Nervous System: Overview/CNS

Card Set Information

Nervous System: Overview/CNS
2014-02-24 22:28:53
Unit One Lecture Five

Lecture two of Unit One from BIO 55
Show Answers:

  1. The Levels of Control
    • High Levels: Forebrain (integration of sensory and motor control; thought, memory, learning).
    • Lower Levels: Brainstem (vegetative functions).
    • Lowest Levels: Spinal Cord (reflexes).
  2. Divisions and Subdivisions of the Nervous System
    • 1. Central Nervous System (CNS)
    • *Brain and Spinal Cord

    • 2. Peripheral Nervous System (PNS)
    • *Somatic Nervous System: Voluntary; Skeletal Muscle
    • *Autonomic Nervous System: Involuntary; Cardiac & Smooth Muscles, Glands
    •    −Sympathetic: Stress Functions
    •    −Parasympathic: Vegetative Functions
  3. Neuralgia
    • Nerve Cell
    • Support and Protection of neurons
    • 50% are brain cells
    • 90% make up all nervous system
  4. Neurons
    • Nerve Cell
    • Conduct nerve impulses.
  5. White Matter
    • General Term of NS
    • An aggregation of myelinated axons from many neurons supported by neuralgia.
  6. Gray Matter
    • General Term of NS
    • Can either be nerve cell bodies and dendrites or bundles of unmyelinated axons and neuralgia.
  7. Nerve
    • General Term of NS
    • Most Myelinated
    • Bundle of nerve fibers found in the Peripheral Nervous System (PNS).
  8. Tract
    • General Term of NS
    • All Myelinated
    • Bundle of nerve fibers found up and down the spinal cord and between the segments in the brain.
    • Central Nervous System (CNS).
  9. Ganglion
    • General Term of NS
    • Group of nerve cell bodies found in the Peripheral Nervous System (PNS).
  10. Nucleus
    • General Term of NS
    • Group of nerve cell bodies found in the Central Nervous System (CNS).
  11. Brain Stem
    • A major division of the brain between the spinal cord and diencephalon.
    • Consists of the Medulla Oblongata, Pons, and Midbrain.
  12. Diencephalon
    • A major division of the brain.
    • Includes the Thalamus and Hypothalamus.
  13. Cerebrum
    • A major division of the brain.
    • Two Parts: Cerebral Cortex and Basal Ganglia
    • Cerebral Cortex has 6 outer layers of brain cells.
    • Basal Ganglia is the inner gray matter of the cerebrum and coordinates slow, maintained muscle movement.
  14. Cerebral Cortex
    • Part of the Cerebrum.
    • Comprises the 6 outer layers of the brain.
    • Interprets incoming sensory information as well as execution of motor responses.
    • Higher level integrative functions which govern the emotional and intellectual processes (will, reasoning, personality, intelligence, judgement, consciousness).
    • Sensory Areas: Interpret sensations to form perceptions.
    • Motor Areas: Control muscular movement.
    • Association Areas: process the incoming sensory information in order to execute the appropriate motor response.
  15. Cerebellum
    • A major division of the brain.
    • Consists of two cerebral hemispheres.
    • Controls subconscious skeletal muscle contraction required for balance and posture.
    • Coordination and planning of skilled voluntary muscle activity.
  16. Meninges
    • CNS, Protection of the Brain
    • 3 connective tissues that lie external to the CNS organs.
    • Dura Mater: "Tough Mother", tough outer layer
    • Arachnoid: "Spider-like", middle layer
    • Pia Mater: "Delicate Mother", innermost layer adjacent to the brain
  17. Cerebrospinal Fluid
    • CNS, Protection of the Brain
    • Clear fluid (i.e. blood plasma) formed in the choroid plexuses (networks of capillaries found in ventricles).
    • CSF formation = CSF absorption (80-150 mls are replaced every 3-4 hrs)
    • Shock absorber
    • Circulation, delivers some nutrients/removes some wastes to some tissues of the CNS.
  18. Ventricle
    Channels througout the brain through which cerebralspinal fluid pass through.
  19. Blood-Brain Barrier (BBB)
    • Decribes the "differential rates of movement" of substances into the brain due to the special structure of the brain capillaries.
    • The brain capillaries along with their associated connective tissue contain very tight junctions permitting only limited movement on certain substances.
  20. Medulla
    • Part of the Brain Stem
    • Relays motor and sensory impulses between the brain and spinal cord.
    • Reflex centers regulate heartbeat, breathing, and blood vessel diameter.
    • Part of R.A.S. functioning in consciousness and arousal.
  21. Pons
    • Part of the Brain Stem
    • Relays impulses within the brain and between parts of the brain and spinal cord.
    • Pneumotaxic area and apneustic area help coordinate breathing.
  22. Midbrain
    • Part of the Brain Stem
    • Relays motor impulses from the cerebral cortex to the pons and spinal cord.
    • relays sensory impulses for the spinal cord to the thalamus.
  23. Thalamus
    • Part of the Diecephalon
    • Relay station for all sensory impulses to the cerebral cortex.
    • Relays motor impulses from cerebral cortex to the spinal cord.
    • Portions function in emotion and memory.
  24. Hypothalamus
    • Part of the Diecephalon
    • Helps control and integrate ANS.
    • Recieves sensory impulses from viscera.
    • Regulates and controls many endocrine functions.
    • Controls the feelings of rage and aggression.
    • Controls body temp., and the intake/outtake of both food and fluid.
    • Helps maintain waking state (part of the R.A.S.)
  25. Limbic System
    • Includes: Cerebral Cortex, Basal Ganglia, Thalamus, and Hypothalamus.
    • Controls emotional aspects of behavior related to survival such as aggression, feeding, motivation, fear sex, reward/punishment.
  26. Reticular Formation (R.A.S.)
    • Interconnected neurons that run throughout the entire brain stem and into the thalamus.
    • Receives and integrates all synaptic input.
    • Part of the reticular formation called the reticular activating system (R.A.S.) which carries signals upward to arouse and activate the cerebral cortex.
    • R.A.S. controls the overall degree of cortical alertness and is important in the ability to direct attention toward specific events.
  27. Spinal Cord
    • Divided into ascending and descending pathways (tracts).
    • Ascending Tracts: Convey sensory info from various receptors (cutaneous and visceral receptors, proprioceptors) to the opposite side of the brain.
    • Descending Tracts: Convey motor impulses from different parts of the brain to the spinal cord.
  28. Reflex
    A quick response to a specific stimulus for the maintenance of homeostasis.
  29. Reflex Arc
    • Receptor -> Sensory Neurons -> CNS -> Motor Neurons -> Effectors
    • Reflexes may be classified according to the processing site, the tissue responding, and the complexity of the circuitry.