BIOL 251 MODULE 6 EXAM | NERVOUS SYSTEM I – ACTION
POTENTIALS, NEUROGLIA & BRAIN ANATOMY | 200
QUESTIONS WITH ANSWERS & RATIONALES
Key Topics Covered:
• Action potential phases, ion channels (voltage-gated Na+, K+, Ca2+), refractory periods,
conduction velocity, myelination, nodes of Ranvier, saltatory conduction
• Neuroglia: astrocytes, oligodendrocytes, Schwann cells, microglia, ependymal cells,
satellite cells, radial glia, NG2 cells, functions and pathologies (MS, glial scar)
• Brain anatomy: cerebral lobes, basal ganglia, thalamus, hypothalamus, cerebellum,
brainstem (midbrain, pons, medulla), limbic system (hippocampus, amygdala), ventricles,
CSF circulation, blood-brain barrier, meninges
• Synaptic transmission: chemical vs electrical synapses, neurotransmitters (ACh, GABA,
glutamate, monoamines), EPSPs/IPSPs, integration, synaptic plasticity
• Brain development: neural tube, neural crest, primary vesicles, alar/basal plates
• Clinical correlates: Brown-Séquard, hemianopia, aphasia, ataxia, hydrocephalus, local
anesthetics
1. A 500-gallon ASME propane tank is equipped with a fixed maximum liquid level gauge. At
what temperature is the gauge calibrated to indicate 80% full?
A) 40°F
B) 60°F
C) 80°F
D) 100°F
Answer B: 60°F
Rationale: NFPA 58 requires fixed liquid level gauges to be calibrated at 60°F to ensure the 80%
fill limit is accurate.
2. A technician finds a 100-lb DOT cylinder with a visible crack near the foot ring. What must be
done?
A) Weld the crack and re-test
B) Remove from service and scrap
C) Install a protective cap
D) Use only for vapor service
Answer B: Remove from service and scrap
Rationale: DOT cylinders with structural cracks cannot be repaired and must be permanently
removed from service.
,3. During a leak test on a new underground propane line, the pressure drops from 30 psig to 28
psig over 30 minutes. The ambient temperature dropped 10°F. What should the technician
conclude?
A) A small leak exists
B) The line is tight; temperature caused the drop
C) The test pressure is too low
D) The gauge is faulty
Answer B: The line is tight; temperature caused the drop
Rationale: A 10°F drop can reduce pressure by about 2 psi; the line likely has no leak.
4. What is the maximum allowable pressure for a propane vapor return line on an ASME tank
equipped with a pressure relief valve set at 250 psig?
A) 125 psig
B) 200 psig
C) 250 psig
D) 312.5 psig
Answer D: 312.5 psig
Rationale: NFPA 58 permits vapor return lines to be designed for 125% of the relief valve set
pressure (250 x 1.25).
5. A house has a propane piping system with a 2 psig regulator at the tank and an 11-inch WC
second-stage regulator inside. The line between regulators is 200 ft of ¾" pipe. What is the
maximum allowable pressure drop in that section?
A) 0.5 psig
B) 1 psig
C) 1.5 psig
D) 2 psig
Answer B: 1 psig
Rationale: NFPA 58 limits pressure drop between first and second stage to 1 psig at maximum
flow.
6. Which of the following is NOT allowed for an underground propane tank in South Carolina?
A) Placing it within 10 ft of a well
B) Anchoring it against flotation
C) Using a corrosion-resistant coating
D) Installing it with a cathodic protection system
Answer A: Placing it within 10 ft of a well
Rationale: SC adopts NFPA 58 requiring 10 ft separation from wells, so placement within 10 ft is
prohibited.
,7. A 20 lb (nominal) exchange cylinder is found with a manufacturing date of 2001 and no
requalification markings. Is it legal to fill?
A) Yes, if it looks sound
B) Yes, but only to 10 lbs
C) No, it must be requalified first
D) No, it is permanently expired
Answer C: No, it must be requalified first
Rationale: DOT cylinders require requalification every 12 years; a 2001 cylinder without
marking has likely expired.
8. When installing a propane hose at a commercial kitchen range, what is the maximum allowed
length of the hose?
A) 3 ft
B) 6 ft
C) 10 ft
D) 15 ft
Answer B: 6 ft
Rationale: NFPA 58 limits appliance connectors (hoses) to 6 feet for movable appliances.
9. A customer reports a "rotten egg" smell inside their home. The installer tests the system and
finds no leaks with a manometer. What should the installer suspect?
