PSY 21 CH 3

Neuroscience

The study of how nerves and cells send and receive information from the brain, body, and spinal cord

Cerebral Cortex

The outermost layer of the brain; supports cognitive skills, complex emotions, and complex mental activity, including your sense of mind and self.

Neurons

The cellular building blocks of the brain

Genes

The basic physical and functional units of heredity; made up of DNA

Neurodiversity

An appreciation of the range of differences in brain function among individuals

Nervous system

A network of neurons running throughout your brain and body

Nerves

A collection of neurons that carries signals from the body to the brain

Motor neuron

A neuron that sends signals to make the body take action

sensory neuron

A neuron that carries information from the outside world and within the body to the brain

interneuron

A neuron that connects neurons and interprets, stores, and retrieves information about the world, allowing you to make informed decisions before you act

spinal cord

The major bundle of nerves, encased in your spine, that connects your body and your brain

Central nervous system (CNS)

The system composed of the brain and spinal cord; information from your body travels to the brain by way of the nerves of your spinal cord

Peripheral nervous system (PNS)

The system composed of the nerves outside of the brain and spinal cord; connects the parts of the body to the brain

Somatic nervous system (SNS)

The system that allows us to feel external sensations from and control volitional movement of the body

Autonomic nervous system (ANS)

The system that allows us to feel internal sensations from and controls automatic movements of the organs, such as heartbeat

Sympathetic nervous system

A division of the autonomic nervous system that acts on blood vessels, organs, and glands in ways that prepare the body for action, especially in life threatening situations

Parasympathetic nervous system

A division of the autonomic nervous system that returns the body to a resting state by counteracting the actions of the sympathetic system

Endocrine system

A network of glands that produces and releases hormones into the bloodstream to regulate the body’s activities

Hormones

The blood-borne chemicals that travel through the circulatory system enabling the brain to regulate the body’s activities

Adrenal glands

The endocrine glands located on top of the kidneys; they produce a variety of hormones, including adrenaline and cortisol, that are central to the stress response

Pituitary gland

The master endocrine gland, located at the base of the brain, that in addition to producing its own hormones regulates hormone production in other glands

Neocortex

The evolutionarily newest cerebral cortex that is the largest part of the human brain; supports complex functions, including language, thought, problem solving, and imagination

Occipital lobe

A lobe that runs along the back portion of the head; contains the primary visual cortex and is largely devoted to vision

Temporal lobe

A lobe that runs alongside the ears; contains the primary auditory cortex and is responsible for the ability to hear and understand language

Parietal lobe

A lobe that runs alongside the head above and behind the ears; contains the primary somatosensory cortex, supporting a map of the body’s skin surface and the sense of touch

Frontal lobe

A lobe located in the front of the head; contains the primary motor cortex and a map of the body’s muscles, essential for movement and planning

Insular lobe

The cortex that is insulated by the overlying cortex; supports the sense of taste and allows perception of the internal organs

Primary sensory areas

The first regions of the cerebral cortex to receive signals from a sensory organ via its sensory nerve

Primary motor cortex

The cortex that is responsible for voluntary movements

Association cortex

The cortex that integrates information coming in from the senses with existing knowledge

Primary somatosensory cortex

The cortex that is responsible for the sense of touch

Limbic system

A system often associated with emotion; it bridges the older, lower brain regions that regulate the body with newer, higher brain structures more related to complex mental functions

Hippocampus

A component of the limbic system crucial for certain aspects of memory, the ability to navigate the environment, and the ability to think about the future

Amygdala

A component of the limbic system important for registering the emotional significance of events

Basal ganglia

A group of interconnected structures that are an evolutionarily older subcortical motor system necessary for planning and executing movement

Thalamus

A subcortical structure deep in the middle of the brain; communicates information to and from all of the sensory systems except the olfactory (smell) system, regulating alertness and consciousness

Hypothalamus

The master controller of the brain and body; integrates bodily signals with their associated feelings and behaviors; regulates specific functions, including hunger, body rythms, rewards seeking, and aggression

Brainstem

The lowest region of the brain; it sits on top and is continuous with the spinal cord, collection sensory signals from the body and sending signals down from the brain to create movement and regulate vital functions

Midbrain

The uppermost region of the brainstem; it includes the tegmentum and substantia nigra, critical for dopamine production

Pons

An upper brainstem structure that controls breathing and relays sensations, such as hearing, taste, and balance, to the subcortex and cortex

Medulla oblongata

A lower brainstem structure that controls autonomic functions, including heart rate and blood pressure, and reflexes like coughing and swallowing

Reticular formation

A structure that runs through the brainstem and is connected to many parts of the brain; plays a central role in arousal and attention

Executive functions

The cognitive processes that allow us to plan, focus attention, and organize multiple tasks to complete our goals; associated with the function of the prefrontal cortex

Corpus callosum

The bridge of fibers that connects the two halves of the brain

Contralateral

The opposite-side organization of the brain, whereby one side of the body is connected to and controlled by the opposite brain hemisphere

Cerebellum

A hindbrain structure that supports a variety of functions, including coordination, precision, balance, and accurate timing

