THE NERVOUS SYSTEM

The nervous system also allows you to react to a stimulus. A stimulus is a change in the environment. Example: A hot stove Or… tripping over a rock

The Nervous System is divided into 2 systems: Central Nervous System and Peripheral Nervous System.

The Central Nervous System controls everything in the body. The Central Nervous System is made of the brain and the spinal cord. The Central Nervous System controls everything in the body.

It all Starts with the Neuron (Nerve) Neural and Hormonal Systems Explains why we feel strong, sad, happy & nervous. It all Starts with the Neuron (Nerve) Neurons are chemical messages that travel from one neuron to the next, sending information like “lift your leg” “be happy”

http://www.youtube.com/watch?v=Qo3BoxUhgzQ&feature=related

Neurons do NOT touch each other- the space in between is call the synapse.

Action Potential It is like a battery. There are positive and negative charges and the message is an electrical message. This change in ions is called the action potential. The firing is an all or nothing response. Like a gun.

http://www.youtube.com/watch?v=90cj4NX87Yk&NR=1

Steps of Action Potential Dendrites receive neurotransmitter from another neuron across the synapse. Reached its threshold- then fires based on the all-or-none response. Opens up a portal in axon, and lets in positive ions (Sodium) which mix with negative ions (Potassium) that is already inside the axon (thus Neurons at rest have a slightly negative charge). The mixing of + and – ions causes an electrical charge that opens up the next portal (letting in more K) while closing the original portal. Process continues down axon to the axon terminal. Terminal buttons turns electrical charge into chemical (neurotransmitter) and shoots message to next neuron across the synapse.

http://www.youtube.com/watch?v=r5nMVAjz0d0

There are 3 Types of Neurons (Nerves) Sensory Neurons Motor Neurons Inter Neurons

Sensory Neurons (Afferent Neurons) For example, touching a Hot Flame would send the signal to the CNS. (red arrow) Sends signals TO the CNS (Central Nervous System) http://www.flatworldknowledge.com/pub/introduction-psychology/67053#web-67053

Motor Neurons Sends signals AWAY from the CNS. For example, if you were about to hit a soccer ball a message will come away from the CNS to tell your leg to kick. http://www.flatworldknowledge.com/pub/introduction-psychology/67053#web-67053

InterNeurons (Get it “in” the brain) hahaha Contained within the CNS. Does the processing in the brain. http://www.flatworldknowledge.com/pub/introduction-psychology/67053#web-67053

Types of Neurotransmitters There are 4 that we need to aware of. Acetylcholine, Dopamine, Serotonin, Endorphines

Acetylcholine (ACH) involved in voluntary movement, learning, memory, and sleep +Too much acetylcholine is associated with depression, and too little in the hippocampus has been associated with dementia -Lack of ACH has been linked to Alzheimer’s disease.

Dopamine Its function is motor movement and alertness. -Lack of dopamine is associated with Parkinson’s disease. +Overabundance is associated with schizophrenia.

Serotonin -Lack of serotonin has been linked to depression. Function deals with mood control. -Lack of serotonin has been linked to depression.

Endorphins Function deals with pain control. We become addicted to endorphin causing feelings. glassrocklife.com

The brain, neurotransmitters, emotions in the brain. http://www.youtube.com/watch?v=r71RoIkftd4&NR=1

Are all neurons the same size?? NO!! Largest one is 15 feet!! About how many neurons are in the spinal cord? 1 Billion About how many neurons are in the human brain? 100 Billion

Drugs and alcohol bind important receptors on neurons

Agonists and Antagonists

Mirror Neurons http://www.pbs.org/wgbh/nova/sciencenow/video/3204/i01.html

Divisions of the Nervous System

The Endocrine System A system of glands that secrete hormones. Similar to nervous system, except hormones work a lot slower than neurotransmitters. Neurotransmitters slow exerts control by releasing special chemical substances into the blood called hormones fast

The Endocrine System Pituitary gland: a small gland located on a stalk hanging from the base of the brain - AKA “The Master Gland” Produces many hormones. Secretion is controlled by the hypothalamus in the base of the brain. Consists of several glands located in various parts of the body. Taken from: http://science.pppst.com/humanbody/human-endocrine-system.html

The Major Endocrine Glands

Taken from different sources on the internet. http://learn.genetics.utah.edu/content/addiction/drugs/index.html Click on the following link to find out what happens with the addicted brain.