Unit 2 Part 1

Nodes of Ranvier

small gaps between myelin that help speed up neural transmission

Terminal Buttons

knobs on the branched end of axons

Neuron

A nerve cell; the basic building block of the nervous system.

Angular Gyrus

lets you read out loud. between wernike’s and broca’s

Cell Body

The part of a neuron that contains the nucleus; the cell's life support center.

Dendrites

A neuron's often bushy, branching extensions that receive and integrate messages, conducting impulses toward the cell body

Axon

The neuron extension that passes messages through its branches to other neurons or to muscles or glands.

Myelin Sheath

A fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next.

Glial Cells

Cells in the nervous system that support, nourish, and protect neurons; they also play a role in learning, thinking, and memory.

Action Potential

A neural impulse; a brief electrical charge that travels down an axon.

Threshold

The level of stimulation required to trigger a neural impulse.

Refractory Period

In neural processing, a brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state.

All-or-None Response

A neuron's reaction of either firing (with a fullstrength response) or not firing.

Synapse

The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap or synaptic cleft.

Neurotransmitters

Chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse.

Reuptake

A neurotransmitter's reabsorption by the sending neuron.

Endorphins

"Morphine within"—natural, opiate-like neurotransmitters linked to pain control and to pleasure.

Agonist

A molecule that increases a neurotransmitter's action.

Antagonist

A molecule that inhibits or blocks a neurotransmitter's action.

Nervous System

The body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.

Central Nervous System (CNS)

The brain and spinal cord.

Peripheral Nervous System (PNS)

The sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

Nerves

Bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sense organs.

Sensory (Afferent) Neurons

Neurons that carry incoming information from the body's tissues and sensory receptors to the brain and spinal cord.

Motor (Efferent) Neurons

Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands.

Interneurons

Neurons within the brain and spinal cord; they communicate internally and process information between the sensory inputs and motor outputs.

Somatic Nervous System

The division of the peripheral nervous system that controls the body's skeletal muscles. Also called the skeletal nervous system.

Autonomic Nervous System (ANS)

The part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms.

Sympathetic Nervous System

The division of the autonomic nervous system that arouses the body, mobilizing its energy.

Parasympathetic Nervous System

The division of the autonomic nervous system that calms the body, conserving its energy.

Reflex

A simple, automatic response to a sensory stimulus, such as the knee-jerk response.

Endocrine System

The body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream.

Hormones

Chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues.

Adrenal Glands

A pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress.

Pituitary Glands

The endocrine system's most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.

Lesion

Tissue destruction. A brain lesion is a naturally or experimentally caused destruction of brain tissue.

EEG (Electroencephalogram)

An amplified recording of the waves of electrical activity sweeping across the brain's surface. These waves are measured by electrodes placed on the scalp.

CT (Computed Tomography) Scan

A series of X-ray photographs taken from different angles and combined by computer into a composite representation of a slice of the brain's structure.

PET (Positron Emission Tomography) Scan

A visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task.

MRI (Magnetic Resonance Imaging)

A technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. They scans show brain anatomy.

fMRI (Functional MRI)

A technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans. They scans show brain function as well as structure.

Brainstem

The oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions.

Medulla

The base of the brainstem; controls heartbeat and breathing.

Thalamus

The brain's sensory control center, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla.

Reticular Formation

A nerve network that travels through the brainstem into the thalamus and plays an important role in controlling arousal.

Cerebellum

The "little brain" at the rear of the brainstem; functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory

Limbic System

Neural system (including the amygdala, hypothalamus, and hippocampus) located below the cerebral hemispheres; associated with emotions and drives.

Amygdala

Two lima-bean-sized neural clusters in the limbic system; linked to emotion.

Hypothalamus

A neural structure lying below (hypo) the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.

Hippocampus

A neural center located in the limbic system; helps process for storage explicit (conscious) memories of facts and events.

Cerebral Cortex

The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information-processing center.

Frontal Lobes

The portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgments.

Parietal Lobes

The portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position

Occipital Lobes

The portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields.

Temporal Lobes

The portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear.

Motor Cortex

An area at the rear of the frontal lobes that controls voluntary movements.

Somatosensory Cortex

An area at the front of the parietal lobes that registers and processes body touch and movement sensations.

Association Areas

Areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking.

Plasticity

The brain's ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience.

Neurogenesis

The formation of new neurons.

Corpus Callosum

The large band of neural fibers connecting the two brain hemispheres and carrying messages between them.

Split Brain

A condition resulting from surgery that isolates the brain's two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them.

Consciousness

Our subjective awareness of ourselves and our environment.

Dual Processing

The principle that information is often simultaneously processed on separate conscious and unconscious tracks.

Blindsight

A condition in which a person can respond to a visual stimulus without consciously experiencing it.

Parallel Processing

Processing many aspects of a problem simultaneously; generally used to process well-learned information or to solve easy problems.

Sequential Processing

Processing one aspect of a problem at a time; generally used to process new information or to solve difficult problems.

Chromosomes

Threadlike structures made of DNA molecules that contain the genes.

Epigenetics

"Above" or "in addition to" (epi) genetics; the study of environmental influences on gene expression that occur without a DNA change.

Resting Potential

when a neuron is not firing

Mirror Neuron

brain’s tendency to mimic what is being seen

Dopamine

in charge of mood, associated with schizophrenia

Serotonin

in charge of sleep and hunger, associated with depression

Epinephrine

adrenaline

Ach

muscles

Where do all senses but smell go to first in the brain?

Thalamus

Strongest sense

smell

Wernike’s Area

allows you to interpret spoken language, on the left

Broca’s Area

allows you to speak, on the left

Split Hemisphere

can help with epilepsy/ grand mal seizures

Pons

connects old and new brain

Exercise

causes endorphines to be produced

Multiple Sclerosis

When the myelin sheath deteriorates

Paradoxical Sleep

muscles are relaxed, but other body systems are active

psychoactive drug

a chemical substance that alters perceptions and moods

alcohol use disorder

alcohol use marked by tolerance, withdrawal, and a drive to continue problematic use

barbiturates

drugs that depress central nervous system activity, reducing anxiety but impairing memory and judgement

opiates

depresses neural activity, temporarily lessening pain and anxiety

cocaine

a stimulant that produces temporarily increased alertness and euphoria

methamphetamines

a powerfully addictive drug that stimulates the central nervous system, with accelerated body functions and associated energy and mood changes

ecstasy

\
a stimulant and mild hallucinogen; produces euphoria, emotional elevation, disinhibition, dehydration, depression, impairs mental/bodily functions; many short-term health risks and longer-term harm to serotonin

posthypnotic suggestion

a suggestion, made during a hypnosis session, to be carried out after the subject is no longer hypnotized

NREM 3

Delta Waves; Deep sleep

Paradoxical

Active Sleep

\
sleep

\
a periodic, natural loss of consciousness

circadian rhythm

\
regularly bodily rhythms that occur on a 24-hour cycle

REM sleep

\
a recurring sleep stage during which vivid dreams commonly occur

alpha waves

the relatively slow brain waves of a relaxed, awake state

suprachiasmatic nucleus

\
causes the pineal gland to adjust melatonin, thus modifying our feelings of sleepiness

insomnia

\
recurring problems in falling or staying asleep