Biological basis of behaviors Flashcards
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.
- dendrites
- cell body/soma
- axon hillock
- axon
- myelin sheath
- nodes of Ranvier
- terminal buttons
- neurotransmitters
- synapse/synaptic cleft
Explain the function of the following part of a neuron:
dendrite
- branch-like arms attached to the cell body
- receive information from other neurons.
Explain the function of the following part of a neuron:
cell body/soma
- the “brain” of the neuron
- making up gray matter, and containing the nucleus.
axon hillock
connects the cell body to the axon
Explain the function of the following part of a neuron:
axon
- tube-like structures
- transmit information (via electrical impulse) from the cell body to the terminal buttons.
Explain the function of the following part of a neuron:
myelin sheath
- fatty layer around some axons
- insulates the electric impulse and allows information to travel faster
- so signals travel just to the intended neuron(s).
Explain the function of the following part of a neuron:
terminal buttons
- where information from the axon ends up
- contain neurotransmitters.
What are synonyms for “terminal buttons”?
end buttons
synaptic knobs
axon terminals
terminal branches of axons
Explain the function of the following part of a neuron:
neurotransmitters
- chemicals in the axon terminals that attempt to communicate with dendrites on other neurons
- “fit” with dendritic receptor sites to continue to the next neuron.
Explain the function of the following part of a neuron:
synapse
- also called the synaptic cleft; between pre synaptic neuron and post synaptic neuron
- gap between terminal button of one neuron and the dendrites of the next.
-
Chemicals travel within the cells, but are transmitted to other neurons electrically. TRUE or FALSE?
FALSE
- electric signal within cells
- chemical signal at synapse
Can a neuron fire at different magnitudes?
No
- fire completely at depolarization threshold
- all or none principle
How is an action potential (or nerve impulse) created?
- charged chemicals enter the dendrite and then the soma
- soma is initially slightly negative charged
- some gets depolarized enough –> action potential
- electric information fired down the axon to the terminal button
Some __________ are excitatory, prodding the cell body to fire, and others are __________, which prevent the creation of a cell’s action potential.
neurotransmitters; inhibitory
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.
receptor sites
threshold
the level of depolarization of soma to produce an action potential
What is the function of this neurotransmitter and what problem(s) are associated with too much/too little of it?
acetylcholine
Neuro-function: memory learning
Somatic Function: muscle contraction coordination and motor movement
Problem: Alzheimer’s disease linked to acetylcholine deficit
What is the function of this neurotransmitter and what problem(s) are associated with too much/too little of it?
endorphins
Function: pleasure and pain control
Problem: endorphins are released when pleasure areas of the brain are stimulated, so addictions are linked to endorphins
What is the function of this neurotransmitter and what problem(s) are associated with too much/too little of it?
dopamine
Neuro function: “reward”, pleasure and motivation
Function: motor movement and alertness
Problems: Parkinson’s disease (dopamine deficiency) and schizophrenia (excessive dopamine), linked to addiction
Dopamineis a monoamine, and part of the catecholamine class.
serotonin
Function: mood control, sleep, dream, appetite
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 informationtothe brain.
Efferent neurons, or motor neurons, carry informationfromthe brain to the body.
What are the subdivisions of the nervous system?
central nervous system
- brain and spinal cord
peripheral nervous system
- somatic
- autonomic
- sympathetic
- parasympatheticWhat is the difference between the central nervous system and the peripheral nervous system?
central nervous system: nerves in bones.
peripheral nervous system: 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?
somaticnervous system – muscle movements.
When your stomach begins to growl before lunch, what part of the nervous system is activated?
autonomicnervous system
- controls the parts of our bodies that work automatically
What does the sympathetic nervous system do?
Responds to stress -> fight or flight
- accelerates what’s immediately needed
- heart rate, pupil dilation, breathing, sweating
- slows
- digestion, immunity
What is the function of the parasympathetic nervous system?
Counteract sympathetic nervous system
active during also “sex, sleep, sustenance” and recovery
How did Phineas Gage contribute to the field of psychology?
