Lecture 16 Flashcards
Central Nervous System
Brain and Spinal cord
Brain and Spinal cord
Neurons and Glia
Peripheral Nervous System
Peripheral nerves and Ganglia
Peripheral nerves and Ganglia
Neurons and Glia
What are neurons?
Cells specialised for transmission of information
Morphological types of neurons
Multipolar, Bipolar, Unipolar and Anaxonic
Multipolar Neuron
Multiple processes emanate from cell body
Bipolar
Two processes emanate from cell body
Unipolar neuron
One process emanates from cell body, then branches into dendrite and axon
Anaxonic neuron
No distinct axon, all processes look alike
Input zone of neuron
Dendrites and cell body receive chemical signals
Summation zone of neuron
Axon hillock where inputs are summated before action potential
Conduction zone of neuron
Axon, carries electrical signals between brain areas, to and from spinal cord or form peripheral sensory receptors to effector cells
Output zone of neuron
Axon terminals, contact with input zone of other neurons or effectors
Release of neurotransmitter
Chemical signal
Dendrites
Receive input and sends info to cell body
Cell body
Contains nucleus and organelles, and sums input
Axon
Carries electrical impulses, may or not be myelinated
Axon terminals
End of the axon and neurotransmitter releaser
Types of glial cells
CNS: Astrocytes, microglia, ependymal cells, oligodendrocytes
PNS: Schwann cells
Astrocytes
Supplies neurons with nutrients, Ensheath blood capillaries, injury response
Microglia
Immune cells of the CNS, engulf microorganisms and debris
Ependymal
Line fluid-filled cells of brain and spinal cord, have cilia to circulate CSF
Oligodendrocytes
Support nerve fibres, Ensheath them with myelin
