Biological Basis of Behavior Flashcards
What is a neuron?
A nerve cell; the basic building block of the nervous system
What is the function of the cell body in a neuron?
It contains the nucleus and cytoplasm, serving as the neuron’s largest part
What do dendrites do in a neuron?
They receive messages and conduct impulses toward the cell body
Where do messages pass to other neurons or muscles?
Through the axon
What is the role of the terminal branches of an axon?
They transmit messages to other neurons through their branched endings
What is a neural impulse?
An electrical signal traveling down the axon, also called action potential
What is the purpose of the myelin sheath in a neuron?
It covers the axon to speed up neural impulses
How does action potential propagate along a myelinated axon?
Through saltatory conduction
What condition involves damage to the myelin sheath in the CNS?
Multiple sclerosis, causing tremors, weakness, and other symptoms
What is the all-or-none response in neurons?
A neuron either fires with full strength or does not fire at all
What type of signal depolarizes the cell membrane to increase firing likelihood?
An excitatory signal
What does an inhibitory signal do to a neuron?
It prevents action potentials by hyperpolarizing the target cell
What is the resting state of an axon characterized by?
More negative particles inside than outside due to anions
How is a neuron’s polarization maintained in the unstimulated state?
By keeping Na+ ions outside and K+ ions inside with other negatively charged proteins
What happens during depolarization of a neuron?
Sodium gates open, allowing sodium into the axon and making it more positive
What is the refractory period of a neuron?
The phase when a neuron cannot generate another action potential after firing
What are neurotransmitters?
Chemical messengers that cross synaptic gaps between neurons
What is a synapse?
The junction where information is transmitted from one neuron to another
What are the functions of dopamine as a neurotransmitter?
It regulates motor behavior, learning, attention, and emotion
Which neurotransmitter enables learning, memory, and muscle contraction?
Acetylcholine
What role does serotonin play in the body?
It affects hunger, sleep, arousal, and mood
What is norepinephrine responsible for?
Controlling alertness and arousal
What type of message does GABA usually communicate?
An inhibitory message
What does glutamate usually communicate?
An excitatory message involved in memory
What is the role of endorphins as neurotransmitters?
They influence the perception of pain or pleasure
What is the nervous system?
The body’s electrochemical communication network, consisting of peripheral and central systems
What are nerves?
Bundled axons forming neural cables that connect the CNS to muscles and glands
What are the types of neurons?
Sensory, motor, and interneurons
What do sensory neurons (afferent) do?
They carry information from sensory receptors to the brain and spinal cord
What do motor neurons (efferent) do?
They carry outgoing information from the CNS to muscles and glands
What does the central nervous system (CNS) include?
The brain and spinal cord, coordinating sensory and motor messages
What is the peripheral nervous system (PNS)?
The sensory and motor neurons connecting the CNS to the rest of the body
What does the somatic nervous system (SNS) control?
Voluntary movement of skeletal muscles
What does the autonomic nervous system (ANS) regulate?
Glands and internal organ muscles, with sympathetic and parasympathetic divisions
What is the function of the sympathetic nervous system?
It arouses the body during stressful situations, increasing energy and alertness
What does the parasympathetic nervous system do?
It calms the body, conserving energy and promoting digestion
What composes the brain?
The cortex and subcortical structures, carrying out various functions
What is the spinal cord’s primary role?
A two-way connection between the PNS and brain, overseeing reflex pathways
What are the steps of a reflex?
Sense receptors send signals via sensory neurons, interneurons process them, and motor neurons direct movement
What is the endocrine system?
A set of glands secreting hormones into the bloodstream for chemical communication
What part of the brain controls the pituitary gland?
The hypothalamus
What does the pituitary gland secrete?
Hormones influencing other glands and body functions
What does growth hormone (GH) regulate?
Body growth and metabolism
What does oxytocin (OT) stimulate?
Uterine contractions, milk release, pair bonding, and trust
What is the function of the thyroid gland?
Regulating metabolism
What do the parathyroids control?
Calcium levels in the blood
What hormones do adrenal glands secrete?
Epinephrine and norepinephrine, which help during stress
What does the pancreas regulate?
The level of sugar in the blood
What hormones are secreted by the testis?
Male sex hormones
What do ovaries produce?
Egg cells and female sex hormones
How is the brain studied using lesions?
By destroying brain tissue and studying the effects on behavior
How does stimulation help study the brain?
By electrically or chemically activating regions to observe their functions
Which methods measure brain structure?
CT, MRI, and fMRI scans
Which methods measure brain function?
EEG, MEG, PET, and fMRI scans
What does an EEG record?
The electrical activity sweeping across the brain’s surface
What does MEG measure?
Magnetic fields from the brain’s electrical activity
What does a CT scan show?
A slice of brain structure using combined x-ray images
What does a PET scan detect?
