Brain Anatomy

Question 1

Gray matter

Answer 1

○ Mainly consists of cell bodies
○ Forms convolutions of the brain (cerebral cortex)
○ In the center of the brain, beneath most white matter is another collection of gray matter (subcortex)
Consists of basal ganglia, limbic system, and diencephelon

Question 2

White matters

Answer 2

○ Mainly consists of axons and glial cells

Lies underneath gray matter

Question 3

Association tracts

Answer 3

Projections between cortical regions in the same hemisphere

Question 4

Commissures

Answer 4

○ Projections between cortical regions in different hemispheres
Most important commissure is the corpus callosum

Question 5

Projection tracts

Answer 5

Projections between cortical and subcortical structures

Question 6

Lateral/Sylvian Fissure

Answer 6

Fissure dividing the frontal and temporal lobes

Question 7

Insula

Answer 7

Island of cortex buried underneath the temporal lobes

Question 8

Brodmann’s Areas

Answer 8

Cytoarchitecture

Cortex divided into 52 areas based on relative distribution of cell types across cortical areas

Provides a way to link brain region to specific function based on neuronal composition

i.e. Motor areas have more motor neurons

Question 9

Basal Ganglia

Answer 9

• Part of the subcortex
• Large rounded masses in each hemisphere
• Surround the thalamus in the center of brain
• Involved in regulating motor activity and programming and termination of action, as well as learning of rewards, skills, and habits
§ When you first learn something, have to think about it a lot (cortex), but with practice, becomes relatively automatic (basal ganglia)

• Disorders result in motor disorders such as Parkinson's or Huntington's disease
• Contains caudate nucleus, putamen, and globus pallidus
	○ Caudate nucleus and putamen channel input into the globus pallidus, which connect to the thalamus

Question 10

Limbic System:

Answer 10

Subcortex
Involved in emotional response
Amygdala, cingulate gyrus, HPC, mamillary bodies, olfactory bulbs

Question 11

Diencephalon:

Answer 11

Subcortex

Thalamus, hypothalamus, lateral and medial geniculate nucleus (visual and auditory cortices)

Question 12

Midbrain:

Answer 12

• Superior Colliculi
○ Midbrain gray matter nucleus that integrates info from several senses (vision, hearing, touch)
• Inferior Colliculi
○ Midbrain gray matter nucleus that is specialized for auditory processing
• These pathways are different fro the main cortical sensory pathways and are evolutionary older
○ Provides a fast route that enables rapid response to stimuli before the stimulus is consciously seen or heard
• Substantia nigra
○ Connected to the basal ganglia
Cell loss in this region related to Parkinson’s

Question 13

Hindbrain

Answer 13

• Cerebellum
○ Important for dexterity, and smooth movement
• Pons
○ Links cerebellum and cerebrum
○ Receive info from visual areas to control eye and body movements
• Medulla Oblongata
Regulates vital functions such as breathing, swallowing, heart rate, sleep/wake cycle

Question 14

Neocortex- Layers 1-III

Answer 14

® Integrative functions

- Short range communication between one region of cortex to another

Question 15

Neocortex- Layer IV

Answer 15

◊ Info coming from sensory organs

- Areas important for sensory processing (i..e visual cortex) will have a large layer IV, small layer I-III

Question 16

Neocortex- Layers V-VI

Answer 16

® Descending output

-Long range communication (i.e. motor neurons)

Question 17

Mesocortex

Answer 17

Paralymbic region

Question 18

Allocortex

Answer 18

HPC