Chapter 4 Flashcards
The Biological Mind: The Physical Basis of Behaviour
action potential
the electrical signal arising in a neuron’s axon
location and function of the amygdala
LOCATION:
a subcortical structure deeply embedded in the temporal lobe
FUNCTIONS:
- receives sensory information and produces emotional and motivational output
- identifies, remembers, and responds to fear and aggression
autonomic nervous system
the division of the PNS that controls tissues other than the skeletal muscle (glands, organs, and smooth muscles) without conscious direction
axons
the branch of a neuron that is usually responsible for transmitting information to other neurons
function and composition of the basal ganglia
FUNCTION:
a subcortical structure involved with voluntary movement; contributes to OCD and ADHD
COMPOSITION:
- caudate
- putamen
- globus pallidus
- nucleus accumbens
brainstem
the part of the brain containing the midbrain, pons, and medulla
cell body
the large, central mass of a neuron, containing the nucleus
central nervous system (CNS)
the brain and spinal cord
functions of the cerebellum
a brainstem structure involved with…
- maintaining balance and motor coordination
- complex cognitive processing
cerebral cortex
the thin layer of neurons covering the outer surface of the cerebral hemispheres
location and functions of the cingulate cortex
LOCATION:
a subcortical structure found above the corpus callosum; the anterior cingulate cortex (ACC) is the forward 2/3, and the posterior cingulate cortex is the rear 1/3
ACC FUNCTION:
- autonomic nervous system control
- decision making
- emotion
- anticipation of reward
- empathy
PCC FUNCTION:
participates in memory and visual processing
corpus callosum
a wide band of nerve fibres connecting the right and left cerebral hemispheres
dendrites
a branch from the neural cell body that usually receives input from other neurons
function of the endocrine system
a collection of glands that release hormones into the blood involved with arousal, metabolism, growth, and sex
function of the enteric nervous system
- communicates with the endocrine system to ensure the release of chemicals essential to digestion
- involved with gastrointestinal pain, hunger, and fullness
- gives rise to a “gut feeling”
- the source of 95% of the body’s serotonin
executive functions
the set of basic and higher-level cognitive processes that enable self-regulation and cognitive control of behaviour (e.g. planning, decision-making, and goal pursuit)
parts of the frontal lobe
- primary motor cortex: provides the highest level of voluntary control over movement
- Broca’s area: participates in the production of speech
- prefrontal cortex: involved with the planning of behaviour, attention, and judgment
- orbitofrontal cortex: a part of the prefrontal cortex located right behind the eyes that participates in impulse control
glia
nervous system cells that perform a variety of support functions, including formation of the blood-brain barrier and myelin
shape and function of the hippocampus
SHAPE:
a subcortical structure that received its name, due to its seahorse-like shape (hippokampus)
FUNCTION:
essential to the formation of long-term memories
functions of the hypothalamus
a subcortical structure that…
- is involved with motivation and homeostasis (regulation of body functions)
- contributes to the 4F behaviours: feeding, fleeing, fighting, and fornication
location and function of the medulla oblongata
LOCATION:
the brainstem structure that lies just above the spinal cord
FUNCTION:
manages life-sustaining functions (i.e. heart rate, breathing, blood pressure)
location and function of the midbrain
LOCATION:
the part of the brainstem that lies between the pons and the cerebral hemispheres
FUNCTION:
involved in sensory reflexes, movement, and pain
myelin
the insulating material covering some axons
neurogenesis
the generation of new neurons
neurons
a cell of the nervous system that is specialized to send and receive neural messages
neuroplasticity
the ability of neurons to change in structure and function throughout the life span
neurotransmitters
chemical messengers that communicate across a synapse
location and function of the nucleus accumbens
LOCATION:
a structure of the nucleus accumbens between the caudate and putamen
FUNCTION:
participates in reward and pleasure/addiction (e.g. eating, having sex, using drugs, gambling)
parts of the occipital lobe
- primary visual cortex: begins the process of interpreting input from the eyes by responding to basic information about an image (e.g. borders, shading, colour, movement)
- pathway connecting the occipital and temporal lobes: allows you to recognize objects you see
- pathway connecting the occipital and parietal lobes: allows you to process the movement of objects
the relationship between the parasympathetic and sympathetic nervous systems
When stressed, the sympathetic nervous system provides the muscles with the resources needed for a fight-or-flight reaction; our hearts race, we breathe faster, our faces become pale, our palms sweat, and our pupils dilate.
When relaxed, the parasympathetic nervous system allows us to store nutrients, repair our bodies, and return the activities of internal organs to baseline levels; our hearts slow down, we breathe slower, our faces colour, and our pupils constrict.
