Unit 3: Biological Bases Of Behavior Flashcards
Dendrite
A neuron’s bushy, branching extensions that receive messages and conduct impulses toward the cell body
Neuron
A nerve cell; the basic building block of the nervous system
Axon
The neuron extension that passes messages through its branches to other neurons or to muscles or glands
Myelin sheath
A fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next.
Action potential
A neural impulse; a brief electrical charge that travels down an axon
Refractory period
A period of inactivity after a neuron has fired
All-or-none response
A neuron’s reaction of either firing (with a full-strength response) or not firing
Synapse
The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap or synaptic cleft
Neurotransmitters
Chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse
Reuptake
A neurotransmitter’s reabsorption by the sending neuron
Endorphins
“morphine within”- natural, opiate-like neurotransmitters linked to pain control and to pleasure
Dopamine
Neurotransmitter/hormone that indicates pleasure
Agonist
A molecule that, by binding to a receptor site, stimulates a response
Antagonist
A molecule that, by binding to a receptor site, inhibits or blocks a response
Peripheral nervous system
The sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body
Central nervous system
the brain and spinal cord
Sensory neurons
Neurons that carry incoming information from the sensory receptors to the brain and spinal cord
Motor neurons
Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands
Endocrine system
The body’s “slow” chemical communication system; a set of glands that secrete hormones into the bloodstream
Hormones
Chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues
Adrenal gland
A pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress
Pituitary gland
The endocrine system’s most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands
Lesion
Tissue destruction; a brain lesion is a naturally or experimentally caused destruction of brain tissue
Brainstem
The oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions
Medulla
The base of the brainstem; controls heartbeat and breathing
Reticular formation
A nerve network that travels through the brainstem and thalamus and plays an important role in controlling arousal
Thalamus
The brain’s sensory control center, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla
Cerebellum
The “little brain” at the rear of the brainstem; functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory
Limbic system
Neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives
Amygdala
Two lima-bean-sized neural clusters in the limbic system; linked to emotion
Hypothalamus
A neural structure lying below (hypo) the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward
Cerebral cortex
The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body’s ultimate control and information-processing center
Frontal lobes
Portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgments
Parietal lobes
Portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position
Occipital lobes
Portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields
Temporal lobes
Portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear
Motor cortex
An area at the rear of the frontal lobes that controls voluntary movements
Somatosensory cortex
Area at the front of the parietal lobes that registers and processes body touch and movement sensations
Association areas
Areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking
Broca’s area
Speaking
Wernicke’s area
Understanding
Plasticity
The brain’s ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience
Neurogenesis
The formation of new neurons
Corpus-callosum
The large band of neural fibers connecting the two brain hemispheres and carrying messages between them
Split brain
A condition resulting from surgery that isolates the brain’s two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them
Left-brain specialization
Verbal, logical (makes sense of something)
Right-brain specialization
Face recognition, movement, making inferences, modulating speech, sense of self
Dual processing
The principle that information is often simultaneously processed on separate conscious and unconscious tracks
Genes
The biochemical units of heredity that make up the chromosomes; segments of DBA capable of synthesizing proteins.
Heritability
The proportion of variation among individuals that we can attribute to genes. The heritability of a trait may vary, depending on the range of populations and environments studied.
Epigenetics
The study of environmental influences on gene expression that occur without a DNA change
Identical Twins
monozygotic; twins who develop from a single fertilized egg that splits in two, creating two genetically identical organisms
Fraternal Twins
dizygotic; twins who develop form separate fertilized eggs. They are genetically no closer than brothers and sisters, but they share a fetal environment
Bouchard’s Twin Studies
Separated twins share similarities
Autonomic nervous system
The part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). It’s sympathetic division arouses; it’s parasympathetic division calms
Genes
The biochemical units of heredity that make up the chromosomes; segments of DNA capable of synthesizing proteins
Glial cells
Cells in the nervous system that support, nourish, and protects neurons; they may also play a role in learning and thinking
Behavior genetics
The study of the relative power and limits of genetic and environmental influences in behavior
Chromosomes
Threadlike structures made of DNA molecules that contain the genes
CT (computed tomography) scan
A series of X-Ray photographs taken from different angles and combined by computer into a composite representation of a slice of the brain’s structure
Electroencephalogram (EEG)
An amplified recording of the waves of electrical activity sweeping across the brain’s surface. These waves are measured by electrodes placed on the scalp
Endorphins
“Morphine within” - natural, opiate-like neurotransmitters linked to pain control and to pleasure
fMRI (functional MRI)
A technique doe revealing blood flow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show brain function as well as it’s structure
Sympathetic nervous system
The division do the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations
Parasympathetic nervous system
The division of the autonomic nervous system that calms the body, conserving its energy
Homeostasis
A tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry, such as blood glucose, around a particular level
Somatic nervous system
The division of the peripheral nervous system that controls the body’s skeletal muscles
Medulla
The base of the brainstorm; controls heartbeat and breathing
PET (position emission tomography) scan
A visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a give task
MRI (magnetic resonance imaging)
A technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. MRI scans show brain anatomy
Parietal lobes
Portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position
Hippocampus
A neural center located in the limbic system; helps process explicit memories for stories
Interneurons
Neurons within the brain and spin cord that communicate internally and intervene between the sensory inputs and motor outputs
Natural selection
The principle that, among the rand of inherited trait variations, those contributing to reproduction and survival will most likely be passed on to succeeding generations
Identical twins (monozygotic twins)
Twins who develop from a single fertilized egg that splits in two, creating two genetically identical organisms
