Question 1

Which of the following best describes the difference between graded potentials and action potentials in neurons?

Accepted Answer

Graded potentials decrease in amplitude as they spread, while action potentials maintain their amplitude due to the all-or-none principle.

Question 2

A patient presents with loss of sensation in the limbs but retains motor function. Which part of the spinal nerve is most likely damaged?

Accepted Answer

Dorsal root

Question 3

Which equation best represents the relationship between stimulus intensity and action potential frequency?

Accepted Answer

$$f = k \cdot I$$

Question 4

Which nerve plexus is primarily responsible for innervating the muscles of the upper limb?

Accepted Answer

Brachial plexus

Question 5

During the knee-jerk reflex, which mechanism ensures that the antagonist muscle relaxes while the agonist contracts?

Accepted Answer

Reciprocal inhibition

Question 6

Which structure develops from the metencephalon during embryonic brain development?

Accepted Answer

Cerebellum

Question 7

Cerebrospinal fluid (CSF) is secreted by which structure, and what is its primary function?

Accepted Answer

Secreted by the choroid plexus; cushions the brain and removes waste.

Question 8

Which brain region is primarily responsible for regulating heart rate and breathing?

Accepted Answer

Medulla oblongata

Question 9

A patient with damage to the hippocampus would most likely experience which deficit?

Accepted Answer

Impaired formation of new memories

Question 10

Which of the following best describes the function of the reticular formation?

Accepted Answer

Regulates arousal and consciousness

Question 11

During REM sleep, which physiological change occurs?

Accepted Answer

Muscle tone decreases and brain activity resembles wakefulness

Question 12

Which structure in the ear is responsible for amplifying sound vibrations from the tympanic membrane to the inner ear?

Accepted Answer

Ossicles

Question 13

How do hair cells in the cochlea convert mechanical vibrations into electrical signals?

Accepted Answer

By opening mechanically-gated ion channels, leading to graded potentials

Question 14

Which formula best describes the relationship between the frequency of a sound and its position on the basilar membrane?

Accepted Answer

$$x = \frac{c}{f}$$

Question 15

Which structure in the vestibular system detects linear acceleration and head position relative to gravity?

Accepted Answer

Maculae

Question 16

A person spins rapidly and then stops. Which structure in the inner ear is primarily responsible for detecting this spinning acceleration?

Accepted Answer

Crista ampullaris in the semicircular canals

Question 17

Which layer of the eyeball provides structural support and protection, and what tissue is it primarily composed of?

Accepted Answer

Fibrous layer; dense connective tissue

Question 18

Which structure in the eye is responsible for the highest visual acuity, and why?

Accepted Answer

Fovea; it has the highest concentration of cones

Question 19

Which equation best represents the relationship between the refractive power ($$P) of $$the eye and the focal length ($$f$$)?

Accepted Answer

$$P = \frac{1}{f}$$

Question 20

A patient is unable to distinguish colors but can see in dim light. Which photoreceptor is most likely functioning, and which is deficient?

Accepted Answer

Rods are functioning; cones are deficient

BIO 259 Exam 4 Study Guide: Nervous System, Special Senses, and Related Structures

Study Guide - Practice Questions