Unit 2 - Biological Bases of Behavior Flashcards
Heredity
The genetic transfer of characteristics from parents to offspring.
Nature
Comes from inheritance or genetics.
Nurture
Environmental factors or external factors that one experiences.
Evolutionary Persepctive
The study of evolution of behavior and the mind using principles of natural selection.
Natural Selection
The principle that inherited traits enable an organism to survive and reproduce in a particular environment; most likely to be passed on to succeeding generations.
Eugenics
View that the genetic makeup of the population can be improved by selective breeding and by preventing reproduction by people of various disabilities.
Twin Studies
Used to assess the relative contributions of heredity and environment by comparing identical twins and fraternal twins who have been reared (raised) together and/or reared apart.
Family Studies
Studies conducted among siblings, parents, and children to assess evidence for genetic links for characteristics or outcomes (often related to health or disease).
Adopted Studies
Studies used to investigate the relationships among genetic and environmental factors by comparing the similarities of biological parent-child pairs with those of adoptive parent-child pairs.
Neuron
Nerve cell that transmits information; basic building block of the nervous system.
Dendrites
Bushy, branching extensions that receive messages from other nerve cells and conduct impulses toward the cell body.
Axon
Extension that sends impulses to other nerve cells or to the muscles or glands.
Myelin Sheath
Layer of fatty tissue that covers many axons and helps the speed of neural impulses.
Multiple Sclerosis
Disease caused by loss of myelin sheath in the CNS resulting in severe fatigue, problems with sensations, and difficulty with motor skills.
Myasthenia Gravis
Autoimmune disorder where the body produces antibodies against ACh receptors causing faulty transmissions on nerve impulses at neuromuscular junctions.
Glial Cells
Guide neural connections and provide nutrients and insulated myelin while helping to remove excess ions and neurotransmitters; support cells.
Resting Potential
When the neuron is at rest, the positive sodium ions are on the outside and the negative potassium ions are on the inside. Action potential makes the ions switch places.
Action Potential
Neural impulse generated by the movement of positively charged atoms in and out of the channels in the axon’s membrane.
Depolarization
The increase in sodium ions moving inside the cell making the inside more positive than negative which results in the potassium ions getting pushed outside.
Threshold
Level of stimulation that must be exceeded for the neuron to fire or generate an electrical impulse.
All or nothing principle
Either cells fire if the charge inside reaches a threshold or it doesn’t fire.
Synapse
Junction between axon tip of the sending neuron and dendrite of the receiving neuron; the tiny gap at this junction is called the synaptic gap or cleft.
Neurotransmitters
Chemicals that are released into synaptic gaps and transmit neural messages from neuron to neuron.
Acetylcholine (ACh)
Involved in learning, memory, muscle contractions, and voluntary movement. Alzheimer’s disease due to ACh producing neurons deteriorate.
Dopamine
Involved with movement, thought processes, and rewarding sensations. Too much dopamine leads to schizophrenia. Too little dopamine leads to Parkinson’s. Also diseases to addictive behaviors (gambling).
Serotonin
Involved with emotional states like mood, emotion, appetite, sexual desire, and sleep. Too little leads to depression.
Norepinephrine
Involved with physical arousal and learning. Too little leads to mania and depression. People with life threatening illnesses can take injections of this due to reduce life threatening responses.
GABA
Involved with inhibiting brain activity and calms the central nervous system. Inadequate action leads to anxiety disorders such as phobias or panic attacks. Undersupply leads to insomnia or seizures.
Endorphins
Involved with pain perception and positive emotions; “runner’s high.” Oversupply with opioid drugs can suppress body’s natural endorphin supply. “Endorphins end pain.”
Substance P
Involved in pain perception and immune response.
Reuptake
Sending neuron reabsorbs excess neurotransmitter molecules left in the synapse.
Agonist
A molecule that excites and is similar enough in structure to the neurotransmitter to mimic its effects on the receiving neuron.
Antagonist
A molecule that excites and is similar enough in structure to the neurotransmitter to occupy its receptor site and block its action.
Stimulants
Psychoactive drugs that excite neural activity and speed up bodily functions; caffeine, nicotine, amphetamines, and cocaine.
Caffeine
Most used drug in the world; acts as adenosine-receptor antagonist causing people to have a rush of energy and stay awake.
Cocaine
Blocks the reuptake of dopamine, serotonin, and norepinephrine; causes an immediate rush followed by an eventual crash.
Depressants
Psychoactive drug that reduces neural activity and slows body functions; alcohol, opiates which relieve pain and barbiturates which induce sleep or reduce anxiety.
Alcohol
Slows neural processing and thinking, impairs physical activity, reduces self-awareness, and impairs memory and REM sleep; intensifies GABA and reduced glutamate, causing sluggish movements, slurred speech, and impaired judgements.
Opioids
A narcotic that reduces neurotransmission and temporarily lessens pain and anxiety by reducing GABA and slows release of dopamine.
Hallucinogens
Psychoactive drugs that distort perception and evoke sensory imagery in the absence of sensory input; marijuana.
THC
Mild hallucinogen and most active ingredient in marijuana causing mild euphoria, relaxation, and increased auditory and visual perceptions; chronic use can impair memory and learning and lower attention.