Personality changed after frontal lobe damage
Leads to the study of the area of the brain where emotion is regulated
What are ways in which psychologists study the functions of different brain areas?
accidents and lesions electroencephalogram (EEG) Computerized Axial Tomography (CAT or CT) Magnetic Resonance Imaging (MRI) Positron Emisson Tomography (PET) Functional MRI (fMRI) Diffusion Tensor Imaging (DTI)
Describe the following method of studying the brain:
lesions
- Lesions by damage
- study by the impaired function
Describe the following method of studying the brain:
electroencephalogram (EEG)
Detects brain waves in different states of consciousness
Used largely in sleep research
Describe the following method of studying the brain:
Computerized Axial Tomography
3-D x-ray images of the brain;
structures known by different densities of the parts
Describe the following method of studying the brain:
Magnetic Resonance Imaging
uses magnetic fields to image brain density by different molecules vibrate differently, thus structures shown
No exposure to harmful radiation
Describe the following method of studying the brain:
Positron Emission Tomography
- Radioactive substances injected
- Detect for the concentration in different parts to glean the blood flows
- Studies brain activities
Describe the following method of studying the brain:
Functional MRI
- magnetic fields to image the density of hemoglobin in different parts of the brain
- see blood flow during cognitive tasks -> brain activity
Norepinephrine
Neuro function: arousal, fight/flight
Somatic function: Heart, rate, BP, Appetite
- connects the brain to the spinal cord
- a primitive part
- control basic functions
- respiration
- heart rate and BP
myelencephalon/medulla
- connects fore brain, midbrain and hindbrain
- helps control facial expression
pons
- the “little brain”
- looks like a smaller brain on the underside of our brain
- partially responsible for mind-body connection (habitual muscle movements)
cerebellum
- located in the midbrain
- believed to be the oldest part
- controls bodily arousal and ability to focus
reticular formation
What are the parts of the brain known as the limbic system, and what function does the limbic system serve?
- thalamus
- hypothalamus
- hippocampus
- amygdala
- septal area
The limbic system is involved in “fight, flight, feeding, and fornication.”
- the “sensory way station”, a relay
- receives info from spinal cord and directs to parts of the forebrain for further processing
thalamus
- controls the endocrine system
- metabolic functions: libido, body temperature, hunger, and thirst
hypothalamus
- convert short-term memories to long-term memories
hippocampus
- controls emotion and fear
amygdala
Function of amygdala
- controls emotion and fear
hippocampus
- convert short-term memories to long-term memories
hypothalamus
- controls the endocrine system
- metabolic functions: libido, body temperature, hunger, and thirst
thalamus
- the “sensory way station”, a relay
- receives info from spinal cord and directs to parts of the forebrain for further processing
_______ is involved in “fight, flight, feeding, and fornication.”
limbic system
reticular formation
- controls bodily arousal and ability to focus
pons
- connects fore brain, midbrain and hindbrain
- helps control facial expression
myelencephalon/medulla
- connects the brain to the spinal cord
- a primitive part
- control basic functions
- respiration
- heart rate and BP
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 calledcontralateral control.
Split-brain patients have had their __________ severed, usually to treat epilepsy. What two doctors pioneered this surgical procedure?
corpus callosum
Roger Sperry and Michael Gazzaniga pioneered this procedure.
the nerve bundle that runs through the middle of the brain, connecting the hemispheres.
corpus callosum
corpus callosum
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 lateralizationandhemispheric specialization
There are four lobes in the brain. Name them.
- frontal
- parietal
- occipital
- temporal
- the brain’s executive functioning center.
- responsible for reasoning and emotional control.
- – long term plans,
- – regulate our emotions,
- – consider consequences.
Prefrontal cortex
What area of the brain allows us to move our muscles to produce speech?
Broca’s area
- 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
the back of the frontal lobe.
The top of the body is controlled by the bottom of the motor cortex.
The top of the body is controlled by ___
bottom of the motor cortex
The top of the motor cortex located at ___
the back of the frontal lobe.
What is the area in the anterior frontal lobe called, and what is it responsible for?
