PSYC289 - Unit 3: Biopsychology

What is the primary function of neurons in the nervous system?

To receive, integrate, and transmit information.

What is the role of glial cells in the nervous system?

They provide support for neurons and supply cerebral spinal fluid to cushion the brain.

How many neurons are estimated to be in the brain?

Approximately 86 billion neurons.

What separates the inside of a neuron from the outside?

The cell membrane.

What is the function of the soma (cell body) in a neuron?

It contains the nucleus and is the site where proteins and neurotransmitters are manufactured.

What is the primary function of dendrites?

To gather incoming information from other cells.

What is the function of the axon?

It is a long, thin fiber that transmits signals away from the soma to other neurons, muscles, or glands.

What is the myelin sheath and what is its primary purpose?

An insulating material derived from glial cells that surrounds parts of the axon to speed up signal transmission and increase energy efficiency.

What occurs at the axon terminals?

Chemicals are released by the neuron to influence the activity of other neurons.

What is a synapse?

A junction where information is transmitted from one neuron to the next.

What is the resting potential of a neuron?

The stable, negative charge of an inactive neuron, typically around -70 millivolts.

What is an action potential?

A brief reversal of polarity (from negative to positive, reaching +30 millivolts) that causes an electrical charge to travel along an axon.

What is the all-or-none law?

The principle that a neuron either fires completely or does not fire at all; no partial action potentials occur.

How does the nervous system convey the intensity of a stimulus?

Through the rate of action potentials; a greater rate indicates a stronger stimulus.

What is the absolute refractory period?

The minimum length of time after an action potential during which another action potential cannot begin.

What is the primary method neurons use to communicate with one another?

Synaptic transmission.

What is the synaptic cleft?

The synaptic cleft is the tiny channel or gap between two neurons.

Where are chemicals involved in neural communication stored?

They are stored in the terminal buttons of the neuron.

What triggers the release of chemicals into the synaptic cleft?

An action potential, which occurs when a neuron is sufficiently stimulated by an electrical impulse.

What are neurotransmitters?

chemicals that are released from the axon terminal of a neuron to convey information to another neuron.

What are synaptic vesicles?

Small, bead-like containers in the axon terminal that store neurotransmitters.

What are the four methods by which neurotransmitters are removed from the synapse?

Deactivation (enzymes), Autoreception (binding to the releasing neuron), Reuptake (taken back into the releasing cell), and Degradation (broken down inside the cell).

What are graded potentials?

changes in polarization where the magnitude of the change varies with the strength of the stimulus

What is the difference between excitatory and inhibitory postsynaptic potentials?

Excitatory potentials increase the chance of an action potential, while inhibitory potentials decrease the chance of an action potential.

Define spatial summation.

The process of combining excitatory and inhibitory inputs arriving at different, but very close, branches of a dendrite.

Define temporal summation.

The process of combining excitatory and inhibitory inputs that arrive at the dendrites in rapid succession.

What is synaptic pruning?

The process of eliminating less-active synapses to form efficient neural networks during development.

What are cell assemblies?

highly interconnected groups of neurons in the brain that activate together to represent specific memories, perceptions, or thoughts

What is the primary function of Acetylcholine?

It is the transmitter between motor neurons and voluntary muscles, and it contributes to attention, arousal, and memory.

What roles does Dopamine play in the brain?

It plays a role in pleasure, rewards, movement, learning, and attention.

What are the primary functions of Norepinephrine?

It affects arousal, alertness, and mood.

What is the role of Serotonin?

It helps regulate mood, eating, arousal, and sleeping, and has links to aggression.

What is the function of GABA?

It produces inhibitory postsynaptic potentials and contributes to the regulation of anxiety and sleep/arousal.

What are the primary functions of endorphins?

They play a role in pain relief, response to stress, and the regulation of eating behavior.

What is the difference between an agonist and an antagonist in neurotransmission?

An agonist mimics the action of a neurotransmitter, while an antagonist opposes its action.

What structures compose the central nervous system (CNS)?

The brain and the spinal cord.

What is the peripheral nervous system composed of?

all nerves outside the central nervous system

What is the function of the somatic nervous system?

It connects to voluntary skeletal muscles and sensory receptors.

What is the difference between afferent and efferent nerve fibres?

Afferent fibres carry information inward to the CNS, while efferent fibres carry information outward from the CNS.

What is the autonomic nervous system made of?

nerves that connect to the heart, blood vessels, smooth muscles, and glands

What is the primary function of the sympathetic division of the autonomic nervous system?

It mobilizes the body's resources for emergencies.

What is the primary function of the parasympathetic division of the autonomic nervous system?

It conserves the body's resources.

How do lesioning and electrical stimulation (ESB) differ as research methods?

Lesioning involves destroying a piece of the brain to study it, while ESB involves sending a weak electric current to stimulate or activate a brain structure.

What is a CT scan?

An x-ray machine is rotated around the brain, taking multiple images of a horizontal slice of the brain. A computer then combines those to make a 2D image of a horizontal slice of the brain.

What type of image does an MRI produce?

An MRI uses magnetic fields, radio waves, and computerized enhancement to map out brain structures. It produces a still 3D image of the brain.

What does an EEG monitor?

It monitors the electrical activity of the brain over time, specifically measuring electric potentials.

What is the primary purpose of a PET scan?

It uses radioactive markers to map chemical activity in the brain over time.

How does an fMRI differ from a standard MRI?

An fMRI monitors blood flow and oxygen consumption to identify areas of high brain activity.

Which structures are located in the hindbrain?

The cerebellum, the medulla, and the pons.

What are the vital functions controlled by the medulla?

