Chapter 3 Flashcards
Chronic traumatic encephalopathy (CTE)
a form of progressive brain damage that has been linked to repeated concussions
Neurons
cells in NS that communicate with one another to perform info-processing tasks
Cell body (soma) What processes occur here?
the part of a neuron that coordinates info-processing tasks and keeps the cell alive; largest component of the neuron; protein synthesis, energy production, and metabolism occur here
Dendrite
the part of a neuron that receives info from other neurons and relays it to the cell body; don’t touch axons
Axon
the part of a neuron that carries info to other neurons, muscles, or glands; don’t touch dendrite
Myelin sheath
an insulating layer of fatty material that covers most of the axon; axons insulated with myelin can more efficiently transmit signals to other neurons
Glial cells
Cells that form the myelin sheath and support the cells in the nervous system
Synapse
the region between the axon of one neuron and the dendrites/cell body of another
What are the 3 major types of neurons?
- Sensory neurons: have specialized endings on their dendrites that receive signals for senses and convey the info to the brain via the spinal cord
- Motor neurons: carry signals from the spinal cord to the muscles to produce movement; have long axons
- Interneurons: most common type of neuron that connects sensory neurons, motor neurons, and other interneurons; some carry info from sensory neurons to NS, some carry info from NS to motor neurons, some perform variety of info-processing functions within NS
What are the two stages that compose the electrochemical actions?
- Conduction: the movement of an electric signal within neurons, from the dendrites to the cell body, then throughout the axon
- Transmission: movement of electric signals from 1 neuron to another over the synapse
Resting potential
the difference in electric charge between the inside and outside of a neuron’s cell membrane; in resting state, high [ K+] and - protein ions inside neuron’s cell membrane, high [Na+] and [Cl-] outside of neuron’s cell membrane
Action potential
an electric signal that is conducted along a neuron’s axon to a synapse; need to reach threshold for AP to occur
What facilitates the conduction of an action potential?
Myelin sheath
Nodes of Ranvier
the breaks between clumps of myelin
Saltatory conduction
When an electric current passes down the length of a myelinated axon, the charge seems to “jump” from node to node rather than having to traverse the entire axon; helps speed the flow of info down the axon
Refractory period
the time following an action potential during which a new action potential cannot be initiated
Terminal buttons
knoblike structures that branch out from an axon and contain neurotransmitters
Neurotransmitters
chemicals that transmit info across the synapse to a receiving neuron’s dendrites
Receptors
located in dendrites of the receiving neuron (postsynaptic neuron), parts of the cell membrane that receive the neurotransmitter and initiate or prevent a new electric signal
Acetylecholine
a neurotransmitter involved in a number of functions (ex. voluntary motor control)
Dopamine
a neurotransmitter that regulates motor behavior, motivation, pleasure, and emotional arousal; high levels linked to schizophrenia, low levels linked to Parkinson’s disease
Glutamate
major excitatory neurotransmitter in brain that enhances transmission of info between neurons
GABA (gamma-aminobutyric acid)
primary inhibitory neurotransmitter in the brain; too much glutamate or too little GABA can cause seizures
Norepinephrine
a neurotransmitter that is particularly involved in states of vigilance, or heightened awareness of dangers in the environment
Serotonin
a neurotransmitter involved in the regulation of sleep and wakefulness, eating, and aggressive behavior
Endorphins
chemicals that act within the pain pathways and emotion center of the brain (ex. “runner’s high”
Agonists
drugs that increase the action of a neurotransmitter
Amphetamine
agonist that prevents the reuptake of norepinephrine and dopamine, resulting in increased activation of their receptors
Cocaine
agonist that prevents the reuptake of norepinephrine and dopamine, resulting in increased activation of their receptors
Prozac
agonist used to treat depression by blocking reuptake of seratonin
Antagonist
drugs that block the function of a neurotransmitter
Propanalol
antagonist that obstructs a receptor site for norepinephrine in the heart, slowing the heart rate
Methamphetamine
has both agonist and antagonist effects that alter the functions of neurotransmitters, helping us perceive and interpret visual images, sometimes resulting in strange hallucinations
Nervous system
an interacting network of neurons that conveys electrochemical info throughout the body
Central Nervous System
