Unit 2

Neuroscience

The scientific study of neurons and the nervous system.

Neuron(s)

The basic "building block" cell of the Nervous System. There are many types.

Dendrite(s)

The branch-like projections on Neurons that *Receive Messages* from other Neurons.

Soma

The *Cell Body* of a Neuron, which is composed of a Nucleus surrounded by cytoplasm enclosed in a membrane.

Axon(s)

The tail of a Neuron along which *Electrical Signals are Carried*, which is achieved by a brief change in the electric charge of the cell.

Axon Hillock(s)

The juncture between the Cell Body and the Axon.

Myelin (Sheath)

A fatty white substance wrapped around the axon that both protects the axon and increases the speed of the Action Potential.

Action Potential

The brief change in electrical charge that radiates down the axon.

Multiple Sclerosis

An autoimmune disease where the body attacks the *Myelin Sheaths* on neurons, which can lead to loss of strength, muscle control, and coordination.

Terminal Button(s)

Knobs at the end of each axon from which neurotransmitters are released into the synapse.

Synapse

Where one neuron's terminal buttons meet another neuron's dendrites to exchange information through neurotransmitters.

Presynaptic

The ___________________ Neuron is the one that comes *Before* the synapse, and releases the neurotransmitters.

Postsynaptic

The ___________________ Neuron is the one that comes *After* the synapse, and *Receives Signals* at its Dendrites.

Neural Chain

A term used to describe the web of interconnections between Neurons.

Depolarization

The first step towards conducting a signal along a Neuron where Na+ Ions rush *Into* the cell and K+ ions temporarily rush *Out* of the cell, leaving more positive charges on the inside.

Firing Threshold

The point at which enough positive charges have built up inside the Neuron that an Action Potential will be produced.

Refractory (Period)

The brief period after a Neuron Fires during which it *Cannot* fire again.

Resting Potential

The electrical state of the cell when not in use, sitting at -70mV.

Vesicle(s)

The sub-cellular structures that *Release Neurotransmitters* when stimulated with an Action Potential.

Reuptake

The process by which chemicals are released by the Synaptic Cleft and *Re-enter* the original Neuron to be used again.

Afferent (Neurons)

Neurons which carry sensory information to the Central Nervous System.

Interneuron(s)

Neurons which make up the brain and spinal chord.

Efferent (Neurons)

Neurons which transmit motor messages from the Central Nervous System to muscles and glands.

Reflex Arc

A term to describe the process by which sensory signals are sent directly to the Spinal Cord and then to motor neurons before the brain is ever engaged, allowing for *Faster Reaction Times*.

Glial (Cells)

Support cells in the brain that far outnumber Neurons. They act to provide *Nutrients* and *Myelin*, as well as function as *Immune* cells in the brain.

(Genetic) Predisposition

An inclination towards some characteristic that could be the result of *Genetics* or the *Environment*.

Epigenetic(s)

The phenomenon where your environment influences which genes are biologically expressed.

Genotype

Which combination of genes are physically in your DNA.

Phenotype

The traits that are actually expressed as a result of Environmental and Genotypic conditions.

23

Humans have _____(#) *Pairs* of Chromosomes

XX

The chromosome pairing for *Biological Females*.

XY

The chromosome pairing for *Biological Males*.

Determinism

Genetic _________________ states that you are *Definitely* going to express some certain trait.

Turner Syndrome

A Genetic Abnormality where there is an *Incomplete Y Chromosome* (XO) that can lead to physical and intellectual defects.

Down Syndrome

A Genetic Abnormality where there is an *Extra 21st Chromosome* that can lead to Intellectual Disabilities, enlarged tongues, and short stature, among other things.

Williams Syndrome

A Genetic Abnormality where there is a deletion of a certain gene on the *7th Chromosome* that leads to *Extreme Extroversion*. They are below average intellectually and cannot form prejudices.

PKU

*Phenylketonuria* - A Genetic Abnormality where to recessive genes lead to the absence of an *Enzyme* that breaks down a certain protein that attacks the Central Nervous System.