Where radioactive glucose is used during brain activity
What does an MRI reveal?
Detailed structures within the brain using magnetic fields
What does an fMRI show?
Changes in blood flow to indicate activity in specific brain areas
What is the brainstem responsible for?
Automatic survival functions like heart rate and respiration
Where is the medulla located, and what does it control?
At the base of the brainstem, controlling heart rate and breathing
What does the pons coordinate?
Sleep and movements
What is the reticular formation responsible for?
Controlling arousal and filtering sensory stimuli
Where does the thalamus relay messages?
To sensory receiving areas and transmits replies to the cerebellum and medulla
Which structures are part of the limbic system?
The hippocampus, amygdala, and hypothalamus, associated with emotions and drives
What is the hippocampus important for?
Storing conscious memories of facts and events
What is the amygdala linked to?
Emotion, fear, and aggression
What does the hypothalamus govern?
Body temperature, hunger, thirst, and the endocrine system via the pituitary gland
What is the cerebral cortex?
The brain’s control and information-processing center
What functions are controlled by the frontal lobes?
Speaking, motor movements, and decision-making
What do the parietal lobes process?
Sensory input for touch and body position
What information is processed in the temporal lobes?
Auditory input, primarily from the opposite ear
What is the function of the occipital lobes?
Processing visual information from the opposite visual field
Which cortex controls voluntary movements?
The motor cortex
What does the somatosensory cortex register?
Touch and movement sensations
What is processed in the auditory cortex?
Sound information from the ears
Where does the visual cortex receive input?
From the eyes
What are association areas involved in?
Higher mental functions like learning, remembering, and speaking
How did Phineas Gage’s injury contribute to neuroscience?
It demonstrated the role of the frontal lobes in personality and emotional regulation
What is the role of Broca’s area?
Expressive language, located in the left frontal lobe
What is Wernicke’s area responsible for?
Receptive language, located in the left temporal lobe
What is brain plasticity?
The ability of the brain to change by reorganizing after damage
What is neurogenesis?
The formation of new neurons
What does split brain surgery involve?
Cutting the corpus callosum, isolating the two hemispheres
What connects the two hemispheres of the brain?
The corpus callosum
How is information processed from the eyes?
Each visual field sends input to the opposite hemisphere
What did Michael Gazzaniga study?
Split brain patients and lateralization of brain function
What functions are associated with the left hemisphere?
Language, math calculations, and literal interpretations
What are right hemisphere functions?
Perceptual tasks, inferences, and visual perception
What is consciousness?
Awareness of ourselves and our environment
What does cognitive neuroscience combine?
Brain activity studies with learning and perception
What is dual processing?
Processing information on conscious and unconscious tracks
What is blindsight?
Responding to visual stimuli without conscious experience
What is parallel processing?
Unconscious handling of multiple aspects of a problem simultaneously
What is sequential processing used for?
New information or solving difficult problems
What is heredity?
Genetic transfer of characteristics from parents to offspring
What does environment include?
Non-genetic influences like nutrition and surroundings
What do behavior geneticists study?
How genetics and environment influence behavior
What is a chromosome?
A threadlike structure carrying genetic information
What is DNA?
A molecule containing genetic information in chromosomes
What are genes?
Units of heredity making up chromosomes
What does the human genome contain?
All genetic instructions for making an organism
What are identical twins?
Monozygotic twins developing from a single fertilized egg
What are fraternal twins?
Dizygotic twins developing from two separate fertilized eggs
What do twin studies reveal?
The impact of genes and environment on behavior
What is heritability?
How much variation among individuals is due to genes
What is molecular genetics?
Studying molecular structure and function of genes
What is epigenetics?
Changes in gene expression without altering DNA
What is evolutionary psychology?
Study of evolution of behavior and mind
What does natural selection explain?
Survival and reproduction of traits in a population
What are adaptive behaviors?
Behaviors that promote survival and reproduction
What are mutations?
Random errors in gene replication leading to changes
What do sex chromosomes determine?
Biological sex, with XX in females and XY in males
What are gender roles?
Behaviors expected for males and females in a society
What does social learning theory propose?
Behavior is learned through observation, imitation, and rewards
What is gender identity?
A person’s sense of being male, female, or non-binary
What is androgyny?
Displaying both traditional masculine and feminine traits
What is gender typing?
Acquiring traditional male or female roles
What are schemas?
Mental frameworks for organizing and interpreting information
What is a gender schema?
A framework for understanding what it means to be male or female
How does testosterone influence development?
Promotes male sex organ development in the fetus
What is estrogen responsible for?
Promoting female sex organ development and other reproductive functions
What is an intersex condition?
An atypical combination of male and female physical features
How does culture shape behavior?
Through shared behaviors, ideas, attitudes, and values
What is a collectivist culture?
Emphasizing group goals and harmony
What is an individualist culture?
Promoting personal goals and identity
