PHGY 209 Lecture Notes - Lecture 16: Extracellular Fluid, Endothelium, Tight Junction
25 Nov 2017
School
Department
Course
Professor
Document Summary
Prevents unwanted substances leaving the blood into the extracellular space of the brain. Capillaries going through the brain (around all the neurons) are lined with endothelial cells. There is a tight junction between the endothelial cells, preventing things to get out of the capillaries. Only substances that can easily diffuse into the brain are water, co2, o2, lipid-soluble substances. If there is a drug that wants to access the extracellular fluid, it must be lipid-soluble or use the transport mechanisms between the blood and extracellular fluid. Caffeine and alcohol are drugs that can cross the blood-brain barrier. Morphine does not cross the blood-brain barrier easily. Heroine is a substance derived from morphine and can cross the blood-brain barrier. Do all the extra support around the neurons. Perception: the understanding of a sensation"s meaning. We do not perceive the energy of a sensory stimulus directly. We only perceive the neural activity that is produced by sensory stimulation.
