Chapter 13 - Brain and Cranial nerves

  1. Brainstem
    • -Connects spinal cord to cerebrum
    • -reticular formation scatter throughout
    • -cranial nerve nuclei
  2. Medulla Oblongata
    • -continuous with spinal cord
    • -Pathway for ascending & descending nerve tracts;
    • -center for reflexes such as heart rate, blood vessel diameter, sneezing, breathing, swallowing, vomiting
    • -Pyramids: descending nerve tracts on anterior surface. Inferior fibers decussate; (each half of the brain controls the opposite half of body)
    • -Olives: protrude from anterior surface.  Nuclei within help regulate balance (cerebellum), coordination, modulation of sound from inner ear
    • -Nuclei of cranial nerves V, IX-XII
  3. Pons
    • -contains ascending and descending nerve tracts;
    • -relays information between cerebrum and cerebellum;
    • site of reflex centers
    • -Pontine: anterior portion, relay between cerebrum and cerebellum
    • -Cranial nerves V-IX
    • -sleep center
    • -respiratory center coordinates with center in medulla
  4. Midbrain (Mesencephalon)
    • contains ascending and descending nerve tracts;
    • serves as visual reflex center;
    • part of auditory pathway
    • Nuclei
    • -of cranial nerves III-V
    • -Tectum: 4 nuclei that form mounds on dorsal surface of midbrain
    • -Corpora quadrigemina
    • --2 superior colliculi involved in visual reflexes; receive info from inferior collicculi, eyes, skin, cerebrum
    • --2 inferior colliculi involved in hearing
    • Red nuclei of tegmentum: aid in unconscious regulation and coordination of motor activities
    • Substanti nigra: pigmented with melanin; interconnected with basal nuclei of the cerebrum  (maintaining muscle tone & coordinating movements)

    • Tracts:
    • Tegmentum: ascending tracts such as spinal and medial leminsus from spinal cord to brain
    • Descending: cerebral peduncles from cerebrum through brainstem to spinal cord
  5. reticular formation
    • scattered throughout brainstem;
    • controls cyclic activities such as sleep-wake cyclce
  6. Cerebellum
    • controls muscle movement and tone; governs balance; regulates extent of intentional movement; involved in learning motor skills
    • Cerebellar peduncles: fiber tracts that communicate with other parts of brain. (Superior, middle, inferior)

    • Gray cortex and nuclei with white matter (tracts between)
    • Cortex folded in ridges called folia, white matter resembles a tree (arbor vitae)
  7. Purkinje Cells in Cerebellar cortex
    • largest in CNS
    • inhibitory
    • only cerebellar cortex neurons that send axons to cerebellar nuclei
  8. Cerebellar Functions
    • Flocculonodular lobe: balance and eye movements
    • Vermis: medial portion of hemispheres; posture, locomotion, fine motor coordination leading to smooth, flowing movements
    • Lateral hemispheres: major portion: works with cerebrum to plan, practice, learn complex movements
  9. Thalamus
    • -major sensory relay center;
    • -influences mood and movement
    • -2 lateral portions connected by the intermediate mass
    • surrounded by third ventricle
    • -sensory information from spinal cord synapses here before projecting to cerebrum
    • --medial geniculate nucleus: auditory info
    • --lateral geniculate nucleus: visual info
    • --ventral posterior nucleus: most other sensory info

    • motor function: ventral anterior & ventral later nuclei
    • mood modification: anterior & medial nuclei connected to limbic system
    • Emotion regulation: lateral dorsal nucleus
    • sensory integration: lateral posterior and pulvinar nuclei
  10. subthalamus
    ascending and descending nerve tracts

    involved in controlling motor function

    contains subthalamic nuclei, parts of red nuclei and substantia nigra
  11. epithalamus
    • Habenula: emotional and visceral responses to odors
    • Pineal gland: may infulence sleepiness, helps regulate biological clock, may play a rolie in onset of puberty
  12. hypothalamus
    • major control center for maintaining homeostasis and regulating endocrine function
    • -Mammilary bodies
  13. Cerebrum
    Controls conscious perception, thought, and conscious motor activity; can override most other systems
  14. Basal nuclei
    controls muscle activity and posture; largely inhibits unintentional movement when at rest
  15. Limbic System
    autonomic response to smell, emotion, mood, memory, and other such functions
  16. Lateral ventricles
    within cerebral hemispheres; separates by septa pellucida
  17. Third ventricle
    with diencephalon
  18. Interventricular foramina
    join lateral ventricles with third
  19. Fourth ventricle
    associated with pons and medulla oblongata. Connected to third ventricle by the cerebral aqueduct, continuous with the spinal cord, and connected to the subarachnoid space by the lateral and medial apertures
  20. Cerebrospinal fluid (CSF)
    • -similar to serum, but most protein removed
    • -bathes brain and spinal cord
    • -protective cushion around CSN
    • -Choroid plexuses produce CSF wich fills ventricles and other parts of brain & spinal cord
    •         >composed of ependymal cells, their support tissue, and associated blood vessels
Card Set
Chapter 13 - Brain and Cranial nerves
Brain and cranial nerves