Unit Two: Biological Bases of Behavior AP Psychology Ms. Egan

The Biology Behind the Psychology “Everything Psychological is ultimately Biological.” – What does this say to you?

Neurons: building blocks of the Nervous System

Neural Communication Action potential: a neural impulse Threshold: minimum intensity needed to fire impulse Neuron firings are all-or-none responses Synapse: gap between neurons (also called a synaptic gap or cleft) Neurotransmitters: chemical messengers that bind to receptor sites on receiving neuron Reuptake: sending neuron reabsorbs excess neurotransmitters

Demonstrations Action Potential Synaptic Transmission

Types of Neurons Sensory Neurons (afferent) ~ 2 million – Sends messages from sense organs  brain Motor Neurons (efferent) ~ 2-3 million – Sends messages from brain  muscles, organs, glands Interneurons ~ Billions & Billions – Relay messages between sensory & motor neurons Glial cells – “The forgotten cell” – Glue cells which help connections, insulate, and clean up

Influence of Neurotransmitters Each neurotransmitter has a specific effect on behavior & emotions Acetylcholine: muscle action, learning, memory Dopamine: movement, learning, attention, emotion Serotonin: mood, hunger, sleep, arousal Norepinephrine: alertness, arousal GABA (gamma-aminobutyric acid): inhibitory neurotransmitter Glutamate: excitatory neurotransmitter, memory Find a condition or disease associated with the blockage or increase in one of these neurotransmitters.

Drugs & Neurotransmitters Endorphins: natural “opiates” released in response to pain or vigorous exercise Why not flood the brain with artificial opiates?? – Brain will stop producing natural ones – Withdrawal symptoms Drugs affect communication at the synapse – Agonist Molecule: excites, mimics neurotransmitter – Antagonist Molecule: inhibits, blocks neurotransmitter

Neuron FAQ’s 100 Billion neurons in the human body – It would take you 3,171 years to count all the neurons (1 per second) Microns wide (1 micron=1/1000 th of a millimeter) Your neurons are for life! You will have less and less as you get older

Central Nervous System Brain & Spinal Cord Peripheral Nervous System Somatic (Skeletal) Autonomic (Internal Organs) Sympathetic (Arousing) Parasympathetic (Calming) (Links CNS with muscles, glands, sense receptors) The Nervous System Nerves: neural cables containing many axon Neuron to neuron communication

Endocrine System Slower than nervous system Uses hormones (another chemical messenger) to communicate Flow from tissues through bloodstream to other tissues Adrenal glands: above kidneys; secrete hormones to arouse body during stress Pituitary glands: controlled by hypothalamus, regulates growth and controls endocrine glands

The Brain How does our brain produce behavior and mental processes?

What’s a brain good for anyway? Case Study: Phineas Gage

Which part of the brain did Gage injure? Why did Gage feel no pain after the injury? What were the “treatments” given to Gage after the injury? What was the major change in Gage after the accident? What is localization of the brain?

Studying the Brain Electroencephalogram (EEG) – Measures brains electrical waves by attaching electrodes to the scalp Positron Emission Tomography (PET Scan) – Injection of radioactive glucose (brain sugar) to detect where fuel goes under different situations Magnetic Resonance Imaging (MRI) – Magnet aligns spinning atoms of brain to show tissue and brain anatomy Functioning MRI (fMRI) – Shows brain function & bloodflow

Brain Structures Brain Map (BBC) OR 3-D Brain (PBS) Brain Map3-D Brain Using the Brain Links, complete your brain concept map. Give an example of how each structure influences your behavior or emotions: YOU SHOULD KNOW THE FOLLOWING!!! BrainstemPonsMedulla Oblongata MidbrainCerebrumFrontal Lobe Cerebral CortexParietal LobesThalamus Occipital LobesTemporal LobesCerebellum Limbic SystemAmygdalaHypothalamus Pituitary GlandHippocampusCorpus Callosum

Split Brain Each brain hemisphere serves a different purpose Vogel & Bogen (1961) – Stop seizures by splitting corpus collosum – Sperry, Myers, Gazzaniga were successful with animals – HE-ART Split Brain Demo

Right vs. Left Brain

We only use 10% of our brain Your brain does not grow new cells Some people are right-brained, others left-brained Brain damage cannot be repaired