Question 1

____________________ is a feature of the axon that helps to determine the speed with which information is transmitted.

Accepted Answer

Axon diameter influences the speed of nerve impulse transmission, with larger diameters allowing for faster transmission due to lower resistance to the flow of ions.

Question 2

Which of the following statements is accurate?

Accepted Answer

Lateral inhibition enhances the contrast in the pattern of action potentials received by the central nervous system, effectively sharpening the perception of sensory input by inhibiting neurons at the periphery of a stimulated region. This mechanism allows for more precise localization and discrimination of sensory stimuli.

Question 3

Which of the following is NOT a function of glial cells?

Accepted Answer

Glial cells do not transmit electrical and chemical signals; this function is primarily performed by neurons. Glial cells support and protect neurons, among other roles.

Question 4

Adjusting to the texture and hardness of the seat you are sitting on, to the point of not paying conscious awareness to these sensations, is reflective of ________________.

Accepted Answer

Habituation is the process by which we become accustomed to a stimulus after repeated exposure, leading to a decrease in our response to that stimulus. In this case, getting used to the texture and hardness of a seat over time is an example of habituation, as we stop paying conscious attention to these sensations.

Question 5

The majority of receptors in the somatosensory system are ____________.

Accepted Answer

Mechanoreceptors are the most numerous type of receptors in the somatosensory system, responsible for detecting mechanical pressure or distortion. They play a key role in sensing touch, pressure, vibration, and proprioception.

Question 6

The process of corollary discharge, or the "previewing" of motor plans, primarily occurs in the _____________.

Accepted Answer

Corollary discharge involves the cerebellum, which helps in coordinating motor plans and predicting sensory outcomes of movements.

Question 7

_____________________ are the primary sources of proprioceptive sensation.

Accepted Answer

Muscle spindles are the primary sources of proprioceptive sensation because they sense changes in muscle length and contraction.

Question 8

Lesions to Brodmann's areas 5 and 7 may result in all of the following EXCEPT ___________.

Accepted Answer

Brodmann's areas 5 and 7 are part of the parietal lobe and are involved in integrating sensory information and in spatial perception. Lesions in these areas can lead to impaired stereognosis (the ability to perceive and recognize the form of an object in the absence of visual and auditory information), deficits in spatial perception, and impaired motor planning. However, loss of tactile acuity, which refers to the sharpness or clarity of touch, is more directly associated with damage to the primary somatosensory cortex (Brodmann areas 1, 2, and 3) rather than areas 5 and 7.

Question 9

All of the following are functions of the cerebellum EXCEPT _________.

Accepted Answer

The cerebellum is primarily involved in coordinating voluntary movements, balance, and posture, not in pain perception and localization. Pain perception is more closely associated with the cerebral cortex and thalamus.

Question 10

The ____________ system is the first sensory system to function in utero.

Accepted Answer

The tactile system is the first sensory system to develop and function in utero, as touch is one of the earliest senses to develop in the fetus.

Question 11

Our internal sense of self and the physiological condition of our body is referred to as ________________.

Accepted Answer

Interoception refers to the internal sense of the physiological condition of the body, including hunger, thirst, heart rate, and more, contributing to one's sense of self.

Question 12

Vestibular nuclei receive input from all of the following EXCEPT ______________.

Accepted Answer

The vestibular nuclei receive input from the vestibulocochlear nerve (CN VIII), the cerebellum, and the visual system to help coordinate balance and spatial orientation. They do not directly receive input from the thalamus; instead, they send projections to the thalamus.

Question 13

Integrity of the vestibular system is often tested clinically by examining ___________.

Accepted Answer

Post-rotary nystagmus is a reflexive eye movement that occurs after spinning. It is used to assess the integrity of the vestibular system, which is responsible for balance and spatial orientation.

Question 14

Discrimination of auditory pitch is possible because of ____________.

Accepted Answer

The basilar membrane within the cochlea of the inner ear has varying degrees of thickness and stiffness along its length, which allows it to respond differently to various frequencies of sound. This mechanical property is crucial for the discrimination of auditory pitch, as different parts of the basilar membrane vibrate in response to different frequencies.

Question 15

Information from both ears first converges at the ___________________________.

Accepted Answer

Information from both ears first converges at the Superior olive, which is part of the auditory pathway in the brainstem. This structure is crucial for localizing sound sources in the environment by comparing the timing and loudness differences of sounds arriving at each ear.

Question 16

Our enjoyment of eating, as well as our motivation to eat, are because of projections from the primary gustatory cortex to the ___________________ and _____________________.

Accepted Answer

The primary gustatory cortex projects to the hypothalamus and amygdala, which are crucial for linking the sensory experience of taste with our emotional response and motivation to eat.

Question 17

Sensory integration (SI) occurs only at the level of the cerebral cortex.

Accepted Answer

SI occurs at subcortical structures such as the tectum process and integrate SI.

Question 18

Active touch allows for better tactile discrimination than passive touch.

Accepted Answer

Active touch involves the movement of fingers or hands to explore objects, which enhances the sensory feedback and allows for better discrimination of textures, shapes, and other tactile properties compared to passive touch, where the object moves against the skin without active exploration.

Question 19

Deep touch pressure is a source of proprioception.

Accepted Answer

Inputs such as deep touch pressure and passive joint compression are not sources of proprioception; rather, they are tactile inputs.

Question 20

Cortical changes in the sensory homunculus (primary sensory cortex) are possible with intense use (or disuse) of certain body parts.

Accepted Answer

The sensory homunculus can undergo cortical reorganization, a process where the brain areas dedicated to processing sensory inputs from the body can change in response to increased or decreased use of certain body parts. This is a manifestation of the brain's plasticity.

Quiz 4: Structure and Function of the Sensory Systems