What is neuroanatomy?
Neuroanatomy relates to the parts and functions of individual nerve cells, known as neurons.
What is a neuron?
A neuron is an individual nerve cell.
Name the parts of a neuron.
nodes of Ranvier
Dendrites are branch-like arms attached to the cell body that receive information from other neurons.
The cell body/soma is the "brain" of the neuron, making up gray matter, and containing the nucleus.
connects the cell body to the axon
Axons are tube-like structures that transmit information (via electrical impulse) from the cell body to the terminal buttons.
The myelin sheath is the fatty layer around some axons that insulates the electric impulse and allows information to travel faster from the cell body to the terminal buttons.
The myelin sheath also acts as insulation so that signals don’t travel to every adjacent neuron, but just to the intended neuron(s).
Terminal buttons are where information from the axon ends up, and contain neurotransmitters.
What are synonyms for "terminal buttons"?
terminal branches of axons
Neurotransmitters are chemicals in the axon terminals that attempt to communicate with dendrites on other neurons.
Neurotransmitters must "fit" with dendritic receptor sites, like a key in a lock, to continue to the next neuron.
The synapse, also called the synaptic cleft, is the gap between the axon terminal of one neuron and the information-seeking dendrite of the next neuron.
The end of the first neuron is the presynaptic cell, and the beginning of the next neuron is the postsynaptic cell.
Chemicals travel within the cells, but are transmitted to other neurons electrically.
Within the cells, information is transmitted as an electric signal, but when it reaches the axon terminal, it is converted into chemicals that move between one neuron and the next.
Can a neuron fire at different magnitudes?
No, a neuron will fire completely if it reaches or exceeds the depolarization threshold, or not at all, which is called the all-or-none principle.
How is an action potential (or nerve impulse) created?
Positively or negatively charged chemical signals enter the dendrite and move to the cell body, which is slightly negatively charged. If these chemical signals depolarize the cell body enough, an action potential will occur, which will fire electrical information down the axon to the axon terminal.
Some __________ are excitatory, prodding the cell body to fire, and others are __________, which prevent the creation of a cell's action potential.
Describe the path of information within a neuron from beginning to end.
Dendrite (chemical signals)⇒cell body (become electrical signals)⇒axon⇒axon terminal (become chemical signals)⇒synapse⇒dendrite of next neuron
When neurotransmitters from the axon terminal are released, they attempt to connect with __________ on the postsynaptic dendrite.
The threshold is the level of depolarization a cell body must reach to produce an action potential.
Function: motor movement
Problem: Alzheimer's disease linked to acetylcholine deficit
Function: pleasure and pain control
Problem: endorphins are released when pleasure areas of the brain are stimulated, so addictions are linked to endorphins
Function: motor movement and alertness
Problems: Parkinson's disease (dopamine deficiency) and schizophrenia (excessive dopamine), linked to addiction
Dopamine is a monoamine, and part of the catecholamine class.
Function: mood control
Problem: deficiency linked to clinical depression
Serotonin is a monoamine, and part of the indolamine class.
What is the difference between afferent and efferent neurons?
Afferent neurons, or sensory neurons, carry information to the brain.
Efferent neurons, or motor neurons, carry information from the brain to the body.
What are the subdivisions of the nervous system?
central nervous system
brain and spinal cord
peripheral nervous system
- brain and spinal cord
What is the difference between the central nervous system and the peripheral nervous system?
The central nervous system includes the nerves in bones. The peripheral nervous system includes the nerves not encased in bone.
When you want to answer a question in class, what part of the nervous system controls your ability to raise your hand?
The somatic nervous system controls voluntary muscle movements.
When your stomach begins to growl before lunch, what part of the nervous system is activated?
The autonomic nervous system is activated, which controls the parts of our bodies that work automatically, like heart beats, breathing, and digestive muscles.
What does the sympathetic nervous system do?
Like the gas pedal in a car, the sympathetic nervous system accelerates functions needed for responding quickly to stress, like breathing, heart rate, and pupil dilation, and slows functions not immediately necessary, like digestion.
What is the function of the parasympathetic nervous system?
The parasympathetic nervous system is like the brake pedal of a car, counteracting the sympathetic nervous system after stress has passed. It is also active during periods of "sex, sleep, and sustenance."
How did Phineas Gage contribute to the field of psychology?
Phineas Gage received frontal lobe damage after an accident, and his personality changed dramatically. This helped researchers conclude that the damaged part of the brain is an area where emotion regulation is controlled.
What are ways in which psychologists study the functions of different brain areas?
