Question 1

Which of the following statements best describes the primary function of dendrites in a neuron?

Accepted Answer

To receive and integrate signals from other neurons to facilitate communication.

Question 2

Which structural class of neurons is the most common type in the human nervous system and is specialized for complex signal integration?

Accepted Answer

Multipolar neurons, which typically have one axon and multiple dendrites, facilitating complex signal integration.

Question 3

Which factor primarily contributes to the establishment of the resting membrane potential in living cells?

Accepted Answer

The selective permeability of the membrane to potassium ions.

Question 4

What is the primary purpose of voltage-gated ion channels in excitable cells?

Accepted Answer

To respond to changes in membrane potential, allowing selective ion flow that contributes to action potentials.

Question 5

Which neurotransmitter is primarily inhibitory, reducing neuronal excitability in the central nervous system?

Accepted Answer

GABA — primarily acts as an inhibitory neurotransmitter, reducing neuronal excitability.

Question 6

Which statement most accurately describes the process of synaptic transmission at chemical synapses?

Accepted Answer

Action potentials trigger the release of neurotransmitters, which bind to receptors on the postsynaptic membrane, leading to a rapid change in membrane potential.

Question 7

Which statement correctly distinguishes between phasic and tonic receptors, including an appropriate example?

Accepted Answer

Phasic receptors adapt quickly to stimuli and are best for detecting changes, such as feeling the weight of a backpack.

Question 8

Which statement about lateral inhibition is most accurate?

Accepted Answer

Lateral inhibition occurs when excited neurons inhibit their neighbors, sharpening sensory perception and contrast, such as in the visual system.

Question 9

How do we perceive different pitches and loudness of sound?

Accepted Answer

Pitch is determined by the frequency of sound waves, while loudness is related to the amplitude of those waves.

Question 10

Which statement about rods and cones in the retina is true?

Accepted Answer

Rods are more numerous in the retina and are responsible for detecting light in dim conditions.

Question 11

Which pair accurately identifies the types of signaling used by neurons to communicate with their targets in the nervous system?

Accepted Answer

Neurotransmitters — released from the presynaptic neuron to bind to receptors on the postsynaptic neuron or target cell.

Question 12

What is the role of tropomyosin in muscle contraction?

Accepted Answer

Tropomyosin shifts position on the actin filament in response to calcium binding to troponin, exposing myosin-binding sites.

Question 13

What would likely occur if tropomyosin were ineffective in its role during muscle contraction?

Accepted Answer

Binding sites on actin would remain exposed at all times, causing continuous and unregulated muscle contraction.

Question 14

A patient is experiencing muscle spasms due to continuous contraction. Which molecular malfunction is most likely responsible?

Accepted Answer

Defective tropomyosin that fails to cover myosin-binding sites on actin.

Question 15

Which equation best represents the Nernst potential for potassium ions ($$K^+) $$across a cell membrane?

Accepted Answer

$$E_{K^+} = \frac{RT}{zF} \ln \left( \frac{[K^+]_{out}}{[K^+]_{in}} \right)$$

Question 16

During an action potential, which ion's rapid influx is primarily responsible for the depolarization phase?

Accepted Answer

Sodium ($$Na^+)$$

Question 17

A patient with a genetic mutation affecting voltage-gated sodium channels would most likely experience which symptom?

Accepted Answer

Impaired ability to generate action potentials, leading to muscle weakness.

Question 18

Which formula describes the relationship between membrane potential ($$V_m$$), ion concentrations, and permeability according to the Goldman-Hodgkin-Katz equation?

Accepted Answer

$$V_m = \frac{RT}{F} \ln \left( \frac{P_{K^+}[K^+]_{out} + P_{Na^+}[Na^+]_{out} + P_{Cl^-}[Cl^-]_{in}}{P_{K^+}[K^+]_{in} + P_{Na^+}[Na^+]_{in} + P_{Cl^-}[Cl^-]_{out}} \right)$$

Nervous System and Muscle Physiology: Exam Review Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards