The Brain

Early Brain Psychology 1800’s- German physician Franz Gall invented phrenology. He thought bumps on the skull could reveal mental abilities and character traits Today, neuroscientists study the effect of the brain on behavior.

Neuron- a brain cell

Neuron- a brain cell Dendrites Axon terminal Soma (Cell Body) Nucleus Myelin Sheath

Parts of the neuron Dendrites- receive messages from other cells Cell body (soma)- keeps the cell alive Axon- passes messages from the cell body to other cells Myelin sheath- fatty covering of the axon that speeds up the message Terminal branches- form junctions with other cells

How neurons communicate The dendrites receive a message from another neuron If the dendrites receive enough “yes” signals, the neuron sends an action potential down the axon http://www.childrenshospital.org/research/_neuron/index.html

How neurons communicate When the message reaches the terminal branches of the axon, they release a neurotransmitter into the synapse. The neurotransmitter attaches to the appropriate spots in the dendrites of the next neuron. http://www.youtube.com/watch?v=90cj4NX87Yk&feature=related

Things to know about neurons All or nothing principle- a neuron either fires or does not, no partial response Threshold- the level of stimulation required to trigger a neural impulse

Neurotransmitters Acetylcholine- enable muscle action, learning and memory Dopamine- influences movement, attention, and emotion Serotonin- affects moods and drives Norepinephrine- controls alertness and arousal Glutamate- major excitatory (YES) GABA- major inhibitory (NO)

Endorphins Feel-good neurotransmitters Endogenous “produced within” morphine Released to help reduce pain

Drugs Blood-brain barrier- a “fence” that keeps unwanted substances from the brain Drugs can either mimic or block the effects of neurotransmitters Mimic- brain may stop producing neurotransmitters Block- the signal doesn’t make it

The Nervous System Organs and glands Muscles Arousing Calming

The Nervous System Central Somatic Peripheral Autonomic Organs and glands Muscles Parasympathetic Sympathetic Arousing Calming

Types of Neurons Sensory- they sense the outside world Motor- they tell the body to move Interneurons- connect sensory and motor neurons

Definitions Neural Networks- groups of neurons that work together to perform a function Reflexes- automatic, inborn responses to sensory input

The Brain

The Brain Parietal Lobe Frontal Lobe Temporal Lobe Brain Stem Cerebellum Brain Stem

Brain Parts Frontal Lobe- thinking and reasoning Parietal Lobe- sensation and spatial thinking Temporal Lobe- hearing Occipital Lobe- sight Cerebellum- “little brain”, coordination and balance Brain Stem- automatic functions such as breathing

Limbic System

Limbic System Thalamus Hypothalamus Amygdala Hippocampus

Limbic Parts Thalamus- sensory control switch Hypothalamus- drives (eating, sleeping, drinking) Hippocampus- memory Amygdala- emotion

Association areas- connections

Definitions Plasticity- the ability of the brain to change itself Unused areas get taken over and reengineered to do something new Corpus Callosum- the neural fibers that connect to the halves of the brain

Hemispheres Left Right Right side Speech Rational Thinking Literal Comprehension Left side Emotion Creativity Subtle Inferences

Endocrine System Hypothalamus Pituitary gland  all other glands (esp. adrenal glands)