Human Movement And Sensation Flashcards
Outline the basic anatomical organisation of the nervous system
The Central Nervous System (CSN): brain and the spinal cord. Both composed of 2 general cell classes - neurons and glia
The peripheral Nervous System (PNS): peripheral nerves and ganglia. Both composed of 2 general cell classes - neurons and glia
What are the 2 general features of neurons
Cells specialised for transmission of information
Four morphological types
What are the 3 general features of Glia
Support for neurons
Five basic types (4 in CNS, 1 in PNS)
Each type has a specific function
What are the 4 structural components to a neuron cell, and their functions
Dendrite - Receive input, send info to cell body
Cell body - contains nucleus and organelles, sums input
Axon - carries electrical impulses (may or may not be myelinated)
Axon terminals - end of the axon, neurotransmitter release
What are groups of cell bodies in the CNS called
Nucleus
What are bundles of axons called in the CNS
Tract
What are groups of cell bodies in cerebral cortex (in CNS) called
Grey matter
What are bundles of axons in the cerebral cortex (in CNS) called
White matter
What are groups of cell bodies in the PNS called
Ganglia
What are bundles of axons in the PNS called
Nerve
What is the input zone of the neuron
Dendrites and the cell body
Receives chemical signals from other neurons
What is the summation zone of a neuron
Structure is Axon Hillock
Summation of inputs
What is the conduction zone of a neuron
Axon - may be quite long
Carry electrical signals between brain areas, to and from spinal cord, or from peripheral sensory receptions and to effector cells
What is the output zone
Axon terminals
Contact with input zone of other neurons or effectors
Release neurotransmitter = chemical signal
What is the axon hillock
Anatomical location where inputs are summated before action potential transmitted
What are the 4 morphological types of neuron cells
Multipolar, Bipolar, Unipolar, Anaxonic
What are the characteristics of Multipolar neurons
Multiple processes emanate from the cell body
What are the characteristics of bipolar neurons
Two processes emanate from the cell body
What are the characteristics of unipolar neurons
One process emanates from the cell body, and then branches into dendrite and axon
What are the characteristics of Anaxonic neurons
Anaxonic - axonless
No distinct axon
All processes look alike
What are the 4 different types of glia in the CNS
Astrocytes, Microglia, Ependymal cells, Oligodendrocytes
What are the features of Astrocytes
Supply nutrients to neurons
Ensheath blood capillaries
Injury response
What are the 2 features of Microglia
Immune cells of the CNS
Engulf microorganisms and debris
What are the 2 features of ependymal cells
Line fluid filled spaces of CNS
Have cilia (hair like processes) to circulate CSF (cerebrospinal fluid)
What are the 2 features of oligodendrocytes
Support nerve fibres
Ensheath them with myelin
What is the glia cell of the PNS, and its 3 features
Schwann
Support peripheral nerve fibres
Ensheath them with myelin
Similar to oligodendrocytes (of the CNS)
What is the myelin sheath, where does it come from, and what is its function
Myelin sheath is lipid (fat/lipid bi layer) wrapped around axon
It comes from oligodendrocytes in the CNS, and Schwann cells in the PNS
It’s function is to increase conduction velocity
What are the gaps between myelin sheaths called, and their function
Nodes of Ranvier
Increase conduction velocity
Communication between neurons occurs through a junction called a…
Synapse
What is the role of the presynaptic neuron involved in a synapse
Releases neurotransmitters (chemical signal) from axon terminal
Contains synaptic vesicles (neurotransmitter containing vesicles)
What is the role of the post synaptic neuron in a synaptic junction
Contains receptors for neurotransmitter
What is information going into the brain called
Afferent / Ascending
What is information coming out of the brain called
Efferent / Decending