Psychoactive Drugs
Chemical substances that alter mood and perception; work by affecting and mimicking the activity of neurotransmitters; able to pass through blood-brain barrier, a semi-permeable membrane that protects the brain from substances that may cause injury.
Addiction
Compulsive craving of drugs or certain behaviors despite adverse consequences.
Tolerance
Diminishing of a psychoactive drug’s effect that occurs with repeated use and need for progressively larger doses to produce the same effect.
Withdrawal
Discomfort and distress that follow the discontinued use of addictive drugs (cravings, tremors, anxiety, depression, seizures, death)
Central Nervous System
Brain and spinal cord; located in the center of the body.
Peripheral Nervous System
Connects the central nervous system to the body’s sense receptors, muscles, and glands; found in the periphery of the body.
Sensory Neurons
Carry information from sense receptors to the central nervous system for processing.
Interneurons
Neurons of the central nervous system that link sensory and motor neurons.
Motor Neurons
Carry information and instructions for action from the central nervous system to muscles and glands.
Somatic Nervous System
Division of the peripheral nervous system that controls voluntary movements of the skeletal muscles.
Autonomic Nervous System
Division of the peripheral nervous system that controls the glands and the muscles of internal organs and thereby controls internal functioning; it regulates automatic behaviors necessary for survival.
Sympathetic Nervous System
Division of the autonomic nervous system that arouses the body and mobilizes energy for stressful situations; pupils dilate, heartbeat accelerates, digestion is inhibited, glucose is released by the liver, adrenal gland secretes epinephrine/norepinephrine.
Parasympathetic Nervous System
Division of the autonomic nervous system that calms the body and conserves energy; pupils contract, heartbeat slows, digestion resumes.
Reflex Arc
Occurs when a signal is sent from a sensory organ to the spinal cord, which processes the information instead of passing it on to the brain.
Lesion
Destruction of tissue; studying consequences of lesions in different regions of the brain helps researchers to determine the normal functions of these regions.
Electroencephalogram (EEG)
Amplified recording of the waves of electrical activity in the brain.
fMRI (functional magnetic resonance imaging)
Technique for revealing blood flow and brain activity by comparing successive MRI scans; shows both brain function and structure.
Brainstem
Oldest and innermost region of the brain, extension of the spinal cord and central cord of the brain; its structures dialect automatic survival functions.
Medulla
Life and Love! Controls breathing and heartbeat; part of the brainstem.
Reticular Activating System
Nerve network that controls arousal; if damaged, a coma occurs (research by Moruzzi and Magoun); runs through the brainstem.
Pons
Helps to coordinate movements because it is the bridge to the cerebellum, pons is part of the brainstem.
Thalamus
Routes incoming messages (“sensory switchboard” except for smell) to the appropriate cortical centers and transmits replies to the medulla and cerebellum; located at the top of the brainstem.
Cerebellum
Assists in fine motor control, posture, balance, and coordination of voluntary movement; “little brain.”
LImbic System
Donut shaped neural system located at the border of the brainstem and cerebral hemispheres; plays an important role in the regulation of emotions and basic psychological drives.
Amygdala
Part of the limbic system involved in regulation of the emotions of fear and rage.
Hypothalamus
Part of the limbic system that regulates hunger, thirst, body temperature, and sex; “the reward or pleasure center of the brain” per Olds and Milner.
Hippocampus
Part of the brain that deals with memory and learning.
Pituitary gland
Controlled by the hypothalamus; regulates growth and controls other endocrine glands; called the “master gland”; issues cause gigantism (excessive growth and height) and dwarfism (slow growth and ill proportioned body size)
Cerebrum or cerebral cortex
Thin outer converting of the central hemispheres that is the seat of the information processing and responsible for complex functions that make us distinctively human.
Frontal Lobes
Front of the brain behind the forehead that is involved in speaking and motor/muscle movements and making plans, reasoning, personality, judgements, willpower, language; referred to as executive functions.
Motor Cortex
Located in the back of the frontal lobes; controls voluntary movement, receiving information from and working with other parts of the brain.
Parietal Lobes
Located between the frontal and occipital lobes; contains the sensory cortex and deals with touch, pressure, temperature, and pain.
Somatosensory Cortex
Located in the front of the parietal lobes; registers and processes body sensations.
Association Areas
Located throughout the Cortex, involved in higher level mental functions such as learning, remembering, and abstract thinking; involved in associating information from different parts of the brain.
Occipital Lobes
Located in the back and base of the brain; contains the visual cortex which receives information from the eyes.
Temporal Lobes
Located at the sides (the temples) of the brain; contain auditory areas with receive information from the ears.
Wernicke’s Area
Located in the left temporal lobe and is involved in language comprehension.
Broca’s Area
Located in the left frontal lobe and is involved in controlling the motor ability to produce speech.
Aphasia
Impairment of language because of damage to any of several cortical areas including Broca’s and/or Wernicke’s area.
Prosopagnosia
Also called face blindness, can see various parts of the face but can’t identify the person whose face it is.
Plasticity
Brain’s capacity for modification; research of brain reorganization following damage.
Corpus Callosum
Large band of neural fibers that links the right and left cerebral hemispheres and without this band of fibers, the two hemispheres cannot interact.
Split Brain
Condition in which the major connections between the two cerebral hemispheres (corpus callosum) are severed resulting in split brain.
