Chap 3 Biological Foundations Part I

2 Neurons

C. Synapses and Neurotransmitters

Synapses are the junctions between neurons--the space between one neuron and the dendrites of another neuron is called the synaptic gap.

At the end of the axon there are fibers that are called terminal buttons. Neurotransmitters are stored in the terminal buttons. The neurotransmitters carry the electrical information across the synaptic gap.

B.The Neural Impulse

In order for a neuron to send information to another neuron, it sends an electrical charge.

Biological Foundations

of Behavior

An action potential is the term given to the electrical impulses flowing down the axon

The all-or-none principle refers to when an electrical impulse reaches a certain level of intensity and it fires and moves all the way down the axon without losing any of its intensity.

Neurons are the nerve cells that control the information-processing function.

A. Specialized Cell Structures

1. Not all neurons are alike, but they all do have a cell body, dendrites, and an axon.

2.The cell body contains the nucleus, which manufactures what the neuron needs for growth and maintenance.

3.Dendrites receive information and send that information on to the cell body.

4. The axon carries information away from the cell body and to other cells

5.A myelin sheath covers and insulates the axon. By insulating the axons, myelin sheaths speed up transmission of nerve impulses.

Characteristics of the Nervous system

The brain and nervous system guide our interactions with the world around us, move our body through the world, and direct our adaptations to the environment.

1. Complexity

The brain is composed of billions of nerve cells and the orchestration of these nerve cells allows a person to carry out a variety of activities such as writing, talking, singing, dancing, and planning---truly awe inspiring.

3. Adaptability

Chapter Three

As the world is constantly changing, the brain and nervous system allow person to adapt to those changes.

Agonist=

The brain has a vast capacity for modification and change.

2. Integration

A drug that mimics a neurotransmitter’s effect.

Question: Does this idea of adapting to meet the challenges of our environment sound familiar? Where have we heard this idea before?

Antagonist=

It is your brain that draws your experiences together into a coherent whole. Sounds, sights, touches, tastes, and smells—the brain integrates all of these sensor inputs so that you can function in the world.

Ex. Morphine is an agonist b/c it mimics the effects of endorphins

#1 The nature and basic function of the nervous system

Activity #2 Designing A Neuron From Food:

A drug that blocks a neurotransmitter’s effect

Each nerve cell in the brain communicates with 10,000 other nerve cells.

With the following food items, each group will design their own neurons.

a. two red vine licorice.

b. 8 large marshmallows

c. pretzel sticks

d. mini M&M's

e. orange slices

ex. Drugs used to treat Schizophrenia interfere with the activity of dopamine.

Design the neurons on paper towels so once finished, groups can move the neurons closer to each other without touching (simulating the synapse between neurons) and explain each part and its function.

Ans. William James "Functionalism".

James saw the mind as flexible and fluid, characterized by constant change in response to a continuous

flow of information from the world, aka, “the stream of consciousness”.

The brain and nervous system are highly adaptive structures that have a vast capacity for modification and change.

Drugs and Neurotransmitters

a. The peripheral nervous system (PNS) is comprised of the somatic nervous system and the autonomic nervous system.

b. The autonomic nervous system (ANS) is comprised of both the sympathetic nervous system and the parasympathetic nervous system. The sympathetic nervous system prepares a person for a stressful situation and the parasympathetic nervous system calms the body down after the stressful situation.

I. The Nervous System

Electrochemical Transmission

The nervous system is the body’s electrochemical communication circuitry.

The brain and the nervous system function as an information-processing system powered by electrical impulses and chemical messengers.

Neuroscience is the field of study of the nervous system. The researchers that conduct research on the nervous system are called neuroscientists.

C. Divisions of the Nervous System

1. The central nervous system (CNS) is comprised of the brain and spinal cord.

2. The peripheral nervous system (PNS) is comprised of the nerves that connect the brain and spinal cord to other parts of the body.

Neurochemical Messengers

There are a variety of neurotransmitters. Each plays a different role and function.

After the neurotransmitter crosses over the synaptic gap, it gets picked up by a receiving neuron

Find your groups.

Pathways in the Nervous System

Read your index card and based on the information provided, identify the nervous system to which you belong.

As we interact with and adapt to the world, the brain and the nervous system receive and transmit sensory input (like sounds, smells and flavors).

Information flows into the brain through input from our senses and the brain makes sense of that information, pulling it together and giving it meaning.

Afferent nerves carry information

to the brain and spinal cord. These

sensory pathways communicate

information about the external

environment (ex, your hand on a steering wheel)

In your groups, imagine walking down a dark street, late at night. All the sudden you hear someone following you. Discuss and write down what would be happening physiologically as the information you are hearing is going through your nervous system.

Each group should have four (4) people.

After you finish, one member of each group can explain the physiological characteristics their group decided on.

