Biopsychology: Genetics, Brain, and Nervous System

Vocabulary flashcards covering biological foundations of psychology, genetics, neurons, nervous system divisions, brain anatomy, and the endocrine system.

Sickle-cell anemia

A genetic condition in which red blood cells, which are normally round, take on a crescent-like shape, causing them to clog blood vessels and block blood flow.

Theory of evolution by natural selection

States that organisms better suited for their environment will survive and reproduce, while those poorly suited for their environment will die off.

Evolutionary psychology

Field of psychology focusing on how universal patterns of behavior and cognitive processes have evolved over time.

Behavioral genetics

Field studying how individual differences arise in the present through the interaction of genes and the environment.

Chromosome

Long string of genetic material known as deoxyribonucleic acid (DNA).

Deoxyribonucleic acid (DNA)

Helix-shaped molecule made of nucleotide base pairs that carries genetic information.

Gene

Sequence of DNA that controls or partially controls physical characteristics known as traits.

Allele

A specific version of a gene.

Genotype

The genetic makeup of an individual based on genetic material inherited from parents.

Phenotype

An individual's observable physical characteristics, determined by a combination of genetic and environmental influences.

Dominant allele

An allele whose phenotype will always be expressed in an individual that possesses that allele.

Recessive allele

An allele whose phenotype will only be expressed if an individual is homozygous for that allele.

Homozygous

Consisting of two identical alleles for a given gene.

Heterozygous

Consisting of two different alleles for a given gene.

Polygenic

Controlled by more than one gene.

Mutation

A sudden, permanent change in a gene.

Range of reaction

Asserts that our genes set the boundaries within which we can operate, and our environment interacts with the genes to determine where in that range we will fall.

Genetic environmental correlation

Concept asserting that our genes influence our environment, and our environment influences the expression of our genes bidirectionally.

Epigenetics

Study of gene-environment interactions focusing on how the same genotype can lead to different phenotypes.

Glial cell

Nervous system cell that provides physical and metabolic support to neurons, including insulation, waste transport, and scaffolding.

Neuron

Interconnected information processing cell essential for all tasks of the nervous system.

Soma

The cell body of a neuron, housing the nucleus.

Dendrite

Branch-like extension of the soma that receives incoming signals from other neurons.

Axon

Major extension from the soma that carries electrical signals down to the terminal buttons.

Terminal button

Axon terminal containing synaptic vesicles that house neurotransmitters.

Neurotransmitter

Chemical messenger of the nervous system.

Myelin sheath

Fatty substance formed by glial cells that coats the axon and increases signal transmission speed.

Nodes of Ranvier

Small gaps found down the length of the myelin sheath on an axon.

Synaptic cleft

Very small space between two neurons where communication occurs via neurotransmitters.

Receptors

Proteins on the cell surface where neurotransmitters attach in a lock-and-key relationship.

Resting potential

The state of readiness of a neuronal membrane's potential between signals.

Threshold of excitation

The charge level in a neuronal membrane required to trigger an action potential.

Action potential

Electrical signal that moves down the neuron's axon.

All-or-none phenomenon

Principle stating that an incoming signal is either sufficient or insufficient to reach the threshold of excitation, with no in-between.

Reuptake

Process where excess neurotransmitter is pumped back into the neuron that released it to clear the synapse.

Agonist

Chemical or drug that mimics or strengthens the effects of a neurotransmitter at receptor sites.

Antagonist

Chemical or drug that blocks or impedes the normal activity of a given neurotransmitter at receptor sites.

Central nervous system (CNS)

Subdivision of the nervous system comprised of the brain and spinal cord.

Peripheral nervous system (PNS)

Connects the central nervous system to the rest of the body through thick bundles of axons called nerves.

Somatic nervous system

Division of the PNS involved in relaying voluntary sensory and motor information to and from the CNS.

Autonomic nervous system

Division of the PNS controlling internal organs and glands, generally operating outside voluntary control.

Sympathetic nervous system

Division of the autonomic nervous system involved in preparing the body for stress-related activities.

Parasympathetic nervous system

Division of the autonomic nervous system associated with returning the body to routine, day-to-day operations.

