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.
MacLean’s Triune theory of function – there’s 3 basic components to the human brain
-Reptilian brain – the brain stem; ability to breathe, eat, have sex, etc. Basic
functions at the level of reptiles.
-Old (paleo) mammalian brain – limbic system; emotions
-Neo mammalian – cortex; higher intellectual functioning
We still have the same behaviors – territoriality, sex, food, etc.
There’s a primary and associational cortex in every lobe.
Associational cortex – processing and integrating info; e.g. oh that’s a human’s face, or a
-The most recent cortex; present in the most advanced species in greater ratios
relative to primary cortex
-“More computer power”
Brodmann – mapped the brain according to its function and numbered the areas
-know numbers for primary cortices
-e.g. area 17 – visual.
-Area, 1,2,3,4,6, 41(speech/hearing) – primary receptive areas
Frontal – controls motor movement
-anterior part controls planning
-inhibiting inappropriate behavior
-primary area is called “motor strip” – precentral gyrus, area 4,6
-organization is not random - homunculus
-As you move further anterior away from primary, it becomes association, and
involves much more complex stuff like planning.
Parietal – not clearly marked from occipital
-somatosensory input – receives info from body’s non-specialized senses (skin)
-primary area: post central gyrus, 3,1,2, primary somatosensory strip
-somatosensory homunculus – involved not in twitching, but sensation of
touch, pain, temperature
Occipital – receives info from eyes
-primary visual receptive area, area 17
Temporal – area 41, primary auditory cortex
-it’s all spinal cord at first; then the anterior part gets bigger and ventricles
-III ventricle – deep inside the thalamus (diencephalon)
-comes from 2 carotid and 2 vertebral arteries (connect to form basilar artery)
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 circadian rhythms 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 appropriate places. Hypothalamus life functions, but not primitive. 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. 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!