Unit Two: Biology Flashcards
Lesion
tissue destruction; a brain lesion is a naturally or experimentally created destruction of brain tissue
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
Dendrite
the fibers at the end of a cell body that receive information and conduct it toward the cell body
Myelin sheath
a layer of fatty tissue that insulates the axon and speeds its impulses
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 the synaptic cleft
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
Threshold
the level of stimulation required to trigger a neural impulse
All-or-none responce
a neuron’s reaction of either firing (with a full-strength response) or not firing
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
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
Nervous system
the body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems
Central nervous system (CNS)
the brain and spinal cord
Peripheral nervous system (PNS)
the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body
Nerves
bundled axons that form neural “cables” connecting the central nervous system with muscles, glands, and sense organs
Sensory neurons
carry messages from the body’s tissues and sensory receptors inward to the brain and spinal cord for processing
Motor neurons
carry instructions from the central nervous system out to the body’s muscles and glands
Interneurons
neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs
Somatic nervous system
the division of the peripheral nervous system that controls the body’s skeletal muscles
Autonomic nervous system (ANS)
the division of the peripheral nervous system that controls our glands and the muscles of our internal organs, influencing such functions as glandular activity, heartbeat, and digestion
Sympathetic nervous system
the division of 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
Reflexes
automatic responses to stimuli
Endocrine system
the collection of glands that secrete hormones directly into the circulatory system
Hormones
chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues
Adrenal glands
the “flight-or-flight” gland that releases epinephrine and norepinephrine
Pituitary gland
the endocrine system’s most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands
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.
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
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
fMRI (functional MRI)
a technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show brain function as well as its structure
PET (positron emission tomography) scan
a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task
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
Pons
help to coordinate movement
Reticular formation
a net-like neuron network that extends from the spinal cord right up through the thalamus; it filters incoming stimuli from the spinal cord and relays important information to other brain areas and enables 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
Cerebrum
the hemispheres that contribute 85% of the brain’s weight
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
Hippocampus
processes conscious memories
Cerebral cortex
a thin surface layer of interconnected neural cells
Glial cells
“worker bees” that provide nutrients and myelin, guide neural connections, and mop up neurotransmitters; they may play a role in learning and thinking
Frontal lobe
portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgments
Parietal lobe
mathematical and spacial reasoning
Occipital lobe
deals with vision, contains visual cortex
Temporal lobe
portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear
recognize faces
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
Prefrontal cortex
located in the forward part of the frontal lobe; aids in judgment, planning, and processing of new memories
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 language, speech
Basil ganglia
deals with habits and automatic processing
Corpus callosum
Optic chiasm
the large band of neural fibers connecting the two brain hemispheres and carrying messages between them
area where visual info crosses
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
Split brain + scientist
a condition resulting from surgery that isolates the brain’s two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them
Gazzania
Consciousness
our awareness of ourselves and our environment
Duel processing
the principle that information is often simultaneously processed on separate conscious and unconscious tracks
Environment
every external influence, from prenatal nutrition to the people and things around us
DNA (deoxyribonucleic acid)
a complex molecule containing the genetic information that makes up the chromosomes
Genes
the biochemical units of heredity that make up the chromosomes; segments of DNA capable of synthesizing proteins
Genome
the complete instructions for making an organism, consisting of all the genetic material in that organism’s chromosomes
Identical twins (monozygotic twins)
twins who develop from a single fertilized egg that splits in two, creating two genetically identical organisms
Fraternal twins (dizygotic twins)
twins who develop from separate fertilized eggs. They are genetically no closer than brothers and sisters, but they share a fetal environment
Molecular genetics
the subfield of biology that studies the molecular structure and function of genes
Heritability
Twin studies- scientist
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
Thomas Boushard- Uni of Minnesota
Epigenetics
the study of environmental influences on gene expression that occur without a DNA change
Acetycholine (Ach)
muscle action (learning, memory), Alzheimer’s if undersupply
Dopamine
muscle control+movement+reward (learning, attention, emotion), Schizophrenia if oversupply Parkinson’s+addiction if undersupply
Serotonin
mood (perception, hunger, sleep, arousal, emotion, inhibitory), Depression+OCD if under supplied
Norephinephrine
alertness+arousal, lessen mood if undersupply
GABA (gamma-aminobutyric acid)
inhibitory, seizures+tremors+insomnia+anxiety if undersupply
Glutamate
excitatory (learning, memory), migraines+seizures if oversupply
Parathyroids
regulate level of calcium in blood
Pancreas
regulate level of sugar in blood
Natural selection
the principle that, among the range of inherited trait variations, those contributing to reproduction and survival will most likely be passed on to succeeding generations
Mutation
a random error in gene replication that leads to a change
Roger Spheri
Neural specificity, taught Gazzania
Testis/Ovary
sex hormones, cortisol
Left or right hemisphere?
Speaking
Left
Left or right hemisphere?
Perceptual tasks
Right
Left or right hemisphere?
Sense of self
Right
Left or right hemisphere?
Calculations
Left
Left or right hemisphere?
Modulate speech
Right
Left or right hemisphere?
Sign language
Left
Left or right hemisphere?
Inferences
Right
Nucleus accumbens
Front of hypothalamus, reward center
