Biology 235 Human Anatomy and Physiology

Study Guide

Chapter 14
The Brain and Cranial Nerves

Objectives

After completing this chapter, you should be able to

  1. identify the principal parts of the brain, and describe how the brain is protected.
  2. explain the formation, circulation, and functions of cerebrospinal fluid (CSF).
  3. compare the structure and functions of the brain stem, cerebellum and diencephalon (including the thalamus and hypothalamus).
  4. describe the cortex, gyri, fissures and sulci of the cerebrum.
  5. name and describe the locations of the lobes of the cerebrum.
  6. describe the functions of the basal ganglia and the limbic system.
  7. describe the locations and functions of the sensory, association and motor areas of the cerebral cortex.
  8. explain the significance of hemispheric lateralization.
  9. define brain waves and explain their significance.
  10. define the term cranial nerve, and identify the twelve pairs of cranial nerves by name, number, and functions.
  11. describe briefly the few main brain disorders.

Keywords and Topics

Make certain that you can define, and use in context, each of the terms listed below, and that you understand the significance of each of the concepts.

  1. Identify the principal parts of the brain, and describe how the brain is protected.
    1. neural tube
    2. primary brain vesicles
    3. secondary brain vesicles
    4. principal parts of the brain
      1. brain stem
      2. cerebellum
      3. diencephalon
      4. cerebrum
    5. protective coverings
      1. cranial meninges (singular is meninx)
      2. dura mater
      3. arachnoid mater
      4. pia mater
    6. blood brain barrier (BBB)
  2. Explain the formation, circulation, and functions of cerebrospinal fluid (CSF).
    1. cerebrospinal fluid (CSF)
      1. subarachnoid space
      2. ventricle
        1. lateral ventricles (2)
        2. septum pellucidum
        3. third ventricle
        4. fourth ventricle
      3. functions of CSF
      4. choroid plexus
      5. blood cerebrospinal fluid barrier
      6. circulation of CSF
        1. interventricular foramina
        2. aqueduct of the midbrain
        3. median aperture
        4. lateral apertures
        5. arachnoid villi
  3. Compare the structure and functions of the brain stem, cerebellum and diencephalon (including the thalamus and hypothalamus).
    1. brain stem
      1. medulla oblongata
      2. pyramids
      3. decussation of pyramids
      4. cardiovascular center
      5. medullary respiratory center
      6. pons
      7. pontine respiratory group
      8. midbrain or mesencephalon
      9. cerebral peduncles
      10. reticular formation
      11. reticular activating system (RAS)
    2. cerebellum
      1. transverse fissure
      2. vermis
      3. cerebellar hemispheres
      4. cerebellar cortex
      5. folia
      6. arbor vitae
      7. cerebellar peduncles (superior, middle and inferior)
    3. diencephalon
      1. thalamus
      2. hypothalamus and functions
      3. epithalamus
        1. pineal gland
        2. melatonin
      4. circumventricular organs
  4. Describe the cortex, gyri, fissures and sulci of the cerebrum.
    1. cerebrum
    2. cerebral cortex
    3. gyrus or convolution (plural is gyri)
    4. fissure
    5. sulcus (plural is sulci)
    6. longitudinal fissure
    7. cerebral hemispheres
    8. corpus callosum
  5. Name and describe the locations of the lobes of the cerebrum.
    1. central sulcus
    2. frontal lobe
    3. parietal lobe
    4. precentral gyrus
    5. postcentral gyrus
    6. lateral cerebral sulcus
    7. temporal lobe
    8. parieto occipital sulcus
    9. occipital lobe
    10. insula
    11. cerebral white matter
      1. association tracts
      2. commissural tracts
      3. projection tracts
  6. Describe the functions of the basal nuclei and the limbic system.
    1. basal ganglia
    2. limbic system
  7. Describe the locations and functions of the sensory, association and motor areas of the cerebral cortex.
    1. functional organization of the cerebral cortex
      1. sensory areas
      2. primary somatosensory area
        1. primary visual area
        2. primary auditory area
        3. primary gustatory area
        4. primary olfactory area
      3. motor areas
        1. primary motor area
        2. Broca’s speech area
      4. association areas
      5. somatosensory association area
      6. visual association area
      7. auditory association area
      8. Wernicke’s area or posterior language area
      9. common integrative area
      10. prefrontal cortex (frontal association area)
      11. premotor area
      12. frontal eye field area

    Note: Learn the summary of the functions of the principal parts of the brain, Table 14.2.

  8. Explain the significance of hemispheric lateralization.
    1. hemispheric lateralization
  9. Define brain waves and explain their significance.
    1. brain waves
    2. electroencephalogram or EEG
      1. alpha waves
      2. beta waves
      3. theta waves
      4. delta waves
  10. define the term cranial nerve, and identify the twelve pairs of cranial nerves by name, number, and functions.
    1. cranial nerves
      1. special sensory nerves
      2. motor nerves
      3. mixed nerves

    Note: There are 12 pairs of cranial nerves (originating from the brain) in the PNS. Their names indicate their distribution or function. The table below provides a brief summary of the numbers, names and major functions of the cranial nerves.

    Although they are not described in your e-textbook, scientists have recently confirmed the presence of a 13th pair of cranial nerves in the human body. This pair is currently numbered “zero” because it is located anterior to the olfactory (first) nerves. These nerves innervate a newly discovered pair of sensory organs called the vomeronasal organs, located in the anterior nasal cavity. The function of the human vomeronasal organs is not yet known; however, there is some evidence that they might detect pheromones, chemical signals passed subconsciously from one individual to another. In other animals, pheromones are known to have effects on reproductive and social behaviours.

    Number   Name   Major Function  

    I

     

    Olfactory

     

    Smell

    II

     

    Optic

     

    Vision

    III

     

    Oculomotor

     

    Control some of the muscles moving the eyeballs, changes in size of pupil and shape of lens

    IV

     

    Trochlear

     

    Control some of the muscles moving the eyeballs

    V

     

    Trigeminal

     

    Carry nerve impulses associated with head sensations and chewing muscles

    VI

     

    Abducens

     

    Control some of the muscles moving the eyeballs

    VII

     

    Facial

     

    Carry nerve impulses associated with taste, salivation and muscles of facial expression

    VIII

     

    Vestibulocochlear

     

    Carry nerve impulses associated with hearing and equilibrium

    IX

     

    Glossopharyngeal

     

    Carry nerve impulses associated with swallowing, salivation and taste

    X

     

    Vagus

     

    Carry nerve impulses to and from many organs in the thoracic and abdominal cavities

    XI

     

    Accessory

     

    Control head and shoulder muscles

    XII

     

    Hypoglossal

     

    Control tongue muscles
  11. Briefly describe the few main brain disorders.
    1. cerebrovascular accident (CVA) or stroke or brain attack
    2. transient ischemic attack (TIA)
    3. Alzheimer disease (AD)
    4. attention deficit hyperactivity disorder (ADHD)

Complete the “Chapter Review and Resource Summary” at the end of the chapter.

Use the “Practice Questions” and the various “Interactivity” tools found in each eText chapter in WileyPLUS. Working through these activities will test your understanding of the material presented and ensure your notes are complete.