Mid Term 1 Vocab

Question 1

Acetylcholine (ACh)

Answer 1

A neurotransmitter liberated by many peripheral nervous system neurons and some central nervous system neurons. It is excitatory at neuromuscular junctions but inhibitory at some other synapses.

Question 2

Action Potential (AP)

Answer 2

An electrical signal that propagates along the membrane of a neuron or muscle fiber (cell); a rapid change in membrane potential that involves a depolarization followed by a repolarization. Also called a nerve action potential or nerve impulse as it relates to a neuron and a muscle action potential as it relates to a muscle fiber.

Question 3

Astrocytes

Answer 3

A neuroglial cell having a star shape that particulates in brain development and the metabolism of neurotransmitters, helps form the blood-brain barrier, helps maintain the proper balance of K+ for generation of nerve impulses, and provides a link between neurons and blood vessels.

Question 4

Autonomic Nervous System (ANS)

Answer 4

The part of the peripheral nervous system that conveys output to smooth muscle, cardiac muscle, and glands. Consists of two main divisions (a sympathetic nervous system and a parasympathetic nervous system) and an enteric nervous system. So named because this part of the nervous system was thought to be self-governing or spontaneous.

Question 5

Axoplasm

Answer 5

Cytoplasm of an axon

Question 6

Axosomatic

Answer 6

From axon to cell body

Question 7

Central Nervous System (CNS)

Answer 7

That portion of the nervous system that consists of the brain and spinal cord

Question 8

Cerebral Cortex

Answer 8

The surface of the cerebral hemispheres, 2-4mm thick, consisting of gray matter; arranged in 6 layers of neuronal cell bodies in most areas

Question 9

Chromatolysis

Answer 9

The breakdown of Nissl bodies into finely granular masses in the cell body of a neuron whose axon has been damaged

Question 10

Continuous Conduction

Answer 10

Propagation of an action potential (nerve impulse) in a step-by-step depolarization of each adjacent area of an axon membrane

Question 11

Convergence

Answer 11

A synaptic arrangement in which the synaptic end bulbs of several presynaptic neurons terminate on one postsynaptic neuron. The medial movement of the two eyeballs so that both are directed toward a near object being viewed in order to produce a single image

Question 12

Cranial Nerves

Answer 12

1 of 12 pairs of nerves that leave the brain; pass through foramina in the skull; and supply sensory and motor neurons to the head, neck, part of the trunk, and viscera of the thorax and abdomen. Each is designated by a Roman numeral and a name

Question 13

Depression

Answer 13

Movement in which a part of the body moves inferiorly

Question 14

Divergence

Answer 14

A synaptic arrangement in which the synaptic end bulbs of one presynaptic neuron terminate on several postsynaptic neurons

Question 15

Electrical Excitability

Answer 15

Ability to respond to certain stimuli by producing electrical signals

Question 16

Enteric Plexuses

Answer 16

The part of the NS that is embedded in the submucosa and muscular layer of the digestive canal; governs motility and secretions of the digestive canal

Question 17

Ependymal Cells

Answer 17

Neuroglial cell that covers choroid plexuses and produces cerebrospinal fluid (CSF); It also lines the ventricles of the brain and probably assists in the circulation of CSF

Question 18

Epinephrine

Answer 18

Hormone secreted by the adrenal medulla that produces actions similar to those that result from sympathetic stimulation. Also called adrenaline

Question 19

Ganglion

Answer 19

A group of neuronal cell bodies lying outside the CNS. The plural is Ganglia

Question 20

Gray Matter

Answer 20

Areas in the CNS and Ganglia containing neuronal cell bodies, dendrites, unmyelinated axons, axon terminals, and neuroglia; Nissl bodies impart a gray color and there is little or no myelin in gray matter.

Question 21

Guillain-Barré Syndrome (GBS)

Answer 21

An acute demyelinating disorder in which macrophages strip myelin from axons in the PNS. It is the most common cause of acute paralysis in North America and Europe and may result from the immune system’s response to a bacterial infection. Most patients recover completely or partially, but about 15% remain paralyzed.

Question 22

Interneurons

Answer 22

Neurons whose axon extends only for a short distance and contact nearby neurons in the brain, spinal cord, or ganglion; comprise the vast majority of neurons in the body. Also called an association neuron.

Question 23

Microglial cells

Answer 23

Neuroglial cell that carries on phagocytosis

Question 24

Motor Neurons

Answer 24

Neuron that conducts impulses from the brain toward the spinal cord or out of the brain and spinal cords into cranial or spinal nerves to effectors that may be either muscles or glands. Also called an efferent neuron.

Question 25

Muscle Action Potential

Answer 25

A stimulating impulse that propagates along the sarcolemma and transverse tubules; in skeletal muscle, it is generated by acetylcholine, which increases the permeability of the sarcolemma to cations, especially sodium ions (Na+).

Question 26

Myelin Sheath

Answer 26

Multilayered lipid and protein covering, formed by Schwann cells and oligodendrocytes, around axons of many peripheral and central nervous system neurons

Question 27

Myelin Sheath Gaps

Answer 27

A space along a myelinated axon between the individual Schwann cells that form the myelin sheath and the neurolemma. Also called a node of Ranvier

Question 28

Nerve

Answer 28

A cordlike bundle of neuronal axons and/or dendrites and associated connective tissue coursing together outside the CNS

Question 29

Nerve Action Potential

Answer 29

An electrical signal that propagates along the membrane of a neuron or muscle fiber; a rapid change in membrane potential that involves a depolarization followed by a repolarization. Also called an Action potential (AP) or nerve impulse as it relates to a neuron and a muscle action potential as it relates to a muscle fiber.

