The Nervous System Unit II Biology and Behavior

The Nervous System Unit II: Biology and Behavior -What is it? -How does it affect our behavior?

The Nervous System Will Explain Why We FEEL… Pain Strong Nervous

The Nervous System is … l. A big communication system between the brain and the body. l Helps ¡ gain us to information that is going on inside and around our body ¡ respond accordingly

The Nervous System is … l Made up of nerves – bundles of long thin cells called neurons. l Nerves send messages between the brain and the body.

The Nervous System is … ¡ Neurons – fundamental unit of the nervous system l nerve cell (5 parts) l have the ability to communicate with one another

Neuron Structure

5 Major parts to a neuron Dendrites 2. Cell Body 3. Axon 1. 4. Myelin Sheath- aids transmission 1. 5. can be thousandths of an inch or up to three feet! Degeneration can result in Multiple Sclerosis Axon Terminals 1. Synaptic Gap- fluid filled and 5 millionth of an inch wide. Takes 10 millionth of a second to cross.

Synaptic Gap

The Nervous System is … l Two Parts ¡ 1. Central Nervous System (CNS) l brain and spinal cord – encased in bone

The Nervous System is… ¡ 2. Peripheral Nervous System (PNS) l Nerves cells/ Neurons l Connects the CNS to the body l Carries information to and from the brain & spine. l “Outer Edge”

2 Parts of the Peripheral Nervous System l Somatic nervous system ¡ Controls voluntary muscles and transmits sensory information to the CNS l Autonomic nervous system ¡ Controls involuntary body functions l Heartbeat, Blood pressure, Breathing, Digestion… ¡ Has two parts Sympathetic l Parasympathetic l

l. A “blueprint” of the Nervous System

How the Autonomic System affects our behaviors… Sympathetic Nervous System l “Fight or Flight” Response l Prepares our body to confront the situation or RUN! l Remember that sympathetic, stress, and sympathy begin with “S”.

How the Autonomic System affects our behaviors… Parasympathetic Nervous System l Restores the body’s energy reserves after an event has occurred. l Remember that parasympathetic and peaceful both begin with “P”.

How it affects our behaviors…Sympathetic VS. Parasympathetic

How the Nervous Systems affects our behaviors … ¡ Neurotransmitters – chemicals released by neurons which help them pass messages to the next neuron. ¡ Three important neurotransmitters (over 100 are known) have a big influence on our feelings and behavior. Serotonin l Dopamine l Endorphins l

Serotonin l Function deals with mood control and sleep l Abnormal levels of serotonin have been linked to depression and obsessivecompulsive disorder (OCD).

Dopamine l l l Deals with motor movement and alertness. Deficiency of dopamine is associated with Parkinson’s disease. Excess is associated with schizophrenia. Antipsychotic drugs block dopamine receptors. Cocaine, nicotine, & amphetamines increase dopamine activity.

Endorphins Regulates pain control/pain perception during stress or trauma. l Can give a euphoric feeling l We can become addicted to endorphin causing feelings. l ¡ ¡ Similar to opiate addiction (morphine, heroin, & codeine). Acupuncture

Another important neurotransmitter Acetylcholine-”uh-seet-ul-KOleen” ¡ Muscle control l Low amounts linked to Alzheimer's l Nerve gas & black widow venom cause too much acetylcholine to be released resulting in convulsions and suffocation. l Nicotine mimics acetylcholine. l