Cells and Organisation of Nervous System Flashcards
Define Homeostasis
The integrating and co-ordinating of internal roles in the nervous system - eg balancing the internal environment of the cell
What are the two types of Nervous Systems?
Peripheral Nervous System (PNS) and Central Nervous System (CNS)
What does the CNS consist of?
Brain and Spinal Cord
What does PNS consist of?
Peripheral Nerves and Ganglia
There are cells of the nervous system, what are the two main types?
Neurons (Nerve Cells) and Glia (Glue)
What are the structural components of Neurons?
Dendrites, Axons, Axon Terminals, Cell Body
What are the four functional zones of Neurons?
Input, Summation, Conduction, Output Zone
What is the Axon Hillock?
Anatomical location where inputs are summated before Action Potentials
What are the four morphological types of Neurons?
Multipolar, Bipolar, Unipolar, Axonless
What are the cells of the CNS?
Astrocytes, Microglia, Ependymal Cells, Oligodendrocytes
What are the 3 main features of a Schwann Cell?
- Support Peripheral Nerve Fibers
- Ensheath them with Myelin
- Similar to Oligodendrocytes (CNS)
What is a Myelin Sheath?
Lipid (fat) wrapped around a Axon
Where does a Myelin SMheath come from in the CNS and PNS?
CNS - Oligodendrocytes
PNS - Schwann Cells
What is a Myelin Sheath used for?
Increases Conduction Velocity.
What is the basic structure of a Myelin Sheath and what is their function?
Myelin Sheath - Multiple Schwann cells in a line
Nodes of Ranvier - Gaps between the myelin and helps increase conduction velocity.
What is communication between Neurons called?
A synapse.
What is the synaptic cleft
Small gap between the presynaptic neuron and the postsynaptic cell (which can be another neuron, muscle cell, or gland cell) at a synapse. T
Functions of presynaptic neuron
- Releases neurotransmitter (chemical signal) from Axon terminal
- Contains synaptic vesicles
Function of postsynaptic neuron
Contains receptors for transmitter
Define Afferent and Efferent
INTO the brain - Afferent
OUT OF the brain - Efferent