During sexual activity, these two divisions cooperate.
major part of the parietal lobe
primary somatosensory cortex: helps us localize touch, pain, skin temperature, and body position
peripheral nervous system (PNS)
the nerves exiting the CNS that carry sensory and motor information to and from the rest of the body
location and functions of the pons
LOCATION:
a brainstem structure located between the medulla and the midbrain
FUNCTIONS:
- serves as a bridge between the higher and lower portions of the brain
- involved with the management of sleep, arousal, and facial expressions
receptors
special channels in the membrane of a neuron that interacts with neurotransmitters released by other neurons
resting potential
the measure of the electrical charge across a neural membrane when the neuron is not processing information
location and functions of the reticular formation
LOCATION:
a collection of structures located along the midline of the brainstem
FUNCTIONS:
participates in the management of levels of arousal; has two settings (fast and slow)
when cells fire quickly, we show signs of awakeness, but when cells fire slowly (or are damaged), we show signs of deep sleep or unconsciousness
reuptake
a process in which molecules of neurotransmitter in the synaptic gap are returned to the axon terminal from which they were released
somatic nervous system
the part of the PNS that brings sensory information to the central nervous system and transmits commands to the muscles
spinal cord
a long cylinder of neural tissue extending from the medulla of the brain down to the middle of the back; part of the CNS
synapse
a point of communication between two neurons
parts of the temporal lobe
- primary auditory cortex: allows us to process incoming sounds
- Wernicke’s area: involved in comprehension of speech; if damaged, patients can speak fluently, but will make no sense
location and functions of the thalamus
LOCATION:
a subcortical structure almost at the centre of the brain
FUNCTIONS:
involved with the processing of sensory information, memory, and states of consciousness; coordinates the activity of cortical neurons, “tuning out” the outside world, making it difficult to awaken
the philosophy that René Descartes proposed
dualism: suggests that our mind is somehow different and separate from our physical being
another name for biological psychology
behavioural neuroscience
two things that biological changes influence
behaviour and cognition
a historical mistake in phrenology, toward the end of the 18th century
Phrenologists proposed that the pattern of bumps on an individual’s skull correlated with that person’s personality traits and abilities, and that the brain worked like a muscle; getting larger through every use.
Frequently used areas of the brain would grow so much that the skull above these areas would bulge.
anatomist Santiago Ramón y Cajal’s (1852-1934) conclusion of the nervous system
Using Camillo Golgi’s microscopic stain, Cajal concluded that the nervous system was made up of separate cells (“the Neuron Doctrine”).
neurologist John Hughlings Jackson’s (1835-1911) conclusion of the nervous system
Using observations of his patients with seizure disorders, Jackson proposed that the nervous system is organized as heirarchy; progressively more complicated behaviours were managed by more recently evolved and complex structures.
two types of neuroscientific methods
- spatial resolution: providing information about the specific location of activity the brain
- temporal resolution: providing information about the specific timing of activity in the brain
the two major components of the nervous system
the central and the peripheral nervous systems
Nerves branch outward from the CNS to all areas of the body - the lungs, heart, and other organs; the eyes and ears; and the arms, legs, fingers, and toes. As soon as this occurs, the nerve is considered part of the…
peripheral nervous system
Nerves of the CNS are encased in…
bone
another name for the nervous system
the body’s electrochemical communication system
characteristics of a neuron
- a nucleus, within a cell body
- an outer membrane that surrons the neuron and forms a barrier between the extracellular and intracellular fluids
what takes place in the cell body
most housekeeping tasks of the cell (e.g. the translation of genetic codes into the manufacture of proteins)
composition of the neural membrane
- insoluble fatty materials
- pores within the membrane that act as channels
two types of branches that extend from a neuron’s cell body
- axons carry information
- dendrites receive information
number of dendrites and axons in a single neuron
many dendrites, but only one axon
two different types of “matter” within the CNS
- white matter: pathways formed by large bundles of nerve fibres or axons
- grey matter: areas with a high density of cell bodies or dendrites
two possible functions of glia
- some provide a structural matrix for neurons, ensuring they stay in place (myelin)
- some are mobile, allowing them to move to a location where neurons have been damaged to clean up debris
the blood-brain barrier
glia form tight connections with the blood vessels in the nervous system, preventing many toxins from entering the brain
In vertebrates such as humans, glia wrap around some axons, forming an important layer of insulation called…
myelin
the effect of myelination on pain
When you hurt yourself, the fast, sharp “ouch” message is carried to the brain by myelinated axons, but the dull, achy message that lasts a lot longer is carried by unmyelinated axons.
two different types of myelin within the nervous system
- myelin in the CNS form scar tissue, inhibiting repair to the damaged nerves
- myelin in the PNS do not form scar tissue, and allow damaged axons to rerow
damage in the CNS vs. damage in the PNS
- CNS damage is permanent due to the growth of scar tissue when met with trauma.
