The Biological Perspective Chapter 2

The Nervous System Neurons – basic cell that makes up the nervous system and that receives and sends messages within that system

The Neuron Dendrites – branchlike structures that receive messages from other neurons The dendrite is connected to a soma – or a cell body of the neuron responsible for maintaining the life of the cell

The Neuron Axon – fiber attached to the soma and carries the neural message to other cells Myelin – fatty substances that coat the axons of neurons to insulate, protect, and speed up the neural impulse

Depolarization Electrical charge – like dominos falling Action potential – impulse is now in action rather than at rest Each action potential sequence takes about one-thousandth of a second 2 miles per hour to 270 miles per hour Hands - slaps

The Neuron Axon terminals – branches at the end of the axon At the end of the axon terminals, there are synaptic vesicles – saclike structures found inside the synaptic know containing chemicals

The Neuron Neurotransmitter – chemical found in the synaptic vesicles that, when released, has an effect on the next cell The synapse reaches the end of the nerve, and sends the neurotransmitters through little locks called receptor sites

Central Nervous System (CNS) Brain and Spinal cord Life-sustaining functions of the body – also thought, emotion, and behavior Without each other, they would be useless

Peripheral Nervous System All the nerves and neurons that are not contained in the CNS Communicates with the eyes, ears, skin, and mouth

Divisions of the PNS Somatic Nervous System – skeletal muscles, voluntarily Autonomic Nervous System – not voluntarily control – breathing digestion, heart rate, hormones

Fight or flight response Anything that gets your heart pumping – autonomic arousal VIDEO

Endocrine Glands System of ductless glands that secrete their chemicals directly into the bloodstream for fast distribution Endocrine glands secrete chemicals called hormones (“to excite”) Project then quiz

Studying the brain How do we study it? Brain-dead people Animals – anesthetized Deep lesioning – inserting a thin, insulated wire into the brain and sending an electrical current that destroys brain cells

Safer ways to study CT scan – computed tomography – mapping MRI – Magnetic resonance imaging – 3D PET scan – radioactive glucose to detect activity Page 55

Neuroplasticity The brains ability to constantly change both structure and function of many cells in response to experience or trauma Old ones die or are damaged, the brain can adapt and form new functions

Neuroplasticity leads to… Stem cells – special cells found in all the tissues of the body that are capable of becoming other cell types when those cells need to be replaced due to damage or wear and tear Found in organs, bone marrow, placentas Very controversial – video - edmodo

What does each part of the brain do!? Hypothalamus Hippocampus Medulla Thalamus Cerebellum Cerebral cortex Corpus callosum

How does the left differ from the right?! Class demonstration Both have four lobes

Mirror Neurons Read page 64 Answer Discuss Quiz

DNA 23 + 23 = 46 Dominant and recessive Predispositions – not guaranteed, but a possibility Look at your family tree…

Hitler Was Hitler born that way, or did something happen to make him the person he was?

Nature vs. Nurture Nature – genetic traits and inherited characteristics Nurture – the environmental factors that surround us throughout our lives and influence our development Class demonstration discussion page 69

What influences you?

Siblings Are you different than your siblings?

Twins Read of James Lewis and James Springer on pg 68 Adoption studies – more than 20 years found that adopted children share more similarities with their biological parents than their adoptive parents Class demonstration page 68

Charles Darwin Evolution Quiz Evolution Natural Selection – traits and behaviors that provide a survival advantage are more likely than other characteristics to be passed on to future generations