Biological Bases of Behavior Flashcards
Neurons
Individual nerve cells made of dendrites, cell body, axon, myelin sheath, terminal buttons, neurotransmitters, and the synapse.
Myelin sheath
A fatty covering around the axon of some neurons that speeds neural impulses.
Axon
Wire like structure ending in the terminal buttons that extends from the cell body.
Terminal buttons
The branched end of the axon that contains neurotransmitters.
Neurotransmitters
Chemicals contained in terminal buttons that enable neurons to communicate. Neurotransmitters fit into receptor sites in the dendrites of neurons.
Synapse
The space between the terminal buttons of one neuron and the dendrites of the next neuron.
Cell body
Also known as the soma; contains the nucleus and other parts of the cell needed to sustain its life.
Dendrites
Rootlike parts of a cell used to make synaptic connections with other neurons.
Resting potential
The normal state of a neuron; ions have a small negative charge; when cells become excited, it triggers an action potential which reverses the charge and causes the electrical signal to race along the axon.
Action potential
Occurs when information travels along the axon in the form of an electrical charge; it is the firing of the signal of the neuron.
Absolute threshold
If the excitatory signals, minus the inhibitory signals exceed a minimum intensity, the action potential is realized or crossed.
Refractory period
Each action potential is followed by a brief recharging period.
All-or-none principle
Once the action potential is released, there is no going back. The axon either fires or does not.
Depolarization
The initial movement of the action potential where the action passes from the resting potential in the cell body into the action potential in the axon.
Acetylcholine
Responsible for motor movement; lack of acetylcholine is associated with Alzheimer’s.
Dopamine
Responsible for motor movement and alertness; lack of dopamine is associated with Parkinson’s, an over abundance of dopamine is associated with schizophrenia.
Endorphins
Responsible for pain control; involved in addictions.
Serotonin
Responsible for mood control; lack of serotonin is associated with clinical depression.
GABA
Important inhibitory neurotransmitter; lack or excess can lead to seizures and sleep problems.
Glutamate
Excitatory neurotransmitter involved in memory; can cause migraines and seizures.
Norepinephrine
Responsible for alertness and arousal; can cause depression.
Afferent neurons
Sensory neurons that take information from the senses to the brain.
Efferent neurons
Motor neurons that take information from the brain to the rest of the body.
Interneurons
Once information reaches the brain or spinal cord, Interneurons take the messages and send them elsewhere in the brain or on to efferent neurons.
Central Nervous System
Consists of brain and spinal cord- all nerves encased in bone. The spinal cord transmit information from the rest of the body to the brain.
Peripheral Nervous System
Consists of all the other nerves not encased in bone; divided into somatic and autonomic nervous systems.
Somatic Nervous System
Controls voluntary muscle movements; motor cortex of brain sends impulses to somatic nervous system which controls the muscles that allow us to move.
Autonomic Nervous System
Controls the automatic functions of our body- our heart, lungs, internal organs, glands, etc. ; divided into sympathetic and parasympathetic nervous systems.
Sympathetic Nervous System
Mobilizes our body to respond to stress; fight or flight response; accelerates functions such as heart rate, blood pressure, and respiration.
Parasympathetic Nervous System
Responsible for slowing done body after a stress response.
Reflex
Instead of waiting until the impulse reaches the brain, the spine moves the muscles in response as soon as the sensory information reaches the spine.
EEG
Electroencephalogram- detects brain waves; can be used to examine types of waves produced during different stages of consciousness and generalize brain function; widely used in sleep research to identity stages of sleep and dreaming.
CAT/CT Scan
Computerized axial tomography- a sophisticated x-ray; reveals brain structure and gives three-dimensional picture; can only show structure, not function; used to find brain tumors.
MRI
Magnetic Resonance Imaging- similar to CT scan but uses magnetic fields to measure the density and location of brain material to make detailed images; shows only structure, not function.
PET
Positron Emission Tomography- lets researches see what areas of the brain are most active during certain tasks; measure chemical consumption of parts of brain; different chemicals can be used for different types of scans.
fMRI
Functional MRI- combines elements of MRI and PET; shows details of brain structure with information about blood flow; combines brain structure and brain activity during cognitive tasks.
Medulla
Controls our blood pressure, heart rate, and breathing.
Pons
Involved with facial expressions, sleep, and dreaming.
Cerebellum
Coordinates muscle movements and balance.
Reticular Formation
Plays a role in arousal and the ability to focus our attention.
Thalamus
Relays information from parts of body and sends them to appropriate areas of the brain.
Limbic System
Emotional control center of the brain; composed of hypothalamus, amygdala, and hippocampus
Hypothalamus
Controls body processes such as thirst, body temperature, hunger, and the endocrine system.
Amygdala
Plays a role in emotions.
Hippocampus
Plays a role in memory.
Cerebral Cortex
Thin top layer of brain composed of tightly packed neurons and contains wrinkles called fissures that increase the surface area of our brain.
Hemispheres
Brain divided into left and right hemispheres and are contralateral.
Contralateral Control
The right hemisphere gets sensory messages and controls the motor function of the left half of the body and vice versa.
Brain Lateralization
The specialization of function in each hemisphere; Left hemisphere is more active during logic and sequential tasks, while right during spatial and creative tasks.
Corpus Callosum
Attaches two hemispheres of cerebral cortex.
Split-brain patient
Cannot orally report information presented to the right hemisphere alone, since the spoken language centers are in the left hemisphere.
Ex:
Dot in middle of screen; the word spoon is shown on the right side, the patient will be able to name the object. If shown on the left side, the patient will not be able to name the object, but will be able to identify it.
Association Area
Any area of the cerebral cortex not associated with receiving sensory information or controlling muscle movements.
Broca’s Area
Responsible for producing speech; located in the left hemisphere in the frontal lobe.
Wernicke’s Area
Responsible for understanding speech; located in temporal lobe.
Frontal Lobe
Responsible for complex thought.
Motor Cortex
Located in the frontal lobe; sends signals to our muscles controlling our voluntary movements.
Parietal Lobe
Responsible for sensory information such as touch and pain; contains sensory cortex aka somato-sensory cortex.
Occipital Lobe
Responsible for processing visual information.
Temporal Lobe
Responsible for processing auditory information.
Brain Plasticity
Ability of brain to modify itself after damage; some of the brain’s neural tissue can reorganize in response to damage and by making new brain cells: neurogenesis; new connections forming in the brain to take over for damaged sections.
Adrenal glands
Produce adrenaline which signals the body for fight or flight.
Turner’s Syndrome
Single X chromosome on the 23rd pair; causes shortness, webbed necks, and differences in physical sexual development.
Klinefelter’s Syndrome
Extra chromosome usually resulting in XXY; usually causes minimal sexual development and personality traits like extreme introversion.
Down syndrome
Extra chromosome on the 21st pair; rounded face, shorter fingers and toes, and mental retardation.