Homeostasis

State of equilibrium or balance in which biological conditions are maintained at optimal levels.

Fight or flight response

Physiological changes from sympathetic activation allowing access to energy reserves and heightened sensory capacity to face or run from threats.

Neuroplasticity

The nervous system's ability to change, adapt, and reorganize in response to experience, development, or injury.

Cerebral cortex

Outer surface of the brain associated with higher-level mental functions, featuring gyri and sulci.

Gyri

Bumps or ridges on the cerebral cortex.

Sulci

Depressions or grooves in the cerebral cortex.

Longitudinal fissure

Deep groove that separates the brain into left and right hemispheres.

Corpus callosum

Thick band of neural fibers connecting the left and right hemispheres to allow interhemispheric communication.

Lateralization

Specialization of function in each hemisphere of the brain.

Frontal lobe

Part of the cerebral cortex involved in reasoning, motor control, emotion, and language; contains the motor cortex, prefrontal cortex, and Broca's area.

Motor cortex

Strip of cortex in the frontal lobe involved in planning and coordinating movement.

Prefrontal cortex

Area in the frontal lobe responsible for higher-level cognitive functioning such as judgment, reasoning, and impulse control.

Broca's area

Region in the left frontal lobe essential for language production.

Parietal lobe

Part of the cerebral cortex involved in processing body sensory information; contains the somatosensory cortex.

Somatosensory cortex

Strip of cortex essential for processing sensory information across the body, such as touch, temperature, and pain.

Temporal lobe

Part of the cerebral cortex associated with hearing, memory, emotion, and language; contains the auditory cortex and Wernicke's area.

Wernicke's area

Region in the temporal lobe important for speech comprehension.

Occipital lobe

Part of the cerebral cortex responsible for visual processing; contains the primary visual cortex.

Thalamus

Forebrain structure that serves as a sensory relay for all senses except smell.

Limbic system

Collection of brain structures involved in processing emotion and memory.

Hippocampus

Limbic system structure essential for learning and memory.

Amygdala

Limbic system structure involved in the experience of emotion and tying emotional meaning to memories.

Hypothalamus

Forebrain structure regulating homeostatic processes (e.g., temperature, appetite, blood pressure) and serving as an interface between nervous and endocrine systems.

Reticular formation

Midbrain structure regulating the sleep/wake cycle, arousal, alertness, and motor activity.

Substantia nigra

Midbrain structure producing dopamine, critical for movement, reward, and addiction.

Ventral tegmental area (VTA)

Midbrain structure producing dopamine, associated with mood, reward, and addiction.

Medulla

Hindbrain structure controlling automatic processes like breathing, blood pressure, and heart rate.

Pons

Hindbrain structure connecting the brain and spinal cord, involved in regulating brain activity during sleep.

Cerebellum

Hindbrain structure controlling balance, coordination, movement, motor skills, and procedural memory.

Computerized tomography (CT) scan

Imaging technique using multiple x-rays to create detailed images of body and brain tissues.

Positron emission tomography (PET) scan

Imaging technique using a mildly radioactive tracer to map active areas of the brain based on blood flow.

Magnetic resonance imaging (MRI)

Technique using magnetic fields to produce detailed pictures of tissue structures based on electromagnetic signals from hydrogen atoms.

Functional magnetic resonance imaging (fMRI)

Imaging technique showing changes in brain activity over time by tracking blood flow and oxygen levels.

Electroencephalography (EEG)

Technique recording overall electrical activity of the brain using electrodes placed on the scalp.

Endocrine system

Series of glands that produce chemical messengers known as hormones directly into the bloodstream.

Hormones

Chemical messengers secreted by endocrine glands that travel through the bloodstream to affect target cells.

Pituitary gland

Master gland of the endocrine system that secretes messenger and growth hormones under instructions from the hypothalamus.

Thyroid gland

Endocrine gland in the neck releasing hormones that regulate growth, metabolism, and appetite.

Adrenal gland

Glands atop the kidneys secreting stress response hormones like epinephrine and norepinephrine.

Pancreas

Internal organ secreting insulin and glucagon to regulate blood sugar levels.

Gonads

Endocrine glands (ovaries/testes) secreting sex hormones that mediate reproduction and sexual behavior.