Chapter 3 Flashcards
Central Nervous SYstem
Brain and spinal cord
Peripheral Nervous System
Consists of all other nerve cells in the rest of the body
-Somatic (voluntary behavior)
-Autonomic (less voluntary action e.g. heart rate)
Neuron
-The basic unit of the nervous system
-Receive, integrate, and transmit information
Neural Networks
-Develop through genetic influence
-They are powered by electrical impulses and communicate with other nerve cells through chemical signals
Sensory neurons
Detect info from the physical world and pass it on to the brain (e.g. touching a hot pot)
Somatosensory nerves
Nerves that provide info from the skin and muscles
Motor neuron
Direct muscles to contract or relax, thereby producing movement
Interneurons
Relay stations facilitating communication between sensory and motor neurons
Dendrites
Short, branchlike appendages detect chemical signals from other neurons
Cell Body (soma)
the info received via the dendrites from thousands of other neurons
Axon
-A long, narrow outgrowth that electrical impulses are transmitted along
-Carry information between the brain and other locations in the body
Terminal buttons
Bulbs at the end of axons
Synapse
The site where chemical communication occurs between neurons, a tiny gap between terminal buttons
Myelin Sheath
A plastic tube encasing many axons
Nodes of ranvier
Small gaps of exposed axon
Membrane
-Outer surface of a membrane
-Selectively permeable
Action potential
Electrical signal that passes along the axon
Resting membrane potential
-The difference between electrical charge on the inside compared to the outside
All-or-none
-Dictates that a neuron fires with the same potency every time
-Never “weak” or “strong”
Presynaptic/postsynaptic neuron
-Pre: Sends the signal
-Post: Receives the signal
Neurotransmitters
Chemicals made in the axon or cell body
Receptors
Specialized protein molecules located in the postsynaptic membrane that respond to the chemical structure of the neurotransmitter
Reuptake
When the neurotransmitter is taken back into the presynaptic terminal buttons
Agonist and Antagonist Drugs
-Agonists ENHANCE the effects of neurotransmitters
-Antagonists INHIBIT their effects
Electroencephalography (EEG)
Method that measures electrical activity in the brain by attaching electrodes to the head
Positron emission tomography (PET)
Injecting a harmless radioactive substance into the bloodstream and measuring the most active areas
Functional magnetic resonance imaging (fMRI)
Assesses changes in the blood oxygen level in the brain
Transcranial magnetic sytimulation (TMS)
Uses a very fast but powerful magnetic field to disrupt neural activity momentarily in a specific region
Difference between methods of brain imaging
-EEG provides info on WHEN a brain response occurs, fMRI and PET provide info about WHERE a response occurs
Cerebral Cortex
The outer layer of cerebral hemispheres, gives the brain its wrinkled appearance
-Lateral & Central fissure
Corpus Callosum
A bridge of millions of myelinated axons (white matter), connects the hemispheres and allows info to flow between them
Occipital Lobe
Back of the head, dedicated to vision
Parietal Lobe
Devoted partially to touch. The left hemisphere receives touch signals from the right side and the right hemisphere receives touch signals from the left
Temporal Lobe
-Holds the primary auditory cortex, the region responsible for hearing
Frontal Lobe
Responsible for planning and movement
Fusiform face area
-Intersection of temporal and occipital lobes, most active when we look at and recognize faces
Primary motor cortex
Along the central fissure, include neurons that project directly to the spinal cord to move muscles
Prefrontal cortex
Frontmost portion of frontal lobe
-Responsible for attention, working memory, decision-making, appropriate social behavior, and personality
Split brain condition
When corpus callosum is severed and brain’s halves don’t communicate with one another
Thalamus
Gateway to the cortex, receives almost all incoming sensory information, organizes it, and relays it to the cortex
Hypothalamus
Brain’s main regulatory structure.
-Regulates body temp, blood pressure, blood glucise levels
-Motivated behavios: Thirst, hunger, aggression, and sexual desire
Hippocampus
Forms new memories
Amygdala
Involved in learning about biologically relevant stimuli, such as those important for survival. Responds to stimuli that elicit fear
Basal Ganglia
A system of subcortical structures crucial for planning and producing movement
Brain stem
An extension of the spinal cord; houses structures that control functions associated with survival
-Control heart rate, breathing, swallowing, vomiting, urination, and orgasm
Cerebellum
A large, protrusion at the back of the brain stem
-essential for coordinated movement and balance, motor learning, and motor memory
Insula
Part of the cerebral cortex that lies deep within the folds of the lateral fissure
Gustatory cortex
Necessary for sense of taste
Subcortical structures
Important for understanding psychological functions include the thalamus, the hypothalamus, the hippocampus, the amygdala, and the basal ganglia
Pituitary gland
Located at the base of the hypothalamus
-“it sends hormonal signals to other endocrine glands, controlling their release of hormones.”
Plasticity
A property of the brain that allows it to change as a result of experience or injury
Neurogenesis
“a type of brain plasticity that involves production of new neurons”
Cortical reorganization
a process where a stimulus changes an existing cortical map and creates a new one (E.g. physical therapy following an injury to the hand-controlling region of motor cortex)
Gene expression
Whether a particular gene is turned on or off
-Can be influenced by the environment (E.g. fur colors changing depending on the season to blend in w/ nature)
Chromosome
-Structures within the cell body made up of DNA, segments that comprise individual genes
-Everyone gets 23
Dominant gene
A gene expressed in the offspring whenever it’s present
Recessive gene
A gene only expressed when it is matched with a similar gene from the other parent
“Can human variation in skin color be understood as a single-gene dominant/recessive trait?”
“No, human skin color is a polygenic characteristic and influenced by the environment”
Monozygotic twins (MZ)
Identical twins
One zygote splitting in tow, the same genetic makeup
Dizygotic twins (DZ)
Fraternal twins
-Result from two different fertilized eggs and don’t have the exact same genetic makeup
Heredity
“Transmission of characteristics from parents to offspring through genes”
Heritability
“A statistical estimate of the extent to which variation in a trait within a population is due to genetics.”
“When studying trait similarity and genes, why do researchers compare monozygotic twins with dizygotic twins”
MZ twins have the same exact genes, so if each pair of twins grew up together, then similarities observed in MZ twins is likely due to genes not other factors
Epigenetics
“the study of how the environment changes genetic expression in a way that might be passed along to offspring”
Optogenetics
uses light to control the activity of cells in living organisms
-helps to understand the relationship between neural firing and behavior
