Cog Neuro Book Ch 2 Vocabulary

Question 1

action potential (p. 31)

Answer 1

The active or regenerative electrical signal that is required for synaptic communication. Action potentials are propagated along the axon and result in the release of neurotransmitters.

Question 2

amygdala (p. 50)

Answer 2

A collection of neurons anterior to the hippocampus in the medial temporal lobe that is involved in emotional processing.

Question 3

association cortex (p. 61)

Answer 3

The volume of the neocortex that is not strictly sensory or motor, but receives inputs from multiple sensorimotor modalities.

Question 4

autonomic nervous system (p. 40)

Answer 4

Also autonomic motor system or visceral motor system. The body system that regulates heart rate, breathing, and glandular secretions and may become activated during emotional arousal, initiating a fight-or-flight behavioral response to a stimulus. It has two subdivisions, the sympathetic and parasympathetic branches.

Question 5

axon (p. 27)

Answer 5

The process extending away from a neuron down which action potentials travel. The terminals of axons contact other neurons at synapses.

Question 6

axon collaterals (p. 27)

Answer 6

Branches off an axon that can transmit signals to more than one cell.

Question 7

axon hillock (p. 32)

Answer 7

A part of the cell body of a neuron where the membrane potentials are summed before being transmitted down the axon.

Question 8

basal ganglia (p. 50)

Answer 8

A collection of five subcortical nuclei: the caudate, putamen, globus pallidus, subthalamic nucleus, and substantia nigra. The basal ganglia are involved in motor control and learning. Reciprocal neuronal loops project from cortical areas to the basal ganglia and back to the cortex. Two prominent basal ganglia disorders are Parkinson’s disease and Huntington’s disease.

Question 9

blood–brain barrier (BBB) (p. 24)

Answer 9

(BBB) A physical barrier formed by the end feet of astrocytes between the blood vessels in the brain and the tissues of the brain. The BBB limits which materials in the blood can gain access to neurons in the nervous system.

Question 10

brainstem (p. 46)

Answer 10

The region of the nervous system that contains groups of motor and sensory nuclei, nuclei of widespread modulatory neurotransmitter systems, and white matter tracts of ascending sensory information and descending motor signals.

Question 11

central nervous system (CNS) (p. 40)

Answer 11

The brain and spinal cord. Compare peripheral nervous system.

Question 12

central sulcus (p. 54)

Answer 12

The deep fold or fissure between the frontal and parietal lobes that separates the primary motor cortex from the primary somatosensory cortex.

Question 13

cerebellum (p. 42)

Answer 13

Literally, “small cerebrum” or “little brain.” A large, highly convoluted (infolded) structure located dorsal to the brainstem at the level of the pons. The cerebellum maintains (directly or indirectly) interconnectivity with widespread cortical, subcortical, brainstem, and spinal cord structures, and plays a role in various aspects of coordination ranging from locomotion to skilled, volitional movement.

Question 14

cerebral cortex (p. 42)

Answer 14

The layered sheet of neurons that overlies the forebrain. The cerebral cortex consists of neuronal subdivisions (areas) interconnected with other cortical areas, subcortical structures, and the cerebellum and spinal cortex.

Question 15

commissure (p. 42)

Answer 15

White matter tracts that cross from the left to the right side, or vice versa, of the central nervous system. The corpus callosum is the largest commissure in the brain. See also anterior commissure and posterior commissure.

Question 16

corpus callosum (p. 42)

Answer 16

A fiber system composed of axons that connect the cortex of the two cerebral hemispheres. It is the largest white matter structure in the brain.

Question 17

cytoarchitectonics (p. 54)

Answer 17

Also cellular architecture. The study of the cellular composition of structures in the body.

Question 18

dendrites (p. 26)

Answer 18

Large tree like processes of neurons that receive inputs from other neurons at locations called synapses.

Question 19

depolarization (p. 32)

Answer 19

A change in the membrane potential in which the electrical current inside the cell becomes less negative. With respect to the resting potential, a depolarized membrane potential is closer to the firing threshold. Compare hyperpolarization.

Question 20

electrical gradient (p. 30)

Answer 20

A force that develops when a charge distribution across the neuronal membrane develops such that the charge inside is more positive or negative than the one outside. Electrical gradients result from asymmetrical distributions of ions across the membrane.

