Unit 1: Biological Basis of Behaviour Flashcards
What are neurons?
Neurons communicate signals across the brain via the brain stem and spinal cord, down to the body. There are over 100 billion neurons in the body, with 80% located in the brain.
What are glial cells?
Glial cells, known as ‘glue cells’, support and protect neurons by providing nutrients, guiding connections between neurons, providing myelin sheath for insulation, and transporting waste.
What are the three main types of neurons?
The three main types of neurons are motor neurons, sensory neurons, and interneurons.
What do motor neurons do?
Motor neurons are responsible for controlling voluntary and involuntary movement in response to environmental stimuli.
What is depolarization?
Depolarization occurs when positive ions from outside the synapse flood into the axon, attracted to the negative charge inside.
What is the refractory period?
The refractory period is when no new action potentials can occur until the axon is at full resting state.
What is the structure of a neuron?
A neuron consists of dendrites, soma, nucleus, axon, myelin sheath, nodes of Ranvier, presynaptic terminal, terminal buttons, and neurotransmitters.
What are excitatory neurotransmitters?
Excitatory neurotransmitters excite the neuron and cause it to fire.
What are inhibitory neurotransmitters?
Inhibitory neurotransmitters block or prevent the chemical message from being passed along any farther.
What is resting potential?
Resting potential refers to the positive charge outside and negative charge inside the neuron.
What do interneurons do?
Interneurons, or relay neurons, help connect messages between the brain and spinal cord, as well as between sensory and motor neurons.
What do sensory neurons do?
Sensory neurons transmit messages related to sensation to the brain.
What is an action potential?
An action potential travels the length of the axon and causes the release of neurotransmitters into the synapse.
What is the all or nothing principle?
The all or nothing principle states that a neuron either fires at full capacity or it does not.
What is neural transmission?
Neural transmission, also known as synaptic transmission, is the process in which one neuron communicates with another.
What does the CNS consist of?
The central nervous system (CNS) consists of the brain and spinal cord.
What does the PNS consist of?
The peripheral nervous system (PNS) consists of the sensory and motor neurons that connect the CNS to the rest of the body.
What is the fight or flight response?
The fight or flight response is a physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival.
What is acetylcholine?
Acetylcholine is a neurotransmitter that plays a role in memory, learning, attention, arousal, and involuntary muscle movement.
What is norepinephrine?
Norepinephrine is both a hormone and a neurotransmitter used to increase and maintain blood pressure in limited short time; it is vital for the fight or flight response.
What are hormones?
Hormones are chemicals produced by glands that regulate the activities of different body cells.
What is the pituitary gland?
The pituitary gland is the endocrine system’s most influential gland, regulating growth and controlling other endocrine glands under the influence of the hypothalamus.
What are stressors?
Stressors are events or situations that cause stress.
What is the function of dopamine?
Dopamine stimulates the hypothalamus to release hormones and gives feelings of pleasure and motivation when we perceive a reward.
What are the effects of dopamine undersupply?
Dopamine undersupply can lead to Parkinson’s disease.
What are the effects of dopamine oversupply?
Dopamine oversupply can lead to schizophrenia.
What is the function of serotonin?
Serotonin regulates arousal, sleep, appetite, moods, and emotions; it is a mood regulator.
What are the effects of serotonin undersupply?
Serotonin undersupply can lead to depression and other mood disorders.
What are the effects of serotonin oversupply?
Serotonin oversupply can lead to autism.
What is the function of endorphins?
Endorphins relieve pain.
What are the effects of endorphin undersupply?
Endorphin undersupply causes the body to experience pain.
What are the effects of endorphin oversupply?
Endorphin oversupply may prevent the body from giving adequate warnings about pain, leading to artificial pain.
What is the function of glutamate?
Glutamate helps chemical messages cross the synapse efficiently and aids in synaptic transmission for other neurons.
What are the effects of glutamate oversupply?
Glutamate oversupply can lead to epileptic seizures.
What is the function of GABA?
GABA helps the brain with major inhibitory neurotransmitters.
What are the effects of GABA undersupply?
GABA undersupply can lead to insomnia and generalized anxiety disorder (GAD).
What are the effects of GABA oversupply?
GABA oversupply can lead to sleep and eating disorders.
What is the function of substance P?
Substance P transmits pain from the peripheral nervous system (PNS) to the central nervous system (CNS).
What is Substance P oversupply associated with?
Leads to chronic pain
What does multiple sclerosis (MS) involve?
The immune system attacks the neurons in the CNS: brain/spinal cord
What does myasthenia gravis (MG) damage?
The communication system between the nerves and muscles, making them weak and easily tired
What causes MS?
Myelin sheath damage
What causes MG?
A problem with signals sent between neurons and muscles (neuron is 100% healthy)
What are common symptoms of MS?
Difficulties with movement and brain function
What is a key symptom of MG?
Fatigue
Symptoms get worse at the end of the day vs the morning
What is hereditary?
Passing of traits from parents to offspring
What does ‘nature’ refer to?
