Comprehensive Neurobiology and Brain Function: Nervous System, Brain Structures, and Influence of Genes and Environment

Nervous system

A network of billions of cells in the brain and the body, responsible for all aspects of what we feel, think, and do.

Central nervous system

The part of the nervous system that consists of the brain and the spinal cord.

Peripheral nervous system

The part of the nervous system that enables nerves to connect the central nervous system to the skin, muscles, organs, and glands.

Neurons

Cells that receive, integrate, and transmit information in the nervous system.

Dendrites

Branchlike extensions of the neuron with receptors that detect information from other neurons.

Cell body

The part of the neuron where information from thousands of other neurons is collected and integrated.

Axon

The long, narrow outgrowth of a neuron that enables it to transmit information to other neurons.

Terminal buttons

Parts of the neuron at the end of the axon(s) that release chemical signals from the neuron into the synapse.

Synapse

The site of communication between neurons through neurotransmitters.

Neurotransmitters

Chemical substances that carry signals from one neuron to another.

Three basic functions of the nervous system

1. Receive sensory input from the world through vision, hearing, touch, taste, and smell. 2. Process the information in the brain by paying attention to it, perceiving it, and remembering it. 3. Respond to the information by acting on it.

Electrical properties of neurons

Parts of the neuron are covered with a membrane, which is semipermeable.

Neural networks

Connections formed by neurons that communicate selectively with each other.

Neurons operate

Through electrical impulses and connect with other neurons through chemical signals.

Neurons communicate

By selectively connecting with other neurons and forming networks.

Neurotransmitter function

To carry signals from one neuron to another across the synapse.

Survival programs in the brain

Basic programs housed in the hindbrain and midbrain that are essential for survival.

Forebrain subcortical structures

Control your motivations and emotions.

Cerebral cortex

Processes your complex mental activity.

Hemispheres of the brain

Work together with some specialization.

Learning disability

How psychology can be used in life to succeed despite challenges.

Endocrine system

Affects your behavior through hormones.

Genes and behavior

Your genes affect your mental activity and behavior.

Gene-environment interaction

Your genes interact with your environment to influence you.

Environmental impact on the brain

Your environment changes your brain.

Action potential

The neural impulse that travels along the axon and then causes the release of neurotransmitters into the synapse.

Myelin sheath

Fatty layer that insulates the axon.

Transmission phase

Neurons pass signals to receiving neurons.

Reception phase

Neurons receive signals from neighboring neurons.

Integration phase

Neurons assess the incoming signals.

Reuptake

Involves reabsorbing neurotransmitters into the presynaptic neuron.

Enzyme degradation

Involves the breaking down of neurotransmitters.

Excitatory signals

Increase the likelihood that the neuron will fire an action potential.

Inhibitory signals

Inhibit the neuron and decrease the likelihood that the neuron will fire an action potential.

Agonists

Drugs that enhance the actions of neurotransmitters.

Antagonists

Drugs that inhibit the actions of neurotransmitters.

Phrenology

Analysis of personality based on the location and size of skull bumps.

Broca's area

A small portion of the left frontal region of the brain, which is crucial for producing speech.

Presynaptic neuron

The neuron that releases neurotransmitters into the synapse.

Postsynaptic neuron

The neuron that receives signals through receptors.

Receptors

Specialized sites that specifically respond to certain types of neurotransmitters.

Fatty layer

The myelin sheath that insulates the axon.

Chemical communication

The process by which neurons communicate through neurotransmitters.

Electroencephalograph (EEG)

This measurement is useful because different behavioral states produce different and predictable EEG patterns.

Functional magnetic resonance imaging (fMRI)

This technique measures changes in the blood's oxygen level.

Transcranial magnetic stimulation (TMS)

This technique uses a very fast and powerful magnetic field to momentarily disrupt activity in a specific brain region.

Spinal cord

The spinal cord is the gateway for information between the brain and body.

Medulla

Located at the top of the spinal cord, it controls survival functions such as heart rate and breathing.

Pons

Located above the medulla, it regulates sleep and arousal and coordinates movements of the left and right sides of the body.

Cerebellum

Located at the back of the brain stem, it is essential for coordinated movement and balance.

Midbrain

The midbrain is involved in reflexive movement of the eyes and body.

