chapter 3.2

Question 1

Cell body

Answer 1

the metabolic center of the neuron (soma)

Question 2

Cell membrane

Answer 2

the semipermeable membrane that encloses the neuron

Question 3

Neurons

Answer 3

specialized for the reception, conduction, and transmission of electrochemical signals

Question 4

Dendrites

Answer 4

the short processes emanating from the cell body, which receive most of the synaptic contacts from other neurons

Question 5

Axon hillock

Answer 5

the cone shaped region at the junction between the axon and the cell body

Question 6

Axon

Answer 6

the long narrow process that projects from the cell body

Question 7

Myelin

Answer 7

the fatty insulation around many axons

Question 8

Nodes of ranvier

Answer 8

gaps between sections of myelin

Question 9

Buttons

Answer 9

button-like endings of the axon branches, which release chemicals into synapses

Question 10

Synapses

Answer 10

The gaps between adjacent neurons across which chemical signals are transmitted.

Question 11

Endoplasmic reticulum

Answer 11

system of folded membranes in the cell body; rough portions (ribosomes) play a role in the synthesis of proteins; smooth portions (w/o ribosomes) play a role in the synthesis of fats

Question 12

Cytoplasm

Answer 12

the clear internal fluid of the cell

Question 13

Ribosomes

Answer 13

internal cellular structures on which proteins are synthesized; on endo

Question 14

Golgi complex

Answer 14

a connected system of membranes that packages molecules in vesicles

Question 15

Nucleus

Answer 15

spherical DNA-containing structure of the cell body.

Question 16

Mitochondria

Answer 16

sites of aerobic (oxygen) energy release

Question 17

Micro tubules

Answer 17

tubules responsible for the rapid transport of material throughout neurons

Question 18

Synaptic vesicles

Answer 18

spherical membrane packages that store neurotransmitter molecules ready for release near synapses

Question 19

Neurotransmitters

Answer 19

molecules that are released from active neurons and influence the activity of other cells

Question 20

Neuron cell membrane layer

Answer 20

composed of a lipid bilayer of fat molecules where protein molecules are embedded. Hydrophilic inside; hydrophobic outside.

Question 21

Channel proteins (cell membrane)

Answer 21

through which certain molecules can pass

Question 22

Signal proteins

Answer 22

transfer a signal to the inside of the neuron when particular molecules bind to them on the outside of the membrane

Question 23

Multipolar neuron

Answer 23

More than two processes extending from the cell body

Question 24

unipolar neuron

Answer 24

one process extending from its cell body

Question 25

bipolar neuron

Answer 25

two processes extending from its cell body

Question 26

inter neurons

Answer 26

short axon or no axon at all; function is to integrate the neural activity within a single brain structure, not to conduct signals from one structure to another

Question 27

Nuceli

Answer 27

clusters of cell bodies in the CNS

Question 28

Ganglia

Answer 28

cluster of cell bodies in the PNS

Question 29

Tracts

Answer 29

bundles of axons in the CNS

Question 30

Nerves

Answer 30

bundles of axons in the PNS

Question 31

Glial cells

Answer 31

about as many of these as neurons.

Question 32

Oligodendrocytes (glia)

Answer 32

have extensions that wrap around the axons of some neurons of the CNS that are rich in myelin and the myelin sheaths they form increase the speed and efficiency of axonal conduction. Each cell provides several myelin segments, often on more than one axon.

Question 33

Schwann cells (glia)

Answer 33

similar to Oligodendrocytes, but in PNS. Each cell is one myelin segment. Only Schwann cells can guide axonal regeneration after damage, which is why mammals can only regenerate in the PNS.

Question 34

Microglia (glia)

Answer 34

smaller than other glial cells; respond to injury or disease by multiplying, engulfing cellular debris, and triggering inflammatory responses.

Question 35

Astrocytes (glia)

Answer 35

largest glial cells, star shaped. Some of their extensions cover the outer surfaces of blood vessels that are in the brain; also make contact w/ neuron cell bodies. Appear to play a role in allowing the passage of some chemicals from the blood into CNS neurons and in blocking other chemicals.

Question 36

used to be assumed that glial cells…

Answer 36

provided support for neurons such as providing nutrients, clearing waste, holding neural circuits together etc. But, Astrocytes, for ex., have been shown to exchange chemical signals with neurons and other astrocytes, to control the establishment and maintenance of synapses between neurons, modulate neural activity, and control the blood-brain barrier