Circulating blood, breathing, maintaining muscle tone, and regulating reflexes like sneezing, coughing, and salivating.

What is the pons?

a bridge of fibres that connects the brainstem with the cerebellum. The pons also contains several clusters of cell bodies involved with sleep and arousal

What is the primary role of the cerebellum?

It coordinates movement and is critical for the sense of equilibrium.

Where is the midbrain?

the segment of the brainstem located between the hindbrain and the forebrain.

What is the purpose of the midbrain?

The midbrain contains a region that integrates sensory processes, including vision and hearing. As well as a dopamine system involved in the performance of voluntary movements

What is the function of the reticular formation?

It modulates muscle reflexes, breathing, pain perception, and regulates sleep and arousal.

What is the forebrain?

the largest and most complex region of the brain, encompassing a variety of structures, including the thalamus, hypothalamus, limbic system, and cerebrum

What is the role of the thalamus?

It acts as a relay station for all sensory information (except smell) before it reaches the cerebral cortex.

What is the primary function of the hypothalamus?

It is involved in the regulation of basic biological needs.

What is the limbic system?

a loosely connected network of structures located roughly along the border between the cerebral cortex and deeper subcortical areas. The limbic system includes parts of the thalamus and hypothalamus, the hippocampus, the amygdala, and other nearby structures.

What is the role of the hippocampus?

plays a role in memory processes

What is the role of the amygdala within the limbic system?

It plays a central role in the learning of fear responses and the processing of basic emotional responses.

The cerebrum is…

…the largest and most complex part of the human brain. It is responsible for the most complex mental activities, including learning, remembering, thinking, and consciousness.

What is the cerebral cortex?

The outer wrinkly layer of the brain, controls consciousness, memory and language

What is the function of the corpus callosum?

It is a band of thick fibers that connects the two cerebral hemispheres.

What are the four lobes of the cerebral cortex?

Frontal, parietal, temporal, and occipital lobes.

Which lobe of the brain is primarily responsible for visual processing?

The occipital lobe.

What is the function of the parietal lobe?

The parietal lobe is involved in integrating visual input and monitoring the body's position in space.

What is the function of the primary somatosensory cortex located in the parietal lobe?

It registers the sense of touch.

What is the role of the temporal lobe?

The temporal lobe contains an area devoted to auditory processing, called the primary auditory cortex

Frontal lobe

The largest lobe in the human brain.

Primary motor cortex

The principal areas that control the movement of muscles.

What is the role of the prefrontal cortex?

It houses an executive control system that organizes and directs thought processes.

What are mirror neurons?

Neurons that are activated both when performing an action and when observing another animal perform the same action.

What are three fundamental roles associated with mirror neurons?

Acquisition of new motor skills, imitation of others, and understanding others' intentions and empathy.

What is brain plasticity?

The brain's ability to change its structure and function in response to experience or damage.

What is neurogenesis?

The formation of new neurons, a process now known to occur in the adult brain.

Which hemisphere is typically superior at verbal processing tasks like language and writing?

The left hemisphere.

Which hemisphere is typically superior at spatial, musical, and visual recognition tasks?

The right hemisphere.

What are the primary functions of Broca's and Wernicke's areas?

They aid in the production and comprehension of language, respectively.

Damage in Broca's area results in

problems with the production of speech

Damage in Wernicke's area leads to

to problems with the comprehension of language

How does the brain's motor control relate to body sides?

Each hemisphere controls and communicates with the opposite side of the body.

How are motor skills processed by the hemispheres?

the left hemisphere controls, and communicates with, the right hand, right arm, right leg, right eyebrow, and so on, whereas the right hemisphere controls, and communicates with, the left side of the body

How is visual information processed by the hemispheres?

Stimuli in the right visual field are registered by the left hemisphere, and stimuli in the left visual field are registered by the right hemisphere.

How is auditory information processed by the hemispheres?

inputs to each ear also go to both hemispheres. However, connections to the opposite hemisphere are stronger and more immediate. As a result, sounds presented exclusively to the right ear are registered in the left hemisphere first, while sounds presented to the left ear are registered more quickly in the right hemisphere

What is the primary function of the endocrine system?

It consists of glands that secrete hormones into the bloodstream to help control bodily functioning.

What are hormones?

chemical messengers secreted by the endocrine glands

How do hormonal messages differ from neurotransmitter signals?

Hormones travel slower and are less specific, acting on many distant cells, whereas neurotransmitters communicate over short distances at high speed.

Which gland is known as the 'master gland' of the endocrine system?

The pituitary gland.

What role does the hypothalamus play in the endocrine system?

It acts as the primary controller of the endocrine system and the pituitary gland.

What is the function of oxytocin?

It is a hormone released by the pituitary gland that regulates reproductive behaviors.

What are behavioural genetics?

the study of how genes and the environment influence behaviour

What are chromosomes?

Threadlike strands of DNA molecules that carry genetic information.

How many chromosomes are in a typical human cell?

46 chromosomes (23 from each parent).

Genes

DNA segments that serve as the key functional units in hereditary transmission.

Polygenic traits

Characteristics that are influenced by more than one pair of genes.

What is the difference between a genotype and a phenotype?

A genotype is a person's genetic makeup, while a phenotype is the observable manifestation of those genes.

Can phenotypic characteristics change over time?

Yes, they can be modified by environmental factors.

According to family studies, what relationship exists between genetic sharing and trait similarity?

There should be greater similarity among relatives who share a higher percentage of their genes.

What is the purpose of twin studies in behavioral genetics?

To assess hereditary influence by comparing the resemblance of identical versus fraternal twins.