EXAM 2 will test. . .

SKIN: THE LEMNISCAL SYSTEM

Your knowledge of the basic structure and function of
the human ‘touch’ pathways, from skin to cortex

  • 4 kinds of mechanoreceptors discussed in class (Basket Cells, Pacinian corpuscles, muscle spindle fibers, Golgi tendon organ)
  • Different functions of different receptor types
  • Identification, Pacinian corpuscles
  • Detection, Basket Cells
  • Kinesthesis, muscle spindle fibers and Golgi tendon organs
  • Spinal cord organization and the lemniscal system (be able to draw the pathway)
  • Relationship between receptive field size and density / identification / size of cortical maps
  • Effects of experience on cortical maps

See Chapter 12 and Lecture Slides (‘Skin’)

SKIN: THE SPINOTHALAMIC SYSTEM

Your knowledge of the basic structure and function of
the human ‘pain/temp’ system, from skin to cortex

  • Free nerve endings (nociceptors and thermal receptors). Why are they called ‘free’? Why are there so many of free nerve endings in human skin?
  • How are nociceptors activated? How do nociceptors amplify weak signals?
  • Role of nociceptors in healing process (Function of pain)
  • Spinal cord organization and the spinothalamic system (be able to draw the pathway)
  • Spinal Gate Theory: What are the two sources of inhibition that ‘gate’ the transmission of nociceptor activity through the spinal cord?
  • Neurotransmitter systems involved in ‘gating’ nociceptor activity through the spinal cord (serotonin, norepinephrine, endogenous opiates, glutamate)
  • Mechanisms of chemical dependence to opiate drugs (neuronal homeostasis, short term vs. long term effects of opiates on neural activity)

See Chapter 12 and Lecture Slides (‘Skin’)

TASTE (detection and identification of soluble chemicals)

  • Taste vs. Flavor: retronasal olfactory sensations (Fig. 14.1, p. 362)
  • Taste seems to be ‘innate’ – know the evidence. How does this relate to the function of taste?
  • Taste buds and taste receptor cells (Fig. 14.4, p.365). Can you see a mechanism for amplification here?
  • Taste receptors – how do the four types of taste receptors work (Fig. 14.5, p. 366)?
  • Neural pathways to gustatory cortex (Fig. 14.6, p. 367)
  • The Four Tastes (p. 368). How is each taste related to cell function? Where is the taste for ‘fat’? How and why do detection thresholds for the four tastes differ?
  • Specific Hungers (p. 373)
  • Genetic Variation in Taste (p. 377)

Lecture Slides and Chapter 14 (also spend some time on the Chapter 14 Website!)

OLFACTION (detection and identification of volatile chemicals)

  • Odors and odorants – what kind of odorantshave we humans ‘tuned’ our olfactory system to? Also be able to name some important volatile chemicals that humans cannot detect.
  • How does olfaction relate to taste (see ‘retronasal olfaction’ in the taste section above)? In other words, why must the significance of most (all?) odors be learned, when taste seems to be completely innate?
  • Receptors and Pathways to the Brain
  • The Olfactory Epithelium: How do olfactory receptors work?
  • The Olfactory Bulb: Why does each glomerulus (mitral cell) receive input from multiple receptors (see Fig. 13.3, p. 333, and Fig. 13.6, p. 335)? Ah-ha – amplification strikes again!
  • Glomeruli and the neural coding of different odorants
  • Check out the differences between Main and Accessory Olfactory Systems in their projections to the brain! Note the lack of a ‘relay’ through the thalamus, and the direct or near-direct projections from the olfactory bulb to brain regions for memory and emotion (hippocampus, amygdala)
  • Olfactory Identification (p. 345) – what’s the problem?
  • Olfactory Hedonics (p. 349)
  • Familiarity and Intensity
  • Nature or Nurture
  • Conditioned Taste Aversions (sometimes called ‘learned’ taste aversions)
  • Olfaction, Memory, and Emotion (p. 352)
  • Pheromones, the Vomeronasal Organ, and the Accessory Olfactory System (p. 354)
  • What are pheromones for?
  • McClintock Effect

Lecture slides and Chapter 13 (also spend some time on the Chapter 13 Website!)

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