PSY 1100 - Columbus State Community College - Chapter 2

Nervous System

the body's electrochemical communication circuitry

"Greater Integrator"

the brain does a wonderful job of pulling information together; sounds, sights, touch, taste, smells—the brain integrates all of these as we function in the world

Plastcity

denotes the brain's special capacity for change

Afferent Nerves, or sensory nerves

carry information to the brain and spinal cord

Efferent Nerves, or motor nerves

carry information out of the brain and spinal cord—that is, they carry the nervous system's output

Neural Networks

interconnected groups of nerve cells that integrate sensory input and motor output

Central Nervous System (CNS)

is the brain and spinal cord.More than 99 percent of all our nerve cells are located in the CNS

Peripheral Nervous System (PNS)

is the network of nerves that connects the brain and spinal cord to other parts of the body; the functions of the peripheral nervous system are to bring information to and from the brain and spinal cord and to carry out the commands of the CNS to execute various muscular and glandular activities

Somatice Nervous System

consists of sensory nerves (afferent); function is to convey information from the skin and muscles to the CNS about conditions such as pain and temperature

Motor Nerves, or efferent

function is to tell muscles what to do

Autonomic Nervous System

is to take messages to and from the body's internal organs, monitoring such processes as breathing, heart rate, and digestion XIV; the autonomic nervous system also is divided into two parts

Sympathetic Nervous System

arouses the body to mobilize it for action and thus is involved in the experience of stress

Parasympathetic Nervous System

calms the body

Stress

the body's response to stressors

Stressors

the circumstances and events that threaten individuals and tax their coping abilities

Chronic Stress

stress that goes on continuously—may lead to persistent autonomic nervous system arousal

Neurons

the nerve cells that handle the information-processing fuction

Glial Cells, or glia

provide support, nutritional benefits, and other functions in the nervous system; keep neurons running smoothly

Mirror Neurons

active while we enact a behavior and when we passively observe another person performing that behavior; appear to respond to both kinds of information, doing and seeing

Cell Body

contains the nucleus, which directs the manufacture of substances that the neuron needs for growth and maintenance

Dendrites

treelike fibers projecting from a neuron; receive information and orient it toward the neuron's cell body

Axon

the part of the neuron that carries information away from the cell body toward other cells

Myelin Sheath

consisting of a layer of cells containing fat, encases and insulates most axons; speed up transmission of nerve impulses

Neurons Resting Potential

between ‒60 and ‒75 millivolts

Action Potential

describes the brief wave of positive electrical charge that sweeps down the axon; lasts only about 1/1,000 of a second, because the sodium channels can stay open for only a very brief time; when a neuron sends an action potential, it is commonly said to be "firing"

All-Or-Nothing Principle

once the electrical impulse reaches a certain level of intensity, called its threshold, it fires and moves all the way down the axon without losing any of its intensity; the impulse traveling down an axon can be compared to the burning fuse of a firecracker

How Synapses and Neurotransmitters Work

A: the axon of the presynaptic (sending) neuron meets dendrites of the postsynaptic(receiving) neuron

How Synapses and Neurotransmitters Work

B: this is an enlargement of one synapse, showing the synaptic gap between the two neurons, the terminal button, and the synaptic vesicles containing a neurotransmitter

How Synapses and Neurotransmitters Work

C: this is an enlargement of the receptor site; note how the neurotransmitter opens the channel on the receptor site, triggering the neuron to fire

Synapses

tiny spaces between neurons

Synaptic Gap

the gap between neurons

Terminal Buttons

each axon branches out into numerous fibers that end in structures

Neurotransmitters

stored in very tiny synaptic vesicles (sacs) within the terminal buttons are chemical substances

Acetylcholine, or ACh

sually stimulates the firing of neurons and is involved in the action of muscles, learning, and memory; found throughout the central and peripheral nervous systems

GABA, or gama aminobutyric acid

is important in the brain because it keeps many neurons from firing ;found throughout the central nervous system

Glutamate

excites many neurons to fire and is especially involved in learning and memory

Norepinephrine

inhibits the firing of neurons in the central nervous system, but it excites the heart muscle, intestines, and urogenital tract

Dopamine

helps to control voluntary movement and affects sleep, mood, attention, learning, and the ability to recognize rewards in the environment; low levels of dopamine are associated with Parkinson disease

Serotonin

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

Endorphines

natural opiates that mainly stimulate the firing of neurons; shield the body from pain and elevate feelings of pleasure

Oxytocin

a hormone and neurotransmitter that plays an important role in the experience of love and social bonding

Agonist

a drug that mimics or increases a neurotransmitter's effects; ex: the drug morphine mimics the actions of endorphins by stimulating receptors in the brain and spinal cord associated with pleasure and pain

Antagonist

a drug that blocks a neurotransmitter's effects; ex: , drugs used to treat schizophrenia interfere with the activity of dopamine

Positron-Emission Tomography, or PET Scan

based on metabolic changes in the brain related to activity; PET measures the amount of glucose in various areas of the brain and then sends this information to a computer for analysis

Magnetic Resonance Imaging, or MRI

involves creating a magnetic field around a person's body and using radio waves to construct images of the person's tissues and biochemical activities; it cannot portray brain function.

