Phys Ch 10

Which of the following would be an adequate stimulus for a mechanoreceptor? ANSWER: oxygen pH cold temperature cell stretch photon of light

Which of the following would be an adequate stimulus for a chemoreceptor? ANSWER: photon of light vibration cold temperature cell stretch oxygen

Identify the FALSE statement regarding sensory receptor cells. ANSWER: -A graded potential is referred to as a receptor potential. -Each type of sensory receptor responds only to the stimulus that defines the receptor. -Sensory transduction converts stimulus energy into a receptor potential. -Threshold is the minimal stimulus intensity required to generate an action potential. -Many sensory receptor cells are NOT nerve cells.

A graded change in membrane potential within a sensory receptor cell is always called a(n) ANSWER: hyperpolarization. depolarization. action potential. receptor potential.

Opening a Na+ channel in a non-neural sensory receptor cell would cause that cell to ANSWER: depolarize. decrease neurotransmitter release. hyperpolarize. generate an action potential.

With the exception of olfaction, all sensory pathways first travel to the ________, which acts as a relay and processing station. ANSWER: hypothalamus cerebellum thalamus medulla oblongata cerebrum

A receptor potential is ANSWER: -the resting membrane potential of a receptor cell. -a graded potential. -an action potential. -always converted to an action potential in sensory receptor cells.

The two-point discrimination test ANSWER: -provides a measure of receptive field size for touch receptors. -is used to test for hearing disorders. -provides information about olfactory receptors. -monitors the activity of taste buds. -is used to determine clarity of vision.

Convergence describes ANSWER: -how one primary sensory receptor neurons synapses with a secondary neuron. -the reason why receptive fields are so small. -how receptive fields can overlap with one another. -how multiple primary sensory neurons synapse on a single secondary neuron.

The larger the receptive field, the ANSWER: -more primary sensory neurons synapse on a secondary sensory neuron. -larger the area of the somatosensory cortex in the brain that perceives the sensation. -stronger the stimulus intensity required to activate a sensory receptor. -fewer primary sensory neurons are involved.

The perception threshold describes the ANSWER: -intensity of stimulus required to generate a receptor potential. -intensity of stimulus required to generate an action potential. -convergence of information from multiple primary sensory neuron onto a single secondary neuron. -concept that neurons higher in the sensory pathway can dampen the intensity of a stimulus.

A decrease in ones perception of a stimulus whose intensity has not changed due to higher neural inhibition is ANSWER: convergence. habituation. divergence. adaptation.

The intensity of a stimulus can be determined within the central nervous system by ANSWER: frequency coding only. labeled line coding and/or frequency coding. population coding and/or frequency coding. labeled line coding only. population coding only.

The modality of a stimulus can be determined within the central nervous system by ANSWER: lateral inhibition. frequency coding. adequate stimulus for the sensory receptor cell. population coding.

Tonic receptors ANSWER: -are quick to adapt to a particular stimulus intensity. -slowly decrease the frequency of action potentials generated to a constant stimulus. -are attune to changes in a parameter, not the extent of that change. -will always decrease to the point where no action potentials are generated.

Phasic receptors ANSWER: -slowly decrease the frequency of action potentials generated to a constant stimulus. -are quick to adapt to a particular stimulus intensity. -are attune to parameters that the body must continuously assess. -once threshold is reached by a stimulus will always generate action potentials.

Which of the following are responsible for a receptor adapting to a stimulus? ANSWER: -Na+ channel inactivation or K+ channel opening -K+ channel inactivation only -opening of Na+ channels only -opening of K+ channels only -Na+ channel inactivation only

Which of the following is NOT a somatosensory modality? ANSWER: vision touch proprioception temperature nociception

Which of the following statements regarding pathways for somatic perception projection is correct? ANSWER: -The synapse for the secondary to tertiary sensory neuron is within the medulla. -Primary sensory neurons that respond to cold sensation project to the same region of the somatosensory cortex. -The tertiary sensory neurons cross-over the body's midline. -Primary sensory neurons from the hands project to a specific region of the somatosensory cortex. -The longest of the secondary sensory neurons transmit fine touch and proprioceptive information

The tactile receptor whose nerve endings are surrounded by concentric connective tissue layers is the ANSWER: Pacinian corpuscle. Meissner's corpuscle. root hair plexus. Merkel disc. Ruffini corpuscle.

Sensory receptors that respond when body temperature is below normal are called ANSWER: -photoreceptors. -cold receptors. -warm receptors. -All receptors respond to temperatures above and below body temperature (no unique name).

Nociceptors are responsible for the perception of ANSWER: itch only. pain and itch. pain only. pain and skin stretch. skin stretch only.

