Question 1

The musculocutaneous nerve is a major nerve of the brachial plexus.

Accepted Answer

The musculocutaneous nerve is one of the five major nerves that originate from the brachial plexus.

Question 2

Vitamin A needed by the photoreceptor cells is stored by the cells of the retina pigmented layer.

Accepted Answer

False

Question 3

The neural layer of the retina prevents excessive scattering of light within the eye.

Accepted Answer

The neural layer of the retina is responsible for processing visual information and sending it to the brain, not for preventing excessive scattering of light; that function is primarily attributed to other structures like the pigmented layer of the retina.

Question 4

The fluid contained within the membranous labyrinth is called perilymph.

Accepted Answer

The fluid contained within the membranous labyrinth is called endolymph, while perilymph is the fluid located in the space between the membranous labyrinth and the bony labyrinth.

Question 5

The meningeal branch of a spinal nerve actually reenters the vertebral canal to innervate the meninges and blood vessels.

Accepted Answer

This statement is true. The meningeal branch of a spinal nerve exits the intervertebral foramen with the spinal nerve, but then reenters the vertebral canal to innervate the meninges and blood vessels.

Question 6

The structure that allows equalization of the pressure in the middle ear with that outside the body is the external auditory meatus.

Accepted Answer

The structure that allows equalization of the pressure in the middle ear with that outside the body is the Eustachian tube, not the external auditory meatus.

Question 7

Precision of eye movement is due to the fact that extrinsic eye muscle motor units contain only8 to 12 muscle cells and in some cases as few as 2 or 3 muscle cells.

Accepted Answer

The statement is true. The small number of muscle cells in extrinsic eye muscle motor units allows for more precise control of eye movements.

Question 8

Irritation of the phrenic nerve may cause diaphragm spasms called hiccups.

Accepted Answer

When the phrenic nerve, which controls the diaphragm muscle, is irritated, it can cause the muscle to contract involuntarily, resulting in hiccups.

Question 9

Drooping of the upper eyelid, and double vision are potential symptoms of damage to the oculomotor nerve.

Accepted Answer

Damage to the oculomotor nerve can cause weakness or paralysis of the muscles that control movement of the eye, leading to symptoms such as drooping of the upper eyelid and double vision.

Question 10

Dorsal and ventral rami are similar in that they both contain sensory and motor fibers.

Accepted Answer

Both dorsal and ventral rami contain sensory and motor fibers. The dorsal rami supply the skin and muscles of the back, while the ventral rami supply the remaining muscles and skin of the trunk and limbs.

Question 11

Static equilibrium involves the sensation of linear acceleration as well as changes in head rotation.

Accepted Answer

Static equilibrium refers to the ability to maintain balance and stability when the body is at rest or standing still, without experiencing any linear or angular acceleration or changes in head rotation.

Question 12

The mucous membrane that lines the eyelids and is reflected over the anterior surface of the eyeball is the conjunctiva.

Accepted Answer

The conjunctiva is a thin, transparent mucous membrane that lines the eyelids and is reflected over the anterior surface of the eyeball.

Question 13

The bending of light rays is called reflection.

Accepted Answer

The bending of light rays is actually called refraction, not reflection. Reflection occurs when light bounces off a surface without bending.

Question 14

The optic disc is forms a blind spot where the optic nerve leaves the eyeball.

Accepted Answer

The optic disc is indeed the area of the retina where the optic nerve exits the eye, and it does not contain any photoreceptor cells, making it a blind spot in our visual field.

Question 15

The second cranial nerve forms a chiasma at the base of the brain for partial crossover of neural fibers.

Accepted Answer

The optic nerve (second cranial nerve) forms a chiasma at the base of the brain for partial crossover of neural fibers, which allows for visual information from each eye to be processed in both hemispheres of the brain. This is why the left hemisphere of the brain processes visual information from the right visual field and vice versa.

Question 16

Sour taste receptors are stimulated by hydrogen ions of acidic food substances.

Accepted Answer

Sour taste receptors are specifically designed to be stimulated by acidic substances, which release hydrogen ions that trigger the receptors.

Question 17

The anterior chamber of the eye is filled with vitreous humor.

Accepted Answer

The anterior chamber of the eye is actually filled with aqueous humor, while the vitreous humor fills the posterior chamber.

Question 18

Lamellar corpuscles can be exteroceptors, interoceptors, or proprioceptor.

Accepted Answer

Lamellar corpuscles are a type of mechanoreceptor and can function as exteroceptors, interoceptors, or proprioceptors depending on their location and function.

Question 19

Ciliary muscles are considered voluntary, skeletal muscle.

Accepted Answer

Ciliary muscles are involuntary smooth muscles, not voluntary skeletal muscles.

Question 20

Reciprocal inhibition means that while one sensory nerve is stimulated, another sensory neuron for synergistic muscles in the same area is inhibited and cannot respond.

Accepted Answer

Reciprocal inhibition refers to the process where the activation of a muscle leads to the inhibition of its antagonist muscle, not the inhibition of another sensory neuron for synergistic muscles.

Quiz 13: The Peripheral Nervous System and Reflex Activity