travel through the neurotubules.
A specialized site where the neuron communicates with another cell.
The transmitting cell at a synapse
Cell recieveing the neurotransmitter, so that sodium ions can go in and Action potenital may occur