- action potential
- electrical signal that moves down the neuron’s axon
- adrenal gland
- sits atop our kidneys and secretes hormones involved in the stress response
- agonist
- drug that mimics or strengthens the effects of a neurotransmitter
- all-or-none
- phenomenon that incoming signal from another neuron is either sufficient or insufficient to reach the threshold of excitation
- allele
- specific version of a gene
- amygdala
- structure in the limbic system involved in our experience of emotion and tying emotional meaning to our memories
- antagonist
- drug that blocks or impedes the normal activity of a given neurotransmitter
- auditory cortex
- strip of cortex in the temporal lobe that is responsible for processing auditory information
- autonomic nervous system
- controls our internal organs and glands
- axon
- major extension of the soma
- biological perspective
- view that psychological disorders like depression and schizophrenia are associated with imbalances in one or more neurotransmitter systems
- Broca’s area
- region in the left hemisphere that is essential for language production
- central nervous system (CNS)
- brain and spinal cord
- cerebellum
- hindbrain structure that controls our balance, coordination, movement, and motor skills, and it is thought to be important in processing some types of memory
- cerebral cortex
- surface of the brain that is associated with our highest mental capabilities
- chromosome
- long strand of genetic information
- computerized tomography (CT) scan
- imaging technique in which a computer coordinates and integrates multiple x-rays of a given area
- corpus callosum
- thick band of neural fibers connecting the brain’s two hemispheres
- dendrite
- branch-like extension of the soma that receives incoming signals from other neurons
- deoxyribonucleic acid (DNA)
- helix-shaped molecule made of nucleotide base pairs
- diabetes
- disease related to insufficient insulin production
- dominant allele
- allele whose phenotype will be expressed in an individual that possesses that allele
- electroencephalography (EEG)
- recording the electrical activity of the brain via electrodes on the scalp
- endocrine system
- series of glands that produce chemical substances known as hormones
- epigenetics
- study of gene-environment interactions, such as how the same genotype leads to different phenotypes
- fight or flight response
- activation of the sympathetic division of the autonomic nervous system, allowing access to energy reserves and heightened sensory capacity so that we might fight off a given threat or run away to safety
- forebrain
- largest part of the brain, containing the cerebral cortex, the thalamus, and the limbic system, among other structures
- fraternal twins
- twins who develop from two different eggs fertilized by different sperm, so their genetic material varies the same as in non-twin siblings
- frontal lobe
- part of the cerebral cortex involved in reasoning, motor control, emotion, and language; contains motor cortex
- functional magnetic resonance imaging (fMRI)
- MRI that shows changes in metabolic activity over time
- gene
- sequence of DNA that controls or partially controls physical characteristics
- genetic environmental correlation
- view of gene-environment interaction that asserts our genes affect our environment, and our environment influences the expression of our genes
- genotype
- genetic makeup of an individual
- glial cell
- nervous system cell that provides physical and metabolic support to neurons, including neuronal insulation and communication, and nutrient and waste transport
- gonad
- secretes sexual hormones, which are important for successful reproduction, and mediate both sexual motivation and behavior
- gyrus
- (plural: gyri) bump or ridge on the cerebral cortex
- hemisphere
- left or right half of the brain
- heterozygous
- consisting of two different alleles
- hindbrain
- division of the brain containing the medulla, pons, and cerebellum
- hippocampus
- structure in the temporal lobe associated with learning and memory
- homeostasis
- state of equilibrium—biological conditions, such as body temperature, are maintained at optimal levels
- homozygous
- consisting of two identical alleles
- hormone
- chemical messenger released by endocrine glands
- hypothalamus
- forebrain structure that regulates sexual motivation and behavior and a number of homeostatic processes; serves as an interface between the nervous system and the endocrine system
- identical twins
- twins that develop from the same sperm and egg
- lateralization
- concept that each hemisphere of the brain is associated with specialized functions
- limbic system
- collection of structures involved in processing emotion and memory