Computerized Axial Tomography (CAT or CT)
Magnetic Resonance Imaging (MRI)
Positron Emisson Tomography (PET)
Functional MRI (fMRI)
When brain lesions happen through damage or as a byproduct of a surgical procedure (to stop seizures, for example), psychologists are able to see what functions are impaired in a real world setting and glean the way the damaged area of the brain works.
Used largely in sleep research, the electroencephalogram (EEG) detects brain waves during different states of consciousness.
Computerized Axial Tomography
Also known as a CAT or CT, this method can get a three-dimensional X-ray image of the brain, which is helpful for detecting structural problems, like tumors, but does not aid in detecting brain activity.
Magnetic Resonance Imaging
Similar to a CAT scan, an MRI provides an image of the brain, rather than clues to its activation. Unlike a CAT scan, however, the MRI uses magnetic fields to image brain density and does not expose the patient to potentially harmful radiation.
Positron Emission Tomography
The PET allows psychologists to see activity in the brain by monitoring how much of a chemical different parts of the brain are using.
The fMRI is able to see blood flow in the brain during cognitive tasks, which suggests brain functioning. It also contains elements of the MRI, which gives structural information about the patient's brain.
What parts of the brain are located in the hindbrain?
metencephalon (pons and cerebellum)
base of reticular formation
The medulla (or medulla oblongata) connects the brain to the spinal cord. One of the most primitive parts of the brain, it helps control basic functions of life, like respiration, heart rate, and blood pressure.
The pons connects the forebrain, midbrain, and hindbrain, and helps control facial expression.
Meaning "little brain," the cerebellum looks like a second, smaller brain on the underside of our brain. It is partially responsible for our mind-body connection, particularly in habitual muscle movements.
Located in the midbrain, the reticular formation controls bodily arousal and our ability to focus.
The reticular formation is believed to be the oldest part of the brain.
Where are the thalamus, hypothalamus, amygdala, and hippocampus located in the brain?
What are the parts of the brain known as the limbic system, and what function does the limbic system serve?
- septal area
The limbic system is involved in "fight, flight, feeding, and fornication."
Known as the "sensory way station" of the brain, the thalamus receives information from the spinal cord and routes it to the appropriate part of the forebrain for further processing.
The hypothalamus controls the endocrine system, as well as metabolic functions like libido, body temperature, hunger, and thirst.
The hippocampus is responsible for converting short-term memories to long-term memories.
The amygdala controls emotion and fear.
Why are our brains wrinkled?
The surface of the brain is covered with neurons, and wrinkles (or fissures) increase the surface area so more neurons can connect with one another to transmit more information.
If you want to kick a soccer ball with your right foot, which hemisphere of the brain controls this, and what principle explains it?
The left hemisphere controls the motor function on the right half of the body and vice versa. This is called contralateral control.
Split-brain patients have had their __________ severed, usually to treat epilepsy. What two doctors pioneered this surgical procedure?
Roger Sperry and Michael Gazzaniga pioneered this procedure.
The corpus callosum is the nerve bundle that runs through the middle of the brain, connecting the hemispheres.
It has been suggested that the right hemisphere of the brain is active during spatial and creative tasks, while the left is activated during logic, spoken language, and sequential tasks. What are the two terms used to describe the differences between the right and left hemispheres?
brain lateralization and hemispheric specialization
There are four lobes in the brain. Name them.
What is the area in the anterior frontal lobe called, and what is it responsible for?
The prefrontal cortex, and it is the brain's executive functioning center. It is the part of the brain that is believed to be responsible for reasoning and emotional control. Without the prefrontal cortex (or PFC), we would not be able to make long term plans, regulate our emotions, or consider consequences.
What area of the brain allows us to move our muscles to produce speech?
Broca's area, which is located in the left frontal lobe in most right-handers
The top of the motor cortex controls voluntary muscle movements in what area of the body?
The feet and toes are controlled by the top of the motor cortex, located at the back of the frontal lobe. The top of the body is controlled by the bottom of the motor cortex.
Located in the parietal lobe behind the motor cortex, the __________ receives touch sensations from the body.
sensory cortex, or somato-sensory cortex
Why is the area where vision is processed counterintuitive?
The processing of vision is located in the occipital lobe, which is at the very back of the brain, as far as possible from the eyes themselves. The left and right halves of the visual cortex process information from the same halves of the retinas (meaning processing is lateralized).
Damage to what area of the temporal lobe would result in an inability to understand written or spoken language?
What sensory modality is the temporal lobe responsible for processing?
