How the nervous system works

1. It never rests2. Controls our emotions, movements, thinking and behavior3. It is divided into 2 parts (Figure 6.1)

a) Central Nervous System (CNS)i. Consists of the brain and spinal cord

b) Peripheral Nervous System (PNS)i. Smaller Branches of nerves that reach other parts of the

body from the spinal cord (thickness of a pencil)ii. Take information from the organs to the CNS and from the

CNS back to the organs4. Each is protected by something

a) Brain by the skull and several layers of sheathingb) Spinal cord by the vertebrae c) Peripheral nerves by layers of sheathing

Neuron connection (Figure 6.3)

1. Synapse – the space between the axon terminals of one neuron and the dendrites of another neuron.

Section 1 Review

The Brain is composed of 3 parts

1. The Hindbraina) Located at the rear base of the skullb) Involved in the most basic processes of lifec) Includes:

i. The cerebellumii. The medullaiii. The pons

2. The Midbrain

a) Integrates sensory informationb) Alerts the rest of the brain to incoming signals and is

involved in the sleep/wake cycle

3. The Forebrain

Lobes of the Brain

1. Cerebrum is split into 2 sides or hemispheresa) Connected by the corpus callosum

2. Occipital Lobea) Where visual signals are processedb) Damage may cause visual impairment

3. Parietal Lobea) Receives and deals with information from all the

senses4. Temporal Lobe

a) Concerns: hearing, memory, emotion and thinking

5. Frontal Lobea) Concerned with organization, planning and creative

thinking6. Somatosensory Cortex

a) Receives information from the touch sensors

7. Motor Cortexa) Sends information to control body movement

The Hemispheres

1. Each work together to compliment and help each other2. Corpus callosum carries information back and forth

between the hemispheres and the lobes (each of the 4 lobes are present in both hemispheres)

3. Left Hemispherea) Controls movement on the right side of the bodyb) Where speech is located (in most people)c) Specialized for mathematical ability, calculation and

logic

4. Right Hemispherea) Controls the left side of the bodyb) Adept at visual and spatial relationsc) Perceptual tasksd) Recognizing patterns (music and art)e) Creativity and intuition

Split Brain Operations

1. Usually done to those with severe seizures

2. Cuts the corpus callosuma) Lowers the severity and number of seizuresb) Information cannot cross into other spheres

i. Person with a split brain can hold a ball in their right hand and say it was a ball, but not holding it in their left hand.

3. Shows how unique and the specialize functions and skills of each hemisphere

4. Remained practically unchanged in intelligence, emotion and personality

How do Psychologists study the brain?

1. Recordinga) Putting electrodes into the brain to record electrical activityb) EEG – electroencephalograph. Millions and millions of neurons

can be studied at one time with an EEG attached to the scalpc) Shows brain waves which show the amount of neural activity

2. Stimulationa) Fires off neurons by electricityb) Can show what areas of the brain do

i. Memoriesii. Songsiii. Smells

3. Lesionsa) Cutting or destroying areas of healthy brain tissue and

studying the results

4. Accidentsa) Studying the results of accidents and medical issues

i. Phineas Gageii. Coma patientsiii. Traumatic head injuries

5. Imagesa) CAT (Computerized Axial Tomography) scans

i. Transfers the amount of radiation absorbed by the density of brain tissue into a 3 dimensional view of the brain

b) PET (Positron Emission Tomography) scansi. Shows the absence or presence state of activity in an area

of the brain through radioactive dyec) MRI (Magnetic Resonance Imaging)

i. Ability to study both activity and brain structureii. Uses both CAT and PET scanning capabilities

d) fMRI (Functional Magnetic Resonance Imaging)i. New, can see the blow flow into active areas to determine

activity and functionality

Section 2 Review

1. Chemical messages used to send are called hormonesa) Produced by the glands and send by blood and other bodily fluidsb) Once in the blood stream, they can only be received by the

specific organs that they can influencec) Ductless, they don’t need pores or ducts (small holes) to release

to an organ (sweat glands, tear glands, salivary glands)d) Various effects on behavior and moodse) Growth of organs, muscles and bones

2. Pituitary Glanda) Directed by the hypothalamusb) Secretes a large number of hormones, many of which control the

output of other hormonesi. Corrects imbalances of hormones in the bodyii. Keeps metabolism in check despite outside influencesiii. Control growth and reproduction

Endocrine system – sends chemical messages to and from the brain

4. Adrenal Glanda) Become active when someone is angry or frightenedb) Release Epinephrine (adrenaline) and norepinephrine (nor

adrenaline)c) Speed up heart rate and breathing; heighten emotion; extra

energyd) Secret cortical steroids

i. Help muscle develop and cause the liver to release stored sugar for extra energy in emergencies

3. Thyroid Glanda) Produces thyroxine

i. Stimulates chemical reactions for all tissuesii. Too little, people feel lazy; too much people lose weight, sleep

too much and are overactive

6. Hormones vs. Neurotransmitters Differencea) When the chemical is released right beside a cell to excite or

inhibit it, it is a neurotransmitterb) When a chemical is released into the blood, it is a hormone

5. Sex Glandsa) 2 Types

i. Testes – malea. Produce sperm and testosterone (sex hormone)

ii. Ovaries – femalesa. Produce eggs and estrogen and progesterone

b) Testosteronei. Important to physical development of males during the

prenatal and adolescence periodsa. Prenatal – helps decide the sex of the fetusb. Adolescence – development of bone and muscle, male sex

characteristicsc) Estrogen and progesterone

i. Development of the female sex characteristicsii. Regulate the reproductive cycle iii. Variances of the hormones cause the symptoms of PMS

Section 3 Review

2. Nature vs. Nuture

a. Genes and behaviori. Reproduced and passed onto childrenii. Occur through their role in building and modifying the physical

structures of the body

1. Is human behavior instinctive (due to heredity) or learned (environment)

a) Heredity is the genetic transmission of characteristics from parents to their offspring

b. Twin studiesi. Identical twins – develop from the same single, fertilized

egg, thus sharing the same genesii. Fraternal twins – develop from 2 fertilized eggs, not more

similar genes than brothers or sistersiii. One study showed that twins growing up apart from one

another showed similar behaviors, despite different socials, cultural and economic backgroundsa. Suggests heredity may contribute to behaviors once

thought more environment in natureb. It is possible though to alter the environment that genes

operate in thus changes these “hereditary” ideas

Section 4 Review

Chapter 6 Study Guide

Chapter 6 Test

Chapter 6 Review Quiz