How the Brain Works The Facts Visually Explained by DK (z-lib.org)

30

THE PHYSICAL BRAIN

The Cortex 31

Parietal cortex

combines

information

from senses to

orientate body

Somatosensory

cortex processes

sensory

information

Vision-related

Brodmann areas

extend from

lateral surface to

medial surface

Premotor cortex

plays a role in

planning movement

Occipital lobe

mainly devoted to

visual processing

Wernicke’s area is

involved in language

comprehension

Broca’s area is associated

with learning language

(s e e pp.126 –27)

LA

TE

RA

L^ S

UR

FAC

E

Brodmann areas

This functional map of the brain is based on

research carried out by neuroanatomist Korbinian

Brodmann, who linked cells by similarities in their

size, shape, and connections. There are 52 regions

in total, and each one can be associated with one

or more approximate functions.

CORTICAL LAYERS

Cell structure

The cells of the human cortex are

arranged in six layers, with a total

thickness of 0.09 in (2.5 mm).

Each layer contains different

types of cortical neurons that

receive and send signals to other

areas of the cortex and the rest

of the brain. The constant relaying

of data keeps all parts of the brain

aware of what is going on

elsewhere. Some of the more

primitive parts of the human

brain, such as the hippocampal

fold, have only three layers.

Layer 4 is linked to

corpus callosum, brain

stem, and thalamus

Layer 3 receives inputs

from other cortical areas

Layer 2 contains a mass

of cortical neurons

Layer 5 cells extend

beneath cortex

Layer 6 sends signals

back to thalamus

THE CORTEX

CONTAIN S

AROUND

28 BILLION

NEURONS

Molecular

External granular

External pyramidal

Internal granular

Internal pyramidal

Multiform

To thalamus White matter

To brain stem

and spinal cord

To opposite

hemisphere

Layer 1 receives

inputs from thalamus

PRIMARY

MOTOR

CORTEX

PARIETAL

CORTEX

ASSOCIATIVE

VISUAL

CORTEX

WERNICKE’S

AREA

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