L16 - Cells and organisation of nervous system Flashcards
What is Integration and co ordination
Integration - Sensing of stimulus eg pin
Co ordination- Shaking your foot away
function of neurons (Nerve Cells)
Cells specialised for transmission of info (4 morphological types)
Function of glia (3)
-Support for neurons
-5 basic types (4 in CNS and 1 in PNS)
-Each Type has a function
Function of dendrites
-recieve input
-send info to cell body
Cell body
-Contains nucleus and organelles
-Sums input
Axon
-Carries Electrical impulses (Action Potential_
-May or may not be myelinated
Axon Terminal
-End of Axon
-Neurotransmitter release
(CNS) Group of cell bodies
Nucleus
CNS Bundle of Axons
Tract
CNS Group of cell bodies in cerebral cortex or spinal cord
Grey matter
CNS Bundle of axons in cerebral cortex or spinal cord
White matter
PNS Group of cell bodies
Ganglion
PNS Bundle of axons
Nerve
4 zones of Neuron
Input, Summation, Conduction, output
Function of axon hillock
-Sums inputs from Dendrites and if the change in membrane potential exceeds threshold, allows for propagation of Information
4 morphological types of Neurons
Multipolar, Bipolar, Unipolar, Axonic
Multipolar
Multiple processes from cell body
Bipolar
Two processes emanate from cell body
Unipolar
One processes emenates from cell body which branch into dendrites and axons
Axonic
No Distinct Axon
All process look alike
CNS Glia (4 types of cells)
Astrocytes, microglia, ependymal cells, oligodendrocytes
Astrocytes (3)
-supplies nutrients to neurons
-cover Blood Capillaries
-Injury response
Microglia (2)
-immune cells of CNS
-Engulf microorganisms and debris
Ependymal Cells (2)
-Line fluid filled spaces of brain and spinal cord
-Have Cilia to circulate cerebrospinal fluid
Oligodendrocytes (2)
-Support nerve fibres
-Covers axons with myelin
Peripheral Nervous System Glia - Shwann Cells
-Support peripheral nerve fibres
-covers axons with myelin
- Similar to Oligodendrocytes (CNS)
What is Myelin Sheath and where does it come from in CNS and PNS
-Lipid wrapped around axon which increases conduction velocity
-CNS: Oligodendrocytes
-PNS: Shwann Cells
What are the nodes of ranvier
-Gaps between myelin which increaseconduction velocity
What is a synsape
Communication between neurons, Neurotransmitter release from axon terminal which travels to dendrites of another neuron
What are synaptic vesicles
little packets of neurotransmitter
What is synaptic cleft
Gap between pre synaptic neurons axons terminals and the post synaptic neurons dendrites
Afferent and Efferent
-Info ‘ascends’ into brain
-response that comes out of brain