Lesion(ing)

A brain research method where a part of the brain is *Surgically Removed*.

Phineas Gage

A 19th century railroad worker who had part of his Frontal/Prefrontal cortex removed by a *Projectile Tamping Iron*. He survived and provided unique insight into the *Specificity* of the brain.

Contralateralization

The term used to describe how each side of the brain controls the opposite side of the body.

Specificity

The term used to describe how certain areas of the brain are designed for certain tasks/events.

Hemispherectomy

The surgical procedure by which one hemisphere of the brain is removed, usually to combat life threatening disorders such as epilepsy.

Frontal (Lobe)

The Cerebral *Lobe* that plays roles in speaking and muscular activity, located towards the *Front* of the head.

Prefrontal Cortex

The brain area that acts as the executive of the brain, carrying out *Planning, Decision Making, Judgement*, and *Self-Control*. It's located towards the *Front* of the Frontal Lobe.

Motor Cortex

The part of the brain responsible for every *Voluntary Movement* and located along the *Border of the Parietal Lobe*.

Somatosensory Cortex

The part of the brain that registers all *Touch Sensations* and is located along the *Border of the Frontal Lobe*.

Broca's Area

The brain area responsible for *Creating Expressive Speech* located in the *Frontal Lobe*.

Parietal (Lobe)

The large *Lobe* on the *Top/Crown* of the head that houses the Somatosensory Cortex.

Occipital (Lobe)

The *Lobe* to the *Rear* of the Cortex that houses the Primary Visual Cortex.

Primary Visual Cortex

The brain area that is responsible for taking *Visual Sensory Input* and interpreting it. It's located in the very *Rear* of the head.

Temporal (Lobe)

The *Lobe* located to the *Sides* of the head, just above the ears, that houses the Auditory Cortex.

Auditory Cortex

The brain area responsible for taking *Auditory Input* and interpreting it. It's located in the Temporal Lobe.

Wernicke's Area

The brain area responsible, at least in part, for *Language Comprehension*, located in the *Temporal Lobe*.

Cortex

The wrinkled, convoluted shell of the brain that is divided into four lobes.

MRI

A *Brain Scan* technique that shows extreme *Structural Detail*. AKA *Magnetic Resonance Imaging*.

PET (Scan)

A *Brain Scan* technique that indicates *Levels of Activity* in general locations by using a tracer shot of *Radioactive Glucose*.

fMRI

A *Brain Scan* technique that shows extreme structure *AND* functional detail by measuring changes in oxygenation. AKA *Functional MRI*.

EEG

A *Brain Scan* technique that shows *Brain Wave* activity. It does *not* show *Location* very clearly, but is used extensively in *Sleep Studies*. AKA *Electroencephalogram*.

CT (Scan)

A *Brain Scan* technique that uses a 3D X-Ray machine to show *Structure* for Injuries. It can be used on other body parts as well.

Cerebellum

The brain structure involved in any *Coordinated Sequence of Movements* and is one *Center of Balance*. It's located at the brain stem below the Occipital Lobe.

Limbic System

The group of brain structures that are mostly responsible for *Emotion* and *Motivation*.

Hippocampus

The part of the *Limbic System* that is responsible for the *Formation* of *New Memories* and *Spatial Navigation*.

Amygdala

The part of the *Limbic System* that is heavily involved in Primitive Emotions like *Anger, Fear, and Aggression* and well as Sex Drive. It is also viewed to determine the *Emotional Relevance* of any incoming stimuli.

Hypothalamus

The part of the *Limbic System* that regulates Appetite, Thirst, Sex Drive, Sleep/Wake Cycle, Body Temperature, and the Fight or Flight Response. It also directs the *Pituitary Gland* in controlling the Endocrine System.

Lateral (Hypothalamus)

The part of the *Hypothalamus* that tells you to eat when you are hungry.

Ventromedial (Hypothalamus)

The part of the *Hypothalamus* that tells you to stop eating when you are satiated.

Pituitary Gland

The brain area considered to be the *Master Gland* that directs the endocrine system. It also secretes *HGH* and *Oxytocin*.

