Biological Bases of BehaviorUnit 3

The Nervous System• The nervous system controls your emotions,

movements, thinking, and behavior• Structurally, the nervous system is divided into

two parts• Central Nervous System (CNS) – the brain and spinal cord• Peripheral Nervous System (PNS) – the smaller branches

of nerves that reach the other parts of the body• The nerves of the PNS conduct information from the

bodily organs to the CNS and back to the organs

• All parts of the nervous system are protected in some way • The bony protection of the spinal cord is vital as an injury

could prevent the transmittal of messages and could result in paralysis

Neurons• Messages to and from the brain travel along the

nerves, which are strings of long, thin cells called neurons

• Transmission between neurons occurs whenever the cells are stimulated past a minimum point and emit a signal

• Neurons have four basic parts:• Dendrites – receive messages from other neurons and

send them to the cell body• Cell body – houses the nucleus• Axon – Carries the messages from the cell body toward

the axon terminal• Axon Terminals – release neurotransmitters to stimulate

dendrites of the next neuron

http://www.google.com/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&docid=KJwcHQd-zuX8GM&tbnid=PYiKAz0KtLk_OM:&ved=0CAcQjRw&url=http://rskbrain.weebly.com/table-of-contents.html&ei=ThogVNvPAoWpyATGroKwBA&bvm=bv.75775273,d.aWw&psig=AFQjCNGyE347D6Wo8zcnujT8a212Wy2g0A&ust=1411476128377047

• The intensity of activity in each neuron depends on how many other neurons are acting on it

• The actual destination of nerve impulses produced by an excited neuron is limited by what tract in the nervous system they are on• Ascending tracts carry sensory impulses to the brain• Descending tracts carry motor impulses from the brain

• There are different types of neurons• Afferent – sensory, relay messages from the sense organs

to the brain• Efferent – motor, send signals from the brain to the glands

& muscles• Interneurons – process signals, connect only to other

neurons

Unit 3 Vocabulary• This is your homework for tonight and it will be

checked tomorrow (9/23)• Your quiz will be THIS Thursday (September 25th)

1. Corpus Callosum2. Neuron3. Nervous system4. Endocrine system5. Heredity6. Perception7. Selective Attention8. Neurotransmitter9. Hormone10.Trait

Vocabulary Check

1. Corpus Callosum -

2. Neuron -

3. Nervous system -

4. Endocrine system -

5. Heredity -

6. Perception -

7. Selective Attention -

8. Neurotransmitter -

9. Hormone -

10.Trait -

Voluntary & Involuntary Activities• Some of the actions that your body makes in

response to impulses from the nerves are either voluntary or involuntary acts

• Somatic Nervous System (SNS) – part of the peripheral nervous system that controls voluntary activities

• Autonomic Nervous System (ANS) – part of the nervous system that controls involuntary activities (i.e. heartbeat, stomach activity, etc.)• The sympathetic nervous system prepares the body for

dealing with emergencies or strenuous activity• The parasympathetic nervous system works to conserve

energy and to enhance the body’s ability to recover from strenuous activity

Studying the Brain• The brain is composed of three parts• The hindbrain – located at the rear base of the skull,

involved in the most basic processes of life. Includes the cerebellum (controls posture, balance, and voluntary movements), medulla (controls breathing and heart rate), and pons (bridge between spinal cord and the brain)

• The midbrain – is a small part of the brain above the pons that arouses the brain, integrates sensory information, and relays it upward

• The forebrain – covers the brain’s central core, responsible for sensory and motor control and the processing of thinking and language

How Psychologists Study the Brain• The methods they use to explore the brain are:• Recording – Scientists insert electrodes into the brain to record

electrical activity in the brain. The activity of whole areas of the brain can be recorded with an electroencephalograph (EEG), which is attached to the scalp. Observed that activity rises and falls rhythmically weather you’re awake, drowsy, or asleep• Stimulating – Electrodes are used to fire off neurons. Can be

used to find malfunctioning parts of the brain• Lesioning – Sometimes scientists create lesions in the brain to

see if an animal behaves differently. If so, they assume that the part of the brain thatwas destroyed was involved with that behavior• Imaging – different scans (CT, PET, MRI) can be used to capture

pictures of the brain to pinpoint parts of the brain that are being used or have been damaged

