12.2 Flashcards
Excitability
Neurons can respond to environmental changes (stimuli)
Conductivity
Neurons generate and propagate electrical signals along axons
-allows for communication
Secretion
At axon terminals neurons realize neurotransmitters that influence the activity of other neurons
Sensory neurons
Detective stimuli and transmit sensory info to CNS
-Afferent
Interneurons
-found in CNS
-connect sensory and motor pathways
-key role in information processing and decision making
Motor neurons
Sends signals from CNS to muscles and glands initiating response and actions
-efferent
Soma
Cell body
-contains nucleus amd organelles
-essential for cellular metabolism and maintenance
Dentrites
Branch like structures that receive signals from other neurons
Critical for synaptic communication
Axon
Long projection that transmits electrical impulse away from the soma
Only one per neuron (typically)
Axoplasm
The cytoplasm within the axon
Where cellular components are suspended
Axolemma
The plasma membrane surrounding the axon
Crucial for maintaining electrical environment
Myelin sheath
Insulating layer formed by glial cells that increase the speed of electrical signals along axons transmission along the axon
Anterograde transport
Movement of materials from soma down the axon
Facilitated by proteins
Retrograde transport
Movement of materials back to soma
Fast axonal transport
Ranges from 200-400mm/day transporting organelles and synaptic vesicles
Slow axon transport
Ranges from 0.2-0.5mm/day primarily for cytoskeleton components and enzymes
Crucial for regeneration after injury
Multipolar neuron
One axon terminal
Most neurons in CNS
Bipolar neuron
One axon and one dendrite
Olfactory cells, retina, inner ear
Unipolar neuron
Single processes leading away from soma
Sensory cells from skin and organs to spinal cord
Anaxonic neuron
Many dentrites but no axon
Retina, brain, adrenal gland
Kinesin
Anterograde transport
Dynein
Retrograde transport
