Neuroscience Quiz: Understanding the Human Nervous System

Jay’s No-Good, Very Bad Day

PART 1 – Jay’s No-Good, Very Bad Day
1. Jay is a 39-year-old contractor in charge of overseeing the construction of several homes within the Durham region. At one of the construction sites, Jay inspects the progress of his more inexperienced crew as they frame the main floor of a house. Seeing that they are struggling to build walls that correspond exactly to the blueprints, Jay sits his crew down, picks up a hammer and begins to demonstrate the proper procedure for framing a wall. Unfortunately, a loud bang from one of the tradespeople in the other room distracts him and he hits his thumb with a hammer.

a. [3 marks] Using the word bank below, list the names of the sensory receptors involved in the following:
Chemoreceptor, osmoreceptor, baroreceptor, photoreceptor, proprioceptor, thermoreceptor, mechanoreceptor, nociceptor, tactile receptor
i. ________ The crew is aware that they are in a sitting position
ii. ________ Light enters Jays eyes as he reads the blueprint
iii. ________ Jay is aware of his arm moving to pick up the hammer
iv. ________ Jay is aware that the hammer is cold as he picks it up
v. ________ Jay experiences pain as the hammer hits his thumb
vi. ________ Jay’s blood pressure increases as he deals with acute pain.

b. [1 mark] What type of neuron is responsible for delivering sensory information from the pain receptor in Jay’s thumb to the interneuron in his
spine? Select-all-that-apply.
 A sensory neuron
 A motor neuron
 An afferent neuron
 An efferent neuron

c. [1 mark] What type of neuron is responsible for delivering motor information from the interneuron in his spine to his arm muscle (an effector) as he pulls his arm away? Select-all-that-apply.
 A sensory neuron
 A motor neuron
 An afferent neuron
 An efferent neuron

2. To conduct sensory and motor information, action potentials are triggered in the neurons of Jay’s body.
a. [8 marks] Describe the 4 stages of an action potential by inspecting the images below and filling in the corresponding chart:
LEGEND:
- Sodium (Na+
channels = yellow
- Potassium (K+
channels = pink
- Sodium-potassium (Na+K+) pumps = green
- Sodium ions = beige balls
- Potassium ions = red balls (with stars)
- The cytoplasm above the

b. [1 mark] Multiple-choice – Which of the following is TRUE regarding hyperpolarization?
i. It prevents an action potential from moving backwards
ii. It creates a refractory period
iii. It occurs immediately after repolarization
iv. All of the above

c. [1 mark] Multiple-choice – Which of the following is TRUE regarding repolarization?
i. The inside of the axon is negative while the outside is positive
ii. The sodium channels are open
iii. The voltage is below -70 mV
iv. The sodium-potassium pump is on

Questions:

d. [1 mark] Multiple-choice – Which is TRUE regarding the direction that an action potential travels down a multipolar neuron?
i. It is present in the dendrites before the axon
ii. It is present in the cell body followed by the axon hillock
iii. It is present in the axon before the axon terminal
iv. All of the above

e. [3 marks] The action potential travelling from Jay’s thumb to his spine is able to travel extremely quickly even though the neuron itself is extremely long (almost 1 meter). IN YOUR OWN WORDS, explain the structural features of a neuron that allow it to send impulses quickly. [TIP: For full marks, you need to incorporate 3 relevant terms.]

3. Jay’s thumb (and pride) has taken a hit, but he’s determined not to let this small incident impact his day. At his next construction location, he climbs up a ladder to inspect the roofing. No sooner does he peek over the side of the roof, when a piece of debris slides directly for his head. In a moment of reflex, he moves his head out of the way, but as he does, he falls off the ladder!

a. [2 marks] Describe a reflex by indicating if the following statements are TRUE or FALSE.
i. _____ Reflexes occur quickly because interneurons are only present in the spine
ii. _____ Reflexes are controlled by part of the somatic nervous system
b. [3 marks] Several structures are working to protect Jay’s body during a fall of this magnitude. Describe these structures by indicating if the following statements are TRUE or FALSE:
i. _____ The cranium is a bone that protects the spinal cord
ii. _____ CSF is a fluid made by ependymal cells that cushions the CNS
iii. _____ In order from superficial to deep, the meninges are the dura
mater, arachnoid mater and pia mater.

4. Unfortunately the fall knocks Jay unconscious and first responders arrive to take Jay to the hospital for emergency treatment for possible head or back injuries. To do this, a magnetic resonance imaging (MRI) scan is used to capture detailed images of his brain and spine.

a. [2 marks] MRI’s can detect gray matter and white matter in the central nervous system. Compare and contrast the neuron structures within gray and white matter by filling in the chart below:
b. [3 marks] Observe the cross-section of spinal cord tissue and fill in the chart with the correct letter labels.
c. [1 mark] TRUE or FALSE – In both the brain and the spine, white matter is more superficial than gray matter.

5. In the recovery room, the neurologist on-call explains to Jay the good news and the bad news. The good news:
Jay didn’t suffer any brain or spine injuries during the fall off the ladder. The bad news: the MRI revealed an undiagnosed tumour in his brain that would require immediate treatment (see image). The doctor asks if he has experienced any odd or unusual symptoms in the last few months. Jay mentions that he had been suffering a lot of headaches, but that he assumed that was due to stress. He also mentioned that his vision had been blurry from time to time but that he thought that was just due to a much needed optometry appointment.
a. [1 mark] Multiple Choice - Based on the image and the information provided, what part of Jay’s cerebrum is likely affected?
i. Occipital lobe
ii. Temporal lobe
iii. Frontal lobe
iv. Parietal lobe
b. [1 mark] Multiple Choice – If Jay’s ability to hear and comprehend speech
becomes affected as well, where might the tumour have spread to?
i. Occipital lobe
ii. Temporal lobe
iii. Frontal lobe
iv. Parietal lobe

6. [7 marks] Luckily, the neurologist is sure that the tumour is not present in Jay’s diencephalon, brainstem, or cerebellum. 
b. [1 mark] Which of the parts (1-9) in the chart above are considered to be part of the brainstem? ______________________________________

7. After further tests, a biopsy is completed where a small piece of the tumour is removed for further study. Using this information the neurologist is able to give Jay a better diagnosis about the tumour. Specifically, she mentions that it is a glioma, i.e. cancer of the glial cells.
a. [1 mark] Multiple Choice – Which of the following is TRUE regarding glial cells?
i. They are cells that conduct action potentials
ii. They nourish and protect neurons
iii. There are fewer glial cells than neurons within the brain
iv. They contain axons
b. [2 marks] Describe the 4 different types of glial cells found within the CNS by filling in the chart below:
c. [2 marks] Within the PNS, ___________________ have a similar function to astrocytes and ___________________ have a similar function to
oligodendrocytes.