SDL: Neurocytology and CSF

Question 1

the trophic (metabolic) center of the neuron

Answer 1

the neuronal soma, defined by presence of the nucleus

Question 2

the longer the axon,

Answer 2

the wider the soma’s diameter

Question 3

three basic shapes of neurons

Answer 3

pseudounipolar, bipolar, multipolar

Question 4

characteristic of pseudounipolar neuron

Answer 4

a single process which extends from the soma then bifurcates

Question 5

characteristic of a bipolar neuron

Answer 5

bipolar neurons have 2 processes, 1 an axon, the other a dendrite

Question 6

characteristic of a multipolar neuron

Answer 6

1 axon and 2 or more dendrites extending from the soma

Question 7

what portion of the nervous system are pseudounipolar neurons found in?

Answer 7

peripheral sensory system

Question 8

the most rare neuronal shape, and where are they found?

Answer 8

bipolar neurons, in the peripheral nervous system

Question 9

most common type of neuron

Answer 9

multipolar

Question 10

characteristics of the cell membrane of neurons

Answer 10

cover axon, soma, dendrites; contains receptors (glycoproteins, glycolipids); contains ion channels

Question 11

name given for rough ER that is large, organized into parallel cisternae with numerous polyribosomes between them

Answer 11

Nissl substance or Nissl bodies

Question 12

where are Nissl bodies found in the neuron, and what do they produce?

Answer 12

found everywhere except the axon; make structural proteins and NT peptides

Question 13

where are neuronal mitochondria often found?

Answer 13

in the presynaptic terminals

Question 14

what is the function of microtubules in neurons?

Answer 14

movement of substances and organelles within the cytoplasm; can move in both directions

Question 15

transport away from the soma is called

Answer 15

anterograde transport

Question 16

transport toward the soma is called

Answer 16

retrograde transport

Question 17

where are microtubules more abundant: axons or dendrites?

Answer 17

dendrites

Question 18

what is a lipofuscin granule?

Answer 18

an inclusion of a neuron that contains substances that were not digested by the lysosome; the older the neuron, the more lipofuscin granules it has

Question 19

byproduct of catecholamine synthesis that is another inclusion found in neurons

Answer 19

melanin

Question 20

what is the level of myelination of peripheral DRG (dendrites)?

Answer 20

unmyelinated or lightly myelinated (like pain and temp. receptors)

Question 21

increased degree of myelination means..

Answer 21

faster rate of conductance of impulses

Question 22

the axon hillock can be distinguished from other processes by..

Answer 22

the lack of Nissl bodies

Question 23

unlike the dendritic tree, the axon of a neuron can

Answer 23

leave the CNS and enter the PNS

Question 24

type of neuron that is important for development and maintenance of the blood brain barrier

Answer 24

astrocyte

Question 25

type of neuron derived from mesoderm (rather than ectoderm); what it functions as

Answer 25

microglia that migrate in and out of the CNS; participates in the inflammatory response and phagocytic processes

Question 26

neurons that line the inner CNS

Answer 26

ependyma cells

Question 27

ependymal cells can participate in passage of substances between

Answer 27

the CNS and CSF

Question 28

cells that form a CSF-blood barrier

Answer 28

choroid epithelial cells (differentiated ependymal cells)

Question 29

makes up the H-shape in the spinal cord

Answer 29

gray matter

Question 30

areas of gray matter which contain intermingled processes like axons and dendrites

Answer 30

neuropil

Question 31

a type of neuronal organization in which the somata are arranged in layers

Answer 31

laminar

Question 32

found deep to the cortex of the brainstem and cerebellum, and surrounds the H shape of the spinal cord cross section

Answer 32

white matter

Question 33

the presynaptic side of the synapse that has the small bulb of the end of the axon is called the

Answer 33

bouton

Question 34

is the synaptic cleft an empty space?

Answer 34

no, it has fine filaments and polysaccharides that bind to the 2 membranes tightly

Question 35

which receptor plays a large role in strengthening of synapses, and what is the mechanism?

Answer 35

NMDA receptor; F actin filaments change the conformation of the post synaptic site, which makes it more capable of processing signals and placing them into "memory"

Question 36

example of a large complex of intracellular proteins called "signaling machines"

Answer 36

CaM Kinase II

Question 37

in what type of junction does an electrical synapse occur?

Answer 37

gap junction, a passage for ions and small molecules

Question 38

the terminal of a synapse on a skeletal muscle is called

Answer 38

motor end plate

Question 39

neuronal-glandular cell terminations

Answer 39

secretomotor synapses

Question 40

axons from neurons such as those in the hypothalamus which pass to the hypophysis

Answer 40

neurosecretory axons

Question 41

describe astrocytic-oligodendritic interaction

Answer 41

astrocytes appear to "prime" axons for myelination

Question 42

describe astrocytic-microglial interactions

Answer 42

produce cytokines, growth factors; play major role in communication between CNS and the remainder of the body (since the CNS lacks lymphatics)

Question 43

an ultrafiltrate of plasma consisting of proteins and electrolytes; circulates through ventricular system and subarachnoid space, reabsorbed by arachnoid granulations

Answer 43

CSF

Question 44

main site that produces CSF

Answer 44

choroid plexus

Question 45

what does the BBB exclude?

Answer 45

macromolecules (proteins), limits small non-lipid soluble molecules

Question 46

Congenital or acquired stenosis of the cerebral aqueduct prevents normal CSF egress and results in dilated lateral and third ventricles and a small fourth ventricle, causing what type of hydrocephalus?

Answer 46

non-communicating or obstructive hydrocephalus

Question 47

causes of non-communicating hydrocephalus

Answer 47

tumor, infection, inter-ventricular bleeding

Question 48

when arachnoid granulation function is compromised due to increased venous back pressure or abnormally low CSF pressure

Answer 48

communicating hydrocephalus

Question 49

CSF can leave the brain, but not the cranial cavity

Answer 49

communicating hydrocephalus

Question 50

CSF can't leave the brain via the cerebral aqueduct

Answer 50

non-communicating hydrocephalus

Question 51

how hydrocephalus (both kinds) are treated

Answer 51

shunts to other body cavities