Question 30

Nerve Fiber

Answer 30

General term for any process (axon or dendrite) projecting from the cell body of a neuron.

Question 31

Nervous System

Answer 31

A network of billions of neurons and even more neuroglia that is organized into 2 main divisions: CNS (Brain and Spinal Cord) and PNS (Nerves, Ganglia, enteric plexuses, and sensory receptors outside the central nervous system).

Question 32

Neuroblastoma

Answer 32

A malignant tumor that consists of immature nerve cells (neuroblasts); occurs most commonly in the abdomen and most frequently in the suprarenal glands. Although rare, it is the most common tumor in infants.

Question 33

Neurolemma

Answer 33

The peripheral, nucleated cytoplasmic layer of the Schwann cell. Also called the sheath of Schwann.

Question 34

Neurology

Answer 34

The study of the normal functioning and disorders of the nervous system

Question 35

Neuropathy

Answer 35

Any disorder that affects the nervous system but particularly a disorder of a cranial of spinal nerve. An example is facial neuropathy.

Question 36

Neurosecretory Cells

Answer 36

A neuron that secretes a hypothalamic-releasing hormone or inhibiting hormone into blood capillaries of the hypothalamus; a neuron that secretes oxytocin or antidiuretic hormone into blood capillaries of the posterior pituitary.

Question 37

Neurotransmitter

Answer 37

One of a variety of molecules within axon terminals that are released into the synaptic cleft in response to a nerve impulse and that changes the membrane potential of the postsynaptic neuron.

Question 38

Norepinephrine (NE)

Answer 38

A hormone secreted by the adrenal medulla that produces actions similar to those that result from sympathetic stimulation. Also called noradrenaline.

Question 39

Oligodendrocytes

Answer 39

A neuroglial cell that supports neurons and produces a myelin sheath around axons of neurons of the CNS.

Question 40

Parasympathetic

Answer 40

One of the 2 main subdivisions of the autonomic nervous system, having cell bodies of preganglionic neurons in nuclei in the brainstem and in the lateral gray horn of the sacral portion of the spinal cord; primarily concerned with activities that conserve and restore body energy. Also known as the craniosacral division.

Question 41

Peripheral Nervous System(PNS)

Answer 41

The part of the nervous system that lies outside the CNS, consisting of nerves and ganglia.

Question 42

Postsynaptic Neuron

Answer 42

The nerve cell that is activated by the release of a neurotransmitter from another neuron and carries nerve impulses away from the synapse

Question 43

Presynaptic neuron

Answer 43

A neuron that propagates nerve impulses towards a synapse

Question 44

Purkinje Cells

Answer 44

Muscle Fiber (cell) in the ventricular tissue

Question 45

Rabies

Answer 45

A fatal disease caused by a virus that reaches the CNS via fast axonal transport. It is usually transmitted by the bite of an infected dog or other meat-eating animals. The symptoms are excitement, aggressiveness, and madness, followed by paralysis and death

Question 46

Satellite Cells

Answer 46

Flat neuroglial cell that surrounds cell bodies of peripheral nervous system ganglia to provide structural support and regulate the exchange of material between a neuronal cell body and interstitial fluid

Question 47

Schwann Cell

Answer 47

A neuroglial cell of the peripheral nervous system that forms the myelin sheath and neurolemma around a nerve axon by wrapping around the axon in a jelly-roll fashion. Also called a neurolemmocyte.

Question 48

Sensory Neurons

Answer 48

Neuron that carries sensory information from cranial and spinal nerves into the brain and spinal cord or from a lower to a higher level in the spinal cord and brain. Also called an afferent neuron

Question 49

Somatic Nervous System (SNS)

Answer 49

The portion of the peripheral nervous system that conveys output to skeletal muscles

Question 50

Spinal Nerves

Answer 50

One of the 31 pairs of nerves that originate on the spinal cord from posterior and anterior roots

Question 51

Stimulus

Answer 51

Any stress that changes a controlled condition; any change in the internal or external environment that excites sensory receptors, a neuron, or a muscle fiber.

Question 52

Sympathetic

Answer 52

One of the two main subdivisions of the autonomic nervous system (ANS), having cell bodies of preganglionic neurons in the lateral gray columns of the thoracic segment and the first two or three lumbar segments of the spinal cord; primarily concerned with processed involving the expenditure of energy. Also called the thoracolumbar division

Question 53

Synapse

Answer 53

The functional junction between two neurons or between a neuron and an effector, such as a muscle or gland; may be electrical or chemical

Question 54

Synaptic Cleft

Answer 54

The narrow gap at a chemical synapse that separates the axon terminal of one neuron from another neuron or muscle fiber (cell) and across which a neurotransmitter diffuses to affect the postsynaptic cell

Question 55

Synaptic End Bulbs

Answer 55

Expanded distal end of an axon terminal that contains synaptic vesicles. Also called a synaptic knob

Question 56

Synaptic Vesicles

Answer 56

Membrane-enclosed sac in a synaptic end bulb that stores neurotransmitters

Question 57

Tract

Answer 57

A bundle of nerve axons in the central nervous system

Question 58

Wallerian degeneration

Answer 58

Degeneration of the portion of the axon and myelin sheath of a neuron distal to the site of injury

Question 59

White Matter

Answer 59

Aggregations or bundles of myelinated and unmyelinated axons located in the brain and spinal cord