Prefrontal cortex
- the brain’s executive functioning center.
- responsible for reasoning and emotional control.
- – long term plans,
- – regulate our emotions,
- – consider consequences.
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?
occipital lobe,
- at the very back of the brain,
- far from the eyes
- 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?
Wernicke’s area
What sensory modality is the temporal lobe responsible for processing?
hearing/audition
Sound coming in one ear is processed by both hemispheres of the brain.
Explain brain plasticity.
Neuronal connections strengthen or weaken to adapt to needed functions to individuals
More pronounced if there’s damage to other areas on the brain
Why is the endocrine system important to the field of psychology?
It secretes hormones that are part of our psychological processes.
Adrenaline by adrenal glands –> fight/flight
Ovaries / Testes produced estrogen/testosterone –> gender differences
Who did the Twins studies?
Thomas Bouchard
Who was Thomas Bouchard and why was his research important?
Bouchard studied identical twins raised in different families versus twins raised in the same home –> nature or nurture argument
Twin and Adoption Research and the nature/nurture argument:
- similarities in personality and IQ to suggest a nature component
- raised in different homes also showed enough differences to suggest that nurture is a major factor in development of intelligence and personality
Explain the function of the following part of a neuron:
nodes of Ranvier
the gap between adjacent myelinated segments on the axon
What are the parts of the mesencephalon (midbrain)?
tectum and the tegmentum.
- includes the inferior and superior colliculi
- controls vision and audition.
the tectum
What is the purpose of the tectum?
The tectum includes the inferior and superior colliculi
It controls audition and vision.
- home to the remainder of the reticular formation
- helps control the sensorimotor system
The tegmentum
The tegmentum
- home to the remainder of the reticular formation
- helps control the sensorimotor system
What does gray matter consist of?
cell bodies and dendrites
What makes up white matter in the brain?
myelin sheathing
axon bundles
nerve fibers
What are the divisions of the forebrain?
- diencephalon
2. telencephalon
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
- hippocampus
- amygdala
- cingulate gyrus
The corticospinal tract, also known as the pyramidal tract, connects what?
the brain and the spine
controls the other glands within the hormonal and endocrine systems
pituitary gland
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
direction of visual gaze and direction of visual attention to stimuli
superior colliculi control
superior colliculi
direction of visual gaze and direction of visual attention to stimuli
receive auditory information
inferior colliculi
inferior colliculi
receive auditory information
These three sheets of tissue comprise the meninges
the dura mater, pia mater, and arachnoid
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?
- tightly-formed group of endothelial cells in blood vessels
- larger, toxic molecules in blood stream can’t enter the brain
What are ventricles?
Fluid-filled cavities, a “cushion”, that protects the brain from shock.
caudate nucleus
putamen
globus pallidus
substantia nigra
basal ganglia
What do the basal ganglia include?
caudate nucleus
putamen
globus pallidus
substantia nigra
What is the function of the basal ganglia, and what can happen when they are not working properly?
- help control motor function
- malfunctioning -> Parkinson’s and Huntington’s diseases
What are the parts of the cerebral cortex?
frontal lobe parietal lobe occipital lobe temporal lobe neocortex gyri and sulci
How many layers does the neocortex have?
six
What are the bumps and ridges in the brain called?
Bumps: Gyrus (plr: Gyri)
Ridges: Sulcus (plr: Sulci; the furrows and fissures)
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)
apraxia
Explain the dysfunction:
apraxia
impairment in ability to start and organize voluntary movements (no muscle paralysis involved)
difficulty in recognition of objects
agnosia
Explain the dysfunction:
agnosia
difficulty in recognition of objects
impairment in language (can be impaired understanding or production)
aphasia
Explain the dysfunction:
aphasia
impairment in language (can be impaired understanding or production)
alexia
inability to read
inability to read
alexia
inability to write
agraphia
Explain the dysfunction:
agraphia
inability to write
What is the result of Broca’s aphasia?
- damage to Broca’s area
- can understand language but can’t produce it
Damage to Wernicke’s area creates what deficiency?
