Question 1

Which of the following best describes the three main steps of nervous system function?

Accepted Answer

1. The PNS receives stimuli and transmits messages to the CNS, 2. The CNS processes information and determines response, 3. The CNS issues commands to muscle and gland cells.

Question 2

Which of the following is NOT a function of astrocytes in the central nervous system?

Accepted Answer

Forming the myelin sheath around axons

Question 3

A patient presents with symptoms of muscle weakness and loss of coordination. MRI reveals demyelination in the CNS. Which disease is most likely?

Accepted Answer

Multiple sclerosis

Question 4

Which of the following best explains why the resting membrane potential (RMP) of a neuron is typically around $$-70\ \mathrm{mV}$$?

Accepted Answer

The membrane is more permeable to $$\mathrm{K}^+$$, which leaks out, leaving the inside more negative, and the sodium-potassium pump maintains the gradient.

Question 5

Which of the following is TRUE regarding the difference between myelinated and unmyelinated axons in the PNS?

Accepted Answer

Myelinated axons are wrapped by Schwann cells in a spiral fashion, while unmyelinated axons are held in surface grooves of Schwann cells.

Question 6

A neuron receives two simultaneous excitatory postsynaptic potentials (EPSPs) from different presynaptic neurons. This is an example of:

Accepted Answer

Spatial summation

Question 7

Which of the following best describes the 'all-or-none law' of action potentials?

Accepted Answer

If threshold is reached, the neuron fires at maximum voltage; if not, it does not fire at all.

Question 8

Which of the following is a correct sequence of events during an excitatory cholinergic synapse?

Accepted Answer

Action potential opens voltage-gated $$\mathrm{Ca}^{2+}$$ channels, $$\mathrm{Ca}^{2+}$$ triggers exocytosis of ACh, ACh binds to ligand-gated ion channels, $$\mathrm{Na}^+$$ enters postsynaptic cell.

Question 9

Which of the following is a function of the sodium-potassium pump ($$\mathrm{Na}^+/\mathrm{K}^+-$$ATPase) in neurons?

Accepted Answer

It moves $$3\ \mathrm{Na}^+$$ out and $$2\ \mathrm{K}^+ in$$, maintaining the concentration gradients and contributing to the RMP.

Question 10

A patient is unable to form new long-term memories but can recall old memories and hold a conversation. Which brain process is most likely impaired?

Accepted Answer

Synaptic plasticity and long-term potentiation

Question 11

Which of the following best describes the role of microglia in the central nervous system?

Accepted Answer

They act as macrophages, engulfing debris and providing defense against pathogens.

Question 12

Which of the following is a characteristic of an action potential but NOT a local potential?

Accepted Answer

It is nondecremental and irreversible.

Question 13

Which of the following is TRUE about the difference between the sympathetic and parasympathetic divisions of the autonomic nervous system?

Accepted Answer

The sympathetic division prepares the body for action, while the parasympathetic division has a calming effect.

Question 14

Which of the following best explains why damaged axons in the peripheral nervous system can regenerate, but those in the central nervous system usually cannot?

Accepted Answer

Schwann cells in the PNS form a regeneration tube, while oligodendrocytes in the CNS do not.

Question 15

Which of the following is a correct example of a neurotransmitter and its effect?

Accepted Answer

GABA produces inhibitory postsynaptic potentials (IPSPs) by allowing $$\mathrm{Cl}^- to $$enter the postsynaptic cell.

Question 16

Which of the following best describes saltatory conduction in myelinated axons?

Accepted Answer

Action potentials are generated only at the nodes of Ranvier, appearing to 'jump' from node to node.

Question 17

Which of the following is a real-life example of neural coding for stimulus intensity?

Accepted Answer

A loud sound causes auditory neurons to fire action potentials at a higher frequency than a soft sound.

Question 18

Which of the following is a correct pairing of a glial cell and its function in the peripheral nervous system?

Accepted Answer

Schwann cell—forms myelin sheath and assists in regeneration of damaged fibers

Question 19

Which of the following best describes the process of presynaptic inhibition?

Accepted Answer

One presynaptic neuron suppresses another by releasing GABA, which prevents voltage-gated $$\mathrm{Ca}^{2+}$$ channels from opening.

Nervous Tissue: Structure, Function, and Integration CH12

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