Neural and Hormonal Systems Will Explain Why We FEEL…… Nervous Strong Sick Pain

Biological Psychologists Study the links between biological activity and psychological events Study the connections between stress and disease, hunger and sex to name a few Not a new idea- phrenology – the study of bumps on our head to determine our character and abilities WRONG!

It all Starts with the Neuron

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

Types of Neurons Sensory Neurons (Afferent Neurons) Take information from the senses to the brain.

Motor Neurons (Efferent Neurons) Take information from brain to the rest of the body. Axons in motor neurons can be 4 feet long. Fun Fact: A giraffe has a neuron from its toe to neck is 15 feet long

Inter Neurons Take messages from Sensory Neurons to other parts of the brain or to Motor Neurons. Found only in Spinal Column and brain

Neuron Video http://www.youtube.com/watch?v=cUGuWh2UeMk

How a Neuron Fires It is an electrochemical process Electrical inside the neuron. Travels from the dendrite to the terminal buttons Chemical travels between cells in the synapse(in the synapse in the form of a neurotransmitter). Electricity does not jump between the neurons The firing is call Action Potential( electric message firing).

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. Terminal buttons turns electrical charge into chemical (neurotransmitter) and shoots message to next neuron across the synapse.

The All-or None Response The idea that either the neuron fires or it does not- no part way firing. Like a gun or a toilet flushing

How Neurons Communicate

https://www.youtube.com/watch?v=8bxpz-YEuao

Neurotransmitters Chemical messengers released by terminal buttons through the synapse. Some neurons house more than one neurotransmitter. More than 1 neuron is present at any given synapse

Acetylcholine The best understood NT. Plays a role in learning and memory. ACh is the messenger at every junction of a motor neuron & skeletal muscle. If Ach transmission is blocked like with anesthesia, muscles can’t contract spider bite with venom can block Receptor sites and paralyzes you Botox works the same way Lack of ACH has been linked to disease. Alzheimer’s. 90% loss of Ach in brains of people with Alzheimer's

Dopamine Lack of dopamine is associated with Parkinson’s disease. Its function is motor movement and alertness. large NT Associated with reward centers Lack of dopamine is associated with Parkinson’s disease. Overabundance in frontal lobes is associated with schizophrenia. Also unsociability and social anxiety. Cocaine, alcohol, heroin etc. release dopamine

Norepinephrine Brings nervous system into high alert In the sympathetic nervous system Increases heart rate and blood pressure Our adrenal glands release it into the blood stream, along with its close relative epinephrine (aka adrenalin). It is also important for forming memories

Serotonin Function deals with mood control, hunger, sleep and arousal. Too little serotonin has been linked to depression, OCD, Anger control & suicide. Mimics LSD and ecstasy

Glutamate Most common NT- Toxic -Too much kills neurons Important for memory ALS (Lou Gehrig’s Disease) associated with an excess of Glutamate Associated with Migraines Found in cold meats, cheeses- MSG

Endorphins We become addicted to endorphin causing feelings. Function deals with pain control and pleasure. Naturally occurring opiate. Structurally similar to opioids(morphine, opium) We become addicted to endorphin causing feelings.

Substance P The body’s pain neurotransmitter. This NT works in opposition with endorphins to regulate pain. Substance P signals the body it is in pain and then endorphins are triggered to inhibit the pain signal

Figure 3A.5 Neurotransmitter pathways Each of the brain’s differing chemical messengers has designated pathways where it operates, as shown here for serotonin and dopamine. Carter, 1998 © 2011 by Worth Publishers

Neurotransmitters and the brain If NT acts on the brainstem, it affects basic functions like breathing and heartbeat If it acts in the midbrain, it affects functions like memory and emotion If it acts on areas of the cortex, it affects higher functions like memory integration, problem solving and perception

Agonists and Antagonists

A Simplified Neural Network Neurons that learn to work together as a team.

A Simple Reflex

The Nervous System http://www.youtube.com/watch?v=6BgfKqc3qhs&list=PL2920A92123EAF834&index=83&safety_mode=true&persist_safety_mode=1&safe=active

Divisions of the Nervous System

Sympathetic Nervous System Flight or Fight Response

Did you know? Sensory neurons connect to the spinal cord in the back? Motor neurons connect in the front of the spinal cord So it is possible to lose feeling in lower portions of the body in a spinal injury but retain the ability to move if the spinal cord is not completely severed

The Endocrine System A system of glands that secrete hormones. Similar to nervous system, except hormones work a lot slower than neurotransmitters. Hormones Neurotransmitters

The Major Endocrine Glands

Endocrine System Pituitary gland- the master gland Adrenal – release epinephrine and norepinephrine ( flight or fight response) Hormones affect heart rate, blood pressure, blood sugar Affect lingers after event Need to create Homeostasis