Good Morning! Think of the most physically challenging thing you’ve ever done. When you completed the task, how did you feel?

How the human brain works! Part I: Neurons and the synapse

The Nervous system All human actions are controlled by the nervous system Walking, feeling pain, making a decision, remembering an answer to a test question Broken down into two parts central nervous system peripheral nervous system

Nervous system Central Nervous System: Brain and spinal cord Peripheral Nervous System: Nerve cells that send messages between the CNS and the rest of the body

Communication Neurons: The nerve cells that run through our entire body sending messages to and from the brain (they communicate). Each of us have more than 100 billion, the majority of which are found in our brain

Parts of the Neuron Cell body: produces the energy that the cell uses to function Dendrites: Fibers that branch out from the cell body and receive information from other neurons (they look) like tree branches

Parts of the Neuron Axon: carries messages away from the cell bodies Can be .23mm Can be 3 ft. Myelin Sheath: fatty wrapping along the Axon that makes messages go faster Axon Terminal: Where messages are sent from the axon to the dendrites of other Neurons

The synapse Synapse: The spot where nerve signals jump from the axons of one neuron to the dendrites of another Neurotransmitters: The axons release neurotransmitters that bind to receptor Remember the Synaptic gap!

Neurotransmitter Notes Neurons send messages across synapses through the release of neurotransmitters. Chemicals that are stored in sacs in the axon terminals Neuron fires (sends message) by releasing neurotransmitters Fire 100’s of times/second. Neuron’s fire to each other until the message arrives at its destination.

Acetylcholine - ACh Assta-ko-leen Found… Effects… In both Central NS & Peripheral NS Muscles of the gastro-intestinal system Effects… Activates muscles Causes muscles to contract Slows the heart rate Induces REM sleep

Norepinephrine – Norepi or NE Also called Noradrenaline Found… Adrenaline Glands All over the brain (Thalamus, amygdala, hippocampus, etc…) Effects… Increases heart rate, brain’s oxygen supply, blood flow & blood pressure When released in the brain it affects attention and arousal

Dopamine Found… Effects… In the brain released by the hypothalamus. Controls muscle sensation & motor behavior Social anxiety, increased heart rate & blood pressure Important role in behavior and motivation, punishment, reward, & movement Deficiency levels plays role in Parkinson’s.

Serotonin Found… Effects… In the Blood and in the Gut (regulates intestinal movements.) Effects… Contributes to feelings of well-being Mood, emotion & concentration “happiness hormone” Or lack of could cause depression

GABA Found… Effects… brain. Helps with anxiety “Buzz Kill” Acts like a break from noradrenaline & dopamine

Glutamate Found… Effects… Central Nervous System (brain). Can ingest it (Soy, meats, poultry, eggs, dairy products, & seaweed.) Effects… Learning and Memory! (that’s why they say you should eat well before you test!)

Endorphin Found… Effects… Produced by the pituitary gland during exercise, excitement, pain, eating spicy food, love, etc… Blood Effects… Pain reduction & pleasure “Endorphin Rush” – feelings of exhilaration brought by pain or danger. Allow us to feel a sense of power and control and persist with activity for extended time.