nervous tissue test 2

Question 1

describe the neural plate

Answer 1

composed of a simple columnar epithelium

cell shape is maintained by microtubules

Question 2

what shape change occurs during the neural fold and why

Answer 2

columnar shape to wedge cell shape
due to actin filaments
wedge shape of cells caused flattened neural plate to bend
bends can be up or down depending on whether apex of wedge-shaped cells are pointed up or down

Question 3

what are the derivatives of the neural tube

Answer 3

telencephalon
diencephalon
mesencephalon
metencephalon
myelencephalon

Question 4

what does the neural crest tissue do

Answer 4

pinches off area where neural epithelium separates from skin ectoderm

Question 5

what are neural crest cells derived from and what do they give rise to

Answer 5

derived from neuroectoderm

gives rise to neurons and neuroglial cells of PNS

Question 6

what is the intermediate zone of pseudo stratified epithelium of neural tube

Answer 6

area of destruction of excess neurons via apoptosis

Question 7

what is the cortical plate (mantle layer) of the neural tube

Answer 7

postmitotic neurons

future grey matter

Question 8

what is in the marginal layer of the neural tube

Answer 8

axons

future white matter (myelinated axon)

Question 9

what are nerve tissue characteristics

Answer 9

irritability (specialized to receive stimuli)
conductibility (specialized to transmit impulses)
cellular components: neurons, neuroglial cells

Question 10

define neuroglial cells

Answer 10

non-conductive cells that support and protect the neurons

Question 11

what do nissl bodies consist of

Answer 11

RER and free ribosomes

Question 12

what are the lipofucsin granules formed form in cell bodies

Answer 12

lysosomes: accumulate with age of neuron

Question 13

what is one major difference between dendrites and cell bodies

Answer 13

dendrites do not have golgi body

Question 14

what are characteristics of the axon hillock

Answer 14

site of origin of axon
devoid of nissl substance
associated with AP generation

Question 15

what do telodendrites form

Answer 15

presynaptic membranes

Question 16

where do axons terminate

Answer 16

in branching telodendrites

Question 17

what do telodendrites contain

Answer 17

synaptic vesicles and related proteins

Question 18

what do interneurons do

Answer 18

transmit impulses within CNS and between sensory and motor neurons

Question 19

define multipolar neurons

Answer 19

most common morphological type

have single axon and multiple dendrites

Question 20

define bipolar neurons

Answer 20

have 2 processes, one at each end of the spindle-shaped neuron
found in association of special senses such as olfactory and visual

Question 21

define pseudounipolar neurons

Answer 21

have a single process from the cell body that bifurcates into a central and peripheral process
found in ganglia alongside spinal cord

Question 22

explain difference between golgi I and II

Answer 22

I: neurons with long axons which leave the grey matter of which they are a part
II: neurons with short axons which ramify through the great matter

Question 23

define a nerve

Answer 23

bundle of axons (fibers) in the PNS

Question 24

define tract

Answer 24

bundle of axons (fibers) in CNS

Question 25

define ganglion

Answer 25

aggregation of cell bodies and dendrites in the PNS

Question 26

define nucleus

Answer 26

aggregation of cell bodies and dendrites in the CNS

Question 27

describe the epineurium

Answer 27

thick fibrous coat covers entire nerve supplied by blood and lymphatic vessels Type I collagen and fibroblasts

Question 28

describe perineurium

Answer 28

dense connective tissue covers bundles of axons (fascicles) within nerve epithelial-like fibroblasts on inner surface are joined by tight junctions blood nerve barrier

Question 29

describe endoneurium

Answer 29

thin layer of reticular connective tissue surrounds individual fibers and schwann cells type III collagen

