Chapter 3 Flashcards
What is the nervous system?
Information highway with a collection of hundreds of billions of specialized and interconnected cells through which messages are sent between the brain and the body.
What is the Central Nervous System (CNS) made up of?
The brain and the spinal cord.
What is the Peripheral Nervous System (PNS)?
Neurons that link CNS to our skin, muscles, and glands.
What does the Endocrine System do?
The chemical regulator of the body.
Contains glands that secrete hormones.
Evolutionary psychologists are interested in what?
In structures, processes, or organs that are genetically the same for everyone.
Keywords - same genetics
What do Behaviour geneticists look for?
Individual differences incur genes to see if these relate to individual differences in thinking, feeling and behaving.
What is a neuron?
A cell in the nervous system whose function is to receive and transmit information.
Neurons are made up of what three parts?
- Soma (cell body) - contains the nucleus of the cell to keep it alive.
- Dendrite - branching, tree-like fibre that collects information from other cells and sends the info to the soma.
- Axon - long, segmented fibre that transmits info away from the cell body toward other neurons or to the muscles and glands.
What is the myelin sheath?
Layer of segmented fatty tissue surrounding the axon of a neutron.
Insulates and allows faster transmission of the electrical signal.
What is the Node of Ranvier?
The gaps between the segmented tissues on the myelin sheath. The segments allow for more efficient transmission of info down the axon.
What is the terminal button?
Axons branch out toward their ends and at the tip of each branch is a terminal button.
What are the electrical signals transmitted by neurons called?
Action potentials.
Neurons can be classified into what three groups?
- Sensory neurons
- Motor neurons
- Relay neurons
What do sensory neurons do?
Nerve cells that carry nerve impulses from sensory receptors towards the central nervous system and brain.
When these nerve impulses reach the brain, they are translated into ‘sensations’, such as vision, hearing, taste and touch.
What do motor neurons do?
They are the nerve cells responsible for carrying signals away from the central nervous system towards muscles to cause movement.
They release neurotransmitters to trigger responses leading to muscle movement.
Where are motor neurons located?
Motor neurons are located in the brainstem or spinal cord (parts of the central nervous system) and connect to muscles, glands and organs throughout the body.
What are the two types of motor neurons, and what do they do?
Upper motor – neurons that travel between the brain and the spinal cord.
Lower motor - neurons that travel from the spinal cord to the muscles.
What does a relay neuron do?
Aka interneuron - allows sensory and motor neurons to communicate with each other.
Relay neurons connect neurons within the brain and spinal cord.
Easy to recognize, due to their short axons.
What is a neurotransmitter?
A chemical that relays signals across the synapses between neurons.
Neurotransmitters travel across the synaptic space between the terminal button of one neuron and the dendrites of other neurons where they bind to the dendrites in the neighbouring neurons.
What is the reuptake?
The process in which neurotransmitters that are in the synapse are reabsorbed into the transmitting terminal buttons, ready to be released again after the neuron fires.
Some medications inhibit the reuptake of neurotransmitters, allowing the neurotransmitter to remain in the synapse for longer and increasing its effectiveness.
What is an agonist?
A drug that has a chemical property similar to a particular neurotransmitter, which allows it to mimic the effects of a neurotransmitter.
When ingested, it binds to the receptor sites in the dendrites to excite the neuron, acting as if MORE of the neurotransmitter had been present.
What is an antagonist?
A drug that reduces or stops the normal effects of a neurotransmitter.
Which glands in the endocrine system are responsible for the production of hormones?
The pancreas, thyroid, and ovaries.
They secrete insulin, melatonin, and testosterone into the bloodstream.
What are hormones responsible for?
For maintaining regular bodily functions, such as growth, digestion, energy and so on.
Define homeostasis.
Endocrine and nervous system work together to create a stable, balanced, and optimal function of the body’s physiological systems.
The body uses both chemical and electrical systems to create homeostasis.
What does the hypothalamus do?
Regulates basic biological needs and sends signals to adjust the endocrine system in response to changing needs via the pituitary gland - “master controller” of the endocrine system.
The pituitary gland signals commands to change the production of hormones to glands in endocrine system.
What are androgens?
Masculizing hormones that cause male sex characteristics. Linked to sex drive in all genders.
Produced mainly in testes in men and ovaries in women, and also in adrenal glands.
Testosterone is the most important androgen.
What is estrogen?
Feminizing hormones that cause female secondary sex characteristics to develop at puberty.
Regulate female fertility linked to learning and memory for all genders.
Produced mainly in ovaries in women, testes in men, and also in adrenal glands.
What do adrenal glands do?
