12. Nervous System Flashcards
(197 cards)
gli/o
glue
neur/o
nerve
astr/o
star
dendr/o
tree
neural functions
- Sensing: collecting data from the environment
- Interpreting: processing this data and choosing a response
- Acting: directing the body to act out that response
central nervous system (CNS)
composed of the brain and spinal cord, operated largely by a network of nerve cells called interneurons
peripheral nervous system (PNS)
extends from the brain and spinal cord to the tissues of the body
organized first into 12 pairs of cranial nerves and 31 pairs of spinal nerves
divided into afferent (sensory) or efferent (motor) nerves
also divided into somatic (controlling voluntary functions) and autonomic (controlling mostly involuntary functions)
afferent nerves
sensory nerves that carry impulses to the CNS
efferent nerves
motor nerves that carry impulses from the brain and spinal cord
interneurons
link the sensory and motor nerves by transmitting signals between them
Alzheimer’s disease (AD)
a progressive degenerative disease of the brain characterized by personality changes, confusion, restlessness, early senility, and a loss of memory that begins as a slight disturbance and progresses to profound dementia
disrupts the neurons’ roles in communication within the system, as well as their roles in metabolism and self-repair
brain in attached photograph shows smaller brain, narrow gyri, and widened sulci in comparison with a normal brain

neurons
any of the basic conducting cells of the nervous system
neuroglia
nur OGG lee uh
supporting or stromal (connective) tissue cells of the CNS
provide a supportive function by holding neurons together and protecting them
astrocyte
a type of neuroglia that forms the blood-brain barrier (BBB)

blood-brain barrier (BBB)
a network of connected neurons and blood vessels that prevents or slows the passage of harmful substances into the CNS

dendrite
one of the threadlike extensions of the cell body of a neuron to receive neural impulses - or action potentials - from a stimulus of some kind, and then delivers that impulse back to the cell body

axon
the extension of a neuron by which impulses travel away from the bell body
capable of conducting action potentials

neurotransmitter
any of a group of substances that travel across the synaptic cleft to inhibit or stimulate a target cell
released on excitation from the axon terminal of a neuron of the CNS or PNS
synapse
the space between the terminal fibers and the dendrites of the next cell
myelin sheath
a cylindrical structure composed largely of phospholipids and protein that covers the axons of some nerves in the body
hypothalamus
controls the PNS and functions such as temperature, sleep, and appetite
the ventral portion of the diencephalon, forming the floor and part of the lateral wall of the third ventricle

cerebrum
the main portion of the brain, occupying the upper section of the cranial cavity
its two hemispheres are connected by the corpus callosum and form the largest part of the CNS

cerebellum
portion of the metencephalon that is located in the posterior cranial fossa, behind the brainstem
coordinates voluntary movements

diencephalon
portion of the brain between the mesencephalon and the cerebrum
consists of the thalamus, hypothalamus, and epithalamus and including most of the third ventricle








































