Exam 43: Sensory Systems

Peripheral shadows or flashes of light can be a sign that the retina is peeling away from the layer below.Why is detachment of the retina a medical emergency?

The discovery that ATP is a pain-signaling factor immediately suggested what possible therapeutic approach to alleviate chronic pain?

The simplest sensory receptors are ________ that respond to mechanical distortion,changes in temperature,or specific chemicals.

In 1908,chemist Kikunae Ikeda identified a new taste modality he called "umami",or "delicious" in Japanese.It gives a savory flavor to meat,seaweed,and tomatoes.What molecule is responsible for umami?

What are the sensory structures that enable invertebrates to determine the orientation of the body with respect to gravity called?

All sensory input arrives at the central nervous system in the same form,as ________ propagated by afferent neurons.Perception of the type and intensity of a stimulus depends on which part of the brain the impulse projects to and the firing frequency of the sensory neuron.

Unlike sweet,salty,sour,or umami,the "bitter" category of tastants includes wide structural variety of detected molecules.Multiple receptors are required to sense the different bitter tastants.What do they have in common? Bitter taste is thought to have evolved as a warning system for toxic compounds. -The bitter receptor hTAS2R38 is activated by glucosinolates found in plants such as turnips and broccoli.Glucosinolates can block synthesis and transport of iodine.Before the advent of iodized salt,this was a particular problem in areas of the world that are naturally low in iodine.Why might the human population include different variants of the hTAS2R38 gene?

Beta-N-Methylamino-L-Alanine,or BMAA,is a glutamate receptor agonist produced by cyanobacteria.Since Glu is an excitatory neurotransmitter,it is not surprising that BMAA is associated with neurological damage.Buildup of BMAA in fruit bats was hypothesized to cause neurodegenerative disease in islanders that fed on the bats.A recent study found high levels of BMAA in sharks,suggesting that consumption of shark fin soup is also dangerous.The researchers suggested that a secondary effect of BMAA may actually make these hazardous foods surprisingly desirable.What might this be?

When membrane proteins on an olfactory neuron are stimulated by the binding of a specific chemical,what is the immediate result?

Cutaneous receptors are classified as interoceptors.These specialized skin receptors can respond to which of the following stimuli?

What is the photopigment in rod cells called?

In "The Disembodied Lady," neurologist Oliver Sacks tells the story of a patient who suffered a catastrophic loss of sensory function.She said,"I feel my body is blind and deaf to itself....It has no sense of itself." The patient's nerve damage was strikingly specific.What single type of neuron most likely suffered damage?

Mutations in the DFNA20/26 locus,which codes for the actin gamma 1 protein,are associated with congenital deafness.An irate senator complains that government money is being wasted on studies of this mutant gene -- in yeast! "I am no biologist," says the senator,"but I am pretty sure yeast don't have ears." How do you respond?

Which animal became numerous and widespread by using sonar to enable a high level of activity in the dark?

You make a knockout of a gene involved in neurological development,and find that the mice have malformed semicircular canals.Instead of being orthogonal (at right angles)to each other,they are parallel.What aberrant behavior might you see in these mice?

Which is NOT a stimulus that interoceptors can sense?

Humans are unique among animals due to our highly-evolved repertoire of sensory receptors.

Color blindness is caused by heritable mutations in cone photoreceptors.How many cone types does the retina of a colorblind individual typically contain?

Which sequence of events is required for the brain to interpret sound? I.Vibration of the basilar membrane relative to the tectorial membrane causes cilia on hair cells to bend and triggers depolarization. II)Hair cells stimulate the production of action potentials in sensory neurons that project to the brain. III)Ganglion cell axons transmit action potentials to the occipital lobe.

What is the most likely hypothesis for the presence of TRP channel agonists in plants?