- longitudinal fissure
- deep groove in the brain’s cortex
- magnetic resonance imaging (MRI)
- magnetic fields used to produce a picture of the tissue being imaged
- medulla
- hindbrain structure that controls automated processes like breathing, blood pressure, and heart rate
- membrane potential
- difference in charge across the neuronal membrane
- midbrain
- division of the brain located between the forebrain and the hindbrain; contains the reticular formation
- motor cortex
- strip of cortex involved in planning and coordinating movement
- mutation
- sudden, permanent change in a gene
- myelin sheath
- fatty substance that insulates axons
- nervous system
- made up of billions of neurons and controls our thoughts, responses, and movements; divided into the central nervous system (CNS) and the peripheral nervous system (PNS)
- neuron
- cells in the nervous system that act as interconnected information processors, which are essential for all of the tasks of the nervous system
- neuroplasticity
- nervous system's ability to change
- neurotransmitter
- chemical messenger of the nervous system
- Nodes of Ranvier
- open spaces that are found in the myelin sheath that encases the axon
- occipital lobe
- part of the cerebral cortex associated with visual processing; contains the primary visual cortex
- pancreas
- secretes hormones that regulate blood sugar
- parasympathetic nervous system
- associated with routine, day-to-day operations of the body
- parietal lobe
- part of the cerebral cortex involved in processing various sensory and perceptual information; contains the primary somatosensory cortex
- peripheral nervous system (PNS)
- connects the brain and spinal cord to the muscles, organs and senses in the periphery of the body
- phenotype
- individual’s inheritable physical characteristics
- pituitary gland
- secretes a number of key hormones, which regulate fluid levels in the body, and a number of messenger hormones, which direct the activity of other glands in the endocrine system
- polygenic
- multiple genes affecting a given trait
- pons
- hindbrain structure that connects the brain and spinal cord; involved in regulating brain activity during sleep
- positron emission tomography (PET) scan
- involves injecting individuals with a mildly radioactive substance and monitoring changes in blood flow to different regions of the brain
- prefrontal cortex
- area in the frontal lobe responsible for higher-level cognitive functioning
- psychotropic medication
- drugs that treat psychiatric symptoms by restoring neurotransmitter balance
- range of reaction
- asserts 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
- receptor
- protein on the cell surface where neurotransmitters attach
- recessive allele
- allele whose phenotype will be expressed only if an individual is homozygous for that allele
- resting potential
- the state of readiness of a neuron membrane’s potential between signals
- reticular formation
- midbrain structure important in regulating the sleep/wake cycle, arousal, alertness, and motor activity
- reuptake
- neurotransmitter is pumped back into the neuron that released it
- semipermeable membrane
- cell membrane that allows smaller molecules or molecules without an electrical charge to pass through it, while stopping larger or highly charged molecules
- soma
- cell body
- somatic nervous system
- relays sensory and motor information to and from the CNS
- somatosensory cortex
- essential for processing sensory information from across the body, such as touch, temperature, and pain
- substantia nigra
- midbrain structure where dopamine is produced; involved in control of movement
- sulcus
- (plural: sulci) depressions or grooves in the cerebral cortex
- sympathetic nervous system
- involved in stress-related activities and functions
- synaptic cleft
- small gap between two neurons where communication occurs
- synaptic vesicle
- storage site for neurotransmitters
- temporal lobe
- part of cerebral cortex associated with hearing, memory, emotion, and some aspects of language; contains primary auditory cortex
- terminal button
- axon terminal containing synaptic vesicles
- thalamus
- sensory relay for the brain
- theory of evolution by natural selection
- states that organisms that are better suited for their environments will survive and reproduce compared to those that are poorly suited for their environments
- threshold of excitation
- level of charge in the membrane that causes the neuron to become active
- thyroid
- secretes hormones that regulate growth, metabolism, and appetite
- ventral tegmental area (VTA)
- midbrain structure where dopamine is produced: associated with mood, reward, and addiction
- Wernicke’s area
- important for speech comprehension