Nerve Notes

1
Nerve Notes
2
NEURON

• Nerve tissue are made of neuron (nerve cell) and
  neuroglia
• Neuron are made of
• Cell body contains nucleus and other organelles
• Dendrites receiving portions, short, tapered
  and highly branched

3
(No Transcript)
4

• Axon conducts nerve impulses to another neuron
  or to an effector organ (muscle or gland)
• Axon arises from the axon hillock
• Axons start as a single fiber, but may give off
  branches called axon collaterals

5
(No Transcript)
6

• Axon and collaterals end in axon terminals which
  end in synaptic end bulbs
• end bulbs contain synaptic vesicles that contain
  neurotransmitters (chemical messengers)

7
(No Transcript)
8
MYELIN

• Most axons are surrounded by a myelin sheath
• Myelin acts as an insulator
• increases the speed at which the impulse travels
• Gaps between myelin sheath are called the nodes
  of Ranvier

9
(No Transcript)
10
(No Transcript)
11
CLASSIFICATION OF NEURON

• Multipolar several dendrites and one axon
  neurons of CNS are mostly this type
• Bipolar one main dendrite and one axon
  usually found in special sense organs

12

• Unipolar - just one process, and are always
  sensory neurons. Axon terminals are in CNS and
  cell bodies in ganglia outside CNS

13
FUNCTIONAL CLASSIFICATION

• Sensory or afferent neurons transmit sensory
  impulses (toward CNS), have specialized receptor
  ends at tips of dendrites or the dendrites are in
  contact with specialized receptor cells in skin
  or sense organs
• Most are unipolar, some are bipolar

14

• Motor or efferent neurons transmit motor nerve
  impulses from CNS to effectors
• Interneurons multipolar neurons in CNS.that
  form links between other neurons

15
(No Transcript)