Types of Cells Flashcards
roundworm (c. elegans)
302 neurons
interneurons
neurons that process information between sensory & motor neurons
neurons
transmit information
glia
supporting cells
synapses
neurons communicate with each other
circuit
neurons organized in a precise order
sea slug (aplysia californica)
18,000 neurons
gill and siphon withdrawal reflex
rat (rattus norvegicus)
~50 million neurons
central nervous system (brain & spinal cord)
peripheral nervous system (sympathetic, parasympathetic, enteric)
parasympathetic nervous system
rest and digest
sympathetic nervous system
fight or flight
enteric nervous system
controlling gut- how colon moves food and absorbs nutrients
human (homo sapiens)
~80 billion neurons
more neurons, more discrete brains regions, more complex circuits
building blocks
neurons
building blocks of nervous system and the element of processing information
connection of neurons
synapses to form circuits in all species
shared aspects of nervous system
shared across all species (sensory neurons) and especially closely related species (brain and spinal cord in mammals)
true or false?
in all animals, circuits formed by neurons drive behavior
TRUE
camillo golgi
staining technique to visualize entire neuron
thought neurons were continuous like tubing (NOT TRUE)
Santiago Ramon y Cajal
used Golgi’s method
thought neurons came close to each other but did not touch (TRUE)
neuron doctrine
each neuron is an independent unit
information must be transmitted across gaps between neurons (synapses)
soma
cell body
integration zone
collecting information from many dendrites and integrate them
neurites
axons & dendrites
dendrites
branches
spines
mushroom-shaped protrusions from dendrites
dendrites/spines
a neuron has many
dendrites/spines from one neuron receive chemical signals from other neurons
input zone
where information/signals are received
mitochondria
produce energy
in the axon terminal-> takes a lot of energy to change signal from electrical to chemical
cell nucleus
contains genetic material
ribosomes
translates genetic instructions into proteins
axon hillock
axon initial segment
final location where integration occurs and the decision to generate an electrical communication signal is made
most neurons have one axon hillock
axon
conduction zone
most neurons have one axon
role #1: conduct electrical signal on the cell membrane
role #2: transport material between soma and axon terminal
anterograde
to axon terminal
retrograde
from axon terminal
axon terminal
output zone
axon terminals from one neuron releases chemical signals onto many other neurons
synaptic cleft
where the chemical signal was released
pre-synaptic axon terminal
the beginning of the axon terminal before the synapse
post-synaptic dendritic spine
part of a different neuron that is sent chemical signals by another neuron
electrical
signal in neuron
chemical
signal between neurons
types of glial cells
astrocytes
oligodendrocytes/Schwann cells
microglial cells
astrocytes
star-shaped cells
monitor & support the metabolic & biochemical needs of neurons
regulate synaptic signaling as part of the “tripartite synapse”
help form the blood brain barrier by sitting between blood capillaries and neurons
react to brain injury (repair & scarring)
microglia
brain immune cell
monitor local environment for threat or injury- monitor through branches
migrate to injury site to remove debris/dead cells
oligodendrocytes & Schwann cells
insulate axons by wrapping myelin around them- white matter- myelin sheath
oligodendrocytes are in the central nervous system (brain & spinal cord)
Schwann cells are in the peripheral nervous system
protects the axon- less likely to be damaged
nodes of ranvier
gaps in myelin sheath
which of the following myelinate neurons in the central nervous system?
a. schwann cells
b. microglia
c. oligodendrocytes
d. astrocytes
c. oligodendrocytes
summary of neurons
polarized
dendrites, soma, axon, axon hillock, axon terminals
synapses
summary of glia
astrocytes
myelinating cells (oligodendrocytes and schwann cells)
microglia