- PNS damage is temporary due to the lack of scar tissue.
the duration of myelin growth
myelin begins to grow before birth, but isn’t completed until early adulthood (about 25 years old)
the last area of the nervous system to be myelinated
the prefrontal cortex
the effect of late myelination within the prefrontal cortex
The prefrontal cortex is involved with judgment and morality. Until myelin in this area is mature, these neurons don’t work as efficiently, which is one of the possible reasons teenagers and adults make different decisions.
When a neuron isn’t processing information it is…
at rest
At rest, relative to its exterior, the interior of the neutron is…
negatively charged
the two possible processes of which neurons undergo when responding to incoming chemical signals
depolarization (moving closer together) or hyperpolarization (moving farther apart)
the effect of depolarization on the electrical charges of the extracellular and intracellular neuronal fluids
the charges decrease
the effect of hyperpolarization on the electrical charges of the extracellular and intracellular neuronal fluids
the charges increase
threshold
the point at which an action potential is initated and inevitable
the four stages of action potential
- sodium channels open; sodium rushes in (depolarization)
- potassium channels open; potassium rushes out
- sodium channels close (hyperpolarization)
- potassium channels close
where the steps of action potentials take place
- polarization takes place in the small segment of the axon connected to the cell body
- propagation takes place along the length of the axon to the axon terminal
propagation
the duplication of the electrical signal down to the axon terminal, where it initiates the release of chemical messengers
differences in propogation of myelinated and unmyelinated axons
- action potentials in unmyelinated axons occur step by step, section by section, down the entire length of the axon
- action potentials in myelinated axons are formed only at nodes of Ranvier; skipping the sections covered by myelin
nodes of Ranvier
sections of the axon membrane between adjacent segments of myelin
acetylcholine
a neurotransmitter found at the neuromuscular junction that influences movement, learning, memory, and autonomic nervous system function
the effects of abnormalities in acetylcholine activity
- paralysis and death
- Alzheimer’s disease
norepinephrine
a neurotransmitter that influences arousal, vigilance, and sympathetic nervous system function
the effects of abnormalities in norepinephrine activity
- bipolar disorder
- PTSD
dopamine
a neurotransmitter that influences movement, planning, and reward
when we engage engage in behaviours that promote survival and successful reproduction (e.g. eating, having sex), or take drugs that produce addiction (e.g. cocaine, meth), there is increased activity in dopamine circuits
the effects of abnormalities in dopamine activity
- Parkinson’s disease
- schizophrenia
- ADHD
serotonin
a neurotransmitter that regulates sleep, appetite, mood, and aggression
endorphins
a neurotransmitter that modifies our natural response to pain; opioid drugs (e.g. morphine, heroin) produce pain-releaving effects my mimicking the action of endorphins
six steps of chemical signalling
- action potential reaches axon terminal
- synaptic vesicles are released from their protein anchors
- synaptic vesicles fuse with the axon membrane at release sites
- vesicles open, releasing neurotransmitters into the synaptic cleft
- reuptake; the vesicle material is recycled
- vesicles are refilled with neurotransmitter
the relationship between receptors and neurotransmitters
they work like locks and keys; only a neurotransmitter with the right shape (key) can bind to the particular receptor (lock)
two possible effects of the interaction between neurotransmitters and receptors
- excitatory effect: the receiving neuron is depolarized, increasing the likelihood that it will reach threshold and initiate an action potential
- inhibitory effect: the receiving nuron is hyperpolarized, reducing the likelihood that it will reach threshold and initiate an action potential
two different types of drugs that influence the actions of neurotransmitters
- Agonists enhance the actions of neurotransmitters
- Antagonists inhibit the actions of neurotransmitters.
