Exam 1 Flashcards
Cells of the Nervous System
- neurons
2. glial cells
neurons
receive and transmit electrochemical signals
glial cells
various types, provide a wide variety of supportive functions
what are the 3 components to a neuron
- cell body or soma
- dendrites
- axon
Neurons _____ info across small spaces, _____ receives info
send; dendrites
cell body/soma
contains genetic material in nucleus, providing nutrients that cell needs
dendrites
receive info from adjacent neurons, membrane has receptors where info is transferred
axon
- transmits info into nearby neurons
- thin fiber of constant diameter, only 1 per neuron
- at end of axon: presynaptic terminals
several axons running together
nerve (when outside the brain) or tract (when inside the brain)
presynaptic terminals
the point at which neurotransmitters are released and signal is passed to another neuron
synapse
gap between adjacent neurons through which signals are sent (space between neurons)
three types of neurons
- sensory neurons
- interneurons
- motor neurons
sensory neurons
convey sensory info to brain
- bring sensory info from body to brain (what we see, hear, etc.)
interneurons
carry out operations involved in thought, feeling, and planning action
motor neurons
transmit commands out into the body to control muscles and organs
afferent
bring info into a structure (the brain) (admission)
efferent
carry info away from a structure (exit)
Glia
provide important roles
serve as a support system
types of glia
- astrocytes
- microglia
- oligodendrocytes
- schwann cells
astrocytes
largest, many functions
- humans have 1.4x astrocytes per neuron
microglia
involved in response to injury/disease
smallest
increase in microglia in altzheimers