a branch of psychology concerned with the links between biology and behavior
A nerve cell; the basic building block of the nervous system.
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 layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next
a neural impulse; a brief electrical charge that travels down an axon. the action potential is generated by the movement of positively charged atoms in and out of channels in the axon's membrane
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.
The tiny gap at this junction is called the synaptic gap or cleft.
chemical messengers that traverse 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.
a neurotransmitter that enables learning and memory and also triggers muscle contraction
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
the brain and spinal cord
peripheral nervous system
The sensory and motor neurons that connect the central nervous system to the rest of the body
neural "cables" containing many axons. These bundled axons, which are part of the peripheral nervous system, connect the central nervous system with muscles, glands, and sense organs
Neurons that carry incoming information from the sensory receptors to the brain and spinal cord
Central nervous system neurons that internally communicate and intervene between the sensory inputs and motor outputs
neurons that carry outgoing information from the central nervous system to the muscles and glands
somatic nervous system
the division of the peripheral nervous system that controls the body's skeletal muscles
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 response to a sensory stimulus, such as the knee-jerk response
interconnected neural cells. With experience, networks can learn, as feedback strengthens or inhibits connections that produce certain results. Computer simulations of neural networks show analogous learning.
tissue destruction. a brain lesion is a naturally or experimentally caused destruction of brain tissue
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.
CT (computed tomography) scan
a series of x-ray photographs taken from different angles and combined by computer into a composite representation of a slice through the body
PET (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
MRI (magnetic resonance imaging)
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