Nervous System Overview

Question 1

gray matter

Answer 1

clusters of cell bodies

Question 2

white matter

Answer 2

groups of myelinated axons

Question 3

What are 3 types of neurons?

Answer 3

sensory, relay, motor

Question 4

Types of neuroglia (CNS)?

Answer 4

Ependymal cells, oligodendrocytes, astrocytes, microglia

Question 5

Types of neuroglia (PNS)?

Answer 5

satellite cells, schwann cells

Question 6

Neurotransmission features

Answer 6

synapes, synthesis, packaging, release, termination

Question 7

monoamine neurotransmitters

Answer 7

dopamine, norepinephrine, serotonin, histamine, epinephrine, acetylcholine

Question 8

major amino acid neurotransmitters

Answer 8

gamma-aminobutyric acid, glycine, glutamic acid

Question 9

blood-brain barrier

Answer 9

formed by endothelial cells of the brain capillaries and astrocyte food processes

Question 10

Peripheral nervous system

Answer 10

carries information to and from CNS and peripheral tissues, organized into nerves and ganglia, blood brain barrier, motor and sensory nerves

Question 11

axonal transport (fast)

Answer 11

moves organelles, vesicles, and associated proteins at up to 400 mm/day
powered by kinesin

Question 12

axonal transport (slow)

Answer 12

moves soluable proteins and neurofilaments at between 1 and 10 mm/day
mechanism is unclear

Question 13

Why is the nervous system susceptible to injury?

Answer 13

High energy demand, neurons must maintain axons, complexity, interconnectivity, lack of regeneration in CNS

Question 14

Nervous system diagnostics/markers for toxicity (7)

Answer 14

glial fibrillary acid protein (GFAP)
Degeneration stains 
Immunostains for specific neurons 
histology 
neurofilament release (NF) 
behaviorial assays (memory, motor activity)

Question 15

chemicals known to disrupt brain development (7)

Answer 15

lead 
mercury 
organophosphates 
phthalates 
polybrominated diphenyl ethers (PBDEs) 
polychlorinated biphenyls (PCBs) 
polycyclic aromatic hydrocarbons (PAHs)

Question 16

Types of injuries to the NS and example (4)

Answer 16

Neuronopathy (methyl mercury)
mylanopathies (lead)
axonopathy (hexane, TOCP) - wallerian degeneration
neurotransmitter-related (glutamate/manganese)

Question 17

organophosphate pesticides (OPs)

Answer 17

degrade faster than organochlorides
used in flea collars
high water solubility and acute toxicity

Question 18

organophosphate pesticide examples (3)

Answer 18

parathion, malathion, chlorpyrifos

Question 19

mechanism of organophosphates

Answer 19

inhibit acetylcholine esterase

Question 20

what does acetylcholine esterase do?

Answer 20

stops the acetylcholine signaling

Question 21

What does acetylcholine do?

Answer 21

parasympathetic nervous system — contracts smooth muscle, dilates blood vessels, increases bodily secretions, and slows heart rate

Question 22

what human disease are organophosphates linked to?

Answer 22

parkinson’s disease

Question 23

Parkinson’s disease

Answer 23

second most common neurodegenerative disorder
affects 1-2% of the population over 65
only 15-20% have a genetic basis

Question 24

What is parkinson’s disease characterized by?

Answer 24

A selective loss of dopamine producing neurons in the substantia nigra
dopamine action depends on type of receptors, excites D1 cells, and inhibits D2 cells
Loss of dopamine leads to problems with initiating movement and fine motor control

Question 25

MPTP

Answer 25

1-methyl-4-phenylpyridinium

is a selective inhibitor of mitochondrial complex I, leads to decreased ATP levels and subsequent neuronal death

Question 26

MPTP and Parkinson’s

Answer 26

Rotenone has been show to cause PD like symptoms in rats by inhibiting complex I
Both MPTP and rotenone appear to increase O2 production and decrease resistance of mitochondrial to Ca2+ induced MPT
subsequent work has identified a number of mutations in mitochondrial DNA coding of complex I that are associated with elevated risk of PD