Intro to Psychology Chapter 2 Textbook Notes

Biological Psychology

the scientific study of the biological bases of behavior and mental processes

Neuroscience

the scientific study of the nervous system

Nervous system

the body's primary communication network

Neuron

where communication throughout the nervous system takes place
-cells that are highly specialized to receive and transmit information from one part of the body to another
-brain contains an estimated 100 billion neurons

Sensory Neurons

convey information about the environment, such as light or sound from a specialized receptor cells in the sense organs to the brain
-also carry information from the skin and internal organs to the brain

Moto Neurons

communicate information to the muscles or glands of the body

Interneurons

communicate information between neurons
-most of the neurons in the human nervous system are interneurons

Mirror neurons

-not structurally different from other motor neurons
-distinct type of motor neuron that becomes activated both when individuals perform a motor act and when they observe the same motor act done by another individual

Characteristics of a Neuron

most neurons have three basic components: a cell body, dendrites, and an axon

Cell body

-also called the stoma
-contains structures that manufacture proteins and process nutrients, providing the energy the neuron needs to function
-contains a nucleus which contains the cell's genetic material in twisted strands of DNA called chromosomes

Dendrites

-short, branching fibers that extends from the cell bodies of most neurons
-receive messages from other neurons or specialized cells
-great surface area, which increasese the amount of information the neuron can receive

Axon

-a single, elongated tube that extends from the cell body in most, though not all, neurons
-some neurons do not have axons
-carry information from the neuron to other cells in the body, including other neurons, glands, and muscles
-a neuron only has one a

Glial Cells

-makes up the human nervous system
-also called glia
-are the most abundant cells in the human brain, outnumbering neurons by about 10 to 1
-provide structural support for neurons throughout the nervous system
-Microgla:remove waste products from the nerv

Myelin Sheath

-made with oligodendrocytes and Shwann cells
-a white fatty covering that is wrapped around the axons of some, but not all, enurons
-helps to insulate one axon from the axons of other neurons
-occurs in segments that are separated by small gaps (nodes of

Multiple slerosis

a disease that involves the degernation of patches of myelin sheath
-causes the transmission of neural messages to be slowed or interrupted, resulting in disturbances in sensation and movement
-muscle weakness, loss of coordination, and speech and visual

Action Potential

messages are gatherd by the dendrites and cell body and then transmitted along the axon in the form of a brief electrical impulse
-produced by the movement of electrically charged particles, called ions, across the membrane of the axon
-axon membrane open

Stimulus Threshold

each neuron requires a minimum level of stimulation from other neurons or sensory receptors to activate it

polarized

there is a difference in the electrical charge between the inside and the outside of the axon

Resting potential

the negative electrical charge of the axon is -70 millivolts
-while at resting potential, the fluid surrounding the axon contains a larger concentration of sodium ions than does the fluid within the axon
-the fluid within the axon contains a larger concen

Action Potential Steps

-triggered when the neuron is sufficiently stimulated by other neurons or sensory receptors
1. the neuron depolarizes: at each successive axon segment, sodium ion channels open for a mere thousandth of a second.
2. The sodium ions rush to the axon interio

All-or-none law

either the neuron is sufficiently stimulated and an action potential occurs, or the neuron is not sufficiently stimulated and an action potential does not occur

Refractory period

after the action potential, lasting a thousandth of a second or less, during which the neuron cannot fire
-the neuron repolarizes and reestablishes the negative-inside/positive-outside condition

Repolarization

occurs progressively at each segment down the axon
-this process reestablishes the resting potential conditions so that the neuron is capable of firing again

Variation in communication speed

Due to:
1. the axon diameter: the larger the axon's diameter, the faster it conducts action potentials
2. the myelin sheath: myelinated neurons communicate much faster than unmyelinated neurons, because the action potential "jumps" from node to node rathe

Synapse

the point of communication between two neurons
-the message sending neuron is referred to as the presynaptic neuron
-the message receiving neuron is called the psotsynaptic neuron
-the presynaptic and postsynaptic neurons are separated by a tiny, fluid-fi