Unlike vision, hearing is not lateralized. Sound coming in one ear is processed by both hemispheres of the brain.
Explain brain plasticity.
As our brains develop, there are skills or functions that are more or less important to perform to each individual. Because of this, the neuronal connections in our brains strengthen or weaken to adapt to those needed functions, especially if there is damage to other areas of the brain.
Why is the endocrine system important to the field of psychology?
The endocrine system secretes hormones that are part of our psychological processes.
- The adrenal glands secrete adrenaline, which is necessary for the fight-or-flight response of the autonomic nervous system
- Ovaries and testes produce testosterone and estrogen, hormones that can help explain gender differences, which are an important part of developmental psychology
Who was Thomas Bouchard and why was his research important?
Thomas Bouchard was a psychologist who studied identical twins raised in different families versus twins raised in the same home. His research was important when considering the nature/nurture argument.
- Twins had enough similarities in personality and IQ to suggest a nature component
- Twins raised in different homes also showed enough differences to suggest that nurture (or environment) was a factor in development of personality and intelligence
nodes of Ranvier
the gap between adjacent myelinated segments on the axon
What are the parts of the mesencephalon (midbrain)?
The midbrain contains the tectum and the tegmentum.
What is the purpose of the tectum?
The tectum, which includes the inferior and superior colliculi, controls vision and audition.
What is the purpose of the tegmentum?
The tegmentum is home to the remainder of the reticular formation and helps control the sensorimotor system.
What does gray matter consist of?
cell bodies and dendrites
What makes up white matter in the brain?
What are the divisions of the forebrain?
The posterior part of the forebrain, the diencephalon, contains what two brain parts?
the thalamus and the hypothalamus
The frontal portion of the forebrain, the telencephalon, contains what parts of the brain?
the limbic system
The corticospinal tract, also known as the pyramidal tract, connects what?
the brain and the spine
What does the pituitary gland do?
controls the other glands within the hormonal and endocrine systems
What part of the brain is implicated in the direction of attention and emotion?
the cingulate gyrus
What do the superior colliculi control?
direction of visual gaze and direction of visual attention to stimuli
What do the inferior colliculi do?
receive auditory information
What do the dura mater, pia mater, and arachnoid make up and what do they do?
These three sheets of tissue comprise the meninges, which surround and protect the brain and spinal cord.
How does the blood-brain barrier help protect the brain from toxic intruders?
The blood-brain barrier is a tightly-formed group of endothelial cells in blood vessels that makes it difficult for larger, potentially toxic molecules within the blood stream to enter the brain.
What are ventricles?
fluid-filled cavities that prevent the brain from shock by acting as a cushion
What do the basal ganglia include?
What is the function of the basal ganglia, and what can happen when they are not working properly?
The basal ganglia help control motor function, so improper functioning can be linked to Parkinson's and Huntington's diseases.
What are the parts of the cerebral cortex?
gyri and sulci
How many layers does the neocortex have?
What are the bumps and ridges in the brain called?
bumps are gyri (singular: gyrus) and furrows or fissures are sulci (singular: sulcus)
What are the parts of the brain called that are linked with certain responses to stimuli?
cortical association areas
impairment in ability to start and organize voluntary movements (no muscle paralysis involved)
difficulty in recognition of objects
impairment in language (can be impaired understanding or production)
inability to read
inability to write
What is the result of Broca's aphasia?
When a person has damage to Broca's area, he is able to understand language, but language production is impaired.
Damage to Wernicke's area creates what deficiency?
Wernicke's aphasia is marked by impaired language comrehension from others and production of fluent but meaningless speech.
excessive overeating, linked with damage to ventromedial hypothalamus
Following damage to or removal of the cerebral cortex, what behavioral side effect might occur?
decorticate rage (or sham rage), which is intense, but not clearly directed rage
What type of tools are used to implant electrodes in the brains of animals?
What floral term is used to describe the beginnings of plasticity in children?
"Blooming and pruning" is the process of growing new neural connections and allowing others to die as young brains learn what is most important for their survival.
What holds neurotransmitters as they are transported to the synaptic cleft?
synaptic vesicles (or synaptic vessels)
In order for an action potential to occur, ions must permeate what?
the cell membrane
What is the function of glial cells?
Glial cells are supporting cells, providing nutrition, materials, and chemical signals to neurons in the brain.
What are the four types of glial cells?
____________ form myelin in the central nervous system, while __________ form myelin in the peripheral nervous system.
oligodendrocytes; Schwann cells
What is the point in transduction when the neuron is negatively charged and an action potential has not yet occurred?