summation
the addition of all incoming action potentials
where adult neurogenesis occurs
stem cells in the the hippocampus and the olfactory bulb
long-term potentiation
a process that enhances communication between two neurons, and plays an important role in learning and memory
meningitis
inflammation of the meninges covering the brain and the spinal cord
cerebrospinal fluid (CSF)
a clear, plasma-like fluid that flows from ventricles and cushions the CNS
spinal nerves
31 pairs of nerves that exit between the bones of the vertebrae to bring sensory information back to the CNS and carry motor commands to muscles
interneurons
form bridges between sensory and motor neurons
functions of the cerebellum
- maintaining balance and motor coordination
- complex cognitive processing
three structures of the brainstem
- medulla
- pons
- midbrain
the gateway to the cortex
sensory systems → thalamus → cerebral cortex
six subcortical structures
a collection of structures that lie below the cerebral cortex, including the…
- thalamus
- basal ganglia
- hypothalamus
- hippocampus
- cingulate cortex
- amygdala
the four lobes of the cerebral cortex
- frontal lobe: responsible for some of the most complex cognitive processes
- parietal lobe: processes sensory information
- occipatal lobe: processes visual information
- temporal lobe: processes auditory information
the three categories of functions performed by different areas of the cerebral cortex
sensory, motor, and association
mirror neurons
some of the same neurons fire when an animal does an action, or sees the action being done
lateralization
a function in either the right or the left cerebral hemisphere
examples of lateralized processes
- lateralization in the somatosensory and voluntary motor systems depicts that movement and sensations on the right side of the body are processed by the left hemisphere, and vice versa
PROCESSES LATERALIZED TO THE LEFT HEMISPHERE:
- language
- positive emotions
- mathematical computation and logical reasoning
PROCESSES LATERALIZED TO THE RIGHT HEMISPHERE
- negative emotions
- music functions
- spatial information
- intuition
- visual arts
advantages of lateralization
- multitasking
- survival advantages
- social cohesion
cranial nerves
12 pairs of nerves that carry sensory and motor information from the brain to the head, neck, and some internal organs
the three divisions of the autonomic nervous system
- sympathetic nervous system: prepares the body for situations regarding energy
- parasympathetic nervous system: directs the storage of energy
- enteric nervous system: a “second brain” that communicates with the endocrine system
six important glands of the endocrine system
- pineal gland
- pituitary gland (“master gland”)
- thyroid gland
- adrenal glands
- islets of Langerhans
- ovaries and testes
function of the pineal gland
an endocrine gland that releases melatonin, involved in sleep-wake cycles; it is normally released in the early evening, and breaks down in the presence of light
functions of the pituitary gland
the posterior pituitary secretes…
- oxytocin - involved in breastfeeding - and vasopressin - involved in maintenance of fluid levels - but are also implicated in cooperation, trust, memory for social information, emotion recognition, and resilience during stress
- human growth hormone (HGH) stimulates growth and regeneration
the anterior pituitary secretes hormones that control the production and release of sex hormones by the ovaries and the testes
location and function of the thyroid gland
LOCATION:
just below the larynx
FUNCTION:
raises or lowers metabolic rate
function of the adrenal glands
when activated by pituitary hormones in stressful moments, adrenal glands release other hormones (e.g. cortisol) that travel throughout the body and the brain to provide a general wake-up message
location and function of the islets of Langerhans
LOCATION:
the pancreas
FUNCTION:
produces insulin, along with other hormones essential to digestion
histology
microscopic examination of the nervous system
skin conductance response
measurement of electricity passed between two surface electrodes placed on the skin of the hand or finger
electroencephalogram (EEG)
measurement of the brain’s electrical activity using electrodes placed on the scalp
event-related potential (ERP)
measurement formed by averaging EEG responses to a stimulus, such as a light or tone
single cell recording
measurement of a single neuron’s activity obtained through a surgically implanted electrode
magnetoencephalograpy (MEG)
recording of the tiny amounts of magnetic output of the brain
positron emission tomography (PET)
measurement that uses the accumulation of radioactively tagged glucose or oxygen to identify activity levels in parts of the brain
functional magnetic resonance imaging (fMRI)
identification of active parts of the brain using magnetism to track the flow of oxygen
electrical stimulation
application of small amounts of electricity through a surgically implanted electrode
optogenetics
genetically inserted light-sensitive proteins allow cells in the brain to be turned on with light
transcranial magnetic stimulation (TMS)
application of magnetic fields to the brain through an instrument held near the scalp
lesions
naturally occurring or deliberate damage to the brain
the number of neurons and neural connections in the brain
100 billion neurons; 100 trillion connections
nodes of Ranvier
located between two adjacent segments of myelin, and makes the formation of action potentials possible
lockjaw
The name given to the severe muscle contraction due to tetanus. Inhibitory input balances contraction to maintain smooth movements. Tetanus blocks motor inhibition, and causes too much muscle contraction.
opponent-process cells
cells that are capable of both speeding up of slowing down firing to communicate different things (e.g. ganglion cells)
the last part of the nervous system to be myelinated
the prefrontal cortex, associated with judgment and morality (why teens tend to make stupid decisions)
