AP Psychology Unit 3: Biological Psychology and Neurotransmission Flashcards
Neuron
A nerve cell; The basic building block of the nervous system
Cell body
The part of a neuron that contains the nucleus; the cell’s life-support center
Dendrites
A neuron’s often bushy, branching extensions that receive and integrate messages, conducting impulses toward the cell body
Axon
The neuron extension that passes messages through its branches to other neurons or to muscles or glands
Myelin Sheath
A fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next. It is not fully developed until the age of 25 and is very important to behavior, movement, and thought.
Deterioration of the myelin sheath can lead to multiple sclerosis
Glial Cells
Cells in the nervous system that support, nourish, and protect neurons; they also play a role in learning, thinking, and memory
Action Potential
A neural impulse; A brief electrical charge that travels down an axon
Threshold
The level of stimulation required to trigger a neural impulse (-55 mV)
When excitatory signals outnumber inhibitory signals, the threshold has been reached and an action potential occurs
Refractory Period
In neural processing, a brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state
All-or-None Response
A neuron’s reaction of either firing (with a full-strength response) or not firing
Synapse
The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the “synaptic gap” or “synaptic cleft”
Neurotransmitters
Chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse
Reuptake
A neurotransmitter’s reabsorption be the sending neuron
Acetylcholine (ACh)
Function: Enables muscle action, learning, and memory
Malfunction: Associated with Alzheimer’s disease or paralysis
Dopamine
Function: Movement, thought process, reward
Malfunction: Oversupply linked to schizophrenia, undersupply linked to Parkinson’s disease
Serotonin
Function: Affects mood, hunger, sleep, and arousal
Malfunction: Undersupply linked to depression and stress. Some drugs that raise serotonin levels are used to treat depression
Norepinephrine
Function: Physical arousal, learning, and memory
Malfunction: Undersupply can depress mood
GABA (gamma-aminobutyric acid)
Function: A major inhibitory neurotransmitter
Malfunction: Undersupply linked to seizures, tremors, anxiety disorders, and insomnia
Glutamate
Function: A major excitatory neurotransmitter; involved in memory
Malfunction: Oversupply can overstimulate the brain, producing migraines or seizures
Endorphins
“morphine within”- natural, opiate-like neurotransmitters linked to pain control and pleasure
Agonist
A molecule that increases a neurotransmitter’s action
Antagonist
A molecule that inhibits or blocks a neurotransmitter’s action
Nervous System
The body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems
Central Nervous System (CNS)
The brain and spinal cord. It is the decision maker, responsible for coordinating incoming sensory messages and outgoing mmotor messages
Peripheral Nervous System (PNS)
The sensory and motor neurons that connect the central nervous system to the rest of the body by gathering information from the senses and transmitting messages from the CNS
Nerves
Bundled axons that form neural cables connecting the central nervous system with muscles, glands, and organs
Sensory (afferent) neurons
Neurons that carry incoming information from the body’s tissues and sensory receptors to the brain and spinal cord
Motor (efferent) 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 part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms
Sympathetic Nervous System
The division of the autonomic nervous system that arouses the body, mobilizing its energy (accelerates heartbeat, raises blood pressure, slows digestion, etc…)
Parasympathetic Nervous System
The division of the. autonomic nervous system that calms the body, conserving its energy (decelerates heartbeat, lowers blood pressure, stimulates digestion, etc…)
Reflex
A simple, automatic response to a sensory stimulus, such as the knee-jerk response
Endocrine System
The body’s “slow” chemical communication system; a set of glands that secrete hormones into the bloodstream
Hormones
Chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues
Adrenal Glands
A pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress
Pituitary Gland
The endocrine system’s most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands. It is known as the “master gland.”
Secretes growth hormones and Oxytocin
Lesion
Tissue destruction. A brain lesion is a naturally or experimentally cause destruction of brain tissue
EEG
Description: 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
How it works: Electrodes are placed on the scalp to measure electrical activity in neurons
MEG
Description: A brain imaging technique that measures magnetic fields from the brain’s natural electrical activity
How it works: A head coil records magnetic fields from the brain’s natural electrical currents
CT scan
Description: A series of X-ray photographs taken from different angles and combined by computer into a composite representation of a slice of the brain’s structure (also called a CAT scan)
How it works: x-rays of the head generate images that may locate brain damage
PET
Description: A visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task. Shows activity
How it works: Tracks where a temporarily radioactive form of glucose goes while the brain of the person given it performs a given task