Due No due date Points 100 Questions 29 Time Limit 60 Minutes Requires Respondus LockDown Browser Attempt History Attempt Time Score LATEST Attempt 1 98 out of 100 Score for this quiz: 98 out of 100 Question 1 3 / 3 pts This is the most superficial layer of the brain meninges. Your Answer: Dura Mater (menix) Dura mater (menix) The fissure separates the right and left cerebral hemispheres. Your Answer: Median Longitudinal Median longitudinal Question 3 4 / 4 pts What is the purpose of the blood-brain barrier? Describe its maintenance from a cellular level. Your Answer: a barrier that prevents most particles from entering the CNS tissue keeping the brain and spinal cord from general blood circulation. The blood-brain barrier is a diffusion barrier which prevents most particles from entering the central nervous system tissue, keeping the brain and spinal cord separate from general blood circulation. The blood-brain barrier is formed by the relatively impermeable brain capillaries, due to the glial cells astrocytes. Maintenance of the blood-brain-barrier is important to provide a stable chemical environment for the nervous system.