- can’t comprehend others
- produce fluent but meaningless speech
Explain the dysfunction:
hyperphagia
- excessive overeating
- linked with damage to ventromedial hypothalamus
Following damage to or removal of the cerebral cortex, what behavioral side effect might occur?
- intense, but not clearly directed rage
- called decorticate rage(or sham rage)
What type of tools are used to implant electrodes in the brains of animals?
stereotaxic instruments
What floral term is used to describe the beginnings of plasticity in children?
- “Blooming and pruning”
- new neural connections grow; some others die by survival importance
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
- Schwann cells
- oligodendrocytes
- astrocytes
- microglia
four types of glial cells
What is the function of glial cells?
- supporting cells to neurons
- provide
- — nutrition,
- — materials
- — chemical signals
What are the four types of glial cells?
- Schwann cells
- oligodendrocytes
- astrocytes
- microglia
____________ 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?
resting potential
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)
2. inhibitory postsynaptic potentials (IPSPs)
excitatory postsynaptic potentials (EPSPs)
- depolarize a cell, -
- increasing the likelihood of the cell reaching threshold for an action potential
inhibitory postsynaptic potentials (IPSPs)
- hyperpolarize a cell,
- decreasing the likelihood of the cell reaching the depolarization threshold.
What is saltatory conduction?
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?
- degradation: broken down by enzymes and removed
- reuptake: transported back into vesicles and recycled
What are the two most important amino acids in the brain?
glutamate
gamma-aminobutyric acid (GABA)
What is the function of glutamate?
- the most common EXCITATORY neurotransmitter; activates neurons
- Neurotoxic in excess –> neurons to fire too quickly
What is the function of Gamma-aminobutyric acid (GABA)?
- most common INHIBITORY neurotransmitter
- balance out glutamate for brain to achieve stasis
What do agonists do?
- act like neurotransmitters to bind to receptors
- increase neurotransmitters effect
- Xanax: a GABA agonist
What do antagonists do?
- prevent action of a neutrotransmitter
- decrease its effect
- Botox: acetylcholine antagonist
A fetus will develop into a male if the _________ is present.
H-Y antigen
During puberty, males release _________and females release __________ to cause genital maturation and development of secondary sex characteristics.
androgens; estrogen
What is the beginning of the menstrual cycle, occurring during puberty, referred to as?
menarche
The menstrual cycle is moderated by changes in which hormone levels?
estriadol
progesterone
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?
- stimulates contraction of uterine muscles during childbirth
- stimulates release of breast milk
- linked to pair bonding
What are the principal effects of vasopressin?
Regulates BP (increases it)
- stimulates water reabsorption of kidneys
- stimulates blood vessel constriction
What signals the thyroid to release hormones?
thyroid-stimulating hormone
What does adrenocorticotropic hormone (ACTH) do?
controls the release of glucocorticoids, mineralocorticoids, and sex hormones
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.
Before sleep
- relaxing and closing eyes
- characterized by alpha waves at low levels
Describe stage 1 sleep.
- slow heart rate
- reduced muscle tension
- irregular frequency of EEG waves
- eyes roll
decreased response to stimuli - theta waves
Describe stage 2 sleep.
heart rate, body temperature, and respiration decline, sleep spindles and K complexes are present in EEG
What are sleep spindles?
bursts of high frequency brain waves during stage 2 sleep
What are K complexes?
K complexes are sharp drops in EEG potential during stage 2
Describe stage 3 sleep.
sleep spindles are less common and delta waves (large amplitude, very slow waves) emerge
Describe stage 4 sleep.
- delta waves are present at least half of the time,
- sleep is the deepest,
- growth hormones are secreted
What are characteristics of REM sleep?
- dreams
- beta waves (neural desynchrony; similar to awake)
- muscles unresponsive and flaccid
- interspersed with non-REM
- roughly 20% of sleep
- lasts b/w 15 and 60 min
Who gets more REM sleep: someone who gets plenty of sleep each night or sleep-deprived graduate students?
sleep-deprived
How many hours do babies sleep? How many hours do the elderly sleep (on average)?
