THE PHYSICAL BRAIN
The Limbic SystemThe Limbic
System
Sitting below the cortex and above
the brain stem, the limbic system is a
collection of structures associated with
emotion, memory, and basic instincts.
Location and function
The limbic system is a cluster of organs
situated in the center of the brain,
occupying parts of the medial surfaces
of the cerebral cortex. Its major structures
form a group of modules that pass signals
between the cortex and the bodies of the
lower brain. Nerve axons link all of its
parts and connect them to other brain
areas. The limbic system mediates
instinctive drives such as aggression,
fear, and appetite, with learning, memory,
and higher mental activities.System parts
The limbic system’s components
extend from the cerebrum inward
and down to the brain stem.
It is usually understood to
include the structures
shown here.THE S-SHAPED
HIPPOCAMPUS IS NAMED
AFTER ITS RESEMBLANCE
TO A SEAHORSE
Fornix is a bundle of nerve
tracts that connects
hippocampus to thalamus
and lower brain beneathES
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MAMILLARY MIDBRAIN
BODIES
PAR AHIPPOC AMPAL
GYRUS
Involved in forming
and retrieving memories
associated with fresh
data from the senses,
the parahippocampal
gyrus helps us recognize
and recall things.The amygdala is most
associated with fear
conditioning, where
we learn to be afraid
of something. It is also
involved in memory and
emotional responses.The small mamillary bodies
act as relay stations for new
memories formed in the
hypothalamus. Damage
leads to an inability to
sense direction, particularly
with regards to location.Smell, which is
processed in the
olfactory bulbs, is the
only sense handled by
the limbic system and
not sent through the
thalamus.US_038-039_Limbic_system.indd 38 20/09/2019 12:32