Neurophysiology Vocabulary

Question 1

One of three major divisions of a typical nerve cell. Consists of bushy, branching extensions. Receives messages from other nerve cells. The messages are effected through a change in the graded electrical potential across the cell membrane.

Answer 1

Dendrite

Question 2

One of three major divisions of a typical nerve cell. The body of a nerve cell; the cell’s life support center. Gathers and evaluates input that is received by the dendrite in the form of a graded electrical potential. Initiates a signal to other cells if the potential reaches a critical value.

Answer 2

Soma

Question 3

third major component of a typical neuron. An extension of a neuron, ending in branching fibers. Carries messages to other cells, muscles, or glands. Can be very long, sometimes projecting several feet throughout the body.

Answer 3

Axon

Question 4

The critical voltage level, perhaps +10mV, that is required to trigger a neural impulse in an axon. Once this value is exceeded, an action potential is sent down the axon. This event opens voltage-gated channels in the axon’s membrane; opening the channels allows ions to flow across the cell membrane, which causes a brief change in electrical charge, which is the action potential.

Answer 4

Threshold

Question 5

A change in the difference of electrical charge between the interior and exterior of the cell toward zero whether it is moving up from negative values (-40mv to -20 mv) or down from positive values (+40 mv to +20 mv). Allows the action potential to be sent down an axon.

Answer 5

Depolarization

Question 6

A brief pulse of positive electrical charge that travels down an axon. Generated by the movement of positively charged sodium ions into the axon. Speed is around 10m/s (32.8ft/s). A myelin sheath or a large axon diameter can increase this speed.

Answer 6

Action potential

Question 7

A very short resting pause in which the neuron pumps the positively charged sodium atoms back outside the axon. During this time, the voltage-gated channels refuse to open no matter what. No action potentials can be sent during this time.

Answer 7

Refractory period

Question 8

the cell junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron that receives electrical or chemical signals. Also called a synaptic cleft. Allows information to be sent in the form of packets of chemicals that produce an electric change on the receiving cell.

Answer 8

Synapse

Question 9

A chemical messenger that crosses the synaptic cleft between neurons within 1/10,000th of a second. Travel across the synapse to bind to receptor sites on the receiving neuron once released by the sending neuron, influencing whether that neuron will generate a neural impulse. Have particular effects on our behavior, thoughts, and emotions.

Answer 9

Neurotransmitters

Question 10

A fatty coating that surrounds the axons of many neurons and enables greater transmission speed of action potentials. Insulates the axon and prevents opening voltage-gated channels at every location of the axon’s membrane. Channels open at gaps in this structure. the action potential skips from gap to gap.

Answer 10

Myelin

Question 11

The amount of activity in a cell in the absence of stimulation. the cell can signal to another either by increasing its firing above this rate or decreasing below. Firing at this rate indicates that the cell is functioning properly but has nothing to ‘report’ to any other cell.

Answer 11

Spontaneous rate

Question 12

A reference to the way neurotransmitter molecules bind to receptor sites on the receiving neurons. A mechanical match. Drugs can inhibit neurotransmitters by filling in the binding sites of a specific neurotransmitter, or by stimulating the receiving cell as the neurotransmitter would.

Answer 12

Lock and key

Question 13

The brain and the spinal cord, structure enclosed in bone. Linked to the body through the peripheral nervous system. This structure receives sensory information from the body through interneurons. This structure also sends out commands with motor neurons.

Answer 13

Central nervous system (CNS)

Question 14

One of the three major divisions of the brain. The most primitive. Arises from the spinal column at the ‘base’ of the brain. Includes the pons, medulla oblongata, and reticular activating system in the brainstem region and the cerebellum.

Answer 14

Hindbrain

Question 15

The ‘little brain’ attached to the rear of the brainstem. helps coordinate voluntary movement and balance. Enables a type of nonverbal learning and memory.

Answer 15

Cerebellum

Question 16

The brain’s sensory switchboard, located on the top of the brainstem (it is located in the center of the brain and is part of the forebrain). Directs messages from the senses (except smell) to higher brain regions and receives some of the higher brain replies and transmits them to the cerebellum and medulla.

Answer 16

Thalamus

Question 17

A neural structure lying below the thalamus. Directs several maintenance activities (drinking, eating, body temperature – homeostasis), helps govern the endocrine systemvia the pituitary gland, and is linked to emotions. Monitors blood chemistry and takes orders from the other parts of the brain.