A) False odor perception
B) Odorant loss (fading)
C) A leak in the tank's vapor space
D) A defective appliance burner
Answer B: Odorant loss (fading)
Rationale: Odorant can adsorb onto new steel piping or degrade, reducing smell even with no
measurable leak.
10. The minimum burial depth for a propane line under a residential driveway in SC is:
A) 12 inches
B) 18 inches
C) 24 inches
D) 36 inches
Answer B: 18 inches
Rationale: SC adopts NFPA 58 requiring 18 inches of cover under driveways and 12 inches
under non-vehicle areas.
11. An installer connects two 420-lb ASME horizontal tanks in parallel. Each tank has a 10 psig
relief valve. The common vapor line relief valve should be set at?
A) 10 psig
, B) 11 psig
C) 12 psig
D) 15 psig
Answer B: 11 psig
Rationale: Common relief valves must be set ≤ the lowest individual tank relief setting; 10 psig is
allowed, 11 psig is not.
12. What is the primary purpose of a liquid level gauge on a propane transport truck?
A) Measure pressure
B) Prevent overfilling
C) Indicate temperature
D) Check odorant concentration
Answer B: Prevent overfilling
Rationale: Liquid level gauges ensure transport tanks do not exceed 80% of water capacity.
13. During a container requalification inspection, you find pitting corrosion deeper than 1/16 inch
on a 500-gal tank. What action is required?
A) Polish and repaint
B) Measure remaining wall thickness
C) Apply a protective coating over pits
D) Reduce maximum fill to 70%
Answer B: Measure remaining wall thickness
Rationale: Deep pits must be evaluated against minimum wall thickness requirements; if below
code, tank is condemned.
14. Which fitting is required between a propane cylinder’s service valve and a copper pigtail that
will be flexed?
A) Brass flare nut only
B) Copper compression ferrule
C) Vibration-resistant flexible connector listed for propane
D) Malleable iron union
Answer C: Vibration-resistant flexible connector listed for propane
Rationale: Flexible connectors designed for vibration prevent work hardening and cracking of
pigtails.
15. A 1,000-gal tank is 10 ft from a building eave. Can this installation pass SC code?
A) Yes, if eave has no opening
B) Yes, if a 1-hour fire wall is between
C) No, the minimum distance is 10 ft for ASME tanks under 2,000 gal
D) No, minimum distance is 15 ft
Answer C: No, the minimum distance is 10 ft for ASME tanks under 2,000 gal
POTENTIALS, NEUROGLIA & BRAIN ANATOMY | 200
QUESTIONS WITH ANSWERS & RATIONALES
Key Topics Covered:
• Action potential phases, ion channels (voltage-gated Na+, K+, Ca2+), refractory periods,
conduction velocity, myelination, nodes of Ranvier, saltatory conduction
• Neuroglia: astrocytes, oligodendrocytes, Schwann cells, microglia, ependymal cells,
satellite cells, radial glia, NG2 cells, functions and pathologies (MS, glial scar)
• Brain anatomy: cerebral lobes, basal ganglia, thalamus, hypothalamus, cerebellum,
brainstem (midbrain, pons, medulla), limbic system (hippocampus, amygdala), ventricles,
CSF circulation, blood-brain barrier, meninges
• Synaptic transmission: chemical vs electrical synapses, neurotransmitters (ACh, GABA,
glutamate, monoamines), EPSPs/IPSPs, integration, synaptic plasticity
• Brain development: neural tube, neural crest, primary vesicles, alar/basal plates
• Clinical correlates: Brown-Séquard, hemianopia, aphasia, ataxia, hydrocephalus, local
anesthetics
1. A 500-gallon ASME propane tank is equipped with a fixed maximum liquid level gauge. At
what temperature is the gauge calibrated to indicate 80% full?
A) 40°F
B) 60°F
C) 80°F
D) 100°F
Answer B: 60°F
Rationale: NFPA 58 requires fixed liquid level gauges to be calibrated at 60°F to ensure the 80%
fill limit is accurate.
2. A technician finds a 100-lb DOT cylinder with a visible crack near the foot ring. What must be
done?
A) Weld the crack and re-test
B) Remove from service and scrap
C) Install a protective cap
D) Use only for vapor service
Answer B: Remove from service and scrap
Rationale: DOT cylinders with structural cracks cannot be repaired and must be permanently
removed from service.
,3. During a leak test on a new underground propane line, the pressure drops from 30 psig to 28
psig over 30 minutes. The ambient temperature dropped 10°F. What should the technician
conclude?
A) A small leak exists
B) The line is tight; temperature caused the drop
C) The test pressure is too low
D) The gauge is faulty
Answer B: The line is tight; temperature caused the drop
Rationale: A 10°F drop can reduce pressure by about 2 psi; the line likely has no leak.
