PHGY 209 Lecture Notes - Stimulus Modality, Sensory Neuron, Sensory Cortex
Document Summary
Astrocytes are part of the blood-brain barrier, because these non-neural cells in our brain and cns. The foot processes of these glial cells are thought to induce the tight junctions in the capillaries that create the blood-brain barrier. Cns: they perform phagocytosis of debris floating in the extracellular space. Now we will talk about the physiology of neural processing and perception. Perception: the understanding of a sensation"s meaning: e. g. Feeling uncomfortable is more of a sensation: e. g. My tooth really hurts and i need to see a dentist is more of a perception. We do not perceive the energy of a sensory stimulus directly. We only perceive the neural activity that is produced by sensory stimulation. Rub your eyes hard and you will see light. Neurosurgeon penfield electrically stimulated somatic sensory cortex and patients perceived somatic sensation in the body. Because he was stimulating a place on the somatic sensory cortex that maps to the foot.
