Key Terms of the Biological Basis of Behaviour
- action potential
- electrical signal that moves down the neurone’s axon
- agonist
- drug that mimics or strengthens the effects of a neurotransmitter
- all-or-none
- phenomenon that incoming signal from another neurone is either sufficient or insufficient to reach the threshold of excitation
- amygdala
- structure in the limbic system involved in our experience of emotion and tying emotional meaning to our memories
- antagonist
- drug that blocks or impedes the normal activity of a given neurotransmitter
- auditory cortex
- strip of cortex in the temporal lobe that is responsible for processing auditory information
- autonomic nervous system
- controls our internal organs and glands
- axon
- major extension of the soma
- biological perspective
- view that psychological disorders like depression and schizophrenia are associated with imbalances in one or more neurotransmitter systems
- Broca’s area
- region in the left hemisphere that is essential for language production
- central nervous system (CNS)
- brain and spinal cord
- cerebellum
- hindbrain structure that controls our balance, coordination, movement, and motor skills, and it is thought to be important in processing some types of memory
- cerebral cortex
- surface of the brain that is associated with our highest mental capabilities
- computerized tomography (CT) scan
- imaging technique in which a computer coordinates and integrates multiple x-rays of a given area
- corpus callosum
- thick band of neural fibres connecting the brain’s two hemispheres
degradation
the process by which an enzyme breaks neurotransmitters in the synaptic cleft down into their components so that they can no longer interact with the receptors on the post synaptic neurone.
- dendrite
- branch-like extension of the soma that receives incoming signals from other neurones
- electroencephalography (EEG)
- recording the electrical activity of the brain via electrodes on the scalp
- fight or flight response
- activation of the sympathetic division of the autonomic nervous system, allowing access to energy reserves and heightened sensory capacity so that we might fight off a given threat or run away to safety
- forebrain
- largest part of the brain, containing the cerebral cortex, the thalamus, and the limbic system, among other structures
- frontal lobe
- part of the cerebral cortex involved in reasoning, motor control, emotion, and language; contains motor cortex
- functional magnetic resonance imaging (fMRI)
- MRI that shows changes in metabolic activity over time
- glial cell
- nervous system cell that provides physical and metabolic support to neurones, including neuronal insulation and communication, and nutrient and waste transport
- gyrus
- (plural: gyri) bump or ridge on the cerebral cortex
- hemisphere
- left or right half of the brain
- hindbrain
- division of the brain containing the medulla, pons, and cerebellum
- hippocampus
- structure in the temporal lobe associated with learning and memory
- homeostasis
- state of equilibrium—biological conditions, such as body temperature, are maintained at optimal levels
- hypothalamus
- forebrain structure that regulates sexual motivation and behaviour and a number of homeostatic processes; serves as an interface between the nervous system and the endocrine system
- lateralization
- concept that each hemisphere of the brain is associated with specialized functions
- limbic system
- collection of structures involved in processing emotion and memory
- longitudinal fissure
- deep groove in the brain’s cortex
- magnetic resonance imaging (MRI)
- magnetic fields used to produce a picture of the tissue being imaged
- medulla
- hindbrain structure that controls automated processes like breathing, blood pressure, and heart rate
- membrane potential
- difference in charge across the neuronal membrane
- midbrain
- division of the brain located between the forebrain and the hindbrain; contains the reticular formation
- motor cortex
- strip of cortex involved in planning and coordinating movement
- myelin sheath
- fatty substance that insulates axons
- neuron
- cells in the nervous system that act as interconnected information processors, which are essential for all of the tasks of the nervous system
- neuroplasticity
- nervous system’s ability to change
- neurotransmitter
- chemical messenger of the nervous system
- Nodes of Ranvier
- open spaces that are found in the myelin sheath that encases the axon
- occipital lobe
- part of the cerebral cortex associated with visual processing; contains the primary visual cortex
- parasympathetic nervous system
- associated with routine, day-to-day operations of the body
- parietal lobe
- part of the cerebral cortex involved in processing various sensory and perceptual information; contains the primary somatosensory cortex
- peripheral nervous system (PNS)
- connects the brain and spinal cord to the muscles, organs and senses in the periphery of the body
- pituitary gland
- secretes a number of key hormones, which regulate fluid levels in the body, and a number of messenger hormones, which direct the activity of other glands in the endocrine system
- pons
- hindbrain structure that connects the brain and spinal cord; involved in regulating brain activity during sleep
- positron emission tomography (PET) scan
- involves injecting individuals with a mildly radioactive substance and monitoring changes in blood flow to different regions of the brain
- prefrontal cortex
- area in the frontal lobe responsible for higher-level cognitive functioning
- psychotropic medication
- drugs that treat psychiatric symptoms by restoring neurotransmitter balance
- receptor
- protein on the cell surface where neurotransmitters attach
- resting potential
- the state of readiness of a neurone membrane’s potential between signals
- reticular formation
- midbrain structure important in regulating the sleep/wake cycle, arousal, alertness, and motor activity
- reuptake
- neurotransmitter is pumped back into the neurone that released it
- semipermeable membrane
- cell membrane that allows smaller molecules or molecules without an electrical charge to pass through it, while stopping larger or highly charged molecules
- soma
- cell body
- somatic nervous system
- relays sensory and motor information to and from the CNS
- somatosensory cortex
- essential for processing sensory information from across the body, such as touch, temperature, and pain
- substantia nigra
- midbrain structure where dopamine is produced; involved in control of movement
- sulcus
- (plural: sulci) depressions or grooves in the cerebral cortex
- sympathetic nervous system
- involved in stress-related activities and functions
- synaptic cleft
- small gap between two neurones where communication occurs
- synaptic vesicle
- storage site for neurotransmitters
- temporal lobe
- part of cerebral cortex associated with hearing, memory, emotion, and some aspects of language; contains primary auditory cortex
- terminal button
- axon terminal containing synaptic vesicles
- thalamus
- sensory relay for the brain
- threshold of excitation
- level of charge in the membrane that causes the neurone to become active
- ventral tegmental area (VTA)
- midbrain structure where dopamine is produced: associated with mood, reward, and addiction
- Wernicke’s area
- important for speech comprehension