Week 3 Objective 1: Brodmann's areas

Question 1

Brodmann’s Areas

Answer 1

primary somatosensory area is made from Brodmann’s areas 1, 2, 3

somatosensory association areas are made up of Brodmann’s areas 5 and 7

Question 2

Route to somatosensory area

Answer 2

primary sensory neuron —> spinal column + secondary neuron —> thalamus + tertiary neuron —> brain or brainstem

Question 3

Bilateral excision of this area causes

Answer 3

loss of ability to differentiate sensations in parts of the body.

inability to judge critical degrees of pressure against the body

inability to weigh objects

inability to judge shapes or forms (asteroreognosis)

inability to judge texture of materials

so pain and temperature preserved but poorly understood

Question 4

Somatosensory area II

Receives signals from

Answer 4

brain stem (from both sides) 
visual and auditory 

projections from somatosensory area I are necessary, but not the other way around

Question 5

Layers of somatosensory cortex (I, II, III, V, VI)

Answer 5

I and II : receive input signals from lower brain centers

II and III: send information through corpus callosum to opposite hemisphere

V and VI (deepest layers): large neurons in layer V project to distant areas such as basal nuclei, brain stem, spinal cord; axons from layer VI project to thalamus