C10: Nerve Signals In Homeostasis

Question 1

Question: What is the CNS made of and what does it do?

Answer 1

Answer: The CNS is made of the nerves in the brain and spinal cord and coordinates information from sensory neurons.

Question 2

Question: What are the areas between the myelin sheath and the axon called?

Answer 2

Answer: The areas between the myelin sheath and the axon are called nodes of Ranvier.

Question 3

Question: What happens when a nerve is excited?

Answer 3

Answer: When a nerve is excited, sodium ions rush into the cell, changing its charge. This is referred to as depolarization.

Question 4

Question: What is threshold level?

Answer 4

Answer: Threshold level is the intensity a stimulus must be to produce a response.

Question 5

Question: What is the blood-brain barrier composed of and what does it do?

Answer 5

Answer: The blood-brain barrier, composed of three membranes called meninges, determines which chemicals will reach the brain.

Question 6

Question: How is balance maintained?

Answer 6

Answer: Balance is maintained by the bending of cilia that initiate a nerve impulse.