part of the nervous system that is composed of the brain and spinal cord; receives sensory info from external world, processes and coordinates info, and sends commands to skeletal and muscular systems for action; spinal cord can control some basic behaviors without input from the brain; brain sends commands for voluntary movement through the spinal cord to motor neurons
Spinal reflexes
simple pathways in the NS that rapidly generate muscle contractions
Peripheral Nervous System
part of NS that connects CNS to the body’s organs and muscles
Somatic Nervous System
1 of 2 compartments of PNS, set of nerves that convey info between voluntary muscles and CNS; humans have conscious control over this system
Autonomic Nervous System
1 of 2 compartments of PNS, set of nerves that carries involuntary and automatic commands that control blood vessels, body organs, and glands
Sympathetic nervous system
subdivision of autonomic nervous system, set of nerves that prepares the body for action in challenging or threatening situations
Parasympathetic nervous system
subdivision of autonomic nervous system, helps body return to a normal resting state
Hindbrain
an area of the brain that coordinates information coming into and out of the spinal cord; controls most basic functions of life (respiration, alertness, motor skills); composed of the medulla, reticular formation, cerebellum, and pons
Medulla
part of hindbrain that is the extension of the spinal cord into the skull that coordinates heart rate, circulation, and respiration
Reticular formation
part of hindbrain that regulates sleep, wakefulness, and levels of arousal
Cerebellum
large structure of hindbrain that controls fine motor skills
Pons
part of hindbrain that relays info from cerebellum to the rest of the brain
Tectum
part of the midbrain that orients an organism in the environment
Tegmentum
part of midbrain involved in movement and arousal; helps orient an organism towards sensory stimuli
Forebrain
controls complex cognitive, emotional, sensory, and motor functions
Cerebral cortex
part of the forebrain that is the outermost layer of the brain, visible to naked eye and divided into 2 symmetrical hemispheres
Gyri
smooth surfaces of cerebral cortex
Sulci
indentations/fissures of the cerebral cortex
What type of control do the two hemispheres of the cerebral cortex have and how are the hemispheres connected?
Contralateral control (L cerebral hemisphere perceives stimuli from and controls movements on L side of body, L hemisphere controls R side) Hemispheres connected by commissures, bundles of axons that allow for communication between parallel areas of cortex
Corpus callosum
largest commissure which connects large areas of the cerebral cortex on each side of the brain and supports communication of info across hemispheres
Each hemisphere is split into 4 lobes. What are they?
- OCCIPITAL: processes visual info
- PARIETAL: processes touch info; contains somatosensory cortex
- TEMPORAL: hearing and language; contains primary auditory cortex
- FRONTAL: movement, abstract thinking, planning, memory, and judgement; contains motor cortex
Association areas
composed of neurons that help provide sense and meaning to info registered in the cortex; neurons in these areas are less specialized and more flexible than neurons in the primary areas
Mirror neurons
neurons active when an animal performs a behavior; activated when another animal observes that animal performing the same behavior (found in frontal and parietal lobes)
Subcortical structures
areas of the forebrain housed under the cerebral cortex near the center of the brain
Thalamus
relays and filters info from the senses and transmits the info to the cerebral cortex; receives inputs from all major senses except smell (which has direct connections to cerebral cortex)
Hypothalamus
Regulates body temp, hunger, thirst, and sexual behavior
Pituitary gland
the “master gland” of the body’s hormone-producing system, which releases hormones that direct the functions of many other glands in the body; releases oxytocin
Limbic system
group of forebrain structures including the hypothalamus, the hippocampus, and the amygdala, which are involved in motivation, emotion, learning, and memory
Hippocampus
critical structure for creating new memories and integrating them into a network of knowledge so that they can be stored indefinitely in other parts of the cerebral cortex
Amygdala
part of limbic system that plays a central role in many emotional processes, particularly the formation of emotional memories; attaches significance to previously neutral events that are associated with fear, punishment, or reward
Basal ganglia
directs intentional movements
Striatum
part of basal ganglia that controls posture and movement
Brain plasticity
the ability of sensory cortices to adapt to changes in sensory inputs; functions assigned to certain areas of the brain may be capable of being reassigned to other areas of the brain to accommodate changing input from the environment
What is the first major bodily system to form in an embryo?
