The human brain

An extension of thespinal cord which hasbecome bigger andbigger as the specieshas evolved.

Cerebral hemispheres

Corpus callosum

Cerebrum (Latin: "brain”):Largest part of the brain.

Cerebellum (Latin: "little brain"):Coordination and control of voluntarymovement

Brain stem:breathing, heartbeat, and bloodpressure

Gross generalizations about function

Frontal lobe: decisions, judgments,

problem solving, emotions.

Temporal lobe: perception, recognition,

many aspects of language

Parietal lobe: movement, orientation,

recognition, perception ofstimuli

Occipital lobe: vision at large

Cortex- about two millimeters thick and has a total surfacearea of about 1.5 square-meters

Blown-up cortex

Subcortical structures: thalamus and thebasal ganglia

Thalamus: Receives and organizes

sensory information fromthe sensory organs

Regulates sleep andwakefulness (during sleepthe thalamus is closed. i.e.,does not take input fromsensory organs).

Subcortical structures: thalamus and thebasal ganglia

Basal ganglia: Caudate nucleus, putamen,

globus pallidus

E.g., voluntary movement

Amygdala: emotion, memory

Corticallayers

Cytoarchitectonics:the arrangement ofnerve cells in thecerebral cortex

Korbinian Brodmann, (1868 - 1918)

Defined the cerebral cortex into 52 distinctregions on the basis of theircytoarchitectonic characteristics.

Brodmann’s areas

Brodmann’s areas

Homunculus

The mind/brain view of the body

Brain lingua

Brain lingua

Brain lingua

Bilateral - On both sidesIpsilateral - On the same sideContralateral - On the opposite side

Neurons

Central nervous system ismade up of about 100billion neurons.

Unlike other cells in thatthey can both receive andsend out signals toneighboring neurons in theform of electrical pulses.

Neurons

Typically a given neuron isconnected to about tenthousand other neurons.

The specific point ofcontact between the axonof one cell and a dendriteof another is called asynapse.

Neurons

We are born with a complete set of neurons. What changes in maturation is the connections

between the neurons. On average, we lose about 20% of our neurons

by the time we die.

Neurons

http://www.dnatube.com/video/1107/Neurons-and-How-They-Work

Grey and white matter

Grey matter cortex

unmyelinated nerve cells

White matter myelinated nerve cells

the tissue through which

messages pass betweendifferent area of grey

matter

How fast is the brain?

After a neuron has fired, it takes it about onemillisecond to return to its normal state.

Much slower than your computer! The secret of the brain lies in the vast number of

neurons (tens of billions) and the complicatedway they are connected.