Nervous System

• Gray Matter - consists of short, nonmyelinated neurons and neuron cell bodies
• White Matter - consists mostly of myelinated axons with some nonmyelinated axons
• Ventricles - continuous with one another and with the central canal of the spinal cord
• Lateral ventricles - one deep within each cerebral hemisphere, are large C-shaped chambers
• Septum pellucidum - a thin median membrane that separates the lateral ventricles
• Third ventricle - located in the diencephalon that communicates with the lateral ventricle, and is continuous with the fourth one
• Cerebral Aqueduct - a canal-like, where the third ventricle is continuous with the fourth
• Fourth Ventricle - lies in the hindbrain dorsal to the pons and superior medulla
• Lateral apertures - the paired opening of the fourth ventricle
• Median Aperture - an opening in the roof of the fourth ventricle
• Subarachnoid Space - a fluid-filled space surrounding the brain
• Ventricles of the Brain

  A) Lateral Ventricle

  B) Anterior horn

  C) Posterior Horn

  D) Inferior Horn

  E) Third Ventricle

  F) Cerebral Aqueduct

  G) Fourth Ventricle

  H) Central Canal

  I) Third ventricle

  J) Lateral Aperture

  K) Median Aperture

  L) Septum Pellucidum

  M) Lateral Aperture

  
• Cerebral Hemisphere - form the superior part of the brain and are the most conspicuous parts of an intact brain
• Gyri - elevated ridges of tissue
• Sulci - separates the gyri by this shallow grooves
• Fissures - are deeper grooves, which separates large regions of the brain
• longitudinal fissure - separates the cerebral hemispheres medially
• transverse cerebral fissure - separates the cerebral hemisphere from the cerebellum below
• Central sulcus - separates the frontal lobe from the parietal lobe
• Parieto-occipital sulcus - located more posteriorly on the medial surface of the hemisphere, separates the parietal and occipital lobes
• Lateral sulcus - outlines the flaplike temporal lobe and separates it from the parietal and frontal lobes
• Insula - the fifth lobe of the cerebral hemisphere, and is buried deep within the lateral sulcus
• Location of Lobes

  A) Frontal Lobe

  B) Precentral gyrus

  C) Central sulcus

  D) postcentral gyrus

  E) Parietal lobe

  F) Parieto-occipital sulcus

  G) Lateral Sulcus

  H) Occipital Lobe

  I) Temporal Lobe

  J) Transverse cerebral fissure

  K) Cerebellum

  
• Brain Parts

  A) Cerebral Hemisphere

  B) Diencephalon

  C) Cerebellum

  D) Brain Stem

  E) Midbrain

  F) Pons

  G) Medulla Oblongata

  
• Cerebral Cortex - the "executive suite" of the nervous system
• Cerebral Cortex - where our conscious mind is found
• Cerebral Cortex - enables us to be aware of ourselves and our sensations, to communicate, remember, understand, and initiate voluntary movements
• PET scans - imaging techniques that show maximal metabolic activity in the brain
• MRI scans - imaging techniques that reveal blood flow in the brain
• Functional Neuroimaging of the Cerebral Cortex

  A) Seeing

  B) Hearing

  C) Speaking

  D) Thinking

  
• Motor Areas - region in the cortex that control voluntary movement
• Primary Motor Cortex - located in the precentral gyrus of the frontal lobe of each hemisphere
• Pyramidal cells - in the precentral gyrus, allow us to consciously control the precise or skilled voluntary movements of our skeletal muscles
• Pyramidal tracts - are long axons, which project to the spinal cord, form the massive voluntary motor tracts
• Premotor Cortex - found just anterior to the precentral gyrus in the frontal lobe
• Premotor Cortex - helps plan movement
• Premotor Cortex - selects and sequences basic motor movements into more complex tasks
• Premotor Cortex - the staging area for skilled motor activities
• Broca's Area - lies anterior to the inferior region of the premotor area
• Broca's Area - becomes active as we prepare to speak and even as we think about many voluntary motor activities other than speech