the nervous system Flashcards
CNS components
brain
spinal cord
PNS components
automatic, somatic
somatic: sympathetic, parasympathetic
CNS function
carry sensory info to spinal cord –> brain via sensory neurons
carries motor messages to PNS via motor neurons
PNS function
carries sensory info –> CNS from body
carries motor messages from brain –> organs & muscles in body
automatic nervous system function
involuntary movements
self-regulating & genera;;y operating independently of brain -e.g. heart rate, digestions
somatic nervous system function
controls voluntary movement
sympatetic NS function
fight or flight
dominates during high emotions
mobilises body’s internal resources to provide extra energy needed for vigorous action, especially in times of stress
parasympathetic NS function
reverses effect of sympathetic- returns body to normal level of arousal
active during rest & digest
keeps us calm
dendrites function & structure
Connected to the soma (Cell body)
Receives the nerve impulse or signal from adjacent neurons
soma/body cell function & structure
Largest part of the neuron
controls metabolism and maintenance of the cell
axon function & structure
The fibre that carries information away from the cell body of a neuron, (electrical signals pass along)
myelin sheath function & structure
Insulates /protects the axon from external influences that might affect the transmission of the never impulse down the axon
axon terminals function & structure
junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron; tiny gap at this junction is called the synaptic gap
has buttons- terminal buttons have sacs that secrete a chemical called a neurotransmitter whenever electrical impulses are sent down the axon.
