Nervous System Flashcards
central nervous system (CNS)
brain and spinal cord
analyzes sensory information
produces motor commands
peripheral nervous system (PNS)
spinal nerves and cranial nerves
communication bridge between sensory receptors and motor effectors
astrocytes
90% of neuroglial cells are involved in signaling the formation of the very tight junctions between endothelial cells that line the blood capillaries of the CNS (blood-brain barrier)
oligodendria
produce myelin around axons in the CNS
microglia
phagocytize microorganisms in the CNS
ependymal cells (w/ cilia)
line the ventricles of the brain and central canal of spinal cord
produce cerebral spinal fluid (CSF)
schwann’s cell
forms the myelin sheath around myelinated axons of the PNS
soma
cell body: contains the nucleus, mitochondria, and other organelles
dendrites
multiple processes: contains receptors or sensors that receive stimuli and conduct impulses towards the stoma
dendrites
multiple processes: contains receptors or sensors that receive stimuli and conduct impulses toward the stoma
axon
single process leaving the stoma, can branch some
myelinated neurons
neurons that contain a segmented fatty sheath around the axon
sheath of myelin
white matter of the brain and spinal cord
node of ranvier
unmyelinated areas of the axon between myelin sheaths
unmyelinated neurons
neurons NOT wrapped in a sheath of myelin
sensory neurons
transmit impulses from senors or receptors found in the peripheral sense organs to the CNS
motor (efferent) neurons
transmit impulses away from CNS and towards effectors in the periphery
interneurons
found in the CNS: transmits impulses up and down the spinal cord and between different areas of the brain
cerebrum
largest portion of the brain
covered in gyri and sulci
hemispheres separated by the longitudinal fissue
cerebral cortex
gray matter
corpus callosum
white matter
lateral ventricles
large fluid-filled area
frontal lobe
speech, movement, emotions
parietal lobe
movement, recognition, computing stimuli
occipital lobe
visual processing
temporal lobe
auditory stimuli, memory, speech
thalamus
brings sensory inputs to the cerebrum
houses CNII - communicated with the retina
hypothalamus
center of homeostasis for the body and junction between nervous and endocrine system
epithalamus
pineal gland, secretes melatonin
cerebellum
2nd largest part of the brain
covered in sulci and gyri
separated from the cerebrum by the transverse fissure
gray matter lines the outer periphery and white matter lines the interior
medulla oblongata
center that regulates heartbeat, blood pressure, respiration, reflexes
pons
center that controls sleep, respiration, and urination
midbrain
centers that control eye, head, and reflex movements (CN III and CN IV)
meninges
layer of connective tissue covering the brain and spinal cord
creates space for nutrient exchange and CSF
three layers
dura matter
outer covering (epidural space) (of meninges)
arachnoid
middle, delicate layer (of meninges)
pia mater
inner layer (of meninges)
cerebrospinal fluid
cushions and lubricates the brain
found in the spaces between the brain and spinal cord
subarachnoid space
space between the arachnoid and pia matter
central canal
fluid-filled canal found in the center of the spinal cord
ventricles
fluid-filled cavities in the brain
spinal cord
extends from the medulla oblongata through foramen magnum in the skull
located within the vertebral foramen in the vertebral column
terminates at the sacral region in quadrupeds
gray matter
interior interneurons and cell bodies of motor neurons
dorsal horns
neurons send sensory info to the brain
ventral horns
neurons send motor impulses to spinal nerves
white matter
exterior myelinated axons called tracts
ascending tracts
send sensory messages up the spinal cord to the brain using sensory axons
descending tracts
send motor impulses down the spinal cord along motor axons
spinal nerves
paired nerves that originate from both sides of the spinal cord
upon exiting the spinal cord, spinal nerves split into the dorsal and ventral branches
dorsal root
afferent sensory neurons coming from sensory in the periphery
ventral root
efferent motor neurons originating in the spinal cord and extend out to effectors muscles or glands)
dorsal and ventral roots
join to form spinal nerves with both motor and sensory function
cranial nerves
12 pairs originating in the brain and extending into the PNS
can consist of sensory, motor, or both types of nerves
CNI
olfactory nerve
CNII
optic nerve
oculomotor nerve
damage to this nerve can result in strabismus
neural pathways
communication between the brain and periphery; movement of electrical impulses through neural pathways
synapse
site where an electrical signal goes from one neuron to another
electrical signals move in ONE direction only
impulse conduction
stimulus activates a neuron
action potentials are conducted along the axon
release of neurotransmitters from the synaptic cleft
reflex
automatic involuntary reaction (ex. blinking, coughing, salivation)
involves an impulse/stimulus generated by a senor to afferent neurons to integrate in the spinal cord to efferent neurons to the effector then a response
