Unit 3- Biological Basis of behavior Flashcards
What are the building blocks of the body’s neural information system (nervous system) ?
Neurons or nerve cells
What are dendrites?
Branching extensions of a neuron that receives information from other cells and conducts it toward the cell body
What is the axon?
A neuron extension passing messages from the cell body to other neurons, muscles, or glands
What encases an axon?
Myelin sheath, a layer of fatty tissue that insulates them and speeds their impulses
What is the action potential?
A brief electrical charge that travels down the axon; a neural impulse
What is the refractory period?
A period of inactivity after a neuron has fired.
What does threshold mean?
The level of stimulation required to trigger a neural impulse
The neuron’s action is an ___ ___ _____ response
all or none
What is the synapse?
A tiny gap at the junction between the axon terminal and dendrites of the receiving neuron
What are neurotransmitters?
Chemical messengers that cross the synapses between neurons
What is reuptake?
A neurotransmitter’s reabsorption by the sending neuron neuron
The sending neuron reabsorbs the excess neurotransmitters
What does the neurotransmitter Acetylcholine do? Give an example of a malfunction.
Enables muscle action, learning, and memory.
AC-h producing neurons deteriorate in those with Alzheimer’s disease
What does the neurotransmitter dopamine do? Give an example of a malfunction.
Influences learning, movement, attention, and emotion.
Oversupply is linked to schizophrenia, undersupply is linked to decreased mobility in Parkinson’s disease.
What does the neurotransmitter serotonin do? Give an example of a malfunction.
Affects mood, hunger, sleep, and arousal.
Undersupply linked to depression, some antidepressant drugs raise serotonin levels.
What does the neurotransmitter norepinephrine do? Give an example of a malfunction.
Helps control alertness and arousal.
Undersupply can depress mood.
What does the neurotransmitter GABA do? Give an example of a malfunction.
A major inhibitory neurotransmitter.
Undersupply linked to insomnia, tremors, and seizures.
What does the neurotransmitter Glutamate do? Give an example of a malfunction.
A major excitatory neurotransmitter, involved in memory.
Oversupply can overstimulate the brain, producing migraines or seizures, which is why some avoid foods with MSG.
What are endorphins?
natural neurotransmitters linked to pain control and pleasure.
What is an agonist?
A molecule that mimics the effects of a neurotransmitters
What is an antagonist?
A molecule that inhibits or blocks a neurotransmitter’s functioning.
What is the central nervous system?
Includes the brain and spinal cord, it is the nervous system’s decision maker.
What is the peripheral nervous system?
Connects the CNS to the rest of the body through nerves
What are the two main divisions of the PNS?
-Somatic nervous system; enables voluntary control of the skeletal muscle
-Autonomic nervous system; controls the involuntary muscles and glands by means of the sympathetic and parasympathetic divisions.
What are the three types of neurons?
Sensory- carry info from sense receptors to the brain and spinal cord
Motor- carry info from brain and spinal cord to the muscles and glands
Interneurons- communicate with brain and spinal cord and between sensory and motor neurons
What is the endocrine system?
A set of glands that secrete hormones into the bloodstream where they travel through the body and affect other tissues, including the brain.
What do the adrenal glands do?
Release hormones that trigger the fight or flight response.
What is the endocrine system’s master gland?
Pituitary gland- produces and releases different hormones that help carry out important bodily functions.
Ex.: Growth, sexual/reproductive development and functions, metabolism
The ____________ influences the pituitary gland
hypothalamus
What is the difference between sympathetic and parasympathetic nervous systems?
sympathetic- arouses and expends energy
parasympathetic- calms the body & conserves energy
What are reflexes?
Our automatic responses to stimuli.
Ex.: Knee-jerk
What does the thyroid gland regulate?
metabolism
What is the process of lesioning?
Tissue destruction.
What is an electroencephalogram?
A recording of the waves of electrical activity across the brain’s surface, which are measured by electrodes placed on the scalp.
What is a CT (computed tomography) scan?
Examines the brain by taking x-ray photographs
What is a PET (Positron emission tomography) scan?
Depicts brain activity by detecting radioactive forms of glucose
What is an MRI (magnetic resonance imaging) scan?
Uses magnetic fields and radio waves to produce computer generated images of soft tissues and show brain anatomy.
What is a fMRI?
Reveals the brain’s functioning as well as structure.
Reveals bloodflow and brain activity
What is the brainstem?
Oldest and central core of the brain, responsible for automatic survival functions
What is the medulla?
The base of the brainstem, controls heartbeat and breathing
Located above the medulla is the pons, what do they do?
Help coordinate movements
On the top of the brainstem is the thalamus, what does it do?
The brain’s sensory control center, directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla.
In the brainstem located between your ears is the reticular formation, what does it do?
A neuron network that extends from the spinal cord right up through the thalamus.
Plays and important role in controlling arousal
What does the hypothalamus do?
Lies below the thalamus, influences hunger/eating, thirst, body temp., and sexual behavior
Also helps govern the pituitary gland, and is linked to emotion and reward
What is the cerebellum?
the “little brain” at the rear of the brainstem
Responsible for processing sensory input, coordinating movement and balance, and enabling non verbal learning and memory.
What is the limbic system?
limbus, meaning border, includes the hippocampus, amygdala, and hypothalamus
associated with emotions and drives (amygdala), processes conscious memories, form new memories, facts, or events (hippocampus)
What are glial cells?
Cells in the nervous system that support, nourish, and protect neurons, also play a role in thinking and learning.
What are the four lobes of your brain?
-frontal (behind your forehead)
-parietal (at the top and rear)
-occipital (back of your head)
-temporal (just above your ears)
What is the motor cortex?
An area at the rear of the frontal lobes that controls voluntary movement
What is the somatosensory cortex?
Area at the front of the parietal lobes that registers and processes body touch and movement sensations
What are association areas?
Areas of the cerebral cortex not involved in primary motor or sensory functions
They are involved in higher mental functions such a learning, remembering, thinking, and speaking.
What is plasticity?
The brain’s ability to change by reorganizing after damage or by building new pathways based on experience.
What is neurogenesis?
The formation of new neurons
What do the frontal lobes do?
Involved in speaking and muscle movements, making plans and judgements
What do the parietal lobes do?
Receives sensory input for touch and body position
What do the occipital lobes do?
Receive info from the visual fields
What do the temporal lobes do?
Auditory, each receiving info from the opposite ear
What is the corpus callosum?
The large band of neural fibers connecting the two brain hemispheres and carrying messages between them.
What is split brains?
A condition resulting from surgery that isolates the two brain hemispheres by cutting the fibers of the corpus callosum.
What is dual processing?
Information is simultaneously processed on separate conscious and unconscious tracks
What does the left hemisphere process?
Speech, logic, analytical thinking
What does the right hemisphere process?
Making inferences, creativity, attention, memory, intuitive, artistic
Genes make up ___________, the thread like coils of ___
chromosomes
DNA
What do behavior geneticists do?
Analyze genetic and environmental influences on our traits.
Shared family environments have little effect on ___________, and the stability of a ____________, suggests a _________ predisposition.
personality x2
genetic
What do molecular geneticists do?
Study the molecular structure and function of genes, including those that affect behavior
What is heritability?
The extent to which variation among members of a group can be attributed to genes.
