STRUCTURAL AND FUNCTIONAL ORGANIZATION OF NERVOUS TISSUE Flashcards
Describe the main structures of the nervous system.
Brain
Spinal Cord
100 billion neurons
Brain
100 million neurons
Spinal Cord
CNS Parts
Brain
Spinal Cord
PNS Parts structural (5)
Cranial Nerves
Spinal Nerves
Sensory Receptors
Ganglia
Enteric Plexus
Cranial Nerves how many
12 pairs of cranial nerves numbered I-XII that emerge from the base of the brain
Spinal Nerves how many
31 pairs of spinal nerves that emerge from the spinal cord each serving a specific region of the body
Sensory Receptors
Specialized cells that monitor change in the internal and external
environment.
Example: Photoreceptors in the retina of the eye.
Ganglia
Small masses of nervous tissue consisting of neuronal cell bodies that
are located outside the brain and spinal cord.
Example: Dorsal root
ganglion
Enteric Plexus
are located in the walls of the
GI Track that help regulate the digestive system.
Three basic function of the Nervous system.
a. Sensory function afferent
b. Integrative function: Information processing
c. Motor function (Efferent)
What is Sensory function of afferent
internal and external stimuli and carry information into brain and spinal cord
Integrative function:
1) Perception = awareness of sensory input
2) Analyzing and storing information to help lead to appropriate responses
Motor function (Efferent)
brain may elicit motor response to muscles or
glands (effectors)
Nervous tissue consists of two cells
Neurons
Neuroglia
Neurons cells
Provide most of the unique functions of the nervous system
Neuroglia cells
Function to provide support, nourishment, and protection
Parts of a Neuron [3] structural
Cell body
Dendrites
Axon
Axon terminals
Axon emerge from what structure?
cone-shaped axon hillock
Structural Classes of Neurons 3 types
Multipolar
Bipolar
Unipolar
Multipolar
Most common type in brain and spinal cord
Bipolar neurons
1) Have one dendrite and one axon
2) Example: In retina of eye and inner ear
Unipolar
1) Have fused dendrite and axon
2) Sensory neurons of spinal nerves
What are the Functional Classes of Neurons 3 types
Sensory (afferent)
Motor (efferent)
Interneurons (association neurons)