The influence of our inherited characteristics on personality, physical growth, intellectual growth, and social interactions
What does ‘nurture’ mean?
To care for
What is genetic predisposition?
An inherited genetic pattern that makes one susceptible to a certain disease
What does the evolutionary perspective focus on?
The biological bases of universal mental characteristics that all humans share
What is natural selection?
Organisms that are more adapted to their environment are more likely to survive and pass on the genes that aided their success
What is eugenics?
Selective breeding of humans
What are the two types of twins in twin studies?
Monozygotic (100% same genes) and Fraternal (50% same genes)
What do family studies assess?
Hereditary influence by examining blood relatives to see how much they resemble one another on a specific trait
What do adoption studies examine?
The resemblance between adopted children and both their biological and adoptive parents
What does adrenaline do?
Increases heart rate, blood pressure, and blood sugar levels, contributing to a surge of energy
What is oxytocin known as?
‘Love hormone’
Enables contractions during childbirth, supports milk flow, facilitates orgasms, promotes bonding, social trust, group cohesion, and attraction
What is the role of leptin?
Helps prevent hunger and regulate energy balances
What does ghrelin signal?
Signals to your brain that it’s time to eat when the stomach is empty
What role does melatonin play?
Plays a role in sleep
What are psychoactive drugs?
Chemicals that change the functions of the nervous system and alter perception, mood, thinking, and behavior
What does addictive mean?
Habit-forming, hard to break away from, easy to say yes to
What is tolerance in the context of drug use?
The diminishing effect with regular use of the same dose of a drug, requiring larger doses for the same effect
What is withdrawal?
The discomfort and distress that follow discontinuing the use of an addictive drug
What do stimulants do?
Excite neural activity; increasing levels of serotonin, dopamine, and norepinephrine
Give an example of a stimulant.
Caffeine or Cocaine
What do depressants do?
Reduce activity of the CNS and induce feelings of relaxation
Give an example of a depressant.
Alcohol or Opioids
What do opioids provide?
Relief from pain and a rush of euphoria
Give an example of an opioid.
Heroin
What are hallucinogens also called?
Psychedelics
What do hallucinogens do?
Alter moods, distort perceptions, and create sensory images
Give an example of a hallucinogen.
Marijuana
What is an agonist?
Any drug that binds to a receptor site on a postsynaptic neuron, causing it to fire
Give an example of a synthetic agonist.
Heroin
What is an antagonist?
Any substance that fits into a receptor site on a postsynaptic neuron, inhibiting it
Give an example of an antagonist.
Narcan: Blocks receptor sites to prevent agonists from binding
What are reuptake inhibitors used for?
To treat depression, anxiety, and other psychiatric conditions
Give an example of a reuptake inhibitor.
Selective serotonin reuptake inhibitors (SSRIs) prevent the reuptake of excess serotonin
What is the brainstem?
The brain’s oldest and innermost region, controlling heartbeat and breathing
What is the medulla?
Base of the brainstem, swelling in the spinal cord just after it enters the skull
What does the pons do?
Helps coordinate movements and control sleep
What is the reticular formation?
A neuron network extending from the spinal cord through the thalamus, managing the brain’s reward center and controlling arousal
What is the thalamus?
The brain’s sensory control center, receiving information from all senses except smell
What does the cerebellum help with?
Non-verbal learning, skill memory, judging time, modulating emotion, and coordinating voluntary movement
What happens if the cerebellum is injured?
Difficulty walking, keeping balance, and movements may be jerky and exaggerated
What is the amygdala linked to?
Aggression and fear; regulates emotional responses
What does the hypothalamus regulate?
Bodily maintenance, including hunger, thirst, body temperature, and sexual behavior
What does the hippocampus process?
Explicit memories
What occurs as we age regarding the hippocampus?
It decreases in size and function
What is contralateral hemispheric organization?
Each hemisphere controls the opposite side of the human body
What is the corpus callosum?
The ‘bridge’ that allows hemispheres to communicate with each other
What is the cerebral cortex?
The brain’s ultimate control and information processing center
What does the occipital lobe control?
Visual information
What is the function of the frontal lobe?
Responsible for voluntary skeletal movement and speech production
What is the prefrontal cortex responsible for?
Judgment, personality, self-identity, planning, and decision making
What does the parietal lobe contain?
The somatosensory strip, dedicated to touch sensations and movement sensations
What does the temporal lobe process?
Auditory information
What is Wernicke’s area responsible for?
Understanding language and forming meaningful sentences
What are association areas?
Areas in all four lobes that help with higher functioning such as learning, remembering, and thinking
What is brain plasticity?
The brain’s ability to change, especially during childhood
What is hemispheric specialization?
The two hemispheres of the brain are functionally different, controlling certain mental processes and behaviors
What is aphasia?
A language disorder that impacts speech
What is Wernicke’s aphasia?
Difficulty with language comprehension
What is Broca’s aphasia?
Difficulty with language production
What does split brain research involve?
Studying how the two hemispheres communicate through the corpus callosum, often in individuals with epilepsy
