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1. List the three major parts of the brain and describe their locations. A. cerebrum- constitutes about 83% of its volume and consists of a pair of half-globes called the cerebral hemispheres. B. cerebellum- lies inferior to the cerebrum and occupies the posterior cranial fossa. C. brainstem- that which remains of the brain if the cerebrum and cerebellum are removed. 2. Gyrus- a wrinkle or fold in the cortex of the cerebrum or cerebellum. Sulcus- a groove in the surface of an organ; as in the cerebrum, the heart, or a bone. 3. Name the parts of the brainstem from caudal to rostral. Medulla oblongata, pons, midbrain, diencephalon 4. Name the three meninges from superficial to deep. Dura mater, arachnoid mater, pia mater 5. Describe three functions of the cerebrospinal fluid. A. Buoyancy- allows the brain to attain considerable size without being impaired by its own weight. B. protection- protects the brain from striking the cranium when the head is jolted. C. chemical stability- rinses metabolic wastes from the nervous tissue and homeostatically regulates its chemical environment. 6. Where does the CSF originate, and what route does it take through and around the CNS? CSF originates in the choroid plexuses. Flow of CSF in the CNS: a. CSF is secreted by choroid plexus in each lateral ventricle. b. CSF flows through interventricular formina into third ventricle c. Choroid plexus in third ventricle adds more CSF.

d. CSF flows down cerebral aqueduct to fourth ventricle. e. Choroid plexus in fourth ventricle adds more CSF.
f. CSF flows out two lateral apertures and one median aperture. g. CSF fills subarachnoid space and bathes external surfaces of the brain and spinal cord. h. At arachnoid villi, CSF is reabsorbed into venous blood of dural venous sinuses. 7. Name the two components of the brain barrier system and explain the importance of this system. It regulates what substances...
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