BIOL 3204 Exam 3

Why do you think the taste receptor cells in a taste bud are joined by tight junctions?

To force dissolved chemicals flowing into a taste pore to interact with the taste receptor cells.

The neurons of the special senses each carry information to cortexes in the brain that are specific to each sense. However, general sensation information is all carried to the...

somatosensory cortex

Which of the below is NOT a characteristic of olfaction that we discussed in class?

Olfaction is one of the three senses contributing to our sense of equilibrium.

A flexor muscles moves bones away from each other, while an extensor brings bones together.

False

Stretching a muscle spindle causes...

reflex contraction of that muscle.

Which is true for a somatic motor neuron action potential but not a skeletal muscle fiber action potential?

leads to release of acetylcholine (ACh)

__________ control allows the body to anticipate a stimulus and begin a movement, whereas _________ feedback will generally result in the cessation of that movement

Feedforward, negative

You step on a lego with your bare foot, the flexor muscles of your injured limb contract and lift while the effectors of your other leg brace and keep you upright. This is an example of the.....

crossed-extensor reflex.

Compared to skeletal muscle, contraction of smooth muscle cells is...

a slower response to stimulus.
and sustained without fatigue.

A decrease in the release of neurotransmitter from the photoreceptor would indicate a(n)...

increase in light intensity.

Why is the eye (iris) pigmented and why might eye color vary among humans?

all of these are possible explanations

What type of receptors are the hair cells that bend to open ion channels in the cochlea

non-neuronal, mechanoreceptors

The way the rods of the eye communicate with their secondary neurons is an example of...

convergence

A person with defective rods will have trouble...

distinguishing shapes at the periphery of the visual field and
seeing well in the dark

If you were floating in outer space experiencing zero gravity, the weightlessness would cause the otoliths in your macula to lose their reference point. Which of these sensations might you expect to have difficulty perceiving?

head position
and
linear acceleration

The sarcolemma of a muscle fiber serves the same function as the _____ in other cells:

cell membrane

In the human eye, if the ________ focuses the light anywhere but the ________ then vision is imperfect.

lens, fovea

If a drug inhibits acetylcholinesterase activity in the neuromuscular junction, what effect does the drug have on the membrane potential of the muscle fiber

It would remain depolarized.

A contraction that generates enough force to move a load is known as _______, whereas one that generates force that equals the load is known as ________.

isotonic, isometric

Which is true about tonic receptors?

They adapt slowly to constant stimulus.

If glutamate is normally an excitatory neurotransmitter, why are some bipolar cells turned ON by light and some OFF by light?

different receptors

In a healthy individual, where would you least expect to find significant amounts of creatine kinase?

circulating in the blood

Alternating the contraction of different groups of muscle fibers helps a muscle sustain contraction and avoid fatigue. This strategy is called...

asynchronous recruitment

In skeletal muscle, after neurotransmitters bind to their receptors the chemically-gated Na+ channels open. What happens next?

The opening of voltage-gated Na+ channels

In stage three (the bottom box), what is happening in the sarcomere?

The thick filament is pulling the thin filament toward the M line.

Bob fell off a ladder trying to clean out his gutters. His wife rushed him to the emergency room. The doctor tested his knee-jerk reflex and found it was normal. These results suggest that?

Bob has no damage to his spinal cord.

sucrose solution

chemoreceptor

muscle tension

mechanoreceptor

temperature

thermoreceptor

Sweet, bitter, and umami signals are communicated through a G-protein coupled ______ which can amplify the signal sent to the primary sensory neuron.

second-messenger system

second-messenger system

long contraction duration AND many mitochondria

Which is the correct order of organization of a skeletal muscle from superficial to deep?

most superficial

epimysium

whole muscle

perimysium

fascicle

most deepest

Most reflex movements are integrated by...

the spinal cord

In smooth muscle, the Ca2+ necessary for contraction can come from...

the extracellular fluid
and
the sarcoplasmic reticulum

Which of the following is NOT required prior to skeletal muscle fiber contraction?

Ca++ must enter the muscle fiber from the extracellular fluid.

What is TRUE about the proteins troponin and tropomyosin in skeletal muscle contraction?

they inhibit the bindings necessary for contraction

Which phase(s) of a muscle twitch require ATP?

relaxation period
and
contraction period

After an injury, Jodie has difficulty recognizing and interpreting certain sounds. These symptoms imply damage to the...

auditory cortex

During crossbridge cycling, the binding of ATP to the myosin head...

releases the myosin head from actin