Brain, Body and Behavior

Focus Questions

How do the different hemispheres of the brain function?

Where are significant parts of the brain and what are their functions?

How do neurons cue the body?

Where and what purpose do different glandular systems serve?

The Make-up of the Brain

Controls every thought, action and feeling – psychologists are interested in human behavior so must understanding the working of the brain

20% of oxygen, most of sugar intake (junky sugar, junky brain), 20 watts of electrical power

The Hemispheres:

Divided into two halves – depression in middle called the fissure

Right hemisphere controls left side of body and Left hemisphere controls right side of body

Midway down two halves is a bundle of fibers called the corpus

The Lobes Four major sections mid way from front to back is another fissure – marks boundary

between two lobes

Frontmost lobe – frontal lobe Remaining area – parietal lobe Frontal lobe has the motor strip – controls every part of the body that

is capable of moving Parietal lobe has the sensory strip – controls the feeling of sensations

in different areas (a pin prick on your leg, a poke on the arm, etc.) Back of the brain – occipital lobe – what we see ‘Thumb’ area – temporal lobe – major centers for hearing and some

related to speech There is a special circular spot that creates sentences – even

when ‘talking’ silently to ourselves For most people this is found only in the left hemisphere, 25% of

lefties have them in the right hemisphere

Brain sits in fluid to act as a shock absorber – when hit hard, brain sloshes around and occipital lobe hits skull, causing the electrical system to stir itself up and causes you to see strange images

The Frontal Association Front of the frontal lobe – heavily packed with nerve cells due to

complex task Interprets what is going on and tells us what to and to feel Forms the core a person’s personality Tries to make sense of the environment How developed tells how advanced the animal is – dog=7%;

chimp=15%; humans=30%

https://www.youtube.com/watch?v=kR7_oMSUBFE

Handedness and the brain 10% of population is left handed Small, fine movements tend to favor one hemisphere – dominant

and controls majority of actions Left-handers will probably be better at art, music and math

Famous left handers:many presidents, including G.W. Bus, Obama and Bill ClintonOprah WinfreyJimi HendrixBill GatesBabe RuthDa Vinci

Tasks of Hemispheres

Left: verbal and speech Right: objects in space, art, music, math and emotional material Work together in everything we do

Cerebral cortex: contain all parts already discussed Outermost layer of brain Controls very high-level thought 2/3 of the brain’s nerve cells – 100 BILLION of them Number of possible different connections the brain can make is

greater than the number of particles in the universe https://www.youtube.com/watch?v=z2iatKwQpSI

Lower Brain: keeps the body running Cerebral cortex fits over and around it (like bark on a tree) Basic functions – animal like lower units https://www.youtube.com/watch?v=9EazWtXzW8k

Other Terms to Know

Thalamus: oval mass of nerve cells; relay station to send incoming and outgoing messages

Cerebellum: looks like ball of yarn larger than a golf ball; hooks into base of brain below the occipital lobe; balance, coordination

Hypothalamus: below the thalamus; size of a large pea; control rage, pleasure, hunger, thirst and sexual desire

Reticular activating system (RAS): base of brain inside spinal cord; looks like a net; catches nerve impulses; regulates how sleepy or alert we are

Neuron: each nerve cell Dendrites: receive information form other nerve cells and sends it to

cell body Axon: carries message from cell to other neurons Synapse: space between axon and dendrites Vesicles: area where axon ends and before synapse – containers that

look like bubbles Neurotransmitters: transmit nerve information from the end of the axon

over the synapse to the dendrite receptor Most common is acetylcholine (ACH) – sends info whenever we

more a body part Dopamine: involved in motor functions or movement – Parkinson’s Endorphins: exist to relieve pain and increase our sense of well-

being; act as a natural form of morphine

Spinal cord: all nerve impulses enter and leave here Reflex: spinal cord activates movement before we even register it