Question 21

electrotonic conduction (p. 31)

Answer 21

Also decremental conduction. Ionic current that flows passively through the cytoplasm and across the membrane of an activated neuron that diminishes with distance from the site of generation.

Question 22

equilibrium potential (p. 32)

Answer 22

The membrane potential at which a given ion (e.g., K+) has no net flux across the membrane— that is, the point where the numbers of ions moving outward and inward across the membrane are the same.

Question 23

frontal lobe (p. 53)

Answer 23

The mass of cortex anterior to the central sulcus and dorsal to the Sylvian fissure. The frontal lobe contains two principal regions—the motor cortex and the prefrontal cortex—each of which can be further subdivided into specific areas both architectonically and functionally.

Question 24

glial cell (p. 24)

Answer 24

One of two cell types (along with the neuron) in the nervous system. Glial cells are more numerous than neurons, by perhaps a factor of 10, and may account for more than half of the brain’s volume. They typically do not conduct signals themselves; but without them, the functionality of neurons would be severely diminished. Tissue made of glial cells is termed glia.

Question 25

gray matter (p. 42)

Answer 25

Regions of the nervous system that contain primarily neuronal cell bodies. Gray matter includes the cerebral cortex, the basal ganglia, and the nuclei of the thalamus. Gray matter is so-called because, in preservative solution, these structures look gray in comparison to the white matter where myelinated axons are found (which look more white).

Question 26

gyrus (p. 52)

Answer 26

A protruding rounded surface of the cerebral cortex that one can see upon gross anatomical viewing of the intact brain. Compare sulcus.

Question 27

hippocampus (p. 50)

Answer 27

A layered structure in the medial temporal lobe that receives inputs from wide regions of the cortex via inputs from the surrounding regions of the temporal lobe, and sends projections out to subcortical targets. The hippocampus is involved in learning and memory, particularly memory for spatial locations in mammals and episodic memory in humans.

Question 28

hyperpolarization (p. 32)

Answer 28

A change in the membrane potential in which the electrical current inside of the cell becomes more negative. With respect to the resting potential, a hyperpolarized membrane potential is farther from the firing threshold. Compare depolarization.

Question 29

hypothalamus (p. 49)

Answer 29

A small collection of nuclei that form the floor of the third ventricle. The hypothalamus is important for the autonomic nervous system and the endocrine system, and it controls functions necessary for the maintenance of homeostasis.

Question 30

insula (p. 54)

Answer 30

Also insular cortex. A part of cortex hidden in the Sylvian fissure. The insula also has extensive reciprocal connections with areas associated with emotion, such as the amygdala, medial prefrontal cortex, and anterior cingulate gyrus; as well as with frontal, parietal, and temporal cortical areas involved with attention, memory, and cognition.

Question 31

ion channel (p. 28)

Answer 31

A passageway in the cell membrane, formed by a transmembrane protein that creates a pore, through which ions of a particular size and/or charge are allowed to pass.

Question 32

ion pump (p. 28)

Answer 32

A protein in the cell membrane of a neuron that is capable of transporting ions against their concentration gradient. The sodium-potassium pump transports sodium ions (Na+) out of the neuron and potassium ions (K+) into the neuron.

Question 33

layer (p. 41)

Answer 33

A common organizational cluster of neurons in the central nervous system.

Question 34

limbic system (p. 50)

Answer 34

Several structures that form a border (limbus in Latin) around the brainstem, named the grand lobe limbique (“limbic lobe”) by Paul Broca, which now include the amygdala, orbitofrontal cortex, and portions of the basal ganglia.

Question 35

medulla (p. 46)

Answer 35

The brainstem’s most caudal portion. The medulla is continuous with the spinal cord and contains the prominent, dorsally positioned nuclear groups known as the gracile and cuneate nuclei (which relay somatosensory information from the spinal cord to the brain) and the ventral pyramidal tracts (which contain descending projection axons from the brain to the spinal cord). Various sensory and motor nuclei are found in the medulla.

Question 36

microcircuit (p. 39)

Answer 36

A small network of localized interconnected neurons that together process specific kinds of information and contribute to information-processing tasks such as sensation, action, and thought. Compare neural network.