PSB-2000 Lecture Notes - Lecture 2: Medulla Oblongata, Cerebrospinal Fluid, Arachnoid Mater
Document Summary
Neurons and glia cells are the two issues in the brain. We can split the brain into three axes: medial/lateral, dorsal/ventral, anterior/ posterior (forward/backward) The skull is the irst thing to protect the brain. Cerebral spinal luid is the second line of defense. The meninges is the third line of defense: it has 3 layers, dura mater, arachnoid mater, pia mater. The spinal cord and the brain are the cns. Segmented-a sensory nerve and a motor nerve project laterally from each segment. Swelling is at the dorsal end or sensory, that"s how you tell the diference between the two. Why: more cell bodies in the cervical for your arm movement, a lot of neurons in the lumbar to get more sensory nerves out to your legs. White mater (mostly going up or down) Gray mater (cell bodies/dendrites and axons going across) receives signals. Tapping on the tendon stretches outside the muscle which stretches the muscle spindle.
