The Brain

Its parts and functions

The Major Parts Left and right hemispheres Four Lobes to a brain

Frontal Parietal Occipital Temporal

The Two Hemispheres

Left and Right Hemispheres Each controls the other half of the body (left

controls right and vice versa) Most people are Left Dominant

Thus right handed

Ambidextrous? Nobody is really sure how we get that way

What are their jobs? BOTH WORK TOGETHER

Connected by the corpus callosum Thick bundle of nerve fibers tying the two sides

together When Separated we find the following:

Left Hemisphere Verbal or Speech issues (grammar, structure)

Right Hemisphere Imagery, Art, spatial issues, music, some math, emotion (why many lefties in Hollywood?)

The Frontal Lobe Contains the “motor

strip” controls the body’s

movements Frontal Association

Area High level thinking,

personality, planning, problem solving, stringing together ideas into a complete whole

The Frontal Lobe - Continued

The Motor Strip Part of frontal lobe Controls movement of the body

The Parietal Lobe

Contains the sensory strip Controls perception of touch, temperature,

pressure, pain

The Occipital Lobe

Back of the brain Deals with vision

The Temporal Lobe

Area that deals with hearing Also deals with memory

“Layers” of the Brain

Cerebral Cortex Outer layer – the “higher brain” Contains most of the cells Controls higher level thinking.

The real “human” part of the brain

Layers of the brain

The Lower Brain areas Control automatic bodily functions (breathing,

blinking, walking, etc) Control instinctual functions (fight, flight, sex

drive, hunger etc)

Thalamus, Cerebellum, Hypothalamus, Reticular Activating System

Lower Brain Areas

Thalamus The relay station or “telephone operator” of

the brain. Signals come in and the Thalamus sends

them out to the correct part of the brain to be handled

Lower brain areas

Cerebellum Back, bottom of brain Coordination, internal “mapping” awareness

of where we are in space Walk down stairs without looking. How does your

foot know where to go?

Lower Brain areas

Hypothalamus Controls basic instincts

Anger, sex, hunger, pleasure

Very small (size of a pea)

What happens when you over stimulate the “eating portion of the hypothalamus

Lower brain areas

Reticular Activating System Determines time for sleep or wake ADD believed controlled by this area

Never gets the message that it is time to relax

Neurons

Brain cells A “web” of cells that carry

info,make associations, control our body

Main parts Cell Body, Dendrites,

Axon

How they Communicate

Neurons do not actually touch Space between neurons (called a

“synapse) is “Jumped” by chemicals that transmit signals. Every type of signal has a different chemical Carries signal to next neuron and so on …

Some of the neurochemicals we know a bit about

Dopamine (see the movie “Awakenings”) Endorphins (the body’s own painkillers or

“feel good” chemicals) Serotonin – helps put us to sleep, relax etc

Getting to the rest of the body

Signals then travel down spinal cord to the body and along the nervous system

Other – non brain parts

Endocrine System Various glands that produce chemicals for various

reasons Adrenal gland – controls release of adrenaline

“superman” chemical Pituitary gland – controls the other glands

Growth, aging, Thyroid – found in throat.

Controls metabolism, how the body uses, stores, expends energy

Gonads – sex organs Androgen – men Estrogen – women Control instinctual sex drive – though humans are not

instinctual.