final Flashcards
PNS divisions
Sensory nervous system and motor nervous system
what is the sensory nervous system
contains receptors
transmits info from receptors to the CNS
what is the motor nervous system
transmits infom from CNS to the rest of the body
what does the SNS contain
somatic sensory and visceral sensory
what sensory info does somatic receive
from skin, fascia, joints, skeletal muscles, special senses
what sensory info does visceral receive
from viscera
what does MNS contain
somatic motor and autonomic motor
what is somatic motor
“voluntary” innvervates skeletal muscle
what is autonomic motor
“involuntary” innvervates cardiac muscle, smooth muscle, glands
what 2 divisions does autonomic motor have
parasympathetic - rest and digest
sympathetic - fight or flight
what are the steps of the function of nervous system
sensory input - integration - motor output
explain neuroglia or glial cells
functions vary but provide supportive scaffolding to neurons
processes and cell bodies but much smaller size
10 times as many neuroglia as neurons
what are the glial cells in CNS
astrocytes, microglia, ependymal cells, oligodendrocytes
what are the glial cells in PNS
satellite cells, schwann cells
explain astrocyte
most abundant CNS glial cells
highly branched
cling to neurons and capillaries
support and brace neurons
anchor neurons to blood supply
control chemical environment around neuron
helps in info processing in brain
explain microglia
small and oval
thorny processes
processes touch neurons
monitor health of neurons
protection
explain ependymal cells
squamous or columnar
some ciliated
line central cavaties of brain and spinal column
separates CNS interstitial fluid from cerebrospinal fluid
circulates cerebrospinal fluid
explain oligodendrocytes
fewer processes
line up along thicker neuron fibres (axons)
wrap processes around neuron fibres to form myelin sheath
explain satellite cells and schwann cells
satellite surronds PNS neuron cell bodies
similar to astrocytes in CNS
schwann surrounds larger nerve fibres (axons) in PNS
form myelin sheaths
vital to regeneration of damaged peripheral nerve fibres
what is neurons
are “nerve cells”
structural units of the nervous system
conduct info throughout body
extreme longevity
amitotic (Cell division)
very high metabolic rate
explain cell body
clusters called nuclei (CNS) or ganglia (PNS)
contains nucleus and mitochondria
processes of neurons are also what
dendrites
bundles called tracts (CNS) or nerves (PNS)
axon terminals are at the end of what
terminal branches
myelin is made of what
protein-lipoid sheath
what is protein-lipoid sheath made and what does it do
made created by Schwann cells (PNS) and oligodendrocytes (CNS)
protects and electrically insulates the axon
increases the speed of nerve impulse transmission
what are nodes of ranvier
gaps in myelin sheath where axonal membrane is exposed
allows for saltatory conduction
principles of electricity
opposite charges attract each other
energy is required to separate opposite charges across a membrane
energy is liberated when the charges move toward one another
if separated, the system has potential energy
voltage definition
measure of potential energy generated
potential difference
voltage measured between 2 points
current
flow of electric charge between 2 points
resistance (R)
hindrance to charge flow
what are 2 types of ion channels
leakage (non-gated) and gated
explain chemically gated ion channels
open when the appropriate neurotransmitter binds to the receptor, allowing movement
explain voltage gated channels
open and close in response to changes in membrane voltage