4. What is the maximum allowable pressure for a propane vapor return line on an ASME tank
equipped with a pressure relief valve set at 250 psig?
A) 125 psig
B) 200 psig
C) 250 psig
D) 312.5 psig
Answer D: 312.5 psig
Rationale: NFPA 58 permits vapor return lines to be designed for 125% of the relief valve set
pressure (250 x 1.25).
5. A house has a propane piping system with a 2 psig regulator at the tank and an 11-inch WC
second-stage regulator inside. The line between regulators is 200 ft of ¾" pipe. What is the
maximum allowable pressure drop in that section?
A) 0.5 psig
B) 1 psig
C) 1.5 psig
D) 2 psig
Answer B: 1 psig
Rationale: NFPA 58 limits pressure drop between first and second stage to 1 psig at maximum
flow.
6. Which of the following is NOT allowed for an underground propane tank in South Carolina?
A) Placing it within 10 ft of a well
B) Anchoring it against flotation
C) Using a corrosion-resistant coating
D) Installing it with a cathodic protection system
Answer A: Placing it within 10 ft of a well
Rationale: SC adopts NFPA 58 requiring 10 ft separation from wells, so placement within 10 ft is
prohibited.
,7. A 20 lb (nominal) exchange cylinder is found with a manufacturing date of 2001 and no
requalification markings. Is it legal to fill?
A) Yes, if it looks sound
B) Yes, but only to 10 lbs
C) No, it must be requalified first
D) No, it is permanently expired
Answer C: No, it must be requalified first
Rationale: DOT cylinders require requalification every 12 years; a 2001 cylinder without
marking has likely expired.
8. When installing a propane hose at a commercial kitchen range, what is the maximum allowed
length of the hose?
A) 3 ft
B) 6 ft
C) 10 ft
D) 15 ft
Answer B: 6 ft
Rationale: NFPA 58 limits appliance connectors (hoses) to 6 feet for movable appliances.
9. A customer reports a "rotten egg" smell inside their home. The installer tests the system and
finds no leaks with a manometer. What should the installer suspect?
A) False odor perception
B) Odorant loss (fading)
C) A leak in the tank's vapor space
D) A defective appliance burner
Answer B: Odorant loss (fading)
Rationale: Odorant can adsorb onto new steel piping or degrade, reducing smell even with no
measurable leak.
10. The minimum burial depth for a propane line under a residential driveway in SC is:
A) 12 inches
B) 18 inches
C) 24 inches
D) 36 inches
Answer B: 18 inches
Rationale: SC adopts NFPA 58 requiring 18 inches of cover under driveways and 12 inches
under non-vehicle areas.
11. An installer connects two 420-lb ASME horizontal tanks in parallel. Each tank has a 10 psig
relief valve. The common vapor line relief valve should be set at?
A) 10 psig
, B) 11 psig
C) 12 psig
D) 15 psig
Answer B: 11 psig
Rationale: Common relief valves must be set ≤ the lowest individual tank relief setting; 10 psig is
allowed, 11 psig is not.
12. What is the primary purpose of a liquid level gauge on a propane transport truck?
A) Measure pressure
B) Prevent overfilling
C) Indicate temperature
D) Check odorant concentration
Answer B: Prevent overfilling
Rationale: Liquid level gauges ensure transport tanks do not exceed 80% of water capacity.
13. During a container requalification inspection, you find pitting corrosion deeper than 1/16 inch
on a 500-gal tank. What action is required?
A) Polish and repaint
B) Measure remaining wall thickness
C) Apply a protective coating over pits
D) Reduce maximum fill to 70%
Answer B: Measure remaining wall thickness
Rationale: Deep pits must be evaluated against minimum wall thickness requirements; if below
code, tank is condemned.
14. Which fitting is required between a propane cylinder’s service valve and a copper pigtail that
will be flexed?
A) Brass flare nut only
B) Copper compression ferrule
C) Vibration-resistant flexible connector listed for propane
D) Malleable iron union
Answer C: Vibration-resistant flexible connector listed for propane
Rationale: Flexible connectors designed for vibration prevent work hardening and cracking of
pigtails.
15. A 1,000-gal tank is 10 ft from a building eave. Can this installation pass SC code?
A) Yes, if eave has no opening
B) Yes, if a 1-hour fire wall is between
C) No, the minimum distance is 10 ft for ASME tanks under 2,000 gal
D) No, minimum distance is 15 ft
Answer C: No, the minimum distance is 10 ft for ASME tanks under 2,000 gal
