Chapter 9: Nerve Tissue

Question 1

Name for nerve cells; respond to environmental stimuli by a reversal of their ionic gradient

Answer 1

Neurons

Question 2

cells that support and protect neurons

Answer 2

Glial cells

Question 3

______ nervous system consisting of the brain and the spinal cord

Answer 3

Central (CNS)

Question 4

_______ nervous system composed of the cranial, spinal, and peripheral nerves

Answer 4

Peripheral

Question 5

The nervous system develops from the ______ of the three early embryonic layers

Answer 5

Ectoderm

Question 6

Step 1 of nervous system development: the overlying layer of ectodermal cells thickens as a bending ___ ___

Answer 6

Neural plate

Question 7

Step 2 of nervous system development: The plate bends further, making the neural ___ and _____

Answer 7

Folds and groove

Question 8

Step 3 of nervous system development: the neural folds rise and fuse at the midline, converting the groove into the ____ ____

Answer 8

Neural tube

Question 9

Cells of the the neural ___ give rise to the entire CNS including neurons and most glial cells

Answer 9

Neural tube

Question 10

Two other names for the cell body of a neuron ___ and ___

Answer 10

Soma and perikaryon

Question 11

The ___ ___ which contains the nucleus and most of the cell;s organelles and serves as the synthetic to tropic center for the entire neuron

Answer 11

Cell body/soma/perikaryon

Question 12

The ______, which are the numerous elongated processes extending from the the perikaryon and specialized to receive stimuli from the other neurons at unique sites called synapses

Answer 12

Dendrites

Question 13

The ____, which is a single long process ending at synapses specialized to generate and conduct nerve impulses to other cells

Answer 13

Axon

Question 14

_____ neuron has one axon and two or more dendrites; most common classification

Answer 14

Multipolar neurons

Question 15

_____ neurons have one dendrite and one axon; comprise the sensory neurons of the retina, the olfactory epithelium, and the inner ear

Answer 15

Bipolar neurons

Question 16

____ or _____ neurons have a single process that splits into two, near the soma, with the longer branch extending to a peripheral ending and the other toward the CNS

Answer 16

Unipolar or pseudounipolar neurons

Question 17

Sensory neurons are _____, receiving stimuli from receptors throughout the body and convert to the CNS

Answer 17

Afferent

Question 18

Motor neurons are _____, sending impulses to effector organs such as muscle fibers and glands from the CNS

Answer 18

Efferent

Question 19

_______ establish relationships among other neurons, forming complex functional networks or circuits in the CNS

Answer 19

Interneurons

Question 20

In the CNS, most synapses on dendrites occur on dendritic ____

Answer 20

Dendritic spines

Question 21

Dynamic membrane protrusions along the small dendritic branches

Answer 21

Dendritic spines

Question 22

Axons originate from a pyramid-shaped region of the perikaryon called the ___ ___, juts beyond which the axolemma has concentrated ion channels that generate the action potential

Answer 22

Axon hillock

Question 23

Each small axonal branch ends with a dilation called a _____ ____ that contacts another neuron or non-nerve cell at a synapse to initiate an impulse in that cell

Answer 23

Terminal bouton

Question 24

Organelles and macromolecules synthesized in the cell body move by _______ transport along axonal microtubules via _____ from the perikaryon to the synaptic terminals

Answer 24

Anterograde transport; Kinesin

Question 25

______ transport from the synaptic terminals to perikaryon via ______ carries certain other macromolecules

Answer 25

Retrograde transport; Dynein

Question 26

Sites where nerve impulses are transmitted from one neuron to another, or from neurons and other effector cells

Answer 26

Synapses

Question 27

Small molecules that bind specific receptor proteins to either open or close ion channels or initiate second-messengers cascades

