Organization of Nervous System
The brain and spinal cord together make up this system.
CNS
The flat bone that protects the brain.
Cranium
This lobe is primarily responsible for vision.
Occipital
The branch-like structures that receive incoming signals.
Dendrites
The resting membrane potential of a neuron (approximate value).
-70 mV
All nerves outside the brain and spinal cord belong to this system.
PNS
The structure that divides the brain into left and right hemispheres.
Longitudinal fissure
This lobe processes sound and contains the auditory cortex.
Temporal
The long “tree trunk” that sends impulses away from the cell body.
Axon
The membrane voltage at which an action potential is triggered.
-55 mV
The PNS is divided into these two major subdivisions.
Somatic & Autonomic
These "peaks" increase surface area for higher-level processing.
Gyri
This lobe handles decision-making, personality, and emotional regulation.
Frontal
The insulating layer that speeds up nerve impulses.
Myelin sheath
The phase where Na⁺ rushes into the cell.
Depolarization
This subdivision of the PNS controls involuntary actions like heart rate and digestion.
Autonomic Nervouse System
These "valleys" separate gyri and allow for increased brain folding.
Sulci
This lobe processes touch, taste, and body position.
Parietal
The tiny gap where neurotransmitters cross between neurons.
Synapse
The phase where K⁺ exits the cell, restoring negativity.
Repolarization
Explain why damage to the PNS might not affect thinking but could affect movement or sensation.
CNS = processing; PNS = signal transmission
Predict how damage to gyri would affect brain function compared to damage to sulci.
Loss of processing surface vs. separation/folding issues
A patient struggles with impulse control and planning—what lobe is likely damaged, and why?
The frontal lobe controls executive function.
Explain how myelin loss would affect reaction time and why.
Slower conduction due to signal leakage
Why does hyperpolarization occur after an action potential, and how does it protect the neuron?
Prevents continuous firing; ensures one-way signaling