Organization of the Brain

Question 1

Slices of the brain

Answer 1

Coronal - view from front
Horizontal - view from top
Sagittal - view from side

Question 2

General areas of the brain

Answer 2

Posterior - back
Anterior - front
Dorsal - top
Ventral - bottom
Medial - towards center
Lateral - towards sides
Bilateral - both sides

Question 3

Triune brain

Answer 3

Theory of three brains - the reptilian (oldest), the Limbic system (old mammalian), the Neocortex (what makes us human

Question 4

Two hemispheres

Answer 4

Completely separate except for the connection via white matter tract known as corpus callosum

Question 5

Four lobes of the brain

Answer 5

Frontal lobe - largest in humans; damage can result in mood changes, social differences
Parietal lobe - integrates sensory information, visualspatial processing, attention
Occipital lobe - sense of sight; lesions can lead to cortical blindness
Temporal lobe - sound as well as processing of stimuli like faces and scenes; medial part involved in memory and emotion

Question 6

Brodmann areas

Answer 6

Brain split into areas based on differences in cytoarchitectonic architecture

Question 7

Talairach coordinates

Answer 7

x, y, z coordinates to locate more specific areas of the brain (x is sagittal, y is horizontal, z is coronal).

Question 8

Gyri and sulci

Answer 8

Gyri are high points in folds of neocortex; sulci are dips.

Question 9

White matter tracts

Answer 9

The means by which the brain is connected. Three superhighways of connection: the arcuate fascicles (temporal parietal junction), corpus callosum, corticospinal tract (motor cortex to the spinal cord; contains mostly motor axons)

Question 10

Dorsal pathway

Answer 10

“Where” pathway: runs from the visual cortex over the parietal cortex and forward to the pre frontal cortex. Spatial reasoning and guidance of actions

Question 11

Ventral pathway

Answer 11

“What” pathway: runs ventrally from the visual cortex to the temporal lobe and frontal cortex. Involved in object processing.

Question 12

Areas for language

Answer 12

Broca’s area (inability to speak if injury to this area); Wernicke’s Area (lesions -> inability to understand words)

Question 13

Areas for memory and attention

Answer 13

Hippocampus - lesions result in amnesia

Parietal cortex - plays a role in switching our attention

Question 14

fMRI

Answer 14

Based on two concepts: takes energy (oxygen and glucose) to think); magnetic properties of oxygenated and deoxygenated blood are different
MRA scanner -> stimulus -> process data -> brain images

Question 15

PET scans

Answer 15

Positron Emission Tomography uses small amounts of radio labeled biologically active compounds. Introduced to body; PET scanner shows distribution of the tracer in body.
Tracer injected -> cyclotron -> stimulus -> process data -> brain images

Question 16

PET vs fMRI

Answer 16

PET - Ad. can tell what neurotransmitters are being used. Dis. slow (need 2 min blocks)
fMRI - Ad. faster and can detected wquick responses. Dis. don’t know what transmitters used. Dis. Magnetic.