Chapter #11: Fundamentals of Nervous System & Nervous Tissue Flashcards
Sensory Input
-allows us to respond to stimuli
-monitors changes that occur inside and outside the body
What is responsible for sensory input
several different sensory receptors
Integration
processing & interpretation of input information –> the nervous system “decides” what response to make
What is responsible for integration?
CNS; usually the brain, but sometimes the spinal cord
Motor Output (motor response)
response is carried out –> travels to effector organ
What is responsible for motor output?
muscles/glands are the most common
Functions of the nervous system
sensory input, integration, and motor output
Components of the nervous system
Central Nervous System (CNS) and Peripheral Nervous System (PNS)
CNS
composed of the brain and spinal cord
What is the function of the CNS?
is responsible for interpreting sensory input and deciding motor output
PNS
Composed of nerves that extend from the CNS to the rest of the body
What is the function of the PNS?
allows information to be sent between the CNS and the rest of the body
Neurons
-nerve cells that can respond to stimuli & transmit electrical signals
-cells of the nervous system specialized to generate or transmit electrical signals (nerve impulses)
Why are neurons important?
-create and send messages to various parts of the body
-integration and motor output could not occur without neurons
Neuroglia (glial cells)
provide support and maintenance to neurons
Why are neuroglias important?
they make sure neurons remain healthy, alive, and functional
Types of neuroglia
astrocytes, microglial cells, ependymal cells, satellite cells, oligodendrocytes, and schwann cells
Astrocytes (CNS)
-most abundant, support & protect neurons in CNS
-Star-shaped, with projections connecting to and wrapping around neurons, nerve endings, and surrounding blood capillaries
What are the functions of astrocytes?
- Provide nutrient supply for neuron cells
- Allows migration of young neurons
- “Clean up” outside neuron cells (leaked K+ ions, neurotransmitters; important for resting membrane potentials)
Microglial Cells (CNS)
-contact nearby neuron cells to monitor neuron health
-migrate toward injured neurons & transform into a macrophage and phagocytize the neuron
Why are microglial cells important?
If a cell is dying off or neuron is damages, they will transform into macrophages because you do not want dead cells taking up space
Ependymal Cells (CNS)
-most ependymal cells have cilia
-lines central cavities of CNS to circulate cerebrospinal fluid within cavities
Satellite cells (PNS)
-Support & protect neuron cell in PNS
-similar to astrocytes in the CNS
Oligodendrocytes (CNS) & Schwann Cells (PNS)
-Wrap around thicker nerve fibers in CNS & PNS
-Function: myelin sheath creates an insulating covering for neurons