Chapter 10

Question 1

By which method do neurotransmitters mediate cell-to-cell communication?

1. Secondary active transport into the neuron.
2. Exposure through the circulatory system.
3. Diffusion into the effector cell.
4. Sodium ligand gated channels.

Answer 1

3. Diffusion into the effector cell.

Question 2

True or false:

Light and pain sensations are regulated through the same cellular pathways.

Answer 2

FALSE.

Question 3

For an animal testing experiement, where you aim to replicate how the animal would behave in the wild, what would be an important factor?

Answer 3

Ensuring that the light exposure, and sleep wake cycle, is similar to the environment they naturally occur in.

Question 4

A study found that rats injected with dopamine showed decreased sensitivity to light, while rats injected with GABA or norepinephrine showed no significant changes. Rats injected with glutamate showed evidence of significant visual abnormalities. The results of this study most support that:

1. Dopamine modulates the light sensitivity of the retina.
2. Dopamine is the neurotransmitter used by bipolar cells at the retina.
3. GABA and Norepi have no impact on the visual system.
4. The production of glutamate is stimulated by photoreception.

Answer 4

1. Dopamine modulates the light sensitivity of the retina.

Question 5

What is the equation for potential energy (stored energy)?

Answer 5

PE = (1/2) (k) (x)^2

k = spring constant (k = F/x)
x = displacement.

Question 6

How can you determine the force of a spring based on the amount of displacement?

Answer 6

Fspirng = k* x

k = spring constant
x = displacement

Question 7

Prosthetic legs need to have shock absorption springs to prevent injury. These springs must be stiff enough not to fail, but still have some give. If the legs “gives” 5 cm from the spring, when 40 kg is placed on top of it, how much energy is stored in the spring?

Answer 7

1) Energy stored = potential energy, lets calculate it
2) PE = (1/2) (k) (x)^2 Since we are not given k we must calculate it
3) F = k*x, so k = F/x.
4) F = 40 kg * 9.8 m/s^2 = 392 N.
4) k = 392 N * 0.05 m = 7840
5) PE = (1/2) (7840) (0.05)^2 = 9.8 Joules

9.8 joules of energy is stored in the spring.

Question 8

What is the equation we can use to determine focal point of a lens for light?

Answer 8

1/f = 1/d (of object) - 1/ d (of image)

Question 9

If the image created by an object, is one the same side of a lens as the object, we can say:

1) this lens in concave
2) this lens is convex
3) The object is closer to the lens than the focal point.
4) The object is further from the lens than the focal point.

Answer 9

2) this lens is convex
3) The object is closer to the lens than the focal point