CNS or PNS
Includes the brain and spinal cord.
CNS
Receives incoming signals.
Dendrite
Responsible for balance and coordination.
Cerebellum
Sleep stage where dreaming happens.
REM sleep
Number of cranial nerve pairs.
12
Includes cranial and spinal nerves.
PNS
Sends signals away from the cell body.
Axon
Relay station for sensory information.
Thalamus
Sleep stage important for physical recovery.
NREM sleep
Cranial nerve for smell.
Olfactory (I)
Carries sensory information to the brain.
PNS (afferent division)
Fatty insulation that speeds conduction.
Myelin
Controls temperature, hunger, water balance.
Hypothalamus
Temporary holding area for information.
Short‑term memory
Cranial nerve that controls internal organs.
Vagus (X)
Integration and command center.
CNS
Neurons that carry impulses to muscles and glands.
Motor (efferent) neurons
Controls breathing, heart rate, and survival functions.
Brain stem
Permanent storage of information.
Long‑term memory
Fluid that cushions the brain and spinal cord.
Cerebrospinal fluid (CSF)
Can regenerate if damaged (as long as the cell body survives).
PNS
Neurons that connect sensory and motor neurons.
Interneurons (association neurons)
Outer layer responsible for conscious thought.
Cerebral cortex
Memory for skills like riding a bike.
Non‑declarative (procedural) memory
Disorder where myelin in the CNS is destroyed.
Multiple sclerosis (MS)