The Brain & Cranial Nerves pt 2
occur during deep sleep in adults, but if seen while awake indicate brain damage.
(4–7 Hz) - indicate emotional stress or a brain disorder.
Alpha waves (8-13 cycles/second, aka hertz or Hz) - present
when awake but disappear during sleep.
transport blood to the brain. Once vessels enter the brain, they are wrapped in a layer of pia mater. On the capillary level, tight junctions in the endothelial cells, in concert with astrocytes, regulate the substances entering the brain from the bloodstream.
The internal carotid and vertebral arteries
A bundle of axons that carry nerve impulses from the retina of the eye between the optic chiasm and the thalamus.
CSF is produced in the choroid plexuses in the ventricle walls. CSF flows through the ventricles of the brain, central canal of the spinal cord and the subarachnoid space of the brain and spinal cord.
The blood-brain barrier and blood-CSF barrier are similar as both involve tight junctions between cells---but in the blood-CSF barrier the junctions are between ependymal cells lining the capillaries of the choroid plexus. In the blood brain barrier, the tight junctions are between the capillary endothelial cells.
Association tracts-within the same hemisphere; Commissural tracts-to the corresponding area (gyri) in the opposite hemisphere. Projection tracts- extend to/from brain areas outside of the cerebrum.