Cells & Organisation of the Nervous System Flashcards
What does integrating and coordinating mean to our nervous system?
Matches sensory environment to our bodies needs
How does our body maintain homeostasis?
Integration (receiving the information), Coordination (what should we do about it), Response
What does the central nervous system (CNS) consist of?
Brain and Spinal Cord - which are composed of neurons and glia cells
What does the peripheral nervous system (PNS) consist of?
Peripheral nerves and Ganglia - which are composed of neurons and glia cells
What are the general features of the two types of cells in these systems, Neurons and Glia?
Neurons:
- Specialised for transmitting information
- 4 Morphological types
Glia:
- Support for neurons
- 5 Basic types
- Each type has a specific function
What are the structural components of Neurons and what do they do?
Dendrites: Receive input and send to cell body
Cell Body: contains nucleus and organelles & sums input
Axon: carries electrical impulses & may or may not be myelinated
Axon Terminal(s): End (terminus) of the axon & neurotransmitter release
Describe the organisation of components of the nervous system
In the CNS:
Groups of cell bodies: Nucleus (pl - nuclei)
Bundles of Axons: tract
Group of cell bodies in cerebral cortex or spinal cord: Grey matter
Bundle of axons in cerebral cortex or spinal cord: White matter
In the PNS:
Groups of cell bodies: Ganglion (pl - ganglia
Bundle of axons: Nerve
What are the functional components (zones) of neurons?
Input zone: Dendrites and Cell body, receives chemical signals from other neurons
Summation zone: Axon hillock, summation of inputs
Conduction zone: Axon - may be quite long, carry electrical signals between brain areas, to and from spinal cord, and or from PN receptors, and to effector cells.
Output zone: axon terminals, contact with input zone of other neurons or effectors, release of neurotransmitter = chemical signal
Neurons look different because…
They have different functions
What are the four morphological types of neurons?
Multipolar (multiple processes come off cell body), bipolar (two processes come off cell body), unipolar (one process comes off cell body, anaxonic (axonless, all processes look alike).
List the Central Nervous System Glia cells
Astrocytes, Microglia, Ependymal cells, Oligodendrocytes
What do astrocytes do?
Supply nutrients to neurons, ensheath blood capillaries, injury response
What do microglia do?
Immune cells of the CNS, engulf microorganisms and debris
What do ependymal cells do?
Line fluid-filled spaces of the brain and spinal cord, have cilia (hair like processes) to circulate CSF.
What do oligodendrocytes do?
Support nerve fibres, ensheath them with myelin (they make up the myelin sheath).
