Nervous system Flashcards
(45 cards)
what are the 2 main divisions of the nervous system
CNS + PNS
What are the main components of the CNS
Brain and spinal cord
What are the main components of the PNS
Cranial nerves, spinal nerves and peripheral nerves
Neuron
functional unit of the nervous system
What is the function of dendrites
receive input from other neurons and convey it to the cell body
what is the function of the axon
carries electrical impulses away from the cell body
what is the role of the axon terminal
releases NT to communicate with other cells
what is the myelin sheath
a fatty covering that increases the speed of impulse conduction
what creates the myelin sheath in the CNS
Oligodendrocytes
What creates the myelin sheath in the PNS
Schwann cells
What are the nodes of ranvier
gaps between myelin segments that facilitate saltatory conduction
What are 3 functions of glial cells
support neurons, maintain homeostasis, fight pathogens
can glial cells regenerate nerves
only in the PNS
What is resting membrane potential (RMP)
-70mV; inside the cell is more negative than outside
What ion contributes most to RMP
Potassium (K+)
Where are action potentials generated
In the neuron
what happens if Na+ channels are blocked
No action potential can be generated (used in anaesthesia)
What is a synapse
the junction where neurons communicate with other cells
what happens when the action potential reaches the axon terminal
NT are released into the synaptic cleft to then bind with the next neurons receptors on the dendrite
3 ways the NT effects are terminated
Enzymatic degradation, re uptake by presynaptic cell, uptake by glial cells
What are the roles of the sensory and motor divisions of NS
Sensory: receives information (afferent)
Motor: sends information to the muscles/glands (efferent)
what part of the NS integrates information
Central Nervous system
what is the somatomotor system
controls voluntary movement
what is the autonomic nervous system
controls involuntary functions (two-neuron pathway)
