Download Answers to Questions — neurons

Answers to Questions
1. How does a threshold prevent a neuron from generating too many action potentials?
A threshold ensures that action potentials are not produced unless the neuron has received
enough stimulation.
2. What might happen if a drug blocked neurotransmitter receptors?
Neurotransmitters would not be able to bind with the receptors and initiate impulses in the
neuron.
3. Hyponatremia occurs when people have very low amounts of sodium in their body. How
might the nervous system be affected if the person had this condition?
Sodium is important in generating action potentials, thus low amounts of sodium would make it
so neurons are less able to transmit signals. In reality, hyponatremia often occurs as a result of
overhydrating. It can cause dizziness, headache, lethargy, slow muscle response, twitching,
cramps, confusion, coma. It is known to happen to marathon runners when they have not be
replenishing sodium levels inside their bodies. This is why drinks with salts such as Gatorade are
popular and beneficial for athletes.
4. Dendrite comes from the Greek word dendron, which means "tree." Explain how the root
word related to the meaning of dendrite.
Dendrites branch out of the cell body, in a way similar to that of branches spreading out from a
tree.
5. How does the structure of a neuron make it effective in carrying out the functions of the
nervous system?
Neurons have long extensions called axons, which allow messages to be carried long distances
without having to pass the signal to another cell.
6. How does the inside of a neuron become positively charged during an action potential, even
thoguh both potassium (K+) and sodium (Na+) ions are positively charged?
The inside of the neuron becomes positively charged because there are more Na+ molecules
moving in than K+ and the charge is relative.