CNS Central Nervous System

CNS  Brain and Spinal Cord

CNS:PROTECTION  Turn to page

CNS:PROTECTION  BONE:  Cranium = brain  Vertebrate = spine

CNS:PROTECTION  Meninges: Fiborus tissue  Color code a,b, b1,c

CNS:PROTECTION  Dura Mater: Toughest connective tissue  Right under cranium

CNS:PROTECTION  Arachnoid: Spider-web covering under dura mater.

CNS:PROTECTION  Subarachnoid: Pockets of the arachnoid that contain cerebral spinal fluid (CSF)

CNS:PROTECTION  Pia Mater: Delicate, contains many blood vessels.

CNS:PROTECTION  CSF: Circulates subarachnoid space  Cushions, and nourishes.  Surrounds entire CNS

Ohio State University: Neurology: College of Medicine.  CSF from the lumbar region contains 15 to 45 mg/dl protein (lower in childen) and mg/dl glucose (two-thirds of blood glucose). Protein concentration in cisternal and ventricular CSF is lower. Normal CSF contains 0-5 mononuclear cells. The CSF pressure, measured at lumbar puncture (LP), is mm of H2O (8-15 mm Hg) with the patient lying on the side and mm with the patient sitting up.

Problems  Increased protein: In bacterial meningitis, CSF protein may rise to 500 mg/dl. A more moderate increase ( mg/dl) occurs in inflammatory diseases of meninges (meningitis, encephalitis), intracranial tumors, subarachnoid hemorrhage, and cerebral infarction. A more severe increase occurs in the Guillain-Barré syndrome and acoustic and spinal schwannoma.

Problem  Xanthochromia (blonde color) of the CSF following subarachnoid hemorrhage is due to oxyhemoglobin which appears in 4 to 6 hours and bilirubin which appears in two days. Xanthochromia may also be seen with hemorrhagic infarcts, brain tumors, and jaundice.

 Normal  Clear as water  Abnormal findings  Faint yellow, orange or pink (Xanthochromia)  CSF Protein >100 mg/dl CSF Protein CSF Protein  Red Blood Cell lysis Red Blood Cell Red Blood Cell  Red Blood Cell >100,000/mm3 (Subarachnoid Hemorrhage) Red Blood CellSubarachnoid Hemorrhage Red Blood CellSubarachnoid Hemorrhage  Cloudy or turbid  CSF Leukocytes > 200 wbc/mm3 CSF Leukocyte CSF Leukocyte  Red Blood Cells > 400 per mm3 Red Blood Cell Red Blood Cell  Brown or Dark CSF  Metastatic Melanoma (meningeal Melanomatosis) Melanoma  Jaundice (Hyperbilirubinemia) JaundiceHyperbilirubinemia JaundiceHyperbilirubinemia  Green CSF  Hyperbilirubinemia Hyperbilirubinemia  Purulent cerebrospinal fluid

 (1) intervertebral discs, (2) vertebral bodies, (3) dura, (4) epidural space, (5) spinal cord, and (6) subdural space

BRAIN

BRAIN  Folded to increase surface area  35 billion neurons (98%)  Adult = 3 lbs

Brain  Brain (3 lbs) at rest needs as much oxygen as 61 lbs of skeletal muscle.

Brain  Turn to page 224

BRAIN  Gyrus: Peaks of the folds, ridges.  Sulcus: furrow or groove between gyrus

Brain  Ventricles: CSF circulate in four major canals. (Travels through brain and into spine) Continuous.  Blue on page 228

BRAINSTEM

BRAINSTEM  Lower brain  Unconscious part

BRAINSTEM  COLOR CODE:  Med. Oblongata = k  Pons = f  Midbrain = a  Reticular formation = g

MEDULLA OBLONGATA  Breathing  Heart rate  Reflex center

PONS  Connects cerebellum to cerebrum  Breathing

Midbrain  Like a hook  Diencephalon to cerebrum  Eye reflexes

Reticular formation  Fibers in the middle of brainstem (connects to RAS)  Inactive so are you! Consciousness.

Diencephalon

COLOR  Color code the Diencephalon to the right.  Thalamus = a  Hypothalamus = b

Diencephalon  On top of brainstem

Thalamus  Relay station for sensory headed to the cerebrum.  Filters out messages.

RAS  Reticular Activation System  Deals with arousal and consciousness.

HYPOTHALAMUS  Maintains homeostasis (temp)  Emotions: Rage, pleasure, pain, thirst, hunger

COLOR CODE  On middle picture page 10  Cerebellum = h  Arbor Vitae = i

CEREBELLUM  Controls muscle balance and coordination.  Lower, posterior part of brain.

Arbor Vitae  White “tree-shaped” structure inside cerebellum.

Cerebrum  Color code  Frontal = a, a1, a2  Parietal = b, b1  Temporal = c, c1  Occipital = d, d1

Cerebrum  Outer layer, largest region, called cortex  About 1 inch thick  4 lobes

Frontal lobe  Higher level thinking  Personality, speech center.

Parietal Lobe  Sensory for touch and pain

Temporal lobe  Sensory for hearing and smell

Occipital lobe  (back) Sensory for vision

 Brain time

Limbic system  Area around center of brain.  Not too much known about area.

Limbic system  Emotion: Emotional states, fear, rage and sexual arousal.

Limbic system  Memory and learning:  Long term memory and retrieval (hippocampus) (learning)

Lateralization  Brain divided laterally into 2 hemispheres.  Connected by corpus callosum

Lateralization  RIGHT  music, art, creative  Left  math, verbal