What allows the postsynaptic cell's ion channels to open?
postsynaptic receptors must recognize the presence of neurotransmitters
What are the types of postsynaptic potentials?
excitatory postsynaptic potentials (EPSPs)
inhibitory postsynaptic potentials (IPSPs)
What is the difference between an EPSP and an IPSP?
Excitatory postsynaptic potentials (EPSPs) will depolarize a cell, increasing the likelihood of the cell reaching threshold and creating an action potential.
Inhibitory postsynaptic potentials (IPSPs) will hyperpolarize a cell, decreasing the likelihood of the cell reaching the depolarization threshold.
What is saltatory conduction?
Characteristic of myelinated axons, saltatory conduction is when an action potential jumps from one node of Ranvier to the next.
After an action potential, a cell is unable to create another action potential during the _______. It will then enter the ________, where it will respond only to strong stimuli.
absolute refractory period; relative refractory period
After release of neurotransmitter into the synaptic cleft, what happens to the unused neurotransmitter?
The excess transmitters in the synaptic cleft are then either broken down by enzymes and removed, a process called degradation, or are transported back into vesicles and recycled, which is referred to as reuptake.
What are the two most important amino acids in the brain?
glutamate and gamma-aminobutyric acid (GABA)
What is the function of glutamate?
Glutamate activates neurons, but can become neurotoxic in excess, causing neurons to fire too quickly.
Glutamate is the most common excitatory neurotransmitter.
What is the function of Gamma-aminobutyric acid (GABA)?
GABA is an inhibitory neurotransmitter, which helps balance out glutamate and allows the brain to achieve stasis.
It is the most common inhibitory neurotransmitter.
What do agonists do?
Agonists act like neurotransmitters, binding to receptor cells, increasing that neurotransmitter's effect.
Xanax is a GABA agonist
What do antagonists do?
Antagonists prevent the action of a neurotransmitter, decreasing its effect.
Botox is an acetylcholine antagonist
A fetus will develop into a male if the _________ is present.
During puberty, males release _________and females release __________ to cause genital maturation and development of secondary sex characteristics.
What is the beginning of the menstrual cycle, occurring during puberty, referred to as?
The menstrual cycle is moderated by changes in which hormone levels?
luteinizing hormone (LH)
follicle stimulating hormone (FSH)
How do the effects of luteinizing hormone (LH) and follicle stimulating hormone (FSH) differ in males and females?
In females, LH and FSH govern ovulation
In males, LH and FSH govern sperm and testosterone production
What are the principal effects of oxytocin?
Oxytocin stimulates the contraction of uterine muscles during childbirth and the release of breast milk.
Oxytocin is also linked to pair bonding.
What are the principal effects of vasopressin?
Vasopressin stimulates water reabsorption by the kidneys and blood vessel constriction, which helps regulate blood pressure.
What signals the thyroid to release hormones?
What does adrenocorticotropic hormone (ACTH) do?
controls the release of glucocorticoids, mineralocorticoids, and sex hormones
What method is used to study sleep states and patterns?
What are the two main categories of sleep?
REM (rapid eye movement) and non-REM (or slow-wave sleep)
How long does it take to get through non-REM sleep?
roughly 90 minutes
Describe stage 0 sleep.
This stage occurs before sleep, when relaxing and closing the eyes, and is characterized by frequently occurring alpha waves at low levels.
Describe stage 1 sleep.
heart rate slowed, muscle tension reduced, irregular frequency of EEG waves, eyes roll, decreased response to stimuli, theta waves occur
Describe stage 2 sleep.
heart rate, body temperature, and respiration decline, sleep spindles and K complexes are present in EEG
What are sleep spindles?
Sleep spindles are bursts of high frequency brain waves during stage 2 sleep.
What are K complexes?
Occurring during stage 2 sleep, K complexes are sharp drops in EEG potential.
Describe stage 3 sleep.
sleep spindles are less common and delta waves (large amplitude, very slow waves) emerge
While people in stage 1 or 2 sleep will frequently deny they were sleeping if awakened, this will not likely occur in stage 3.
Describe stage 4 sleep.
delta waves are present at least half of the time, sleep is the deepest, growth hormones are secreted, and if woken up, one would be extremely groggy
What are characteristics of REM sleep?
beta waves (neural desynchrony) occur similar to waking states
muscles are unresponsive and flaccid
interspersed with non-REM sleep
roughly 20% of total sleep
lasts between 15 and 60 minutes
Who gets more REM sleep: someone who gets plenty of sleep each night or sleep-deprived graduate students?
