The Brain

  1. Central Nervous System
    • brain and spinal cord protected by the cranium and vertebrae
    • also protected by the meninges and cerebrospinal fluid (CSF)
  2. Dura Mater
    the tough, thick, outermost part which forms four partitions

    • falx cerebri-extends between the cerebral hemispheres, attaches to the crista galli (ethmoid)
    • tentorium cerebelli-between the cerebrum and cerebellum
    • epidural space- (spinal cord) between bone and dura mater
    • subdural space-between dura and arachnoid
  3. Arachnoid Mater
    • thin, middle portion
    • some subarachnoid space is filled with CSF
  4. Pia Mater
    very thin, vascular, adheres to the surface
  5. Meningitis
    inflammation of the meninges due to bacteria or virus. bacterial is usually more serious, viral is generally self-limiting. also fungal
  6. Encephalitis
    inflammation of the brain
  7. Choroid Plexuses
    network of capillaries in the ventricles which produce CSF. CSF circulates through the ventricles and sub-arachnoid space then in reabsorbed by the arachnoid granulations
  8. Hydrocephalus
    water on the brain, excess CSF
  9. Brain
    • only 2% of body weight, but uses 20% of the oxygen supply..
    • 1,000,000,000,000,000 synapses for the 25 billion neurons
    • blood delivered by 2 carotid arteries and 2 vertebral arteries which branch into the Circle of Willis
    • the brain is one of the most metabolically active organs of the body, and when deprived of blood, irreversible damage may occur
    • the brain has a limited carbohydrate resources, so a continuous supply of glucose is mandatory
  10. Blood-Brain Barrier
    allows glucose, O2, amino acids, and certain ions to pass rapidly, but slows or stops many other substances. substances that do not cross are small and require a carrier molecule.
  11. Prosencephalon

    • telencephalon-cerebrum
    • diencephalon-thalamus, hypothalamus
  12. Mesencephalon
  13. Rhobencephalon

    • metencephalon- cerebellum, pons
    • myelencephalon- medulla
  14. Brain Stem
    medulla + pons + midbrain
  15. Fourth Ventricle
    • posterior, medulla and spinal cord
    • cerebral aqueduct connects it with the third ventricle
  16. Third Ventricle
    • within diencephalon
    • the interventricular foramina connects it with the lateral ventricles
  17. Lateral Ventricles (First and Second Ventricles)
    in cerebrum
  18. White Matter
    myelinated, conducting portion
  19. Gray Matter
    large masses of cell bodies, dendrites of association, unmyelinated axons
  20. Medulla Oblongata
    • contains white and gray matter
    • pyramidal tracts contain axons from the cerebrum, major motor pathways (descending)
    • fasciculi gracilus and faciculi cuneatus- ascending tracts (touch, pressure)
    • peduncle-thick bundle of nerve fibers containing: cardiac centers, vasomotor centers (blood pressure), and respiratory centers
    • 4 of 12 cranial nerves originate at the medulla: 9th, 10th, 11th, and 12th.
  21. Pons (Varolii)
    • superior to the medulla
    • helps regulate respiration
    • reflexes from the trigeminal (5), abducens (6), and facial (7)
  22. Midbrain
    • contains cerebral peduncles
    • nerve fibers contain much dopamine (involved with Parkinson's)
    • red nucleus-neurons conveying impulses of muscle tone
    • superior colliculi-visual reflex centers
    • inferior colliculi-relays for auditory info
    • many other reflexes integrated here
  23. Diencephalon
    pineal gland or Epiphysis-endocrine gland
  24. Thalamus
    • influence emotions
    • either side of the 3rd ventricle
    • relay station for all sensory into except smell
  25. Hypothalamus
    inferior to the thalamus
  26. Optic Chiasma
    crossing of optic nerve, floor of the hypothalamus
  27. Infundibulum
    connects hypothalamus to pituitary
  28. Mammilary Bodies
    involved with feeding reflexes
  29. Hypothalamus Functions
    • link between nervous and endocrine systems
    • link between cerebrum and lower autonomic centers
    • regulate temperature
    • helps maintain H2O balance (ADH)
    • influences emotional and sexual behavior
    • regulates appetite
  30. Cerebellum
    separated from the cerebrum by the transverse fissure

    • the two hemispheres are connected by the vermis and partially separated by the falx cerebelli
    • mostly white matter under a layer of gray
    • when cut, appears as the arbor vitae
    • 30 million purkinje cells (cortex area) helps to integrate info for motor activity
    • inferior cerebellar peduncle:spinal cord to cerebellar cortex
    • middle cerebellar peduncle: pons to cerebellar cortex
    • superior cerebellar peduncle: cerebellum to CNS
  31. Cerebellum Functions
    • making muscle movement smooth and coordinated
    • maintain posture (muscle tone)
    • maintain equilibrium
  32. Ataxic
    uncoordinated muscle movement
  33. Gyri
  34. Sulci
    shallow grooves
  35. Fissures
    deep grooves
  36. Cerebral Cortex
    thin outer layer of gray matter of Cerebrum
  37. Lobes of the Cerebrum
    • Frontal Lobe: motor cortex (Broca's area for speech)
    • Parietal Lobe: receives sensory info and integrates it
    • Occipital Lobe: receives and interprets visual info
    • Temporal Lobe: receives and interprets auditory info; also emotion, personality, behavior, and memory
    • Central Lobe: autonomic and somatic activities
    • Limbic Lobe: offaction and emotional behavior
  38. Associative Fibers
    transmit impulses within a hemisphere
  39. Commissure Fibers
    connects hemispheres
  40. Corpus Callosum
    connects the neocortex of the two hemispheres
  41. Fornix
    connects the old cortex with the thalamus
  42. Projection Fibers
    pathways to and from the brain
  43. Basal Ganglia
    • gray areas in the white matter
    • responsible for subconscious movements such as swinging the arms while walking
  44. 3 Primary Functions of Cerebrum
    • Sensory
    • Motor
    • Associative (intellectual activities, memory)
  45. Brodmann's Classification
    map of brain and functions
  46. Broca's Area
    formation of words
  47. Aphasia
    inability to express oneself through words
  48. Left Hemisphere
    generally dominant for motor skills, right handedness, language, intellectual skills
  49. Right Hemisphere
    may be dominant for creative abilities and spaciotemporal matters
  50. Limbic System
    emotions, sexuality, biological rhythms, autonomic responses, motivation, reward and punishment centers

    • Consists of:
    • Limbic Lobe
    • Hippocampus (area of old cortex)
    • Amygaala (nuclei near optic tract)
    • Oflactory Structures
    • parts of Thalamus
    • parts of Hypothalamus (mammillary body)
    • Fornix (connects mammillary to hippocampus)
  51. EEG

    monitor brain activity
  52. RAS
    reticular activating system

    maintain consciousness (when its activity slows, you may become sleepy)
Card Set
The Brain
Anatomy and Physiology: Central Nervous System