Chapter 2: The Biological Perspective

Biological psycology

focuses on the biological process of psychological processes, behavior, and learning

Neuron

the basic cell that makes up the NS and sends messages

Dendrites

branch-like structures that receive messages from other neurons

Soma

the cell body of a neuron, maintains life of cell

Axon

long, tube-like structure carries neural messages to other cell

Axon terminals

rounded areas at end of branches, responsible for chemical part of neural communication

Glial cells

produce myelin, deliver nutrients to axons, provide support for neurons to grow on and around

Myelin

fatty substance, coats axons to insulate, protect, and speed up neural impulses

Ions

charged particles

The charge inside of the neurons is…

Negative

The neuron outside of the cell is…

positive

Resting potential

the state of the neuron when not firing an impulse, -70 mV

electrostatic gradient

+ ions attracted to - ions inside the cell

concentration gradient

ions move from areas of high to low concentration (diffusion)

Action potential

the release of neural impulses reversing the electrical charge within the axon, flips from -70 mV to +40 mV

Synaptic vesicles

sac-like structures found inside axon terminal, contains chemicals

all-or-none

a neuron either fires completely or not at all

neurotransmitter

have an effect on the cell, chemical found in synaptic vesicles

synapse (synaptic gap)

fluid-filled space between axon terminal of one cell to the dendrites or soma of another cell

Receptor sites

3D proteins on the surface of dendrites or certain cells, fit only certain neurotransmitters

Excitatory synapse

synapse at which a neurotransmitter causes the receiving cell to fire

Inhibitory synapse

synapse at which a neurotransmitter causes the receiving cell to stop firing

Antagonists

chemical substances that block/reduce a cell’s response to chemicals/neurotransmitters

Agonists

chemical substances that mimic/enhance the effect of a neurotransmitter, increasing or decreasing cell activity

Acetylcholine

muscle actions, learning, memory

GABA (Gamma Amino-butyric Acid)

primary inhibitory neurotransmitter

Glutamate

• excitatory

• learning and memory

• involved in many psychological disorders

• plays a role in seizure disorders and damage from head trauma/stroke

Norepinephrine

regulates attention, blood flow, and sleep/wakefulness

Dopamine

• voluntary movement

• reward anticipation and addictive behaviors

• stimulant drugs: activate dopamine receptors

Serotonin

regulation of sleep, mood, attention, and learning

Endorphins

• natural opiates

• mediate feelings of pleasure and pain, both physical and emotional

Oxytocin

• both a hormone and a neurotransmitter

• related to onset of lactation in new mothers

• related to attachment/emotional bonds

• block oxytocin, monogamous species no longer mate for life and become promiscuous

Reuptake

process by which neurotransmitters are taken back into the synaptic vesicles

Enzymatic degradation

process by which the structure of a neurotransmitter is altered so it can no longer act on a receptor

Medulla

• the first large swelling at the top of the spinal cord, forming the lowest part of the brain

• responsible for life-sustaining functions such as breathing, swallowing, and heart rate

Pons

• larger swelling just above the medulla that connects the top of the brain to the bottom

• plays a part in sleep, dreaming, left–right body coordination, and arousal

Reticular formation

• area of neurons running through the middle of the medulla and the pons and slightly beyond

• responsible for general attention, alertness, and arousal

Cerebellum

• part of the lower brain located behind the pons

• controls and coordinates involuntary, rapid, fine motor movement and may have some cognitive functions

Limbic system

a group of several brain structures located primarily under the cortex and involved in learning, emotion, memory, and motivation

Thalamus

• part of the limbic system located in the center of the brain

• relays sensory information from the lower part of the brain to the proper areas of the cortex

Olfactory bulbs

receive information from neurons in the sinus cavity

Hypothalamus

• small structure in the brain

• located below the thalamus and directly above the pituitary gland

• responsible for motivational behavior such as sleep, hunger, thirst, and sex

Hippocampus

• curved structure located within each temporal lobe

• responsible for the formation of long-term declarative memories

Amygdala

• brain structure located near the hippocampus

• responsible for fear responses and memory of fear

• also interpreting facial expressions

Cingulate cortex

• the limbic structure actually found in the cortex

• plays important roles in cognitive and emotional processing

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Cortex

• outermost covering of the brain consisting of densely packed neurons

• responsible for higher thought processes and interpretation of sensory input

Corticalization

• wrinkling of the cortex

• allows a much larger area of cortical cells to exist in the small space inside the skull

Cerebrum

the upper part of the brain

Cerebral hemispheres

the two sections of the cortex on the left and right sides of the brain

Corpus callosum

thick band of neural fibers that connects the right and left cerebral hemispheres

Frontal lobes

areas of the cortex located in the front and top of the brain; responsible for higher mental processes and decision-making as well as the production of fluent speech

Motor cortex

• rear section of the frontal lobe

• responsible for sending motor commands to the muscles of the somatic nervous system

Mirror neurons

neurons that fire when performing an action or observing others performing actions

Parietal lobes

sections of the brain located at the top and back of each cerebral hemisphere containing the centers for touch, temperature, and body position

Somatosensory cortex

• area of neurons running down the front of the parietal lobes

• responsible for processing information from the skin and internal body receptors for touch, temperature, and body position

Temporal lobes

areas of the cortex along the sides of the brain, starting just behind the temples, containing the neurons responsible for the sense of hearing and meaningful speech

Occipital lobe

section of the brain located at the rear and bottom of each cerebral hemisphere containing the visual centers of the brain

Association areas

areas within each lobe of the cortex responsible for the coordination and interpretation of information, as well as higher mental processing

Broca’s aphasia

• condition resulting from damage to Broca’s area (usually in left frontal lobe)

• causes the affected person to be unable to speak fluently, to mispronounce words, and to speak haltingly

Wernicke’s aphasia

condition resulting from damage to Wernicke’s area (usually in left temporal lobe)

causes the affected person to be unable to understand or produce meaningful language

Spatial neglect

• condition produced by damage to the parietal lobe association areas of the right hemisphere

• results in an inability to recognize objects or body parts in the left visual field

CNS

part of the nervous system consisting of the brain and spinal cord

Spinal cord

a long bundle of neurons that carries messages to and from the body and the brain and is

responsible for very fast, lifesaving reflexes

Afferent (sensory) neuron

a neuron that carries information from the senses to the central nervous system

Efferent (motor) neuron

a neuron that carries messages from the central nervous system to the muscles of the body

Interneuron

a neuron found in the center of the spinal cord that receives information from the sensory neurons and sends commands to the muscles through the efferent neurons

Reflex arc

the connection of the afferent neurons to the interneurons to the efferent neurons, resulting in a reflex action

PNS

all nerves and neurons that are not contained in the brain and spinal cord but that run through the body itself

Somatic nervous system

nerves that control the voluntary muscles of the body

Sensory pathway

nerves carrying messages from the sensory organs to the CNS

Motor pathway

nerves coming from the CNS to the voluntary muscles, consisting of efferent neurons

Autonomic nervous system

nerves that control the involuntary muscles, organs, and glands

Sympathetic division (fight or flight system)

part of the ANS that is responsible for reacting to stressful events and bodily arousal

Parasympathetic division (eat, drink, and rest system)

part of the ANS that restores the body to normal functioning after arousal and is responsible for

the day-to-day functioning of the organs and glands