Biology of the Brain - Glossary
- The `cable' for outgoing signals. It may be up to one
meter in length.
- Brain stem:
- The oldest part of the human brain sharing many
features in common with the reptilian brain. Basic functions
such as heart rate and breathing are controlled here.
- The structure which overlies the midbrain and brain stem
and is common to all mammals.
- The most striking feature of the human brain. A folded
hemispherical sheet covering the cerebrum. Most high level
brain function takes place here.
- The `cables' which deliver electrical signals to a neuron.
Typically each neuron possesses tens of thousands. They are
usually only one hundred thousandth of a meter in length.
- The frontal lobes:
- The frontal part of the cortex associated with reasoning
- Part of the limbic system. The hippocampus plays a crucial
role in laying down long term memories.
- Left and right hemispheres:
- The cortex is roughly symmetric between left and right sections
called hemispheres because of their shape. The left hemisphere
is associated with the right side of the body and vice versa.
Usually the left hemisphere dominates as it contains the centers
for language and reasoning.
- Medulla and cerebellum:
- Part of the brain stem
- Contains the thalamus, hypothalamus and the limbic system.
The latter which is alike in all mammals consists of a number of
interconnected structures relating to drives, hormones and emotion.
- Motor Cortex:
- The region of the cortex close to the parietal lobes
concerned with voluntary muscle movement.
- Neural pathways:
- The set of networking connections between neurons which
are responsible for brain activity. There are something like
ten million million such pathways in the brain.
- Neurons are the nerve cells which make up the central
nervous system of which the brain is the major part. The consist
of a nucleus, a single axon which conveys electrical signals to
other neurons and a host of dendrites which deliver
- A complex molecule which acts as a chemical messenger for
conveying electrical signals between neurons at synaptic points.
- Occipital lobes:
- The rear section of the cortex associated with the visual
- Parietal lobes:
- A section of the middle of the cortex which contains a
schematic map of the body's surface.
- An example of an neurotransmitter. Used in regulating
aggressive behavior. Other examples are dopamine and
- The junction of an axon of one neuron and a dendrite of
another. The passing of a signal across this gap is mediated
by neurotransmitter chemicals.