Lecture 2b (Sullivan): CNS: Sensory, Motor, and association areas, limbic

Question 1

Ancient origins of the Brain

Answer 1

telencephalon used to be olfactory dominated:”rhinencephalon”

primordial cortex was 3 layers
then neopallium or new-cortex has 6 layers

Question 2

cerebral cortex composition

Answer 2

mostly 6-layered neocortex
2-3mm thick
80% of brain mass
2.5 sq ft in area

gray matter consists of cell bodies and proximal dendrites while underlying white matter

Question 3

cerebral cortex FUNCTION

Answer 3

perception and conscious understanding of all sensations and integration of sensory modalities

higher cognitive functions

emotion personality intellect

planning and executing complex voluntary motor activities

anterior expressive
posterior receptive

Question 4

state the location of the following cortical (cortex) landmarks:

1. somatosensory cortex
2. motor cortex
3. auditory cortex
4. visual cortex

Answer 4

1. Post central gyrus
2. pre-central gyrus
3. transverse gyrus, area 41, 42
4. cortex surrounding the calcarine sulcus - area 17

Question 5

Two main early neuroscientists who used histological examination to figure out structure of cortex

Answer 5

Golgi and Ramon y Cajal

Question 6

Six layers of the Neocortex differ in what ways (3)

Answer 6

1. Cell types
2. Density of cell packing
3. Myeloarchitecture

Question 7

MI primary motor cortex

vs.

SI primary sensory cortex

Answer 7

Motor: LARGE (cortical) layer 5, small layer 2,3,4 (long projections=big neurons)

Sensory: LARGE layers 2,3,4, and small layer 5 (Big receptive fields)

Question 8

layers of cerebral cortex from superficial to deep

Answer 8

( 6 Gray Matter Layers:)
molecular
ext. Granular
ext. Pyramidal
int. Granular
int. Pyramidal
multiform/fusiform

(then it’s white matter)

Question 9

molecular layer 1 contents

Answer 9

apical dendrites of pyramidal cells

Question 10

ext. granular layer 2 contents

Answer 10

recipient zone of diffuse thalamic projections (intralaminar nuclei) AND other subcortical nuclei (basal forebrain, brainstem, and hypothalamus)

Question 11

ext. pyramidal layer 3 contents

Answer 11

cortico-cortical projections

Question 12

int. granular layer 4 contents

Answer 12

recipient zone of precise, topographically organized projections from specific thalamic nuclei

Question 13

int. pyramidal layer 5 contents

Answer 13

principal output layer to subcortical targets