Neurons and Immune practice questions

Which of the following will happen at a chemical synapse?

A neurotransmitter will be released into the synaptic cleft

Multiple sclerosis (MS) is a disease where the immune system attacks and destroys the myelin sheath on neurons. What is a consequence of MS?

A significant reduction in action potential speed

In the immune system, clonal selection is associated with which of the following processes?

An Ig gene undergoes gene segment rearrangement of its V, J, and C segments

Helper T-cells recognize class II MHC proteins on antigen-presenting cells. This means they:

Are involved in enhacing the immune response

What is one major difference between Class I and II MHC receptors?

Class II are only found on immune system cells

At a neuromuscular junction, what process releases neurotrasnmitter into the synaptic cleft?

Exocytosis

Which of the following is a characteristic of an electrical synapse?

Gap junction

To prevent neurotransmitters from re-activating a post-synaptic neuron:

Glial cells take up the neurotransmitter and neurotransmitter release is in a positive feedback loop

Thinking about weak vs strong stimuli, a weak stimulus would cause a neuron to

Have a subthreshold change in the membrane potential

Antigens are recognized by lymphocytes and they come from all of the following except:

Healthy body cells

Secreted antibodies are _____ and they are secreted by _______

Immunoglobulins and B- cells (plasma cells)

How does a sodium potassium pump affect membrane potential?

It pumps sodium ions out of the cell and potassium ions into the cell

Once a splinter punctures the skin, what will happen first?

Mast cells will release histamine

Botox is derived from botulinum toxin A, a neurotoxin that prevents synaptic vesicles from fusing with the cell membrane at neuromuscular junctions. What is a consequence of this?

Neurotrasmitter is not released into the synaptic cleft and no signal is received in the postsynaptic cell

To hyperpolarize a membrane, a neuron can:

Open potassium channels

When a neuron is at rest, what establishes the concentration of Potassium inside the cell?

The Na+/K+ pump

What part of a neuron functions as the integrating center, where the membrane potential reflects the summed effect of all excitatory and inhibitory signals?

The axon hillock

B-cells are lymphocytes that mature in:

The bone marrow

Given two neurons that each connect an interneuron in the spinal cord to a motor neuron, which will transmit the signal to contract the muscle faster?

The myelinated neuron

If a sensory neuron had a very small dendritic field, you would expect

The neuron to only be receptive to signals from a very specific location

Cyanide reduces ATP production in neurons. This will result in

The resting potential of the neuron will get closer to 0

All antigen receptors on a single B-cell or T-cell recognize

The same epitope

You and your friend were exposed to the flu virus on the same day, but over the next few days, only your friend acquired flu-like symptoms and was ill for almost a week before recovering. Which one of the following is a logical explanation for this?

You had an immunological memory of that virus

Cone snails produce conotoxins, some of which block voltage-gated sodium channels. What would be an immediate conequence to you if you were exposed to a cone snail harpoon?

Your neurons wouldn't be able to trigger action potentials

Which of the following is expected in a neuron that is receiving input through tens of thousands of synapses?

highly branched dendrites

A boy falls while riding his bike. A scrape on his hand almost immediately begins to bleed and becomes red, warm, and swollen. Which type of response is most consistent with these symptoms?

inflammatory response

Why do Na+ ions enter the cell when voltage-gated Na+ channels are opened in neurons?

the Na+ concentration is much higher outside the cell than it is inside, and the Na+ ions are attracted to the negatively charged interior

Which of the following components of the immune system is most likely to be the same in identical twins?

the kinds of major histocompatibility (MHC) molecules produced

Benadryl is an antihistamine. Which of the following is most likely to occur if a person that was stung by a bee takes Benadryl?

the site of injury will become less red and swollen

Which of the following best explains why a bone marrow transplant may not be appropriate from a given donor to a given recipient even though they are compatible for blood transfusions?

their blood-types may match but major histocompatibility (MHC) proteins may not be a match

Vaccination offers protection against future exposure to pathogens because it ________.

triggers clonal expansion of lymphocytes

Which of the following would most likely occur if you experimentally depolarize the middle of an axon to threshold using an electronic probe?

two action potentials will be initiated and will proceed in opposite directions