a nerve cell; the basic building block of the nervous system
Neurons that carry incoming information from the sensory receptors to the brain and spinal cord
neurons that carry outgoing information from the brain and spinal cord to the muscles and glands
Neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs
The bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body
the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands
a fatty substance that helps insulate neurons and speeds the transmission of nerve impulses
a neural impulse; a brief electrical charge that travels down an axon
the level of stimulation required to trigger a neural impulse
The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron
Chemicals that transmit information from one neuron to another
a neurotransmitter's re-absorption by the sending neuron
natural, opiatelike neurotransmitters linked to pain control and to pleasure
the body's speedy, electrochemical communication system, consisting of all the nerve cells of the peripheral and central nervous systems
Central Nervous System
brain and spinal cord
Peripheral Nervous System
the sensory and motor neurons that connect the central nervous system to the rest of the body
Bundled axons that form neural "cables" connecting the central nervous system with muscles, glands, and sense organs
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
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 in stressful situations
Parasympathetic Nervous System
the division of the autonomic nervous system that calms the body, conserving its energy
a simple, automatic, inborn response to a sensory stimulus, such as the knee-jerk response
a pair of endocrine glands just above the kidneys. The adrenals secrete the hormones epinephrine(adrenaline) and norepinephrine, which help to arouse the body in times of stress.
the endocrine system's most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands
tissue destruction. A brain lesion is a naturally or experimentally caused destruction of brain tissue
eletroencephalogram; an amplified recording of the waves of electrical activity that sweep across the brain's surface. These waves are measured by electrodes placed on the scalp
Positron Emission Tomography Scan
a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task
a technique that uses magnetic fields and radio waves to produce computer-generated images that distinguish among different types of soft tissue; allows us to see structures within the brain
a technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans. MRI scans show brain anatomy; fMRI scans show brain function.
the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions
the base of the brainstem; controls heartbeat and breathing
a nerve network in the brainstem that plays an important role in controlling arousal
Neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives.
two almond-shaped neural clusters that are components of the limbic system and are linked to emotion
an area at the rear of the frontal lobes that controls voluntary movements
the area at the front of the parietal lobes that registers and processes body sensations
the brain's ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience
the large band of neural fibers connecting the two brain hemispheres and carrying messages between them.
a condition in which the two hemispheres of the brain are isolated by cutting the connecting fibers (mainly those of the corpus callosum) between them.