Glossary Of Terms

Question 0

Action potential

Answer 0

Brief change in the membrane potential caused by the rapid opening and closing of ion channels; the action potential is the nerve signals that moves down the axon of a neuron during neurotransmission

Question 1

Acetylcholine

Answer 1

Primary neurotransmitter of the parasympathetic nervous system; effects include decreasing respiration, blood pressure, and heart rate, and increasing gastrointestinal secretions and motility

Question 2

Afferent nerve

Answer 2

Sensory – nerve of the PNS that carry impulses from receptors in the body towards the central nervous system also called sensory nerves

Question 3

Agonist

Answer 3

Substance that mimics the action of a neurotransmitter enhancing it’s intended effect; Agonists are often similar in structure and function to the naturally occurring neurotransmitter

Question 4

Antagonist

Answer 4

Substance that blocks the actions of a neurotransmitter at its receptor site; by binding with the receptor antagonist prevent the neurotransmitter from causing it’s intended effect

Question 5

Astrocytes

Answer 5

Most abundant type of glial cells; in addition to facilitate the exchange of nutrients between capillaries and neurons, they help mop up residual potassium ions and neurotransmitters

Question 6

Autonomic nervous system ANS

Answer 6

Subdivision of the motor division of the peripheral nervous system; controls involuntary functions; e.g., conducts impulses to the heart smooth muscles in the digestive tract and blood vessels walls, and to glands

Question 7

Axon

Answer 7

Part of a neuron that emerges from the cell body in a single long, slender process; nerve impulses travel down the axon and are transmitted to other neurons or cells of you find extensions at the end of the axon

Question 8

Axon terminal

Answer 8

In the region of an axon; usually the site of synaptic contact with another cell; Also called the presynaptic terminal

Question 9

Brainstem

Answer 9

Collective term for three structures of the brain

The midbrain , pons, medulla oblongata

Processes sensation from the skin and joints in the head, neck, and face; sensory input and motor output of the brainstem are carried out by the cranial nerves

Question 10

Carotid sheath

Answer 10

Casing of fibrous tissue that encloses the Vegas nerve, along with the carotid artery, internal jugular vein, and sympathetic nerves that supply the head

Question 11

Cell body

Answer 11

Area of a neuron containing the nucleus; region where metabolism occurs and where incoming signals are integrated

Question 12

Central nervous system

Answer 12

One of the two main divisions of the nervous system; Consists of the brain and spinal cord

Question 13

Cerebellum

Answer 13

Sometimes called the small brain - coordinates movements

Large, Cauliflower-like organ that is exceeded in size only by the cerebrum; provides the precise timing and patterns of skeletal muscle contraction needed for smooth coordinated movements

Question 14

Cerebral cortex

Answer 14

Convoluted surface of the brain, covering the left and right cerebral hemispheres; origin of most cognitive abilities and conscious behavior

Question 15

Cerebral hemispheres

Answer 15

Left and right hemispheres that are the most prominent features of the brain; collectively called the cerebrum includes three deep-lying structures – basal ganglia, hippo campus, and amygdaloid nuclei

Question 16

Cerebrum

Answer 16

Collective term for the right and left cerebral hemispheres

Question 17

Channel-linked receptor

Answer 17

Major type of neurotransmitter receptors composed of protein subunits around a central pore;

e.g., binding of neurotransmitters to the subunits causes the receptor to change its shape, thereby opening the central channel and allowing ions to enter the neuron

Question 18

Complex partial seizures

Answer 18

Seizures that affect consciousness and a persons ability to interact normally with the environment

Question 19

Corpus callosum

Answer 19

Large tract of myelinated nerve fibers that act as a bridge connecting the left and right hemispheres

Question 20

Cranial nerves

Answer 20

12 pairs of nerves that originate in the brain and pass through various openings called foramina of the school other than the Vagus nerve which extends well into the abdomen, the cranial nerves serve only head and neck structures

Question 21

Dendrites

Answer 21

Branching extensions from the neuronal cell body; receive information from other neurons and convey them to the cell body

Question 22

Depolarization

Answer 22

Process during neurotransmission in which positive sodium ions rushing the axon through ion channels, reducing the negative potential of cell membrane and thereby creating an action potential (electrical signal)

Question 23

Diencephalon

Answer 23

Structure located in the central core of the forebrain, surrounded by the cerebral hemispheres and above the brainstem; includes the thalamus and hypothalamus

Question 24

Down-regulation

Answer 24

Decreased production of receptors by a neuron in response to, for example, excessive neurotransmitter levels in the synaptic cleft; also called desensitization