Chapter 10: Sensory Systems Quiz

Odorant molecules must be dissolved in mucus in order to bind to olfactory receptors. This is because olfactory receptors are located on the cilia of olfactory sensory neurons, which are surrounded by a layer of mucus. The mucus acts as a medium for the odorant molecules to dissolve in, allowing them to interact with the receptors and trigger a signal to the brain, resulting in the perception of smell. Without being dissolved in mucus, the odorant molecules would not be able to effectively bind to the receptors and stimulate the olfactory system.

Phasic receptors are sensory receptors that rapidly adapt to a constant stimulus. This means that they quickly stop responding to a continuous or prolonged stimulus, allowing them to focus on detecting changes or new stimuli in the environment. This adaptation helps prevent sensory overload and allows the body to prioritize detecting important or novel information.

Rods and cones are two types of photoreceptor cells in the retina of the eye. They differ in the type of opsin they contain. Opsin is a protein that is responsible for capturing light and initiating the process of vision. Rods contain a type of opsin called rhodopsin, which is responsible for vision in low light conditions and the perception of black and white. Cones, on the other hand, contain three different types of opsins, known as red, green, and blue opsins, which are responsible for color vision and visual acuity in bright light conditions.

The pitch of sound refers to how high or low a sound is perceived to be. The frequency of a sound wave determines its pitch. Higher frequency waves have a higher pitch, while lower frequency waves have a lower pitch. Therefore, the statement that the pitch of sound vibration reflects its frequency is correct.

Taste receptor cells do not respond to only one of the four primary tastes. Instead, each taste receptor cell is capable of responding to multiple tastes. This is because taste perception is a complex process that involves the activation of different combinations of taste receptors in response to different stimuli. Therefore, the statement that a taste receptor cell responds to only one of the four primary tastes is false.

Transduction refers to the process by which a receptor converts a stimulus, such as light or sound, into an electrical signal that can be transmitted to the brain. This electrical signal is then interpreted by the brain, allowing us to perceive and respond to the stimulus. Conduction, convection, modulation, and propagation are not directly related to the conversion of a stimulus into an electrical signal, making them incorrect choices.

The ability to perceive different frequencies in sound vibrations is based on the fact that different areas of the basilar membrane resonate at different frequencies such that a sound of a particular frequency causes only a certain region of the membrane to vibrate. This means that when sound waves enter the ear, they cause specific regions of the basilar membrane to vibrate based on their frequency. The hair cells located in these specific regions are then stimulated, sending signals to the brain that are interpreted as different frequencies of sound.

The stereocilia for hearing are exposed to endolymph in the cochlear duct. Endolymph is the fluid that fills the cochlea, which is the part of the inner ear responsible for hearing. The stereocilia are tiny hair-like structures located on the sensory cells in the cochlea. When sound waves enter the cochlea, they cause the fluid in the cochlear duct to move, which in turn causes the stereocilia to bend. This bending of the stereocilia triggers the sensory cells to send electrical signals to the brain, allowing us to perceive sound.

Touch information detected on the left side of the body is transmitted to the brain through the dorsal columns on the left side of the spinal cord. The spinal cord is responsible for relaying sensory information from the body to the brain. In this case, since the touch is detected on the left side, the sensory information is transmitted through the corresponding left dorsal columns of the spinal cord.

The ganglion cells are the first neurons in the visual pathway that generate action potentials. These cells receive input from bipolar cells, which in turn receive input from photoreceptors. The ganglion cells transmit the processed visual information from the retina to the brain via their axons, forming the optic nerve. Therefore, they play a crucial role in the transmission of visual signals from the eye to the brain.

A single ganglion cell can be excited or inhibited by light applied to its visual field. The response of a ganglion cell depends on the type of photoreceptors that are stimulated in its receptive field. Some ganglion cells are excited by light, while others are inhibited. Therefore, the statement that a single ganglion cell will either be excited or inhibited by light applied to its visual field is false.

Receptors are most sensitive to energy from the adequate stimulus. This means that receptors are designed to respond most effectively to a specific type or range of stimuli. The term "adequate" refers to the stimulus that is best suited for activating a particular receptor. Therefore, the correct answer is "adequate."

Hair cells in the cochlea are responsible for detecting sound vibrations and converting them into electrical signals that can be interpreted by the brain. Each hair cell is specialized to respond to a specific frequency of sound, meaning that different hair cells are excited by different frequencies. Therefore, it is true that a hair cell in the cochlea can be excited by sounds of different frequencies.

Thermoreceptors are sensory receptors that detect changes in temperature. They are responsible for sensing both warm and cold stimuli. Therefore, the two types of thermoreceptors are warm thermoreceptors, which detect warm stimuli, and cold thermoreceptors, which detect cold stimuli.

Accommodation refers to the process by which the lens of the eye adjusts its shape in order to focus on objects at different distances. When focusing on close-up objects, the lens becomes stronger, or more curved, allowing for clearer vision at close range. This adjustment in lens shape is known as accommodation.

Rotation of the head stimulates certain receptors in the vestibular system but not those in the visual system. This best illustrates the concept of an adequate stimulus because the vestibular system is specifically designed to detect changes in head position and movement, while the visual system is designed to detect light and visual stimuli. The rotation of the head is the appropriate and specific stimulus for the receptors in the vestibular system, making it an adequate stimulus for those receptors.

The parasympathetic nervous system is responsible for controlling various involuntary functions of the body. In the case of the eye, it causes the contraction of the ciliary muscle. This muscle is located in the eye and is responsible for changing the shape of the lens to allow for proper focusing on near objects. Therefore, when the parasympathetic nervous system is activated, it leads to the contraction of the ciliary muscle.

The question asks for the three types of nociceptors, which are sensory receptors that respond to potentially damaging stimuli. The correct answer is "mechanical, thermal, and polymodal." Mechanical nociceptors respond to mechanical stimuli such as pressure or stretching, thermal nociceptors respond to temperature extremes, and polymodal nociceptors respond to a combination of mechanical, thermal, and chemical stimuli.