Sharp, localized (fast) pain is rapidly transmitted to the central nervous system along ANSWER: large, myelinated A-beta fibers. small, unmyelinated C fibers. small, myelinated A-delta fibers. large, unmyelinated C fibers.

Visceral pain is poorly localized and can be perceived to originate from a region of the body that is different from it's actual location; this is called ANSWER: analgesia. latency. tonic reception. referred pain. adaptation.

Chronic pain is ANSWER: -only the result of short-term changes in the nervous system. -only treated by analgesic drugs. -only pathological. -pathological and treated by analgesic drugs.

Chemicals such as histamine, prostaglandins, serotonin, and substance P ANSWER: sensitize, activate and inhibit nociceptors. only activate nociceptors. only inhibit nociceptors. only sensitize and activate nociceptors. only sensitize nociceptors.

In addition to temperature, cold receptors respond to ANSWER: water. menthol. capsaicin. alcohol.

The gate control theory of pain modulation states that pain transmission can be blocked by ANSWER: -tonic activity of the inhibitory neurons in the dorsal horn. -mechanical stimulation of A-beta fibers. -stimulation of C-fibers. -cold stimulation of the A-delta fibers.

Beta-endorphin is produced from the same prohormone as ANSWER: aldosterone. glucagon. insulin. adrenocorticotropin (ACTH). thyroxine.

Neuronal cells that are short-lived and therefore are frequently replaced are ANSWER: Pacinian corpuscles. retinal cells. olfactory receptors. gustatory receptors. nociceptors.

When Golf is activated, which of the following steps in the olfactory cells contribute to their depolarization? ANSWER: -increases in adenylate cyclase activity, cAMP concentrations and closure of cAMP gated cation channels -increases in adenylate cyclase only -increases in the closure of cAMP gated cation channels only -increases in cAMP concentrations only -increases in adenylate cyclase activity and cAMP concentrations

Gustatory cells that respond to sour via release of serotonin are called ANSWER: type I taste cells. type II taste cells. type III taste cells. basal taste cells.

Gustatory cells that respond to sweet, bitter or umami are called ANSWER: type I cells. type II cells. type III cells. type IV cells.

________ is released from type II cells to stimulate primary gustatory neurons. ANSWER: Gustducin Acetylcholine Serotonin Glutamine ATP

Umami is ANSWER: -a taste receptor cell activated by glutamate and nucleotides. -another name for salty taste. -the name of the ion channel activated by glutamate. -a flavor enhancer that is part of olfaction.

Signal transduction in the type II taste cells relies on the G protein ANSWER: Golf. gustducin. Ggus. transducin.

There are ________ primary taste (gustation) sensations. ANSWER: 20 400 2 4 5

The loudness or intensity of a sound wave is related to its ANSWER: pitch. frequency. amplitude. duration.

The pitch of a sound wave is related to its ANSWER: amplitude. decibels. frequency. duration.

The primary purpose of the middle ear bony structures (maleus, incus and stapes) is to ANSWER: -transmit otitis media to the cochlea. -transduce the sound waves into vibration. -dampen the vibration as it conducts to the cochlea. -equalize pressure in the middle ear. -amplify the vibration as it conducts to the cochlea.

The ion channels that transduce the vibration of the cochlea into receptor potentials are located on the ANSWER: tectorial membrane. basilar membrane. helicotrema. stereocilia. cochlear duct.

The external auditory canal ends at the ANSWER: cochlear oval window. malleus. vestibule. tympanic membrane. pinna.

The bones within the middle ear connect the ANSWER: cochlea to the oval window. oval window to the round window. tympanic membrane to the round window. tympanic membrane to the oval window. cochlea to the tympanic membrane.

Sound waves are converted into mechanical movements (vibrations) by the ANSWER: round window. oval window. tympanic membrane. cochlea. malleus.

A structure that allows the middle ear to communicate with the nasopharynx is the ANSWER: eustachian tube. auditory meatus. pinna. bony labyrinth. membranous labyrinth.

The structure that overlies the organ of Corti and is attached to the tips of the hair cells is the ANSWER: stapedius. basilar membrane. perilymph. endolymph. tectorial membrane.

The structure that separates the cochlear duct from the tympanic duct is the ANSWER: basilar membrane. tectorial membrane. membranous labyrinth. stapedius. bony labyrinth.

The highest frequency sound is detected by ANSWER: -the frequency at which the stereocilia vibrate. -hair cells located near the oval window end of the basilar membrane. -hair cells located near the helicotrema end of the basilar membrane. -unique hair cells located anywhere along the basilar membrane. -hair cells located near the middle of the basilar membrane.

Louder noises result in action potentials in the sensory neuron that are ANSWER: less frequent. taller. broader. shorter. more frequent.

The receptors of equilibrium and hearing are the ANSWER: utricles. hair cells. ampullae. supporting cells. saccules.