Infants: 16 hours
Elderly: 6 hours
REM more pronounced in babies (50%)
Decreases to 20~25% for Elderly
What are interneurons?
- Neurons between other neurons
- associated with reflexes
- imperative for survival
What allows reflexes to occur quickly instead of having to be routed through the brain?
neural networks known asreflex arcs.
the study of evolutionary development
phylogeny
Define:
phylogeny
the study of evolutionary development
What are the subdivisions of the hypothalamus?
- lateral hypothalamus
- ventromedial hypothalamus
- anterior hypothalamus
The hypothalamus uses ________ to regulate the balance of water in the body, a process known as _______.
osmoreceptors; osmoregulation
What is the function of the lateral hypothalamus?
it controls hunger; lesions can result inaphagia, or a refusal to eat
What is the function of the ventromedial hypothalamus (VMH)?
- signaling satiety
- Lesions lead to hyperphagia
What is the function of the anterior hypothalamus?
- controls sexual behavior
- lesion leads to sexual dysfunction
Along with the nucleus accumbens, the _______ is a major pleasure center of the brain.
septal area (or septum)
What is Klüver-Bucy syndrome?
Bilateral lesions to the amygdala:
- docility
- hypersexuality
- hyperphagia
- hyperorality
What is another name for the visual cortex?
thestriate cortex
When the sensations from one side of the body communicate with the same side of the cortex, they are communicating _______.
ipsilaterally
ipsilaterally
the sensations from one side of the body communicate with the same side of the cortex
What are the three most abundant catecholamines in the body?
Also classified as monoamines:
- dopamine
- epinephrine
- norepinephrine
What is the dopamine hypothesis of schizophrenia?
Caused by excessive dopamine
BUT: patients who have normal levels of dopamine can also have schizophrenia
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?
L-dopa
Antidepressants like Prozac are called what?
selective serotonin reuptake inhibitors (SSRIs)
What is the monoamine theory of depression?
Excessive or inadequate monoamines are linked with mania and depression
What are peptides?
two or more amino acids combined, e.g.,
- endorphins (natural painkillers)
- enkephalins
What behaviors are associated with epinephrine?
fight or flight
What is another terms for sedative-hypnotic drug?
depressants
What are some examples of sedative-hypnotic drugs, and what neurotransmitter do they affect?
Used as tranquilizers or sedatives - alcohol - benzodiazepines(like Valium) - barbituates They enhance GABA
What is Korsakoff’s Syndrome?
- thiamine (vitamin B1) deficiency from malnutrition and chronic alcoholics
- causes anterograde amnesia
What are behavioral stimulants?
- reduce fatigue or increase motor functioning
- increase receptors for monoamines and serotonin
What are some examples of behavioral stimulants, and what are they used for?
amphetamines –> narcolepsy
antidepressants –> to improve sleep patterns, increase activity, and elevate mood
methylphenidate(Ritalin) –> treat attention deficit disorder
What are the three main types of antidepressants?
- tricyclics
- monoamine oxidase (MAO) inhibitors
- selective serotonin reuptake inhibitors (SSRIs)
How do tricyclic antidepressants work?
they prevent the reuptake of norepinephrine and serotonin; so more of them will be in the synapse
How do monoamine oxidase (MAO) inhibitors work?
they prevent MAO from breaking down norepinephrine and serotonin; so more of those neurotransmitters are in the synapse.
What is the purpose of antipsychotic drugs?
- prevent dopamine from binding to postsynaptic membrane, reducing its effects, thus lower:
- -> hallucinations
- -> agitation
- -> delusions
What are some disorders that can be treated with antipsychotics?
schizophrenia bipolar disorder delusional disorder psychotic depression Tourette's syndrome dementia in the elderly
What antipsychotic is used frequently to treat bipolar disorder?
lithium
What are common narcotics (or opiates) and what do they do?
opium, heroin, and morphine; they are natural painkillers
What is ablation?
Ablation
- surgically induced brain lesions
- also called: extirpation
What is dementia?
a loss of cognitive functioning (including disorientation and memory failure)
