THE HUMAN BRAIN

• 3.5 pounds of gelatinous material at the root of everything we do/are

• Characterized by sulci (sulcus) and gyri (gyrus)

– sulcus—valley– gyrus—peak

• Divided into hemispheres—right and left—via the longitudinal fissure

• Cerebrum and cerebellum

• Cerebrum divided into four lobes

• Frontal lobe—thinking and motor movement• Parietal lobe—incoming sensory information• Occipital lobe—vision• Temporal lobe—memory and audition

• Right hemisphere from the left side

sulci and gyricorpus callosumthalamushypothalamuspituitary

medullaponscerebellumspinal cordamygdalahippocampus

Another way to talk about the brain is in terms of development.

ONTONGENY RECAPITULATES PHYLOGENY

HINDBRAINMIDBRAINFOREBRAIN

• HINDBRAIN—oldest part; buried deep in brain tissue; processes vital functions; consists of the medulla, the pons and the cerebellum

• MIDBRAIN—next oldest; processes visual and auditory information; consists of the thalamus and other smaller structures

• FOREBRAIN—newest part; cortex and limbic system structures; processes thinking, feelings and motor activity; consists of the four lobes, hypothalamus, amygdala, hippocampus and others

• THERE ARE 100 TRILLION NEURONS IN THE BRAIN

• WHAT IS A TRILLION?