Overview of the nervous system Flashcards
It is the network of nerve cells and fibers which transmits nerve impulses between parts of the body.
The Nervous System
Two major parts
Peripheral and Central nervous system
serves as the control center of the body.
Brain
It is composed of the brain and the spinal cord
Central Nervous System (CNS)
It is composed of neurons outside the central nervous system.
They communicate through electrochemical signals or nerve impulses.
The Peripheral Nervous System (PNS)
serves as the passageway for nerve impulses.
Spinal Chord
The Peripheral Nervous System (PNS) communicate through?
electrochemical signals or nerve impulses.
These are the nervous system’s most basic cell units, also called nerve cells.
Neurons
They transmit signals in the form of electrical impulses or chemical signals.
Neurons
Parts of A Neuron
Parts of A Neuron
Dendrites
Axon
Soma
Terminal button
Synapse
are the long transmitting parts that conduct electrical impulses away from the nerve cell’s body
Axons
are the short, tree-like extensions of nerve cells, along which electrical impulses are received from other cells.
Dendrites
contains the cell’s nucleus and is responsible for regulating the actions of a neuron.
Soma or cell body
Neurons may be classified according to their functions and structure.
Functional Classification
Structural Classification
In the Functional Classification of Neurons, Neurons may be classified based on how they carry impulses such as:
Sensory Neurons
Motor Neurons
Interneurons
These carry impulses from the body to the CNS and relay signals back to the spinal cord or the brain.
These are also known as afferent neurons.
Sensory Neuron
These carry impulses and signals back to the body from the central nervous system.
They also known as efferent neurons.
Motor Neurons
These serve as connection points in between sensory and motor neurons.
are also known as association neurons.
Interneurons
What are Sensory neurons also known as?
Afferent Neurons
What are motor neurons also known as?
Efferent neurons
What are Interneurons known as?
association neurons.
Neurons may also be classified based on structure, or what parts they contain
Structural Classification of Neurons
Types of neurons based on structure
Multipolar Neuron
Bipolar Neuron
Unipolar Neuron
This contains one axon but multiple dendrites.
It is capable of integrating large amounts of information because of multiple dendrites
Multipolar neuron
This has two distinct nerve processes, usually in the form of one axon and one dendrite.
This is commonly seen associated with sensory organs.
Bipolar dendrite
This has one distinct nerve cell body.
This is commonly seen associated with ganglia.
Unipolar neuron
These are named for their stellar shape and also known as astroglia.
These are for structural support for the brain, tissue repair, modulation, and metabolic regulators.
are the most abundant neuroglial cells in the CNS.
Astrocytes
Neuroglial Cells in the Central Nervous System
Astrocytes
Microglial Cell
Ependymal cell
Oligodendrocyte
These act as the defenders of the CNS against infections.
These are macrophages and serve the function of destroying pathogens
Microglial cells
These produce cerebrospinal fluid, which is a fluid that acts as a cushioning agent for the CNS.
Ependymal Cell
These are also known as oligodendroglia.
They produce the myelin that makes up the myelin sheaths of the cells of the CNS.
Oligodendrites
are found as coatings of the nerve cells of the PNS.
Satellite cells
are the** PNS equivalent of oligodendrocytes** that produce myelin for the nerve cells.
Schwann cells
Concentric wrapping of Schwann cells around the axon forms the
Myelin Sheath
is used for insulating the electrical signals for a more efficient transmission.
Myelin Sheath