Adrenal hormones are produced by adrenal glands above kidneys in response to physical or emotional stress or threat. They produce epinephrine and norepinephrine, the hormones responsible for our reactions to stress.
Release of cortisol, epinephrine/adrenaline and norepinephrine is activated by the sympathetic nervous system. Active in the flight-or-fight response.
What do endorphins do?
Reduce pain and induce pleasure. Released when under stress.
Similar effects to natural opiates such as morphine. Sometimes classified as neurotransmitters or neuromodulators. Referred to here as hormones for convenience.
What does melatonin do?
Promotes sleep and helps to regulate circadian rhythm. (Physical, mental, and behavioural changes that follow a 24-hour cycle).
Released by pineal gland.
What does the cerebral cortex do?
A very large and highly developed outer layer of the forebrain responsible for memory, social interactions and emotions.
What does the brainstem consist of, and what does it do?
The hindbrain includes the brainstem, cerebellum, pons, reticular formation, and medulla.
Responsible for breathing, attention and motor responses.
The brain stem begins where the spinal cord enters the skull and forms the medulla - area of the brain stem that controls heart rate and breathing.
What does the medulla do?
The area of the brain stem that controls heart rate and breathing.
What does the pons do?
The spherical shape above the medulla is the pons.
Structure of the brain stem helps control movements of the body, such as chewing, and carries sensory info to other area of the brain.
What does the reticular formation do?
A narrow network of neurons that runs through the medulla and the pons.
Filters out excess stimuli coming into the brain from the spinal cord.
Relays the remainder of the signals to other areas of the brain.
Reticular formation plays roles in walking, eating, sexual activity and sleeping.
What does the cerebellum do?
“Little brain” consists of two wrinkled ovals behind the brain stem.
Functions to coordinate voluntary movement.
What does the substantial nigra do?
A layer of neurons within midbrain that produces the neurotransmitter dopamine and also coordinates movement.
This area is damaged in Parkinson’s disease.
What does the cerebrum do?
Sits in the forebrain.
Responsible for thought, planning, language and sensory information.
We make sense of the world in the cerebrum.
What does the cortex do?
The cortex covers the cerebrum with a wrinkled layer.
What does the thalamus do?
Egg-shaped structure above the brain stem.
Applies more filtering to the sensory info coming up from the spinal cord and through the reticular formation. Relays some of these remaining signals to higher brain levels.
Also receives some of the higher brain’s replies and forwards them to the medulla and the cerebellum.
Important to sleep because is shuts off incoming signals from the senses and allows us to rest.
What does the limbic system do?
lt is largely responsible for memory and emotions—including responses to reward
Located between the brain stem and the two cerebral hemispheres.
Includes the amygdala, hypothalamus, and hippocampus.
Pituitary gland also controlled by the limbic system.
What does the amygdala do?
It consists of two almond-shaped clusters. Responsible for regulating our perceptions of, and reactions to, aggression and fear.
Amygdala also helps us learn from situations that create fear. When we experience dangerous events, amygdala stimulates brain to remember the details of the situation so that we learn to avoid it in the future.
What does the sympathetic nervous system do?
The amygdala has connections to other bodily systems related to fear.
Important in fear responses, facial responses to perceive and express emotions, the processing of smells, and the release of neurotransmitters related to stress and aggression.
What does the hypothalamus do?
Located just under the thalamus. Contains a number of small areas responsible for regulation of hunger and sexual behaviour.
Links the nervous system to the endocrine system via the pituitary gland. Helps regulate body temp, hunger, thirst and sex; it responds to the satisfaction of these needs by creating feelings of pleasure.
What does the hippocampus do?
Consists of two “horns” that curve back from amygdala. Responsible for long-term memory and navigation.
If this is damaged, a person cannot build new memories. New memories fade away, while older memories from the time before the damage occurred are untouched.
What is the cerebral cortex?
Outer, bark-like layer of our brain that allows to use language acquire complex skills, create tools, and live in social groups.
Allows for increased capacities for learning, remembering, and thinking. The folding of the cerebral cortex is known as the corticalization.
Cortex is only about one-tenth of an inch (2.5mm), but makes up more than 80% of the brain’s weight.
What are glial cells?
The cells that surround and link to the neurons, protecting them, providing them with nutrients and absorbing unused neurotransmitters.
The myelin sheath surrounding the axon of many neurons is a type of glial cell.
Glia are essential partners of neurons. Without them, the neurons could not survive or function.
Cerebral Cortex - divided into two hemispheres. Each hemisphere is divided into four lobes. Each is separated by folds known as fissures.
What are the four lobes?
- Frontal lobe - located behind the forehead. Responsible for thinking, planning, memory and judgement.
- Parietal lobe - located from the middle to the back of the skull. Responsible for processing information about touch.
