Nervous Tissue Flashcards
The nervous system receives stimuli from the body and environment via
Sensory receptors
Neurons transmit
Stimulus to muscles, glands, and other neurons via synapses
Neurons are supported by
Neuroglial cells
The Na-K pump maintains
A negative potential inside the neuron’s plasma membrane
Two main parts of the nervous system are
-Central Nervous System (CNS)
-Peripheral Nervous System (PNS)
The CNS includes
-brain
-spinal cord
All nervous tissue outside of the CNS is part of the
Peripheral nervous system
The PNS is subdivided into
-Afferent Sensory Pathways (towards the CNS)
-Efferent Motor Pathways (away from CNS)
Afferent division of the PNS can be divided into
-somatic sensory receptors
-visceral sensory receptors
The Efferent division of the PNS can be further divided into
-Somatic Nervous System to skeletal muscle
-Autonomic Nervous System to viscera
The Autonomic Nervous System of the Efferent PNS can be further divided into
-sympathetic (fight or flight)
-parasympathetic (rest and digest)
Somatic Afferent division of the PNS (3)
-sensory
-TO the CNS from skeletal muscle and skin
-pressure and pain receptors
Visceral Afferent division of the PNS (2)
-sensory
-TO CNS from the heart, GI tract, urinary and reproductive systems
Somatic Efferent division of the PNS (2)
-motor
-FROM the CNS to skeletal muscle
Both the sympathetic and parasympathetic (3)
-part of autonomic nervous system of PNS
-motor
-FROM the CNS to cistern and secretory cells
All neurons contain (3)
-Soma (cell body)
-one axon
-one or more dendrites
The cell body of neurons (4)
-large, round, centrally placed nucleus
-prominent nucleolus
-most located in the CNS
-sensory and terminal effector neuron cell bodies located in peripheral ganglia
Dendrites (7)
-processes which extend from the neuron’s cell body
-may have one or many
-irregular in shape
-branch
-form synapses (connections) with other axons
-conduct nerve impulses unidirectionally
-studded with dendritic spines (gemmules)
The site of a neuron synapse is
The dendritic spine (gemmule)
Neurons can be classified as (3)
-multipolar
-bipolar
-unipolar (pseudo-unipolar)
The axon / nerve fibre (4)
-single, long cytoplasmic process
-nerve impulse travels along axon and away from cell body
-may be insulated in a myelin sheath
-terminate at fine branches called Telodendrons that end at their Synaptic Terminal
The Axolemma is the
Plasma membrane (plasmalemma) of the axon
Multipolar Neurons (4)
-one axon
-many dendrites
-common
-motor neurons
Bipolar Neurons (4)
-one axon
-one dendrite
-rare
-receptors for smell, sight, and balance