Ch. 3– Brain Communication, Central Nervous and Endocrine System Goals: Describe a nerve cell and summarize its role in brain/body communication. Analyze central nervous system and peripheral nervous systems.

Biological Psychology Branch of psychology concerned with the links between biology and behavior- focuses on the structure of the brain, and the nervous, and endocrine system. Biological psychologists call themselves behavioral neuroscientists neuropsychologists behavior geneticists physiological psychologists biopsychologists

The Nervous System The electrochemical communication system of the body Brings information to the brain from the senses Sends messages from the brain to the body for movement

Brain Communication Neuron – nerve cell- building block of brain- receives, carries and passes on information Dendrite- message receptors Axon-passes messages away from cell to other neurons Soma – main cell body where nucleus is- determines health of the neuron Myelin Sheath – covers the axon and helps speed up the impulses Terminals – End of axon- these form junctions with dendrites of other neurons for passage of nerve pulses

Neurons Neurons “fire”—send an impulse down their length—or they don’t “fire” Neurons come in a variety of shapes, sizes, etc. All or None principal … like a toilet. Whether it is tasting fresh baked chocolate chip cookies, experiencing your first kiss, being tickled or suffering from depression… all begin with neurons either firing or not firing. Neurological disorders: MS, Parkinson’s, Lou Gehrig’s… Variety of shapes, sizes, but all have similar structure. Very short to a meter long ( in legs)

Neural Communication (#2) Action Potential A neural impulse A brief electrical charge that travels down the axon of the neuron. Considered an “on” condition of the neuron Generated by the movement of positively charged atoms in and out of channels in the axon’s membrane

Refractory Period The “recharging phase” when a neuron, after firing, cannot generate another action potential Once the refractory period is complete the neuron can fire again

Resting Potential The state of a neuron when it is at rest and capable of generating an action potential The neuron is set and ready to fire

All or None Principal The all-or-none law is the principle that the strength by which a neuron responds to a stimulus is independent of the strength of the stimulus. As long as there is enough energy to trigger the cell, it will give a complete response; otherwise, there is no response.

Brain Communication Synapse- fluid filled gap between neurons Neurotransmitter-chemical messengers between neurons- can either trigger or inhibit impulses (action potentials) (Know the three mentioned in the text on p.128)

Neural Pulse Demonstration Think Pair Share Share one thing you learned and one question you have about the neural impulse If you can, help each other out in answering your questions. Neural Pulse Demonstration

Central Nervous System Central Nervous System -Two main components: the Brain and the Spinal Cord BRAIN- main information processing center SPINAL CORD- main pathway for information in and out of brain Reflexes- neural impulses that are initiated by the spinal cord without involving the brain.

Peripheral Nervous System -Two parts – Somatic and Autonomic Somatic Nervous System- functions- Motor nerves that are activated voluntarily, large muscle group movements initiated by you. Autonomic Nervous System- movements and actions that happen without you conciously thinking about them – 2 parts -Sympathetic- triggered by threats challenging situations (fight or flight) these actions prepare you for an emergency response (giant automatic on switch) -Parasympathetic- this response is designed to calm you down and return you to your “normal” – (automatic off switch)

Endocrine System Hormone Glands Know four major glandular systems and their functions Pituitary- (growth hormone) Thyroid- (metabolism) Adrenal- (adrenaline) Gonads- (androgen & estrogen)