Unit 1 Part 1 A Terms Flashcards
Sensory (afferent) neurons
Neurons that carry incoming information from the body’s tissues and sensory receptors to the brain and spinal cord
Motor (afferent) neurons
Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands
Interneurons
Neurons within the brain and spinal cord; they communicate internally and process information between the sensory inputs and motor outputs
Somatic nervous system
The division of the peripheral nervous system that controls the body’s skeletal muscles. Also called the skeletal nervous system.
Autonomic nervous system (ANS)
The portion of the nervous system innervating (supplying with nerves) smooth muscle and glands, including the circulatory, digestive, respiratory, and reproductive organs. It is divided into the sympathetic nervous system and parasympathetic nervous system.
Depressants
Drugs that reduce neural activity and slow body functions
Barbiturates
Drugs that depress central nervous system activity, reducing anxiety but impairing memory and judgment
Opioids
Opium and its derivatives; they depress neural activity, temporarily lessening pain and anxiety
Agonist
A molecule that increases a neurotransmitter’s action
Antagonist
A molecule that inhibits or blocks a neurotransmitter’s action
Endocrine system
the body’s “slow” chemical communication system; a set of glands and fat tissue that secrete hormones into the bloodstream
Psychoactive drug
A chemical substance that alters the brain, causing changes in perceptions and moods
Limbic system
Neural system located mostly in the forebrain — below the cerebral hemispheres — that includes the amygdala, hypothalamus, hippocampus, thalamus, and pituitary gland; associated with emotions and drives
Amygdala
Two lima-bean-sized neural clusters in the limbic system; linked to emotion
Hypothalamus
A limbic system neural structure lying below (hypo) the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system, and is linked to emotion and reward
Hippocampus
A neural center located in the limbic system; helps process explicit (conscious) memories — of facts and events — for storage
Cerebral cortex
The layer of gray matter that covers the outside of the cerebral hemispheres in the brain and is associated with higher cognitive functions, such as language, learning, perception, and planning.
Frontal lobes
The portion of the cerebral cortex lying just behind the forehead. They enable linguistic processing, muscle movements, higher-order thinking, and executive functioning (such as making plans and judgments)
Stimulants
Drugs that excite neural activity and speed up body functions
Hallucinogens
Psychedelic (“mind-manifesting”) drugs that distort perceptions and evoke sensory images in the absence of sensory input
Resting potential (polarization)
The electric potential across the plasma membrane of a neuron when it is in the nonexcited, or resting, state
Myasthenia gravis
An autoimmune disorder in which the body produces antibodies against acetylcholine receptors, causing faulty transmission of nerve impulses at neuromuscular junctions. Affected muscles—initially those of the face and neck—are easily fatigued and may become paralyzed temporarily
Neuroplasticity
The brain’s ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience
Lesion
Brain lesions may occur naturally (from disease or trauma), during surgery, or experimentally (using electrodes to destroy brain cells)
Any disruption of or damage to the normal structure or function of an organ or part of an organ due to injury, disease, or a surgical procedure
EEG (electroencephalogram)
An amplified recording of the waves of electrical activity sweeping across the brain’s surface. These waves are measured by electrodes placed on the scalp
Dopamine
A catecholamine neurotransmitter that has an important role in motor behavior and is implicated in numerous mental conditions and emotional states
Serotonin
Has roles in emotional processing, mood, appetite, sexual desire and performance, sleep, pain processing, hallucinations, and reflex regulation
MRI
A technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. MRI scans show brain anatomy.
fMRI
A technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show brain function as well as structure
Hindbrain
Consists of the medulla, pons, and cerebellum; directs essential survival functions, such as breathing, sleeping, and wakefulness, as well as coordination and balance
Midbrain
Found atop the brainstem; connects the hindbrain with the forebrain, controls some motor movement, and transmits auditory and visual information
Forebrain
Consists of the cerebral cortex, thalamus, and hypothalamus; manages complex cognitive activities, sensory and associative functions, and voluntary motor activities
Brainstem
The central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions
Medulla
The hindbrain structure that is the brainstem’s base; controls heartbeat and breathing
Thalamus
The forebrain’s sensory control center, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla
Reticular formation
A nerve network that travels through the brainstem into the thalamus; it filters information and plays an important role in controlling arousal
Cerebellum
The hindbrain’s “little brain” at the rear of the brainstem; its functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory
Parietal lobes
The portion of the cerebral cortex lying at the top of the head and toward the rear; it receives sensory input for touch and body position
Occipital lobes
The portion of the cerebral cortex lying at the back of the head; it includes areas that receive information from the visual fields
Motor cortex
A cerebral cortex area at the rear of the frontal lobes that controls voluntary movements
Multiple sclerosis
A disease of the central nervous system (brain and spinal cord) characterized by inflammation and multifocal scarring of the protective myelin sheath of nerves, which damages and destroys the sheath and the underlying nerve, disrupting neural transmission
Somatosensory cortex
A cerebral cortex area at the front of the parietal lobes that registers and processes body touch and movement sensations
Association area
Areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking
Neurogenesis
The formation of new neurons
Corpus callosum
The large band of neural fibers connecting the two brain hemispheres and carrying messages between them
Split brain
A condition resulting from surgery that isolates the brain’s two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them
Norepinephrine
A neurotransmitter of the brain that plays an essential role in the regulation of arousal, attention, cognitive function, and stress reactions
Blindsight
A condition in which a person can respond to a visual stimulus without consciously experiencing it
Parallel processing
Processing multiple aspects of a stimulus or problem simultaneously
Sequential processing
Processing one aspect of a stimulus or problem at a time; generally used to process new information or to solve difficult problems
Sleep
a periodic, natural loss of consciousness — as distinct from unconsciousness resulting from a coma, general anesthesia, or hibernation
Circadian rhythm
Our biological clock; regular bodily rhythms (for example, of temperature and wakefulness) that occur on a 24-hour cycle
REM sleep
Rapid eye movement sleep; a recurring sleep stage during which vivid dreams commonly occur. Muscles are relaxed, but some other body systems are active.
Alpha waves
The relatively slow brain waves of a relaxed, awake state
NREM sleep
Non-rapid eye movement sleep; encompasses all sleep stages except for REM sleep