Axon terminals

the end of the axon, several small branches

synaptic vesicles

float in the interior fluid of the axon terminals, tiny sacs

Neurotransmitters

special chemical messengers manufactured by the neuron

Synaptic transmission

the entire process of transmitting information at the synapse
-when the action potential reaches the axon terminals, some of the synaptic vesicles "dock" on the axon terminal membrane, then release their neurotransmitters into the synaptic gap
-these chem

Reuptake

-when neurotransmitter molecules detach from the receptor and are reabsorbed by the presynaptic neuron so they can be recycled and used again
-also occurs with many of the neurotransmitters that failed to attach to a receptor and were left floating in the

Neurotransmitter Facts

-each has a chemically distinct shape
-shape must precisely match that of a receptor site on the postsynaptic neuron for the neurotransmitter to affect that neuron
-communicates either an excitatory or an inhibitory message to a postsynaptic neuron
-excit

Acetylcholine

-found in all motor neurons
-stimulates muscles to contract, including the heart and stomach muslces
-found in many neurons in the brain: is important in memory, learning and general intellectual functioning

Dopamine

-is involved in movement, attention, learning, and pleasurable or rewarding sensations
-degeneration of the neurons that produce dopamine in one brain area causes Parkinson's disease (characterized by rigidity, muscle tremors, poor balance, and difficulty

Seratonin

involved in sleep, sensory perceptions, moods, and emotional states, including depression

Norepinephrine

implicated in the activation of neurons throughout the brain and helps the body gear up in the face of danger or threat
-plays a key role in the regulation of sleep, learning, and memory retrieval
-norepinephrine dysfunction is implicated in some psycholo

The most abundant neurotransmitters in the brain

-glutamate
-gamma-aminobutyric acid (GABA)

glutamate:

conveys excitatory messages
-involved in learning, memory, and sensory processes

GABA

communicates inhibitory messages
-regulates the level of neural activity in the brain
-too much impairs learning, motivation, and movement bu too little can lead to seizures

Endorphins

another important class of neurotransmitter
-hundreds of times more potent are are released in response to stress trauma, and pain
-are implicated in the pain-reducing effects of acupuncture,
-associated with positive mood, may cause "runner's high

Drugs and how they affect synaptic transmission

-blocking the reuptake of the neurotransmitters by the sending neuron
-ex: category of antidepressant medications that are referred to as SSRI (selective serotonin reuptake inhibitors) inhibits the reuptake of serotonin, increasing the availability of ser

Agonist

is a drug or other chemical that binds to a recepto
-chemically similar to a specific neurotransmitter and produce the same effect

Antagonist

-drug blocks the effect of neurotransmitters
-may fit into receptor sites and prevent neurotransmitters from acting

The nervous system is divided into two main divisions

-central nervous system
-peripheral nervous system

Central Nervous System

-includes the grain and spinal cord
-entirely protected by bone - the brain by the skull and the spinal cord by the spinal column
-surrounding and protecting the brain and the spinal cord are three layers of membranous tissues, called meninges
-the brain

Peripheral Nervous System

communication occurs along nerves (made up of large bundles of neuron axons)
-the word peripheral means "lying at the outer edges" the peripheral nervous system comprises all the nerves outside the central nervous system that extend to the outermost borde

Somatic Nervous System

takes it name from the Greek word soma, which means body
-plays a key role in communication throughout the entire body
-communicates sensory informatoin received by sensory receptors along sensory nerves to the central nervous system
-carries messages fro

Autonomic Nervous System

the word autonomic means "self-governing" the autonomic nervous system regulates involuntary functions, such as heartbeat, blood pressure, breathing, and digestion
-these processes occur with little to no conscious involvement
-the autonomic nervous syste

Sympathetic nervous system

arouses the body to expend energy
-the body's emergency system, rapidly activating bodily systems to meet threats or emergencies
-when you are frightened your breathing accelerates, your heart beats faster, digestion stops, and the bronchial tubes in your

Parasympathetic nervous system

helps the body conserve energy
-conserves and maintain your physical resources
-calms you down after an emergency
-acting much more slowly than the sympathetic nrvous system, the parasympathetic nervous system gradually returns your body's systems to norm

Endocrine System

-made up of glands that are located throughout the body
-endocrine glands communicate information from one part of the body to another by secreting messenger chemicals called hormones into the bloodstream. the hormones circulate throughout the bloodstream

