Transcript Nervous Tissue

Objectives
• To identify the roles of the three types of
neurons and the transmission pathway of
a reflex arc.
• To analyze case studies (patient
symptoms) to hypothesize possible
regions of the brain damaged or affected.
Questions to Ponder….
Record the following questions in your
notebooks. You will answer these at the
end of the block.
1. Where are interneurons found?
2. Anesthesia blocks which type of neuron
from communicating with the brain?
Think about how form follows function of a neuron
below…can you determine what each component does
based on what you already know about nervous tissue?
Types of Neurons
• Motor: impulses from CNS to muscles or
glands (mostly multipolar).
• Sensory: impulses from sensory receptors
to the CNS (many are unipolar).
• Interneurons: impulses conducted within
the CNS (often multipolar).
Nervous Tissue
• All nervous tissue is composed of only two types
of cells: Nerve cells (neurons) and supporting
cells (neuroglia).
• Neurons vary in appearance, but all have 1) cell
body, 2) dendrite, and 3) axon.
• Neurolemmocyte (Schwann cell): specialized
neuroglial cell of the PNS that creates myelin.
Motor Neuron
Sensory Neuron
Interneuron
CNS: Spinal Cord Function
• Communication between the Brain and the PNS.
• Example: hand touched sensory fibers
generate nerve impulses  passes through
sensory neurons  spinal cord  ascending
tract  brain.
• Center for reflex arcs. A stimulus causes
sensory receptors to generate nerve impulses
through sensory nerves these go to interneurons
that integrate the data and respond.