Functional Magnetic Resonance Imaging, or fMRI

allows scientists literally to see what is happening in the brain while it is working; rests on the idea that mental activity is associated with changes in the brain

Medulla

begins where the spinal cord enters the skull; this structure controls many vital functions, such as breathing and heart rate, it also regulates our reflexes

Cerebellum

extends from the rear of the hindbrain, just above the medulla; consists of two rounded structures thought to play important roles in motor coordination

Brain Stem

includes much of the hindbrain (it does not include the cerebellum) and the midbrain; gets its name because it looks like a stem; connects with the spinal cord at its lower end and then extends upward to encase the reticular formation in the midbrain.

Midbrain

located between the hindbrain and forebrain; an area in which many nerve-fiber systems ascend and descend to connect the higher and lower portions of the brain

Reticular Formation

a diffuse collection of neurons involved in stereotyped patterns of behavior such as walking, sleeping, and turning to attend to a sudden noise

Forebrain

the brain's largest division and its most forward part

Limbic System

a loosely connected network of structures under the cerebral cortex; is important in both memory and emotion

Hippocampus

has a special role in the storage of memories

Thalamus

a forebrain structure that sits at the top of the brain stem in the central core of the brain

Basal Ganglia

Above the thalamus and under the cerebral cortex lie large clusters, or ganglia, of neurons; work with the cerebellum and the cerebral cortex to control and coordinate voluntary movements; enable people to engage in habitual behaviors such as riding a bicycle and typing a text message

Hypothalamus

a small forebrain structure just below the thalamus, monitors three pleasurable activities—eating, drinking, and sex—as well as emotion, stress, and reward; helps direct the endocrine system

Cerebral Cortex

part of the forebrain and is the most recently developed part of the brain in the evolutionary scheme

Neocortex, or "new bark"

the outermost part of the cerebral cortex

Hemispheres

the wrinkled surface of the cerebral cortex is divided into two halves

Four Regions, or lobes

1. Occipital

2. Temporal

3. Frontal

4. Parietal

Occipital Lobes

located at the back of the head; respond to visual stimuli

Temporal Lobes

the part of the cerebral cortex just above the ears; involved in hearing, language processing, and memory

Frontal Lobes

the portion of the cerebral cortex behind the forehead, are involved in personality, intelligence, and the control of voluntary muscles

Prefrontal Cortex

important part of the frontal lobes; involved in higher cognitive functions such as planning, reasoning, and self-control

Parietal Lobes

located at the top and toward the rear of the head; involved in registering spatial location, attention, and motor control

Somatosensory Cortex

processes information about body sensations; located at the front of the parietal lobes

Motor Cortex

at the rear of the frontal lobes; processes information about voluntary movement

Association Cortex, or association areas

refers to regions of the cerebral cortex that integrate sensory and motor information; the highest intellectual functions occur in the association cortex, such as thinking and problem, solving

Broca's Area

plays an important role in the production of speech

Wernicke's Area

if damages, causes problems in comprehending language

Corpus Callosum

come from studies of patients with severe, even life-threatening, forms of epilepsy

Epilepsy

caused by electrical "brainstorms" that flash uncontrollably across the corpus callosum

Right hemisphere receives information from...

the left side of the body

Left hemisphere receives information from...

the right side of the body

Lateralization

people with intact brains or specialized functions; occurs in some areas

Left Hemisphere

The most extensive research on the brain's two hemispheres has focused on language; speech and grammar are localized to the left hemisphere

Hormones

chemical messengers produced by the endocrine glands

Pituitary Gland

a pea-sized gland just beneath the hypothalamus; controls growth and regulates other glands

Master Gland

anterior (front) part of the pituitary; almost all of its hormones direct the activity of target glands elsewhere; controlled by the hypothalamus

Adrenal Gland

located at the top of each kidney; regulate mood, energy level, and the ability to cope with stress. Each adrenal gland secretes epinephrine and norepinephrine (adrenaline and noradrenaline)

Pancreas

located under the stomach; a dual-purpose gland that performs both digestive and endocrine functions

Ovaries

located in the pelvis on either sides of the uterus in women; are the sex-related endocrine glands that produce hormones related to sexual development and reproduction

Testes

located in the scrotum in men; are the sex-related endocrine glands that produce hormones related to sexual development and reproduction

Collateral Sprouting

the axons of some healthy neurons adjacent to damaged cells grow new branches

Substitution of function

the damaged region's function is taken over by another area or areas of the brain

The nucleus of each human cell contains

46 chromosomes/23 pairs

Deoxyribonucleic Acid (DNA)

a complex molecule that carries genetic information

Genes

the units of hereditary information, are short segments of chromosomes composed of DNA

Dominant-Recessive Genes Principle

the dominant gene overrides the recessive gene; a recessive gene exerts its influence only if both genes of a pair are recessive; if you inherit a recessive gene from only one parent, you may never know you carry the gene

Molecular Genetics

involves the manipulation of genes using technology to determine their effect on behavior

Selective Breeding

a genetic method in which organisms are chosen for reproduction based on how much of a particular trait they display

Behavior Genetics

is the study of the degree and nature of heredity's influence on behavior; less invasive than molecular genetics and selective breeding

Genotype

a person's genetic heritage, his or her actual genetic material

Phenotype

the individual's observable characteristics

Gene x Environment (GxE) Interaction

the interaction of a specific measured variation in DNA and a specific measured aspect of the environment; the idea that genes and environments interact to produce characteristics in any organism (including people) is appealing.