Pituitary Gladn

a pea-sized gland just under the brain
-hormones regulate the production of other hormones by many of the glands in the endocrine system
-often referred to as the master gland
-controls hormone production in other endocrine glands
-produces some hormones

Oxytocin

hormone produced by the hypothalamus and released into the bloodstream by the pituitary gland
-the hormone that produces the let-down reflex, in which stored milk is "let down" into the nipple
-also signals the uterus to contract during childbirth
-promot

Adrenal glands

consist of teh adrenal cortex, which is the outer gland, and the adrenal medulla, which is the inner gland. Both the adrenal cortex and the adrenal medulla produce hormones that are involved in the human stress response
-the adrenal medulla plays a key ro

Gonads

sex organs (ovaries and testes)
-the ovaries secrete the hormones estrogen and progesterone
-the testes secrete androgens, the most important of which is testosterone (testosterone is also secreted by the adrenal glands in both males and females)
-influen

Phrenology

popular pseudoscience founded in the 1800s by German physician Franz Gall
-convinced that the size and shape of the cortex were reflected in the size and shape of the skull
-variations in the size and shape of the human skull might reflect individual diff

Neuroplasticity

the brain's ability to change function and structure (plasticity)

Functional plasticity

refers to the brain's ability to shift functions from damaged to undamaged brain areas

Structural plasticity

refers to the brain's ability to physically change its structure in response to learning, active practice, or environmental stimulation (changes in your environment or behavior can lead to structural changes in the brain)

Neurogenisis

the development of new neurons

The brainstem

the structures of the hindbrain and the midbrain
*Hindbrain
-connects the spinal cord with the rest of the brain
-sensory and motor pathways pass through the hindbrain to and from regions that are situated higher up in the brain
-sensory information comin

Midbrain

important relay station that contains centers involved in the processing of auditory and visual sensory information.
-auditory sensations from the left and right ears are processed through the midbrain, helping orient toward the direction of sound
-involv

Forebrain

-represents about 90 percent of the brain
-cerebral cortex: the outermost portion. divided into two cerebral hemispheres. A thick bundle of axons called corpus callosum connects the two cerebral hemispheres. The corpus callosum serves and the primary comm

Temporal Lobe

contains the primary auditory cortex, which receives auditory information

Occipital lobe

includes the primary visual cortex, where visual information is received

Parietal lobe

involved in processing bodily or somatosensory information, including touch, temperature, pressure, and information from receptors in the muscles and joints. A band of tissure on the parietal lobe, called the somatosensory cortex, receives information fro

Frontal lobe

-largest lobe of teh cerebral cortex
-involved in planning, initiating, and executing voluntary movements (movemetns of different body parts are represented in a band of tissue on the frontal lobe called the primary motor cortex. almost one third of the p

Limbic System

beneath the cerebral cortex
-form complex neural circuits ath play critical roles in learning, memory, and emotional control

Hippocampus

large structure embedded in the temporal lobe in each cerebral hemisphere
-looks like the curved tail of a sea horse
-plays an important role in your ability to form new memories of events and information

Thalamus

-rounded mass of cell bodies located within each cerebral hemisphere
-processes and distributes motor information and sensory information going to and from the cerebral cortex
-also though to be involved in regulating levels fo awareness, attention, motiv

Hypothalamus

located below the thalamus
-size of a peanut
-contains more than 40 neural pathways which ascend to other forebrain areas and descend to the midbrain, hindbrain, and the spinal cord
-involved in so many different functions, is sometimes referred to as the

Amygdala

almond-shaped clump of neuron cell bodies at the base of the temporal lobe
-involved in a variety of emotional responses, including fear, anger, and disgust
-responds to many emotional stimuli
-some neuroscientists now believe that the amygdala aids in de

Broca's area

Pierre Paul Broca treated a series of patients who had great difficulty speaking but could comprehend written or spoken language
-lower left frontal lobe
-play a crucial role in speech production

Wernicke's area

Karl Wernicke's patients had gerat difficulty understanding spoken or written communications. They could speak quickly and easily, but their speech sometimes made no sense
-left temporal lobe

lateralization of function

the notion that one hemisphere exerts more control over or is more involved in the processing of a particular psychological function (speech and language are lateralized on the left hemisphere)
-the left hemisphere is superior in language abilities, speec