Nervous System Cells Flashcards
Central Nervous System consists of (2):
- Brain
- Spinal cord
Structural and functional center of the nervous system that integrates sensory information
Central Nervous System
Nerves that lie in “outer regions” of the nervous system
Peripheral Nervous System
nerves that originate from the brain and brain stem (12 pairs)
cranial nerves
nerves that originate from the spinal cord (31 pairs)
spinal nerves
All incoming sensory pathways (northbound)
afferent division
all outgoing motor pathways (southbound)
efferent division
system that carries information to the skeletal muscle (or glands)
somatic motor division
system that carries feedback information from skeletal muscle (or glands) to ____ integration centers in the CNS
somatic sensory division
somatic
carries info to the visceral effectors (smooth and cardiac muscles and glands)
efferent division of autonomic nervous system
carries feedback info to _____ integrating centers in the CNS
afferent/visceral sensory division
autonomic
The autonomic nervous system is normally _____.
involuntary
The somatic motor division is ____ and under conscious control.
voluntary
2 subdivisions of efferent division of ANS:
- sympathetic division
- parasympathetic division
prepares the body for immediate threats to its internal environment (fight, flight, or freeze response)
sympathetic division
coordinates body’s normal resting activities (rest and repair)
parasympathetic division
2 main types of cells in the nervous system:
- neurons
- glial cells (neuroglia)
excitable cells that make nervous system functions possible. Form the “wiring” of the nervous system’s information circuits.
neurons
cells that do not usually conduct information. They support the function of neurons in various ways.
(Helper cells)
glial cells (neuroglia)
5 main types of glial cells:
- astrocytes
- microglia
- ependymal cells
- oligodendrocytes
- schwann cells
star-shaped, largest, and most numerous type of glial cell. They transfer nutrients from blood to the neurons, help recycle neurotransmitters at synapses, and form tight sheaths around brain capillaries
astrocytes
double barrier made up of astrocytes and the endothelial cells that make the capillary walls
blood-brain barrier, BBB
The ________ helps maintain a very stable environment required for normal functioning of the brain by forming a barrier that regulates passage of most ions between the blood and brain tissue.
Blood-Brain Barrier, BBB
Some ions could disrupt the transmission of nerve impulses if _____ did not exist.
Blood-Brain Barrier, BBB
small, usually stationary cells that engulf and destroy microorganisms and cellular debris. The “Macrophages” of the nervous system.
Microglia
____ are usually quiet and inactive, but if brain tissue is inflamed or degenerating, they will enlarge and become mobile, allowing them to carry out phagocytosis.
Microglia
cells that form thin sheets that line fluid-filled cavities in the CNS. Some take part in producing the fluid that fills these spaces. Some have motile cilia that help circulate fluid.
ependymal cells
The fluid filled cavities in the CNS
ventricles
smaller than astrocytes with fewer processes. They hold nerve fibers together and produce the myelin sheath around nerve fibers in CNS only
Oligodendrocytes