04. Definitions

Question 1

Define neuron

Answer 1

A single cell in the nervous system

Question 2

Define nerve

Answer 2

a bundle of many neurons

Question 3

Sensory neurons

Answer 3

carry information from sensory organs into the central nervous system

Question 4

Motor neurons

Answer 4

carry messages out from the central nervous system to operate muscles and glands

Question 5

Interneurons

Answer 5

entirely within the central nervous system. Carry messages from one set of neurons to another (vastly outnumber sensory and motor neurons)

Question 6

Axon terminal

Answer 6

end of a branch of an axon. Shaped like a small swelling. Designed to release chemical transmitter molecules onto other neurons, motor cells or glandular cells

Question 7

myelin sheath

Answer 7

A casing of fatty cells wrapped tightly around the axon of some neurons

Question 8

Action potentials

Answer 8

Neural impulses; the all-or-nothing electrical bursts that begin at one end of the axon of a neuron and move along the axon to the other end

Question 9

Cell membrane (encloses each neuron)

Answer 9

The thin, porous outer covering of a neuron or other cell that separates the cell’s intracellular fluid from extracellular fluid.

Question 10

Resting potential

Answer 10

charge across the membrane of an inactive neuron, it is the source of electrical energy which makes an action potential possible

Question 11

Synapse

Answer 11

Junction between axon terminal and the cell body or dendrite. The functional connection through which neural activity in the axon of one neuron influences the action of another neuron, a muscle cell, or a glandular cell.

Question 12

Neurotransmitter

Answer 12

A chemical substance released from the axon terminal of a neuron, at a synapse, that influences the activity of another neuron, a muscle cell, or a glandular cell; also called a transmitter.

Question 13

Excitory synapse

Answer 13

A synapse at which the neurotransmitter increases the likelihood that an action potential will occur, or increases the rate at which they are already occurring, in the neuron on which it acts

Question 14

Inhibitory synapse

Answer 14

A synapse at which the neurotransmitter decreases the likelihood that an action potential will occur, or decreases the rate at which they are already occurring, in the neuron upon which it acts.

Question 15

Neurogenesis

Answer 15

The creation of new neurons in which neuronal stem cells divide and replicate themselves by mitosis.

Question 16

selective cell death (apoptosis)

Answer 16

Early developmental process in which neurons die.

Question 17

mirror neurons

Answer 17

Neurons in the brain that become active both when the individual makes a particular motion and when the individual sees another individual making that same motion. These neurons are believed to facilitate observational learning. Found in the cerebral cortex

Question 18

transcranial magnetic stimulation (TMS)

Answer 18

A procedure for temporarily altering the responsiveness of a localized area of the cerebral cortex by creating a magnetic field over that brain area. It is also used as a treatment for depression.

Question 19

positron emission tomography (PET)

Answer 19

A method for visually displaying brain activity that is based upon the uptake of a radioactive form of oxygen into active areas of the brain.

Question 20

functional magnetic resonance imagining (fMRI)

Answer 20

A method for visually displaying brain activity that is based on the fact that protons in certain molecules can be made to resonate and give off radio waves indicating relative amounts of neural activity in each portion of the brain.

Question 21

cranial nerve

Answer 21

A nerve that extends directly from the brain.

Question 22

spinal nerve

Answer 22

A nerve that extends directly from the spinal cord

Question 23

somatosensation

Answer 23

The set of senses that derive from the whole body—such as from the skin, muscles, and tendons—as opposed to those senses that come from the special sensory organs of the head.

Question 24

sympathetic division of the autonomic motor system

Answer 24

The set of motor neurons that act upon visceral muscles and glands and mediate many of the body’s responses to stressful stimulation, preparing the body for possible “fight or flight.”

Question 25

parasympathetic division of the autonomic motor system

Answer 25

The set of motor neurons that act upon visceral muscles and glands and mediate many of the body’s regenerative, growth-promoting, and energy-conserving functions.

Question 26

Spinal cord

Answer 26

connects spinal nerves to the brain and organises some reflexes such as walking, running, etc.

Question 27

pattern generators

Answer 27

Networks of neurons that stimulate one another in a cyclic manner and thereby produce bursts of action potentials that wax and wane in a regular, repeating rhythm. They help to control rhythmic sequences of muscle movements, such as those involved in walking, running, flying (in birds), or swimming (in fish)

Question 28

Subcortical strurctures

Answer 28

The lower more primitive parts of the brain

Question 29

brainstem

Answer 29

The primitive, stalk-like portion of the brain that can be thought of as an extension of the spinal cord into the head; it consists of the medulla, pons, and midbrain

Question 30

Medulla

Answer 30

The lowest portion of the brainstem, bounded at one end by the spinal cord and at the other by the pons. It is responsible, with the pons, for organizing reflexes more complex than spinal reflexes.

Question 31

Pons

Answer 31

The portion of the brainstem that is bounded at its lower end by the medulla and its upper end by the midbrain and is responsible, with the medulla, for organizing reflexes more complex than spinal reflexes.