Pons

The jutting area on the Upper Spinal Chord that may be responsible for *Dreams*, but also plays a role in maintaining some vital functions.

Medulla

A band of nerve fibers below the Pons that controls *Autonomic Functions* like Heart Rate, Blood Pressure, and Swallowing. This

Medulla

Which structure is more important in controlling *Vital Autonomic Functions*, the Medulla or the Hypothalamus (Medulla/Hypothalamus)?

Corpus Callosum

A large bundle of fibers connecting the right and left hemispheres.

Thalamus

An egg shaped structure in the *Center* of the brain that takes in *All Sensory Information* (Except Smell), and reroutes it to it's corresponding cortex.

Reticular Formation

The *Brain Stem Structure* that *Alerts the Brain* to *Incoming Signals* so that the Brain is ready to react quicker. (AKA Reticular Activating System).

Ventricle(s)

Interconnected fluid filled extensions of the spinal chord that branch out within the interior of the brain. They provide *Cushioning* against damage.

Human Growth Hormone

*HGH* - Secreted by the Pituitary Gland throughout life, especially in Puberty.

Oxytocin

The *Tend and Befriend* hormone that helps humans create bonds between each other, especially between lovers and close friends.

Pineal (Gland)

A *Gland* located in the *Inner Central Brain* that secretes *Melatonin* to induce sleep.

Melatonin

A hormone that induces *Sleep* and is secreted by the *Pineal Gland*.

Thyroid (Gland)

A *Gland* located in the *Neck* that secretes *Thyroxine* and regulates *Growth and Metabolism*.

Thyroxine

A hormone that increases *Metabolism* and thus induces *Growth*. It is secreted by the *Thyroid*.

Adrenal(s)

*Glands* that are located above the *Kidneys* that secrete *Adrenaline/Epinephrine*.

Epinephrine

A hormone (and also a Neurotransmitter!) that is secreted by the *Adrenals* which induces the *Fight or Flight* response.

Pancreas

A *Gland/Organ* located in the *Central Abdomen* that secretes *Insulin*.

Insulin

A *Hormone* that promotes the absorption of Glucose into cells and is secreted by the *Pancreas*.

Testes

*Male Reproductive Glands* that secrete *Androgens* such as Testosterone.

Ovaries

*Female Reproductive Glands* that secrete *Estrogen*.

Hormones(s)

Chemical messengers carried throughout the *Blood* that are the primary communicators of the *Endocrine System*. They take longer to get to where they are going, but *Last Longer*.

Neurotransmitter(s)

Chemical messengers of the *Nervous System* that carry signals *Almost Instantly* in the synapses between Neurons.

Central (Nervous System)

The part of the *Nervous System* that is directly in the center of the body and consisting of the *Brain and Spinal Chord* that controls your survival.

Peripheral (Nervous System)

The part of the *Nervous System* that consists of all of the nerve cells that are *Not* part of the Central Nervous System.

Autonomic (System)

The division of the *Peripheral Nervous System* which controls things that happen *Sub-Consciously* (Hormone Secretion, Blood Pressure, etc.)

Somatic (System)

The division of the *Peripheral Nervous System* which controls *Voluntary Movements*.

Sympathetic (System)

The division of the *Autonomic System* which controls the *Fight or Flight* response.

Parasympathetic (System)

The division of the *Autonomic System* which is the *Opponent Process* to the Sympathetic System and works to return the body to a calm state.

Glutamate

The primary *Excitatory* neurotransmitter in the Brain.

Glutamate

*Too Much* _______________ activity can result in Seizure Disorders. It may also play a role in Bipolar degenerative disorders of CNS.

GABA

The primary *Inhibitory* neurotransmitter in the Brain (AKA Gamma Aminobutyric Acid).

GABA

*Low Levels* of ___________ are linked with *Anxiety* and *Seizure Disorders*.

Substance P

*High Levels* of this neurotransmitter that *Sends Pain Messages* may be linked with Fibromyalgia and other pain disorders.

Endorphin(s)

Neurotransmitters which *Alleviate Pain* (AKA Endogenous Morphine).