Phineas Gage• Psychologists can also learn from the tragedies when people suffer

accidents• Phineas Gage was a respected railroad foreman who demonstrated

restraint, good judgment, and the ability to work well with others• His crew was about to explode some dynamite to clear a path for the

railroad as Gage was filling a hole with dynamite it went off• The tamping iron, which was 13 lbs and 3 ft long, shot up in the air

and entered into Gage’s head right below the left eye and exited through the top of his skull

• Gage survived the accident but his personalitychanged greatly (short-tempered, difficult to be around, said inappropriate things)

• Scientists later found that damage to the frontal lobes prevents censoring of thoughts and ideas.

The Endocrine System• The nervous system is one of two communication

systems for sending information to and from the brain; the second is the endocrine system

• The endocrine system sends chemical messages, called hormones (which are produced in the endocrine glands and distributed by blood and other body fluids)• Though hormones circulate throughout the bloodstream,

they are only received at the particular organ that they influence• Hormones affect the growth of bodily structures such as

muscles and bones, metabolic processes, moods, and drives

Glands of the Body• Pituitary Gland• Acts as the master gland• Located near the midbrain and the hypothalamus, it secretes a

large number of hormones (which the hypothalamus monitors and can correct imbalances)• Carry messages to organs involved in regulating and storing

nutrients; also controls growth and reproduction

• Thyroid Gland• Produces the hormone thyroxine, which stimulates certain

chemical reactions that are important for the tissues of the body• Too little thyroxine makes people feel lazy and lethargic

(hypothyroidism)• Too much thyroxine may cause people to lose weight, sleep,

and be overactive (hyperthyroidism)

• Adrenal Glands• Become active when a person is angry or freightened• Release epinephrine and norepinephrine into the

bloodstream, which cause the heartbeat and breathing to increase• Can also heighten emotions, fear, and anxiety which help

a person generate extra energy to handle a difficult situation• Also secrete cortical steroids which help muscles develop

and cause the liver to release stored sugar for extra energy

• Sex Glands• Two types of sex glands: testes (males) and ovaries

(females)• Testes produce sperm and testosterone which is important

in the physical development of amles• Ovaries produce eggs, estrogen, and progesterone which

regulate the reproductive cycle of females

Right Brain or Left Brain• Each hemisphere of the brain is responsible for

different functions

Left Hemisphere• Sends signals to the right arm and

leg• Responsible for many of the logical

and thinking process of the brain:• Using Facts• Analyzing• Working with numbers• Sequential thinking and details

• If you have a dominance in the left brain, then you are a verbal learner (do better reading or hearing information)

Right Brain or Left Brain• Each hemisphere of the brain is responsible for

different functions

Right Hemisphere• Sends signals to the left arm and

leg• More creative half and is involved

in visual tasks like:• Visual imagery• Music, including rhyming• Creative writing, like drama and

poetry• Imagination

• If you have a dominance in the right brain, then you are a visual learner (do better with visual aids, drawings, or charts)

Right Brain or Left Brain• Your task is to figure out which is your dominate

hemisphere• Go to:

http://capone.mtsu.edu/studskl/hd/hemispheric_dominance.html

• When you have finished the quiz, show me your score so I can add this participation to your grade

• To get full credit on this assignment, you need to write down 3 ways that you can incorporate your dominate side into your study/school work and hand these in

Biological Bases of Behavior• Your tasks for today and tomorrow are to make

sure you understand the biological bases of behavior

• Go to http://education-portal.com/academy/topic/biological-bases-of-behavior.html• Chapter 2 (which is the chapter you’ll link to) has all of

this information broken down into groups• We’ve briefly discussed some of these groups, however,

there is a lot of new information that we did not discuss• You need to read through the chapter or watch the videos

included and take detailed notes over the sections• You WILL need to know this information on the test so

make sure you are working to get this information down