Answer 27

Neurotransmitters

Question 28

_____ synapse: branched axon terminals associated with and transmit a nerve impulse to another neuron’s cell body (soma)

Answer 28

Axosomatic synapses

Question 29

_____ synapse: branched axon terminals associated with and transmit a nerve impulse to a dendritic spine

Answer 29

Axodendritic synapses

Question 30

____ synapse: an axon terminal forms a synapse with an axon terminal of another neuron

Answer 30

Axoaxonic synapses

Question 31

The fibrous intercellular network of CNS tissue emerging from neurons and glial cells

Answer 31

Neuropil

Question 32

______ extend many processes, each of which becomes sheetlike and wraps repeatedly around a portion of a nearby CNS axon

Answer 32

Oligodendrocytes

Question 33

The ____ ____ electrically insulates the axon and facilitates rapid transmission of nerve impulses

Answer 33

Myelin sheath

Question 34

______ originate from progenitor cells in the embryonic neural tube and are by far the most numerous glial cells of the brain

Answer 34

Astrocytes

Question 35

Astrocytes extend fibrous processes with expanded ________ feet that cover endothelial cells, capillaries

Answer 35

Perivascular feet

Question 36

________ mediate the exchange of ions, oxygen, and other molecules; form part of the blood brain barrier; control vasodilation

Answer 36

Astrocytes

Question 37

Astrocytes form a barrier layer of expanding protoplasmic processes, called the ___ ___ membranes which lines the meninges at the external CNS surface (Pia Matter)

Answer 37

Glial limiting membrane

Question 38

Form scar tissue in the CNS at sites of damage

Answer 38

Astrocytes

Question 39

Columnar or cuboidal cells that line the fluid-filled ventricles of the brain and the central canal of the spinal cord

Answer 39

Ependymal cells

Question 40

______ cells joined tightly together; no basal lamina; attached to neuropil; some areas apical end can have microvilli

Answer 40

Ependymal cells

Question 41

Consisting of small cell bodies from which radiate many long, branched processes, are less numerous than oligodendrocytes or astrocytes but nearly as common as neurons in some CNS regions

Answer 41

Microglia

Question 42

______ cells also constitute the major mechanism of immune defense in the CNS, removing any microbial invaders and secreting several immunoregulatory cytokines

Answer 42

Microglial cells

Question 43

These cells originate from blood monocytes

Answer 43

Microglial cells

Question 44

____ cells are only found up the PNS and differentiate from precursors in the neural crest

Answer 44

Schwann cells

Question 45

Form myelin around a portion of only one axon per cell

Answer 45

Schwann cells

Question 46

Derived from the embryonic neural crest, small ______ cells form a thin, intimate glial layer around each large neuronal cell body in the ganglia of the PNS

Answer 46

Satellite cells

Question 47

Loose areas of cytoplasm in Schwann cells myelin sheath; uncompacted regions

Answer 47

Schmidt-Lanterman clefts

Question 48

The major structures comprising the ______ are the cerebrum, cerebellum, and spinal cord

Answer 48

CNS

Question 49

The main components of ______ matter are myelinated axons and the myelin-producing oligodendrocytes

Answer 49

White matter

Question 50

_____ matter contains abundant neuronal cell bodies, dendrites, astrocytes, and microglial cells, and is where most synapses occur

Answer 50

Gray matter

Question 51

In the cerebrum and cerebellum, ______ matter makes up the periphery and ____ matter makes up the center

Answer 51

Grey; white

Question 52

In the spinal cord, ______ matter makes up the periphery and ____ matter makes up the center

Answer 52

White; grey

Question 53

Neurons of the _____ cortex function in the integration of sensory informations and the initiation of voluntary motor responses

Answer 53

Cerebral cortex

Question 54

The main components of the ______ are the nerves, ganglia, and nerve endings

Answer 54

PNS

Question 55

Btw adjacent Schwann cells on an axon, the myelin sheath shows small ____ ___ ____, where the axon is only partially covered by interlocking Schwann cell processes

Answer 55

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