Question 32

Midbrain

Answer 32

The upper portion of the brainstem, bounded at its lower end by the pons and at its upper end by the thalamus, that contains neural centers that organize basic movement patterns.

Question 33

cerebellum

Answer 33

The relatively large, conspicuous, convoluted portion of the brain attached to the rear side of the brainstem; it is especially important for the coordination of rapid movements.

Question 34

basal ganglia

Answer 34

The large masses of gray matter in the brain that lie on each side of the thalamus; they are especially important for the initiation and coordination of deliberate movements.

Question 35

Thalamus

Answer 35

The brain structure that sits directly atop the brainstem; it functions as a sensory relay station, connecting incoming sensory tracts to special sensory areas of the cerebral cortex.

Question 36

limbic system

Answer 36

An interconnected set of brain structures (including the amygdala and hippocampus) that form a circuit wrapped around the thalamus and basal ganglia, underneath the cerebral cortex. These structures are especially important for the regulation of emotion and motivation and are involved in the formation of long-term memories.

Question 37

Amygdala

Answer 37

A brain structure that is part of the limbic system and is particularly important for evaluating the emotional and motivational significance of stimuli and generating emotional responses.

Question 38

Hippocampus

Answer 38

A structure in the limbic system of the brain that is essential for encoding explicit memories for long-term storage.

Question 39

occipital lobes

Answer 39

The rearmost lobes of the cerebral cortex, bounded in front by the temporal and parietal lobes; they contain the visual areas of the brain.

Question 40

temporal lobes

Answer 40

The lobes of the cerebral cortex that lie in front of the occipital lobes and below the parietal and frontal lobes and that contain the auditory areas of the brain.

Question 41

parietal lobes

Answer 41

The lobes of the cerebral cortex that lie in front of the occipital lobes, above the temporal lobes, and behind the frontal lobes; they contain the somatosensory areas of the brain.

Question 42

frontal lobes

Answer 42

The frontmost lobes of the cerebral cortex, bounded in the rear by the parietal and temporal lobes; the frontal lobes contain the motor area and parts of the association areas involved in planning and making judgments.

Question 43

primary motor area

Answer 43

An area in the rear part of the frontal lobe of the cerebral cortex that is directly involved in the control of movements, especially finely coordinated movements of small muscles, as in the fingers and vocal apparatus

Question 44

primary sensory areas

Answer 44

Specialized areas of the cerebral cortex that receive input from sensory nerves and tracts by way of the relay nuclei in the thalamus. They include the visual area (in the occipital lobe), auditory area (in the temporal lobe), and somatosensory area (in the parietal lobe)

Question 45

association areas

Answer 45

(perception, thought and decision making) Areas of the cerebral cortex that receive input from the primary or secondary sensory areas for more than one sensory modality (such as vision and hearing) and are involved in associating this input with stored memories, in the processes of perception, thought, and decision making.

Question 46

premotor areas

Answer 46

Portions of the brain’s cerebral cortex that lie directly anterior to (in front of) the motor area. They provide neural programs for producing organized movements.

Question 47

prefrontal cortex

Answer 47

The front-most portion of the frontal lobe of the brain’s cerebral cortex.

Question 48

hormone

Answer 48

Any chemical substance that is secreted naturally by the body into the blood and can influence physiological processes at specific target tissues (such as the brain) and thereby influence behavior.

Question 49

androgen

Answer 49

A category of hormones, including testosterone, which are produced by the testes in male animals and are normally thought of as “male hormones.” These hormones are also produced at lower levels by the adrenal glands, in females as well as in males.

Question 50

corpus callosum

Answer 50

A massive bundle of axons connecting the right and left hemispheres of the higher parts of the brain, including the cerebral cortex.

Question 51

aphasia

Answer 51

Any loss in language ability due to brain damage.

Question 52

What are the two best studied aphasia’s

Answer 52

Broca’s (non-fluent) aphasia, Wernicke’s (fluent) aphasia

Question 53

Broca’s aphasia

Answer 53

A specific syndrome of loss in language ability that occurs due to damage in a particular part of the brain called Broca’s area; it is characterized by telegraphic speech in which the meaning is usually clear but the small words and word endings that serve grammatical purposes are missing; also called nonfluent aphasia.

Question 54

Wernicke’s aphasia

Answer 54

A specific syndrome of loss of language ability that occurs due to damage in a particular part of the brain called Wernicke’s area. Speech in a person with this disorder typically retains its grammatical structure but loses its meaning due to the speaker’s failure to provide meaningful content words (nouns, verbs, adjectives, and adverbs); also called fluent aphasia

Question 55

long-term potentiation (LTP)

Answer 55

A process by which repeated activation of synapses results in strengthening of those synapses.

Question 56

encephalization quotient (EQ)

Answer 56

Formula for evaluating the expected ratio between brain weight and body weight for animals.