Unit 2

Nervous System

The body’s electrochemical communication circuitry.

Plasticity

The brain's special capacity for change.

Neuron

Nerve cell that allows electrical impulses to travel.

Afferent Nerves

Sensory nerves that carry information to the brain and spinal cord.

Efferent Nerves

Motor nerves that carry information out of the brain and spinal cord to communicate with muscles.

Neural Networks

Interconnected groups of nerve cells that integrate sensory input and motor output.

Central Nervous System

The brain and spinal cord.

Peripheral Nervous System

The network of nerves that connects the brain and spinal cord to other parts of the body.

Somatic Nervous System

Sensory and motor nerves that convey information between the skin, muscles, and central nervous system.

Autonomic Nervous System

The system that takes messages to and from the body’s internal organs.

Sympathetic Nervous System

Part of the autonomic nervous system that mobilizes the body for action.

Parasympathetic Nervous System

Part of the autonomic nervous system that calms the body.

Stress

The responses of individuals to environmental stressors.

Stressors

Circumstances and events that threaten individuals and cause physiological changes.

Corticosteroids

Powerful stress hormones released during stress.

Acute Stress

Momentary stress in response to life experiences.

Chronic Stress

Continuous stress that may lead to persistent autonomic nervous system arousal.

Mirror Neurons

Neurons activated during both performing and observing an action.

Glial Cells

Supportive cells in the nervous system that provide nutritional benefits.

Cell Body

The part of the neuron containing the nucleus.

Dendrites

Treelike fibers that receive information and direct it towards the cell body.

Axon

The part of the neuron that carries information away from the cell body.

Myelin Sheath

A layer of fat cells that insulates most axons.

Semipermeable

Membranes that allow fluids to flow in and out.

Ions

Electrically charged particles that create electrical signals in neurons.

Ion Channels

Open and close to allow ions to pass into and out of the cell.

Resting Potential

A stable negative charge of an inactive neuron.

Action Potential

A brief wave of positive electrical charge that sweeps down the axon.

All-or-nothing principle

The principle that an impulse fires completely or not at all.

Synapses

Tiny spaces between neurons where communication occurs.

Neurotransmitters

Chemicals that transmit information across the synaptic gap.

Reuptake

The process of reabsorbing neurotransmitters by the axon.

Acetylcholine

A neurotransmitter involved in stimulating neuron firing and muscle action.

GABA

A neurotransmitter believed to be involved in one-third of the brain's synapses.

Glutamate

A neurotransmitter key in exciting neurons and involved in learning and memory.

Norepinephrine

A neurotransmitter that inhibits CNS neurons but excites heart and digestive muscles.

Dopamine

A neurotransmitter that helps control voluntary movement and affects mood and learning.

Serotonin

A neurotransmitter involved in regulating sleep, mood, and attention.

Endorphins

Natural opiates that stimulate neuron firing.

Oxytocin

A hormone and neurotransmitter important for love and social bonding.

Agonist

A drug that mimics or increases a neurotransmitter's effects.

Antagonist

A drug that blocks a neurotransmitter’s effects.

Brain Lesioning

Disruption in brain tissue due to injury or disease.

Electroencephalograph (EEG)

A device that records the brain's electrical activity.

Positron-emission Tomography (PET)

A scan measuring metabolic changes in the brain.

Magnetic Resonance Imaging (MRI)

Imaging technique using magnetic fields and radio waves.

Hindbrain

The lowest portion of the brain, including the medulla, cerebellum, and pons.

Medulla

Controls vital functions like breathing and heart rate.

Cerebellum

Important for motor coordination.

Pons

Connects the hindbrain and brain stem, involved in sleep and arousal.

Brain Stem

Includes parts of the hindbrain and midbrain, resembling a stem.

Midbrain

Connects higher and lower brain portions.

Reticular Formation

A midbrain system involved in behavior patterns.

Forebrain

The largest and most important brain division.

Limbic System

A network of structures central to emotion and memory.

Amygdala

 An almond shaped structure located inside the brain towards the base involved in discrimination of objects that are necessary for the organisms survival such as appropriate mates, food ect (limbic)

Hippocampus

Has a special role in the storage of memories (limbic)

Thalamus

 A structure that sits on top of the brain stem; serves as an essential relay station, functioning much like a server in a computer network

Basal Ganglia

A cluster of neurons that sit below the cerebral cortex and atop the thalamus which works with the cerebellum and cerebral cortex to control and coordinate voluntary movements

Hypothalamus

 A small structure just below the thalamus which monitors three pleasurable activities: eating, drinking, and sexual behavior; regulates the bodys internal state

Cerebral Cortex

Outer layer of the brain responsible for the most complex mental functions such as thinking and planning

Neocortex

The outermost part of the cerebral cortex making up 80% of the brains cortex

Occipital Lobes

 Located at the back of the brain, respond to visual stimuli

Temporal Lobes

The part of the cerebral cortex just above the ears, involved in hearing, language processing, and memory

Frontal Lobes

The portion of the cerebral cortex behind the forehead are involved in personality, intelligence, and the control of voluntary muscles

Prefrontal Cortex

 A part of the frontal lobe that is involved in higher cognitive functions such as planning, reasoning, and self-control

Parietal Lobes

 Located at the top of the head are involved in registering spatial location, attention, and motor control

Somatosensory Cortex

 A region in the cerebral cortex that processes information bout body sensations

Motor Cortex

 A region in the cerebral cortex located just behind the frontal lobe that processes information about voluntary movements

Association Cortex

Sometimes called association areas is the region that holds the highest intellectual functions such as thinking and problem solving

Broca’s Area

plays an important role in the production of speech

Wernicke’s area

Comprehending language

Corpus Callosum

The bundle of axons connecting the brains two hemispheres and is responsible for relaying information

Left Hemisphere

Speech and grammar are localized to the left hemisphere; most language comes from this side

Right hemisphere

 Dominates nonverbal information such as spatial perception, visual recognition, and emotion

Endocrine System

Consists of a set of glands that regulate the activities of certain organs by releasing their chemical products into the bloodstream

Glands

- Organs or tissues in the body that create chemicals that control bodily functions

Hormones

The chemical messages that are produced by endocrine glands

Pituitary Gland

A pea sized gland that controls growth and regulates other glands

Adrenal Glands

Located at the top of each kidney which regulates mood, energy level, and ability to cope with stress

Pancreas

- Located under the stomach performs both digestive and endocrine functions

Ovaries/Testes

Sex related endocrine glands that produce hormone related to sexual development and reproduction

Collateral Sprouting

 Axons of some healthy neurons adjacent to damaged cells grow new branches

Substitution of function

Damaged region’s function is taken over by another area

Neurogenesis

The process by which new neurons are generated

Brain Grafts

Implants of healthy tissue into damaged brains

Stem Cells

Primitive cells that have the capacity to develop into most types of human cells

Chromosomes

Threadlike structures that come in 23 pairs that contain DNA

DNA

A complex molecule in the cells chromosomes that carries genetic information

Genes

 The units of hereditary information consisting of short segments of chromosomes composed of DNA

Dominant-recessive Gene Principles

If one gene of a pair is dominant and another is recessive, the dominant one overrides the recessive gene

Linkage Analysis

Link between what genes cause blue eyes for example

Genotype

- A person's genetic heritage

Phenotype

 Observable characteristics

Gene x environment interaction

 The interaction of a specific measurable variation in DNA and a specific measured aspect of the environment

Risk Factor

Characteristics, experiences, or exposures that increase the likelihood that a person will develop a psychological disorder