Split-brain procedure

The severing of the corpus callosum to reduce the spread of seizures across brain hemispheres

Brain networks

The collections of brain regions that are connected and work together to support brain functions

Magnetic resonance imaging (MRI)

A structural imaging technique that uses magnetic fields and radio waves to create images of the brain

Phrenology

An early pseudoscience suggesting that mental abilities and personality traits could be read from bumps on the skull

Neuropsychology

The study of the brain’s workings; done by examining the brain’s altered function following brain damage

Lesion

An abnormal tissue resulting from disease, trauma, or surgical; intervention

Dissociation

The neuropsychological evidence, following brain damage or lesion, that a specific brain area is involved in a particular function but not in others

Single-cell recording

A measurement of the electrical activity of a single neuron

Electroencephalography (EEG)

The recording of electrical waves from many thousands of neurons in the brain, gathered using electrodes placed on the scalp

Magnetoencephalography (MEG)

The recording of the magnetic fields produced by the brain’s electrical currents

Positron emmision tomography (PET)

The injection of radioactive glucose into a person’s bloodstream to measure blood flow associated with higher brain activity or the brain’s use of specific neurochemicals

Functional magnetic resonance imaging (fMRI)

A variation of MRI that measures brain function by tracking oxygen in the blood flow through the brain

Deep brain stimulation (DBS)

The insertion of an electrode deep in a patient’s brain to alter the activity of brain regions that have been abnormally active

Transcranial magnetic stimulation (TMS)

A temporary and reversible disruption of enhancement of cortical brain function that allows scientists to study brain regions and their functions

Transcranial direct current stimulation (TDCS)

A gentler form of neurostimulation that uses very low levels of direct current delivered via electrodes on the head to stimulate brain function, such as enhancing hand-eye coordination

Dendrites

The part of the neuron that receives chemical messages from other neurons

Axon

The part of the neuron that transports electrical impulses to other neurons via the terminal branches

Terminal branch

The part of the neuron that converts electrical signals into chemical messages to other neurons

Myelin sheath

A layer of fatty tissue that covers and insulated an axon to ensure that electrical messages travel fast and meet less resistance

Glia

The cells that make up myeline sheath around neurons to insulate, support, and nourish neurons and modulate neuronal function

Action potential

A rapid change in voltage created by a neuron when it is sufficiently stimulated to surpass a critical threshold; serves as the basis for neural signaling

Ion channel

The channels that allow chemical ions to enter and exit the neuronal membrane to generate the voltage for the resting and action potential

Depolarization

Occurs when a neuron’s voltage becomes more positive; the first phase of the action potential

voltage threshold

The voltage necessary for a neuron to start an action potential

Repolarization

The portion of the action potential during which the neuron returns to its resting potential

Cell body

The part of the neuron that collects neural impulses, contains the nucleus, and provides life-sustaining functions for the cell; also called soma

refractory period

The period of time required for a neuron to return to its resting state before it can fire another action potential

Synapse

The gap where a sending neuron communicates with the dendrites or cell body of the receiving neuron

Neurotransmitter

The chemical messenger released at the terminal branch to allow communication between neurons

Amino acids

The brain’s most abundant class of neurotransmitters, including glutamate (important for neuronal excitation) and gamma-aminobutyric acid (GABA, important for neuronal inhibition and the regulation of muscle tone).

Monoamines

A neurochemical class that includes norepinephrine, dopamine, and seratonin.

Acetylcholine

A major neurotransmitter class that can behave as both an inhibitory and an excitatory signal , supporting heart and skeletal muscle, and cognitive function

Agonist

A chemical that mimics the action of a neurotransmitter

Antagonist

A chemical that competes with naturally occurring neurotransmitter to block neurotransmission

Phenotype

The observable characteristics of an individual resulting from the interaction of genotype and environment

Genotype

The genetic makeup of an organism composed of the organism’s complete set of genes

Allele

A variant form of a gene; humans have two alleles per gene, one inherited from each parent

Gene expression

The turning on and off of genes in a particular cell to determine how that cell functions

Epigenetics

The study of how the interactions between your genes and the environment regulate gene expression

Behavioral genetics

The study of how genetic factors influence trait variation between individuals

Heritability

An indication of how much variation in phenotype across people is due to differences in genotype

Monozygotic

Twins who share 100% of their genetic material because they developed from the division of a single fertilized egg

Dizygotic

Twins who share 50% of their genetic material because they developed from two seperate fertilized eggs

Neural plasticity

The brain’s capacity to physiologically modify, regenerate, and reinvent itself constantly over the course of a lifetime

Critical periods

The periods early in life during which very specific experiences must occur to ensure the normal development of a characteristic behavior

Damage plasticity

The neural modification following injury that largely takes the form of brain reorganization

Phantom limb

The experience of sensations, such as pain, in a limb that no longer exists following its amputation

Adult plasticity

The shaping and reshaping of neural circuits throughout adulthood

Stem cell

A cell that has not yet undergone gene expression to differentiate into a specialized cell type such as a skin cell, liver cell, or neuron

Neurogenesis

The process by which new brain cells are born in adult brains