Answer 17

Hypothalamus

Question 18

A tendency to maintain a balances or constant internal state. The normal process of the body in which it attempted to keep the humors in balance, which produced good health. Now refers to the regulation of any aspect of body chemistry or internal state around a particular level, such as blood glucose or temperature. Every system of this type has to have a variable that is regulated, a way to measure values of that variable, and a way to change values of that variable.

Answer 18

Homeostasis

Question 19

Implicated as a satiety center, involved in telling the organism to stop eating because it is ‘full.’ If this area is stimulated, then the organism will stop eating. If it is destroyed, the stomach and intestines will process food more rapidly, and the organism will eat more often, becoming extremely obese. People with tumors that damage this part of the brain eat excessively.

Answer 19

Ventromedial hypothalamus (VMH)

Question 20

The basal ganglia surround the thalamus. A network of nuclei immediately surrounding the basal ganglia. The major components of this structure include the amygdala and the hippocampus. Has long been associated with emotion, but it is now also though to be a center for consciousness, especially an awareness of where and when one is.

Answer 20

Limbic system

Question 21

Two almond-shapes neural clusters that are components of the limbic system and are linked to expression of anger and fear. Psychologist Heinrich Kluver and neurosurgeon Paul Bucy performed a procedure, surgically creating a lesion in the brain of an ill-tempered monkey, causing the monkey to become tranquil even when hassled.

Answer 21

Amygdala

Question 22

A neural center located in the limbic system that appears to help process explicit memories for storage. The right part of this structure affects verbal information and the left part of this structure affects visual designs and location information

Answer 22

hippocampus

Question 23

The large band of myelinated fibers that connect two brain hemispheres and carry messages between them. Procedures on humans have severed this structure to successfully reduce seizures. In these patients, hemispheric specialization (e.g., language function in the left hemisphere for most people) has been dramatically demonstrated.

Answer 23

Corpus callosum

Question 24

One of the four major divisions of the cerebral cortex. The portion that lies just behind the forehead and extends to the parietal lobe. Segments of this structure directly generate muscle movements, including speaking, and other parts are involved in forming plans and judgments about making movements and more abstract decisions and problem solving.

Answer 24

frontal lobe

Question 25

The portion of the cerebral cortex lying at the top of the head, extending from the central sulcus (the border with the frontal lobe) to the occipital lobe. It includes the sensory cortex that receives information for touch and taste, with different body locations represented by specific locations in the cortex (the homunculus). The bulk of this structure involves higher-level analysis of visual information and integration of information from the various senses.

Answer 25

parietal lobe

Question 26

the ‘little man (body),’ that is present in brain areas used to move and sense our physical body. Used to refer to the distorted human figure drawn in proportion to the relative space our body parts occupy on the cerebral bortex. the more sensitive parts on our body, like lips, feet, and hands are relatively large on this structure because they are represented in relatively large amounts of the cortex. In turn, these body parts which receive more analysis are more sensitive.

Answer 26

Homunculus.

Question 27

Controls the movements of our skeletal muscles; these are voluntary movements that you control.

Answer 27

somatic nervous system

Question 28

Controls involuntary movements especially our glands and the muscle of our internal organs. Self-regulated and automatic, not subject to voluntary control. Has an opponent process structure, with one subdivision (the sympathetic nervous system) that arouses and another (the parasympathetic nervous system) that calms bodily functions.

Answer 28

Autonomic nervous system

Question 29

Subdivision of the autonomic nervous system that arouses the body for defensive action, mobilizing its energy in stressful situations.

Answer 29

Sympathetic nervous system

Question 30

Subdivision of the autonomic nervous system that has the opposite effect of the sympathetic nervous system. Calms the body and conserves its energy and activates digestion.

Answer 30

parasympathetic nervous system

Question 31

A pea-sized structure in the base of the brain, just below the hypothalamus. The endocrine system’s most influential gland. Regulates growth and controls other endocrine glands under the influence of the hypothalamus, which then influences brain and behavior.

Answer 31

Pituitary gland

Question 32

The body’s ‘slow’ chemical communication system. Consists of a set of gland that secrete hormones into the bloodstream. Generates hormones, which affects many aspects of our life including growth, reproduction, metabolism, and mood. Attempts to keep everything in the body in balance and stable.

Answer 32

Endocrine system