CNS; starts with a neural tube that becomes the spinal cord
Ontogeny
how the brain develops within a given individual
Phylogeny
how the brain develops within a particular species
Genes
major unit of hereditary information
Chromosomes
strands of DNA wound around each other in a double-helix configuration
Degree of relatedness
probability of sharing genes
Monozygotic twins
identical twins
Epigenetics
environmental influences that determine whether or not genes are expressed, or the degree to which they are expressed, without altering the basic DNA sequences that constitute the genes themselves
Epigenetic marks
chemical modifications to DNA that can turn genes on/off
DNA methylation
adding a methyl group to DNA
Histone modification
adding chemical modifications to histones that are involved in packaging DNA
Heritability
a measure of the variability of behavioral traits among individuals that can be accounted for by genetic factors
Electroencephalograph (EEG)
device used to record electrical activity in the brain
3 major approaches to studying the link between the brain and behavior
- Observing how perceptual, motor, intellectual, and emotional capacities are affected following brain damage.
- Examining global electrical activity in the brain and the activity patterns of single neurons using EEG
- Using brain imaging to scan the brain as people perform different perceptual or intellectual tasks. Correlating energy consumption in particular brain areas with specific cognitive/behavioral events suggests that those brain areas are involved in specific types of perceptual, motor, cognitive, or emotional processing.
Which of the following is NOT a function of a neuron?
a. processing info
b. communicating with other neurons
c. nutritional provision
d. sending messages to body organs and muscles
c. nutritional provision
Signals from other neurons are received and relayed to the cell body by
a. the nucleus
b. dendrites
c. axons
d. glands
b. dendrites
Signals are transmitted from one neuron to another
a. across a synapse
b. through a glial cell
c. by the myelin sheath
d. in the cell body
a. across a synapse
Which type of neuron receives information from the external world and conveys this information to the brain via the spinal cord?
a. sensory neuron
b. motor neuron
c. interneuron
d. axon
a. sensory neuron
An electric signal that is conducted along the length of a neuron’s axon to the synapse is called
a. a resting potential
b. an action potential
c. a node of Ranvier
d. an ion
b. an action potential
The chemicals that transmit information across the synapse to a receiving neuron’s dendrites are called
a. vesicles
b. terminal buttons
c. postsynaptic neurons
d. neurotransmitters
d. neurotransmitters
The ____ automatically controls the organs of the body.
a. autonomic nervous system
b. parasympathetic nervous system
c. sympathetic nervous system
d. somatic nervous system
a. autonomic nervous system
Which part of the hindbrain coordinates fine motor skills?
a. the medulla
b. the cerebellum
c. the pons
d. the tegmentum
b. the cerebellum
What part of the brain is involved in movement and arousal?
a. the hindbrain
b. the midbrain
c. the forebrain
d. the reticular formation
b. the midbrain
The _____ regulates body temp, hunger, thirst, and sexual behavior.
a. cerebral cortex
b. pituitary gland
c. hypothalamus
d. hippocampus
c. hypothalamus
What explains the apparent beneficial effects of cardiovascular exercise on aspects of brain function and cognitive performance?
a. the different sizes of the somatosensory cortices
b. the position of the cerebral cortex
c. specialization of association areas
d. neuron plasticity
d. neuron plasticity
During the course of embryonic brain growth, the _____ undergoes the greatest development.
a. cerebral cortex
b. cerebellum
c. tectum
d. thalamus
a. cerebral cortex
The first true CNS appeared in
a. flatworms
b. jellyfish
c. protozoa
d. early primates
a. flatworms
Genes set the _______ in populations within a given environment.
a. individual characteristics
b. range of variation
c. environmental possibilities
d. behavioral standards
b. range of variation
Identifying the brain areas that are involved in specific types of motor, cognitive, or emotional processing is best achieved through
a. recording patterns of electrical activity
b. observing psychological disorders
c. psychosurgery
d. brain imaging
d. brain imaging