Those who are sleep-deprived spend more time in REM sleep.
How many hours do babies sleep? How many hours do the elderly sleep (on average)?
Infants typically sleep 16 or so hours per day. The elderly, however, only sleep roughly six hours per night.
REM sleep decreases with age, as well. Half of babies' sleep is REM sleep, but decreases to 20-25%.
What are interneurons?
They are the neurons between other neurons, and are linked with reflexes, which are imperative for survival.
What allows reflexes to occur quickly instead of having to be routed through the brain?
neural networks known as reflex arcs.
the study of evolutionary development
What are the subdivisions of the hypothalamus?
The hypothalamus uses ________ to regulate the balance of water in the body, a process known as _______.
What is the function of the lateral hypothalamus?
it controls hunger; lesions can result in aphagia, or a refusal to eat
What is the function of the ventromedial hypothalamus (VMH)?
The VMH tells us when we have had enough to eat. Lesions in the VMH can lead to hyperphagia, or uncontrollable eating, since there is nothing to signal satiety.
What is the function of the anterior hypothalamus?
It controls sexual behavior. Lesions can lead to inhibited sexual urges and activity.
Along with the nucleus accumbens, the _______ is a major pleasure center of the brain.
septal area (or septum)
What is Klüver-Bucy syndrome?
It is a syndrome resulting from bilateral lesions to the amygdala, marked by docility, hypersexuality, hyperphagia, and hyperorality.
What is another name for the visual cortex?
the striate cortex
When the sensations from one side of the body communicate with the same side of the cortex, they are communicating _______.
What are the three most abundant catecholamines in the body?
They are also classified as monoamines, and play a part in emotional processes.
What is the dopamine hypothesis of schizophrenia?
This hypothesis states that schizophrenia is cause by an excess of dopamine.
However, problems with this theory include: many patients with schizophrenia have normal levels of dopamine, and antipsychotics block dopamine quickly, but psychosis doesn't go away immediately.
What two mood disorders are linked to norepinephrine imbalance?
depression and mania
What is the synthetic form of dopamine sometimes used to treat patients with Parkinson's disease?
Antidepressants like Prozac are called what?
selective serotonin reuptake inhibitors (SSRIs)
What is the monoamine theory of depression?
This theory believes that excessive or insufficient levels of monoamines (specifically norepinephrine) are linked with mania and depression.
What are peptides?
When two or more amino acids combine, they form peptides.
Important peptides to remember are endorphins (which serve as natural painkillers) and enkephalins.
What behaviors are associated with epinephrine?
Epinephrine (or adrenaline) is linked to the fight or flight response.
What are the functions of serotonin?
Serotonin helps regulate mood and eating, as well as sleep and dreaming.
What is another terms for sedative-hypnotic drug?
What are some examples of sedative-hypnotic drugs, and what neurotransmitter do they affect?
alcohol, benzodiazepines (like Valium) and barbituates; they enhance GABA, and are used as tranquilizers or sedatives.
What is Korsakoff's Syndrome?
Stemming from malnutrition in chronic alcoholics, Korsakoff's syndrome causes anterograde amnesia.
What are behavioral stimulants?
They are drugs that reduce fatigue or increase motor functioning, and are believed to increase receptors for the monoamines (dopamine, epinephrine, norepinephrine) and serotonin.
What are some examples of behavioral stimulants, and what are they used for?
amphetamines: used for narcolepsy
antidepressants: used to improve sleep patterns, increase activity, and elevate mood
methylphenidate (Ritalin): used to treat attention deficit disorder
What are the three main types of antidepressants?
monoamine oxidase (MAO) inhibitors
selective serotonin reuptake inhibitors (SSRIs)
How do tricyclic antidepressants work?
they prevent the reuptake of norepinephrine and serotonin
How do monoamine oxidase (MAO) inhibitors work?
they prevent MAO from breaking down norepinephrine and serotonin
What is the purpose of antipsychotic drugs?
Generally, they are believed to prevent dopamine from binding to the postsynaptic membrane, reducing hallucinations, agitation, and delusions.
What are some disorders that can be treated with antipsychotics?
dementia in the elderly
What antipsychotic is used frequently to treat bipolar disorder?
What are common narcotics (or opiates) and what do they do?
opium, heroin, and morphine; they are natural painkillers
What is ablation?
Ablation (or extirpation) is the term for surgically induced brain lesions.
What is dementia?
a loss of cognitive functioning (including disorientation and memory failure)