Substantia nigra

Initiation of voluntary motor activity; this region is critical for the production of dopamine.

Parkinson's disease

Caused by the death of substantia nigra cells and the resulting loss of dopamine produced by those cells.

Thalamus

Gateway to the brain for almost all incoming sensory information before that information reaches the cortex.

Hypothalamus

Involved in regulating bodily functions and influences our basic motivated behaviors.

Hippocampus

Associated with the formation of memories.

Amygdala

Vital for processing the emotional significance of stimuli, especially fear, and involved in memory processing during times of emotional arousal.

Left hemisphere

One of the two halves of the cerebral cortex.

Right hemisphere

The other half of the cerebral cortex.

Corpus callosum

A massive bridge consisting of millions of axons that connects the two hemispheres.

Occipital lobes

Regions of the cerebral cortex at the back of the brain; these regions are important for vision.

Parietal lobes

Regions of the cerebral cortex in front of the occipital lobes and behind the frontal lobes; these regions are important for the sense of touch and for picturing the layout of spaces in an environment.

Temporal lobes

Regions of the cerebral cortex involved in processing auditory information and memory.

Frontal lobes

Regions of the cerebral cortex associated with reasoning, planning, and problem-solving.

Homunculus

The primary somatosensory and motor representation in the brain.

Prefrontal cortex

Occupies 30 percent of the brain; its complexity and organization differ from those of other animals.

Lobotomy

A deliberate damaging of the prefrontal cortex to control behavior.

Split brain

A condition in which the corpus callosum is surgically severed, preventing direct information transfer between the two hemispheres.

Split-brain patient

A patient whose hemispheres are separated, preventing information transfer between them.

Gazzaniga's experiment

Found that a split-brain patient could be aware of an object touched by the left hand but could not verbalize it due to lack of communication between hemispheres.

Left brain/right brain myth

The misconception that left-brain thinkers are more rational and analytical while right-brain thinkers are more creative and holistic.

Examples of learning disabilities

Whoopi Goldberg with dyslexia and Michael Phelps with ADHD.

Professional assistance for learning disabilities

Recommended if one suspects they may have a learning disability.

Equal opportunity in education

Schools must provide equal opportunity to the benefits of education for people with learning disabilities.

Peripheral Nervous System (PNS)

Includes the nerves throughout the body, in addition to the central nervous system (CNS).

Central Nervous System (CNS)

Composed of the brain and spinal cord.

Somatic nervous system

A subdivision of the peripheral nervous system that transmits sensory and motor signals between the central nervous system and the skin, muscles, and joints.

Autonomic nervous system

The second subdivision of the peripheral nervous system that transmits sensory and motor signals between the central nervous system and the body's glands and internal organs.

Sympathetic nervous system

One of the two divisions of the autonomic nervous system that controls the activity of organs and glands.

Parasympathetic nervous system

The second division of the autonomic nervous system that controls the activity of organs and glands.

Hormones

Chemical substances released from endocrine glands that travel through the bloodstream to targeted tissues, influencing them.

Gonads

The testes in males and the ovaries in females.

Androgens

Hormones, such as testosterone, that are more prevalent in males.

Estrogens

Hormones, such as estradiol, that are more prevalent in females.

Growth hormone (GH)

A hormone that prompts bone, cartilage, and muscle tissue to grow and helps them regenerate after injury.

Natural selection

The idea that those who inherit characteristics that help them adapt to their environments have an advantage over those who do not.

Genes

Units of heredity that partially determine an organism's characteristics.

Genotype

The genetic code that never changes.

Phenotype

The observable result of genetic code that can also be affected by the environment.

Behavioral genetics

The study of how genes and environment interact to influence mental activity and behavior.

Twin studies

Research methods that compare and contrast monozygotic (identical) twins and dizygotic (fraternal) twins.

Adoption studies

Research methods that compare the similarities between biological relatives and adoptive relatives.

Epigenetics

A field that studies how closely the environment affects gene expression.

Plasticity

A property of the brain that causes it to change through experience, drugs, or injury.

Neurogenesis

The production of new neurons, which can occur in some areas of the brain.

Neural pruning

The process where connections that are not strong and not needed are 'pruned' so that other connections can be strengthened.

Brain reorganization

The development of entirely new connections between neurons, which is a major factor in recovery from brain injury.