HUBS L16 Flashcards
central nervous system (CNS) consists of
Brain and Spinal cord
central nervous system (CNS) is composed of what general cell classes
Neurones and Gila
Peripheral Nervous System (PNS) consists of
Peripheral nerves and ganglia
Peripheral Nervous System (PNS) is composed of what general cell classes
Neurones and Gila
Neurons two general features are?
Cells specialised for
transmission of information
Four morphological types
Glia (Greek: glue) three general functions are?
Support for neurons
Five basic types
4 in CNS, 1 in PNS
Each type has a specific
function
Neurons – Structural Components: dendrites
Dendrites
* Receive input
* Send info to cell body
Neurons – Structural Components: Cell body
Cell body
* Contains nucleus & organelles
* Sums input
Neurons – Structural Components: Axon
Axon
* Carries electrical impulses
* May or may not be myelinated
Neurons – Structural Components: Axon terminal
Axon terminal(s)
* End (terminus) of the axon
* Neurotransmitter release
Input zone, is where? and does what?
Input zone:
Dendrites and cell body
Receives chemical signals from other neurons
Summation zone, is where? and does what?
Summation zone
Structure = Axon hillock
Summation of inputs
Conduction zone, is where? and does what?
Conduction zone
Axon, may be quite long
Carry electrical signals between brain
areas, to and from spinal cord, or from
peripheral sensory receptors and to
effector cells
Output zone, is where? and does what?
Output zone
Axon terminals
Contact with input zone of other neurons or
effectors
Release of neurotransmitter = chemical signal
Multipolar structure is?
Multiple processes
emanate from the cell
body
Bipolar structure is?
Two processes
emanate from the cell
body
Unipolar
One process emanates
from the cell body,
Then branches into
dendrite and axon
Central Nervous System Glia - Astrocytes
Supply nutrients to neurons
Cover blood capillaries
Injury response
Central Nervous System Glia - Microglia
Immune cells of the CNS
Engulf microorganisms and
debris
Central Nervous System Glia - Ependymal cells (Greek: epéndyma (covering))
Line fluid-filled spaces of brain and
spinal cord
Have cilia (hair-like processes) to
circulate CSF
Central Nervous System Glia - Oligodendrocytes (Greek: Oligos (small, few) + Déndron (tree)
Support nerve fibres
Ensheath them with myelin
Central Nervous System Glia - Schwann cells
Support peripheral nerve fibres
Ensheath them with myelin
Similar to oligodendrocytes (CNS)
The Myelin sheath is made from?
Lipid (fat) wrapped around axon
what does Myelin sheath do
increase conduction velocity
