Introduction to the Nervous System Flashcards
Learning Objectives
Review the function and general organization of the central and peripheral nervous systems
Summarize the differences between gray and white matter with regard to location, composition, and nomenclature.
Contrast the general features of the sympathetic and parasympathetic nervous systems.
Briefly describe the meningeal layers of the brain and spinal cord.
Identify the major areas of the ventricular system.
Identify the different lobes and divisions of the brain and their associated functions.
Describe the features of a transverse section of spinal cord.
Briefly describe the basic anatomy of a typical spinal nerve.
What does the Central nervous system consist of?
Consists of the spinal cord, brain stem, cerebellum and cerebrum
What does Peripheral nervous system consist of?
Cranial and spinal nerves consisting of ganglia
What does the encephalon (brain) consist of?
Consists of brain stem, cerebellum and cerebrum
What are three parts of the brain stem from superiorly to inferiorly?
Midbrain, medulla and pons
Know where the CNS is and where the parts are anatomically
Use Flash cards to self test
What is a neuron
An excitable nerve which transmits information as electric signals or action potentials
What does a neuron consist of?
A neuron consists of a cell body (soma) and neurite. A neurite can either be an axon or dendrite
What is an axon
An axon is a single long dendrite covered with myelin or Schwann sheath
What is a dendrite?
They are short, multiple, thin neurites.
What are glial cells?
Glial cells maintain homeostasis, form myelin, and provide support and protection for neurons in the central and peripheral nervous systems
Name the glial cells in the PNS and their functions
Satellite cells: cells that cover the surface of nerve cell bodies in sensory, sympathetic and parasympathetic ganglia
Schwann cells: Myelin production
Name the glial cells in the CNS and their functions
Oligodendrocytes: Myelin production
Astrocytes: Blood brain barrier
Microglia: Remove unwanted material
Ependymal cells: CSF production
What does Myelin do?
Myelin makes electrical conduction faster and with less energy required
What cell makes unmyelinated axons?
Oligodendrocytes
Explain how neurons communicate
Neurons communicate through vesicles holding neurotransmitters in an axon going to the synapse and jumping across to the receptor of a dendrite
What is a ganglion?
The ganglion is a group of nerve cell bodies where usually the synapse takes place
What is gray matter?
Cell bodies of neurons and unmyelinated neurites
What is white matter?
Usually myelinated axons
Where do you find gray matter?
Grey matter is found on the surface of the brain and cerebellum and in the middle of the spinal cord
Where do you find white matter?
On the brain it is deep from the grey matter and is found on the surface of the spinal cord
What is afferent division?
Sensory neurons which conveys info from receptors in peripheral tissues and organs to the CNS
What is efferent division?
Comprises motor neurons which transmits signals from CNS to the effector cells (skeletal and smooth muscles, organs and glands)
Describe the basic task of the nervous system
A sensory input which is conveyed by afferent neurons goes to CNS. CNS decides to act on it by sending an impulse to the efferent neurons to the effector cells