- Occipital lobe - located at the back of the skull. Processes visual info.
- Temporal lobe - responsible for hearing and language.
What is the motor cortex?
Part of the cortex that controls and executes movements of the body by sending signals to the cerebellum and the spinal cord.
Located in the left hemisphere, responsible for body’s right side.
What is the sensory cortex?
Part of the cortex that allows us to process sensory input.
Located in the left hemisphere, but receives input from the body’s right side.
What is the somatosensory cortex?
Located behind and parallel to the motor cortex at the back of the frontal lobe.
Receives info from the skin’s sensory receptors and the movements of different body types. Our lips occupy a large area in the sensory cortex, as do our fingers and genitals.
What is the visual cortex?
Located in the occipital lobe at the very back of the brain that processes visual info.
If you are stimulated by the visual cortex, you would see flashes of light and color. “Seeing stars” when you are hit or fall on the back of your head.
What do the auditory cortex and the temporal lobe do?
Temporal lobe, located on the lower side of each hemisphere contains the auditory cortex.
Responsible for hearing and language. Temporal lobe processes visual info and provides us with the ability to name objects.
Association areas are the remainder of the cortex. What do they do?
Remainder of cortex is made up of association areas that sensory and motor info are combined and associated with our stored knowledge.
Creates an “association” with our stored knowledge.
Association areas are involved in higher mental functions like learning, thinking, planning, judging, moral reflecting, figuring, and spatial reasoning.
Define contralateral control.
The brain is wired that in most cases the left hemisphere receives sensations from and controls the right side of the body, and vice versa.
For vision processing, the left half of the visual field from each eye is processed in the right hemisphere, while info from the right halves of the visual fields of both eyes goes to the left hemisphere.
Left hemisphere - processing of language and analytical-math reasoning
Right hemisphere - processing of visuospatial imagery and music
What is neuroplasticity?
Refers to the brain’s ability to change its structure and function in response to experience or damage.
Enables us to learn and remember new things.
Our brains are the most “plastic” when we are children.
What is neurogenesis?
The forming of new neurons in the brain.
What is brain lateralization?
the idea that the left and right hemispheres of the brain are specialized to perform different functions.
What is the corpus callosum?
The region that normally connects the two halves of the brain and supports communication between the hemispheres.
What is an interneuron?
The most common type of neuron located primarily within the CNS.
Responsible for communicating among the neurons.
Allow the brain to combine the multiple sources of info to create a coherent pic of the sensory info being conveyed.
What does the spinal cord do?
A long, thin, tubular bundle of nerves and supporting cells that extends down from the brain. Central pathway of info for the body.
What is a reflex?
An involuntary and nearly instantaneous movement in response to a stimulus.
Reflexes in your spinal cord order the appropriate responses before your brain even knows what is happening.
What does the peripheral nervous system (PNS) do?
Links the CNS to the body’s sense receptors, muscles, and glands.
Divided into two subsystems, one controlling external responses and one controlling internal responses.
What does the somatic nervous system do?
Is a division of the PNS.
Controls external aspects of the body (skeletal muscles, skin and sense organs).
Consists primarily of motor nerves responsible for sending brain signals for muscle contraction.
What does the autonomic nervous system do?
Somatic?
ANS is the division of the PNS that governs the internal activities of the human body—heart rate, breathing, digestion, salivation, perspiration, urination, and sexual arousal.
Heart rate and digestion are automatic and out of conscious control, but breathing and sexual activity can be controlled and influenced by conscious processes.
Somatic division of PNS that processes voluntary movement.
What does the sympathetic division do?
This division of the ANS is involved in preparing the body for behaviour, particularly in response to stress by activating organs and glands in the endocrine system.
Acts like the accelator, while the parasympathetic division acts like the brake.
What does the parasympathetic division do?
The division of the ANS that helps to calm the body by slowing the heart and breathing and by allowing the body to recover from the activities that the sympathetic system causes.
Acts like the brake, while the sympathetic division acts like the accelerator.
What is the primary function of the sympathetic and parasympathetic nervous systems?
To interact with the endocrine system to release chemicals that provide another method for influencing our feelings and behaviours.
Parasypathetic - responsible for calming
Sympathetic - responsible for fight or flight
The sympathetic system controls “fight-or-flight” responses. In other words, this system prepares the body for strenuous physical activity. The events that we would expect to occur within the body to allow this to happen do, in fact, occur. The parasympathetic system regulates “rest and digest” functions.
What is error management theory?
The evolution of how we think, make decisions, and evaluate uncertain situations—situations where there is no clear answer of how we should behave. What are the costs of errors in judgement?
