Fill in the blank.
1. a nerve signal is also called a/n
2. the
is the part of the neuron that transmits the signal, and is often covered in a
myelin sheath for insulation.
3. cells are usually negatively charged inside their membranes, but a/n
is created when
this charge is changed temporarily to send a signal.
4. the is associated with impulse control and spontaneity in the brain.
5. the regulation of body temperature is done by the _in the brain.
6. the lobe of the brain processes vision impulses from the eyes.
7. drug addiction can alter levels of the neurotransmitter
in the brain.
respond to the following based on your reading.
8. describe how a nerve impulse affects a neuron, travels the length of a neuron, and how the
neuron recovers to be ready for the next nerve impulse it receives.

On a backpacking trip, kenny hikes all day at a steady pace, covering 30 kilometers and burning 4000 calories. at the school track, janelle runs the 100-meter sprint in 13.5 seconds, burning 10 calories. afterward, janelle’s leg muscles are aching and she is breathing hard, while kenny maintains normal breathing all day, even though he burns 400 times more calories than janelle. which two statements offer the best explanation for this phenomenon? a. if the aerobic pathway—cellular respiration—cannot meet the energy demand, then the anaerobic pathway—lactic acid fermentation—starts up, resulting in lactic acid buildup and "oxygen debt." b. aerobic cellular respiration produces more energy, but its use is limited because of lactic acid buildup in the muscles and the resulting "oxygen debt." c. after about 90 seconds of intense exercise, the muscles become depleted of oxygen, and anaerobic respiration can no longer function to produce atp, resulting in "oxygen debt." d. the rate of energy demand determines how the muscles will obtain energy, either from cellular respiration or from lactic acid fermentation if not enough oxygen is present.