Efferent nerves, or motor nerves, carry information out of the brain and spinal cord to other areas of the body.

ex. adjusting the steering wheel to stay on the road.

Late to class one day, Adam Lepak, a nineteen year old community college student was speeding along on his motorcycle, he lost control and crashed.

After six months of lying in a coma, Adam began to regain consciousness. Adam's accident had

damaged the regions of his brain

responsible for the warm glow

that comes from recognizing others.

He did not recognize his friends and

loved ones.

Adam has had to relearn how to walk and talk and struggled to regain the feeling of familiarity

that provides human beings

with a sense of self.

Dr. Davidson researches affective disorders such as depression. He believes states of mind such as happiness or compassion are a skill that can be developed with practice. As the brain is malleable and plastic we can develop and strengthen our ability to access such states of mind.

The brain is a flexible

organ that can adapt to the

trauma suffered from serious

motor vehicle accidents.

The brain has the capacity to help us recognize familiar things and provide us a sense of “who we are.”

King uses this story to illustrate three important topics covered in the chapter;

1. the enormous role our nervous system plays in our lives.

2. the brains role in the precious human experience of having an identity and the feeling of warmth toward others.

3. the brain’s remarkable capacity to healing and compensation through a process we call neuroplasticity.

Part of the autonomic nervous system responsible for arousing the body to mobilize it for action.

Somatic Nervous System

Sympathetic Group:

Richard Davidson is a neuroscientist. His research involves exploring the idea of plasticity to intentionally develop and strengthen neural pathways making it easier to access positive emotions such as compassion and sense of well-being through practices such as mediation.

Autonomic Nervous System:

1. Your heart begins to race as you sense someone following you down a dark alley

2. blood flows away from your digestive system to supply oxygenated blood to your

muscles as a large dog begins to chase you.

3. a near collision sends adrenaline through your body and your hands begin to shake

4. the soldier has heightened awareness and a surge of energy as the sound of gunfire

alarms him of danger.

Neurotransmitters: Activity #3

Part of the A.N.S. that calms the body.

1. you felt the pain after getting a nasty paper cut

2. you put gloves on b/c your hands felt cold

3. you get stung in the arm while gardening.

4. you find the coffee table in the dark with your shin

Parasympathetic Group:

Adam Lepak's slow recovery demonstrates the brain's plasticity. You might believe that thinking is a mental process, not a physical one. Yet thinking is a physical event, because every thought you have is reflected in physical activity in the brain.

Plasticity shows us the brain can be changed by experience.

When you change they way you think, you are literally changing the brain's physical processes and even its shape.

The brain is constantly wiring and re-wiring itself through experience and learning.

1. you are feeling hungry

2. this system allows your heart to beat without having to think about it

3. this system allows you to remember to breathe without having to think about it.

4. you wake up and feel a lot of pressure from your bladder

consists of sensory nerves, whose function is to convey information from the skin and muscles to the CNS.

takes messages to and from the body's internal organs, monitoring breathing, heart rate and digestion

In your groups, find the purpose of two neurotransmitters. Then share the information with the class.

1. your heart begins to slow down after you realize the stranger following

you was your BFF.

2. your breathing returns to normal as you calm down after you realize that

large dog chasing you was a chiwawa

3. blood flow moves from your muscles to the digestive tract after your

workout

4. you begin to drift into a comfortable sleep as you curl up in bed

Neurotransmitters and their purpose

Acetylcholine: stimulates neurons and is involved in muscle action and learning.

The venom from the bite of a black widow causes Ach to gush out of synapses producing violent muscle spasms.

For Next Week:

Endorphins

a. read chapter 3

Dopamine

Serotonin

helps control voluntary movement, sleep, mood, attention and learning.

natural opiates--depress nervous system activity and eliminate pain.

involved in the regulation of sleep, mood, attention and learning.

Somatic Nervous Sys:

low levels of serotonin are associated with depression.

Autonomic Nervous Sys:

low levels of dopamine are associated with Parkinson disease, a degenerative neurological disorder in which a person develops jerky movements and tremors.

Sympathetic Group:

endorphins-operate to shield the body from pain and elevate feelings of pleasure.

Parasympathetic Group:

b. work on your discussion board posts

Oxytocin

c. chap 3 pretest

Part of the A.N.S. that calms the body.

consists of sensory nerves, whose function is to convey information from the skin and muscles to the CNS.

a hormone and neurotransmitter. Plays an important role in the experience of love and social bonding.

Part of the autonomic nervous system responsible for arousing the body to mobilize it for action.

takes messages to and from the body's internal organs, monitoring breathing, heart rate and digestion

d. begin exploring ideas for term paper

ex. a parents strong feelings of love for their newborn baby.

e. Email me with any questions

Have a Great Week!