EMT predicts that whenever uncertain situations present us with a safer vs more dangerous decision, we will psychologically adapt to prefer choices that minimize the cost of errors.
What are cost asymmetries?
The kinds of choices that have low cost, but high reward or high cost and low reward (eg. Walking through leaves and risk getting bitten by a snake).
What is visual descent illusion?
States that people will overestimate the distance when looking down from a height, compared to looking up, so that people will be wary of falling from great heights, which would result in death or injury.
What is auditory looming bias?
People overestimate how close objects are when the sound is moving toward them compared to when it is moving away from them.
If we think that a threat is closer when moving toward us, we will be quicker to escape.
What is sexual over perception bias?
Predicts that men often misread sexual interest from a woman when it’s just a friendly smile.
EMT predicts that men, more than women, will over-infer sexual interest based on minimal cues, and empirical research confirms this adaptive mating bias.
What is a heritability coefficient?
Measures how strongly differences among individuals are related to differences among their genes.
The heritability coefficient decides the determinants of a trait into two portions—genes and environments—which are then calculated together for the total variability. Similar to asking how much of the experience of a symphony comes from the horns and how much from the strings.
The autonomic nervous system is divided into two parts. What are they, and what are they responsible for?
Parasympathetic - slows heart rate, pupils contract, stimulates digestive activity.
Sympathetic - accelerates heart rate, dilates pupil, inhibits digestive activity, stimulates glucose release, and stimulates epinephrine and norepinephrine.
What does the autonomic nervous system do?
ANS is the division of the PNS (peripheral) that governs the internal activities of the human body, including heart rate, breathing, digestion, salivation, perspiration, urination, and sexual arousal.
Many of the actions of the ANS, such as heart rate and digestion, are automatic and out of our conscious control, but others, such as breathing and sexual activity, can be controlled and influenced by conscious processes
What does the somatic nervous system do?
The somatic nervous system (SNS) is the division of the PNS that controls the external aspects of the body, including the skeletal muscles, skin, and sense organs.
Consists primarily of motor nerves responsible for sending brain signals for muscle contraction.
What does the peripheral nervous system do?
If the central nervous system is the command centre of the body, the peripheral nervous system represents the front line.
The peripheral nervous system (PNS) links the CNS to the body’s sense receptors, muscles, and glands. The peripheral nervous system is itself divided into two subsystems, one controlling external responses and one controlling internal responses.
What is a gland?
A gland in the endocrine system is made up of groups of cells that function to secrete hormones.
What does a hormone do?
A hormone is a chemical that moves throughout the body to help regulate emotions and behaviours.
What is transcranial magnetic stimulation (TMS)?
Transcranial magnetic stimulation is used to temporarily and safely deactivate a small brain region with the goal of testing the causal effects of the deactivation on behaviour.
What is a functional magnetic resonance image (fMRI)?
Measures blood flow in the brain during different activities.
Provides info about the activity of neurons and, thus, the functions of brain regions.
What does a computerized tomography (CT) scan do?
CT scans are essentially X-rays taken around the head that can be combined to produce three-dimensional images of the brain.
Allows cross-sectional “slices” of the brain to be imaged. CT scans are the least expensive type of brain imaging system.
What does an electroencephalography (EEG) do?
Records electrical activity produced by the brain’s neurons through the use of electrodes that are placed around the research participant’s head.
Useful for understanding epilepsy, and is also useful for children who have a hard time staying still.
What is the frontal lobe responsible for?
Moral reasoning and judgement.
What is the HPA axis and what is it responsible for?
A major component of the homeostatic response is the hypothalamic-pituitary-adrenal (HPA) axis.
A neuroendocrine mechanism that mediates the effects of stressors by regulating numerous physiological processes, such as metabolism, immune responses, and the autonomic nervous system (ANS).
The HPA axis is responsible for the neuroendocrine adaptation component of the stress response. The response creates a hypothalamic release of corticotropin-releasing factor (CRF). CRF is also known as CRH or corticotropin-releasing hormone.
What happens when the HPA axis is suppressed?
The body is not able to properly regulate stress and energy levels, which can manifest into symptoms such as fatigue, suppressed immune system, depression, and anxiety.
What is the limbic system made up of?
Hypothalamus, hippocampus, amygdala, thalamus and basal ganglia.
What does the neuroendocrine system do?
Cells that receive signals from neurons (via release of neurotransmitters) that in turn release hormones into the circulatory system.
The master controller of the endocrine system is:
The pituitary gland
What does the hypothalamus regulate?
Our basic biological needs and sends signals to adjust the endocrine system in response to changing needs via the pituitary gland.
Where is melatonin released?
In the pineal gland.
Melatonin promotes sleep and helps regulate circadian rhythm.
