Nervous system Flashcards
(47 cards)
The Nervous System is composed of:
Brain
Spinal Cord
Sensory receptors of sense organs
Nerves and Neuroglia
What are Nerves?
bundles of nerve fibers
What are Neuroglia?
tissues that support the nerve cells
Function of the Dendrite
branching extensions of a neuron that receive information and conduct impulses toward the soma.
What is the Soma?
the cell body of a neuron, which contains the nucleus.
Function of the Axon
the extension of a neuron through which neural impulses are sent.
Function of the Axon terminal
the endpoint of a neuron where neurotransmitters are stored. Form junctions with other cells.
Function of the Myelin Sheath
protects the axon and influences the speed of the neural impulses.
What is the Nucleus?
the “brain” of the cell.
What is the Nodes of Ranvier?
unmyelinated gaps between internodes. Axons may branch.
Neurons perform three basic functions, including:
Receiving information
Carrying the information
Passing the information on to the next neuron
What are Unipolar Neurons?
Cell body with a single process that divides into two branches and functions as an axon.
What are Bipolar Neurons?
Cell body with a process, arising from each end, one axon and one dendrite.
What are Multipolar Neurons?
Cell body with many processes, one of which is an axon, the rest dendrites.
What do interneurons do?
Transmits nerve impulses between neurons within the brain and spinal cord.
Connect sensory and motor neurons.
What do motor neurons do?
Conducts nerve impulses from the brain or spinal cord out to effectors– muscles or glands.
What do sensory neurons do?
Conducts nerve impulses from receptors in peripheral body parts into the brain or spinal cord.
Describe the 2 major efferent systems? motor neuron
Somatic: innervate skeletal muscles.
Visceral: innervate all other peripheral effectors (smooth muscle, cardiac muscle, glands, adipose tissue).
Describe the 2 major afferent systems? sensory neuron
Visceral: monitor internal environment
Somatic: monitor effects of external environment
What Neuroglial cells are found in the CNS?
Astrocytes
Oligodendrocytes
Microglia
Ependyma
What Neuroglial cells are found in the PNS?
Schwann Cells
Satellite Cells
List what is and function of Astrocytes?
Star-shaped cells that are located between neurons and blood vessels.
Functions:
Maintain blood-brain barrier.
Create three-dimensional framework for the central nervous system.
Repair damaged neural tissue.
Guide neuron development.
Control interstitial environment.
Communication with other nerve cells.
List what is and function of Oligodendrocytes
Shaped like astrocytes, but have fewer cellular processes.
Occur in rows along axons.
Functions:
Form myelin sheaths within the brain and spinal cord.
Produce nerve growth factors.
List what is and function of Microglial
Small cells with few cellular processes.
Migrate through neural tissue.
Functions:
Structural Support
Clean up cellular debris, waste products, and pathogens.