Question 30

what channels are on axons

Answer 30

voltage-gated Na+ and Ca++ channels & potassium channels

Question 31

what type of channels are on dendrites and cell bodies

Answer 31

ligand-gated channels

Question 32

what membrane specializations are in the presynaptic membrane

Answer 32

``` synaptic vesicles vesicular docking proteins and synapsin filaments dense bodies mitochondria voltage-gated calcium channels ```

Question 33

what membrane specializations are in the postsynaptic membrane

Answer 33

receptors | ligand--gated ion channels

Question 34

what direction does anterograde transport go

Answer 34

cell body toward distal end of axon

Question 35

what does anterograde transport utilize

Answer 35

kinesin

Question 36

what are the 2 systems of slow anterograde transport

Answer 36

SCa: preassembled microtubules and neurofilaments SCb: enzymes, actin, clathrin

Question 37

what uses intermediate rate anterograde transport

Answer 37

mitochondria and other membrane-bound organelles

Question 38

where does fast anterograde transport occur

Answer 38

synaptic vesicles and neurotransmitters

Question 39

what is the direction of retrograde transport

Answer 39

axon toward cell body

Question 40

what does retrograde transport utilize

Answer 40

cytoplasmic dynein

Question 41

what does retrograde transport carry

Answer 41

endocytosed materials and recycled proteins

Question 42

define glial-cells

Answer 42

non-neuronal cells typically derived from embryonic neural crest tissue (except microglia)

Question 43

what are the types of glial cells

Answer 43

astrocytes, oligodendrocytes, schwann cells, microglial cells, ependymal cells

Question 44

where are astrocytes found

Answer 44

CNS

Question 45

what is the difference between fibrous and protoplasmic astrocytes

Answer 45

fibrous: found predominantly in white matter and have long processes with few branches protoplasmic: found predominantly in gray matter and have shorter processes with many short branches

Question 46

where are oligoendrocytes found

Answer 46

CNS

Question 47

what are the functions of oligodendrocytes

Answer 47

closely associated with neuron cell bodies in gray matter and function as satellite cells surround axons of unmyelinated fibers in gray matter myelinate axons in CNS

Question 48

what is the function of schwann cells

Answer 48

myelinate axons in the PNS (each one myelinated a section of a single axon)

Question 49

what are microglial cells derived from

Answer 49

macrophage precursors (bone marrow)

Question 50

what are the functions of microglial cells

Answer 50

phagocytic in PNS, recruit leukocytes across the BBB, modulate initiation and progression of immune responses along with astrocytes

Question 51

what do satellite cells do

Answer 51

``` derived from neural crest form moons (crescents) around cell bodies in ganglia function as insulators ```

Question 52

define intraperiod line

Answer 52

electron-dense line created by extracellular space between adjacent outer leaflet

Question 53

define major dense line

Answer 53

electron-dense line created by cytoplasmic space remnant between adjacent inner leaflets

Question 54

define synapsins

Answer 54

filaments in the presynaptic membrane

Question 55

define axosomatic

Answer 55

axon terminal synapses with the neuron cell body

Question 56

define axoaxonic

Answer 56

axon terminal synapses with another axon terminal

Question 57

define axodendritic

Answer 57

axon terminal synapses with a dendrite

Question 58

define axospinous

Answer 58

axon terminal synapses with a dendritic spine

Question 59

define excitatory

Answer 59

more positive end plate potential

Question 60

define inhibitory

Answer 60

more negative end plate potential

Question 61

list meninges in order from superficial to deep

Answer 61

epidural space dura mater subdural space leptomeninx (arachnoid membrane, arachnoid villi, pia mater)

Question 62

define choroid plexus

Answer 62

highly unfolded simple cuboidal epithelium that extends into the ventricles from the roof plate

Question 63

how are the cuboidal cells of the choroid plexus linked

Answer 63

tight junctions

Question 64

define ependyma

Answer 64

layer of simple cuboidal epithelium that lines the ventricular walls

Question 65

how are the cuboidal epithelial cells of the ependyma linked

Answer 65

zonula adherens

Question 66

define tanycytes

Answer 66

in third ventricle: tightly linked to the adjacent ependymal cells and send processes through the glia limitans to form end foot processes on underlying blood vessels