Human brain is similar to other mammals in terms of organization.
Cerebellum – sensorimotor integration
•Allows you to stand up on 2 legs, erect – balance
•Damaged cerebellum – you look drunk
Medulla – basic life processes
-not where you wanna have a stroke
Reticular formation – many nuclei
-damage causes coma – the brain doesn’t wake you up
Forebrain – most of the mass of the brain, favoured by evolution
-Thalamus – major relay centre, particularly in humans & higher mammals
who have a huge neocortex. Info goes thru thalamus, which sends it into
-Hypothalamus – life functions, but not primitive. Anything that feels good
(drugs too). Controls thirst, hunger, territoriality, sexual behavior. Four F’s of
-Limbic system – amygdala, hippocampus, cingulate cortex, hypothalamus
deals with emotions
-Cerebral cortex – the most anterior and newest structure; aka neocortex.
Higher intellectual functions: speech, reasoning, intelligence,
university stuff – specific to humans
We’re not absolutely the most involved. If I were a bird, and I were to construct an
evolutionary tree, I’d put birds at the top: well, look at humans, they can’t even fly! What
Animals under environmental pressure developed nuclei in their anterior portion of the brain.
These bumps were associated with a particular pathway – skin, vision, etc, and helped with
survival, since it helped with info processing. Forebrain is different in size in diff. animals;
humans have a huge cerebral cortex (dolphins have larger cortex to body ratio).
Humans depended heavily on the evolution of the neocortex.
Size of the structure is directly related to use and importance of the function in that particular
species, e.g. rat’s olfactory bulbs.
Ontogeny recapitulates phylogeny – what an individual goes through ontogenetic
development is similar to what we go through in the evolution of species.
-humans have gill slits, tail, mammary glands all the way down the body,
embryonic fluid resembles sea water.
-This is also true for the brain: very anterior in early development, then it
moves back over the cerebellum, then it begins to fold.
-It turns from lissencephalic to gyrencephalic
The highest structures in the brain are usually the most anterior and newest structures.