Question 1

Fiber pathways carrying information about touch cross the midline in the

Accepted Answer

The pathway for touch sensation involves the ascending sensory fibers crossing over to the opposite side of the body at the level of the medulla oblongata. Therefore, the correct choice is B) medulla.

Question 2

Deja is doing a class activity called the two-point discrimination test. Assuming she has no injuries, which part of her body should be the most sensitive?

Accepted Answer

The lips are one of the most sensitive areas of the body with a high level of tactile acuity. They are able to detect fine differences in touch and pressure, making them the most appropriate area for the two-point discrimination test.

Question 3

Meissner's corpuscles, Pacinian corpuscles, Merkel's disks, and Ruffini's endings are served by _________ fibers.

Accepted Answer

Meissner's corpuscles, Pacinian corpuscles, Merkel's disks, and Ruffini's endings are served by Alpha-beta (Aβ) fibers, which are responsible for transmitting touch and pressure signals.

Question 4

Danielle began taking violin lessons when she was only four years old, and she spends many hours practicing each week. When she volunteered to participate in an imaging study at her university, the researchers noticed that

Accepted Answer

The fact that Danielle began taking violin lessons at a young age and spends many hours practicing each week suggests that she is likely to have a larger area of her somatosensory cortex devoted to her fingers. This is because the somatosensory cortex is responsible for processing information about touch and sensation in different parts of the body, and extensive use of the fingers would cause the corresponding area of the somatosensory cortex to become larger.

Question 5

Which of the following mechanoreceptors have large receptive fields?

Accepted Answer

Pacinian corpuscles and Ruffini's endings have large receptive fields, allowing them to detect changes and stimuli over a broader area of skin compared to Meissner's corpuscles and Merkel's disks, which have smaller receptive fields and are more sensitive to fine details.

Question 6

Christopher's grandfather was diagnosed recently with shingles. Based on what he had learned in his biological psychology class, Christopher knew that his grandfather would experience unpleasant skin eruptions in

Accepted Answer

Shingles typically affects a single dermatome, which is an area of skin supplied by a single spinal nerve, leading to a localized rash on one side of the body.

Question 7

Input from mechanoreceptors travels to

Accepted Answer

Input from mechanoreceptors is processed through the ventral posterior (VP) nucleus of the thalamus before it reaches the somatosensory cortex.

Question 8

C fibers carry information about

Accepted Answer

C fibers carry information about pain and temperature.

Question 9

Ellie can't feel the bracelet on her arm unless she shakes her arm and the bracelet moves. This indicates that _____ are the somatosensory receptors mediating her awareness of her jewelry.

Accepted Answer

Meissner's corpuscles are specialized for detecting light touch and changes in texture, which would be stimulated when the bracelet moves on Ellie's arm.

Question 10

Which of the following is the outer layer of skin, which is actually composed of dead cells?

Accepted Answer

The epidermis is the outermost layer of skin and is composed of dead skin cells. The other options, glabrous tissue, dermis, and subcutaneous tissue, are all located beneath the epidermis.

Question 11

Primary somatosensory cortex is located in the _________ lobe.

Accepted Answer

The primary somatosensory cortex is located in the parietal lobe, specifically in the postcentral gyrus.

Question 12

A dermatome is an area of skin

Accepted Answer

A dermatome is an area of skin that is supplied by sensory nerves that originate from a single spinal nerve root, specifically the dorsal roots. The other choices do not accurately describe a dermatome.

Question 13

Sensations from the mechanoreceptors in the skin of the face, mouth, tongue, and the dura mater of the brain travels centrally along branches of

Accepted Answer

Sensations from the mechanoreceptors in the skin of the face, mouth, tongue, and the dura mater of the brain are primarily carried centrally by cranial nerve V (trigeminal nerve). The medial lemniscus and dorsal column pathways primarily transmit sensations related to touch, position, and vibration from the limbs and trunk, and cranial nerve VIII (vestibulocochlear nerve) carries signals related to hearing and balance.

Question 14

Anna and Jean are having a discussion in class about touch and representation of various body parts in the primary somatosensory cortex. They decided that the ____ would have the largest representation.

Accepted Answer

The thumb has the most representation in the primary somatosensory cortex compared to any other body part. This is due to the fact that the thumb is crucial for fine motor movements and grasping objects, which requires a high level of sensory feedback.

Question 15

Professor Stover is lecturing about touch and tells the class that the dorsal column nuclei can be found in the

Accepted Answer

The dorsal column nuclei are located in the medulla, which is part of the brainstem. They receive input from touch receptors in the skin via the dorsal columns of the spinal cord and are involved in relaying this information to the somatosensory cortex in the parietal lobe.

Question 16

Fibers from the mechanoreceptors make their first synapses in the

Accepted Answer

Fibers from the mechanoreceptors first synapse in the dorsal column nuclei of the medulla. From there, the information is relayed to the thalamus and then to the primary somatosensory cortex. The dorsal root ganglia are where the cell bodies of sensory neurons are located, but they do not contain synapses. The VP nucleus of the thalamus is involved in processing visual information, not somatosensory information.

Question 17

David lost a foot when an explosive detonated under his Humvee during an army convoy mission in Iraq. While recovering in a hospital, David's physician warned him that he might experience "phantom pain." This means that David may

Accepted Answer

Phantom pain is the sensation of pain that seems to originate from a limb or body part that is no longer there. In this case, David may experience pain as if it is coming from his missing foot. The other options are not consistent with the definition of phantom pain.

Question 18

Primary somatosensory cortex is located in

Accepted Answer

The primary somatosensory cortex is located in the postcentral gyrus of the parietal lobe. This is where sensory information from the skin, muscles, and joints is processed.

Question 19

Neglect syndrome typically results from damage to _________ somatosensory cortex in the _________ hemisphere.

Accepted Answer

The answer of  Neglect syndrome typically results from damage to...

Question 20

Which type of mechanoreceptor is encapsulated, adapts rapidly, has a small receptive field, and senses pressure?

Accepted Answer

Meissner's corpuscles are encapsulated, adapt rapidly, have a small receptive field, and sense pressure. Pacinian corpuscles also adapt rapidly and sense pressure, but they have a larger receptive field. Merkel's disks have a small receptive field and sense light touch, while Ruffini's endings have a large receptive field and sense stretch.

Quiz 7: Nonvisual Sensation and Perception