Chemosensation S2M1

  1. What are the regenerative cells in the olfactory system
    Basal Cells
  2. What happens upon the binding of an odorant in the olfactory system
    • Odorant receptor activates G-Protein
    • Adenylate cyclase activates cAMP (via ATP)
    • cAMP opens Na+/Ca++ channels
    • Ca++ opens Cl- channels
    • Membrane depolarizes
  3. Each Olfactory neuron expresses
    1 receptor protein (which can bind to different oderants)
  4. Bowmans capsule secretes what
    Olfactory binding protein
  5. How do the neurons in the olfactory system vary
    • Some are responsive to a single odorant
    • Some many
    • The perception of odor can change with concentration
  6. The main output cell of the olfactory bulb is what
    Mitral cell
  7. Primary neurons of the olfactory system synapse in specific
    Glomeruli (bundle of axon ends) within the olfactory bulb
  8. What does the primary olfactory cortex consist of
    • Pyriform cortex
    • Entorhinal cortex
    • Amygdala
    • (PEA)
  9. What does the olfactory association cortex consist of
    Orbital gyri of the prefrontal cortex
  10. What is the Medial Olfactory Tract
    • Medial Olfactory Tract
    • - Axons project ipsilaterally to the basal limbic forebrain structures
    • - Others arise from the contralateral anterior Olfactory Nucleus (via anterior commissure)
  11. What is the Lateral Olfactory pathway
    • Lateral Olfactory Tract
    • - Axons project to the primary olfactory cortex amygdala and entorhinal cortex, then to the prefrontal cortex
  12. Anosmia
    Loss of smell
  13. Hyposmia
    Decreased ability to smell
  14. Hyperosmia
    Increased ability to smell
  15. Dysosmia
    Distorted perception of smell
  16. Phantosmia
    Perception of odour where there is none
  17. Agnosmia
    Loss of verbal ability to classify, contrast and identify odour sensation even though ability to detect between odorants is present
  18. What can cause the decline in olfactory ability
    • Psychotic disorders
    • Age
    • Seizure
    • Head trauma
    • Tumor
    • Alzheimers
    • "PASHTA"
  19. What are the basic taste sensations of the tongue
    • Sweet
    • Bitter
    • Salty
    • Sour
    • Unami
  20. What are the projections of the tongue called
  21. What are the three different papillae in the tongue
    • Foliate papillae (Leaf like)
    • Vallate papillae (Circle like)
    • Fungiform papillae (Mushroom like)
  22. What is the make up of a papillae
    • Each has 1-100+ taste buds
    • Each taste bud has 50-150 taste receptors
  23. What cells are found in a taste bud
    • Epithelial cells
    • Supporting cells
    • Gustatory receptor cells with gustatory hairs
    • Basal cells (10 day life cycle)
  24. The anterior 2/3 portion of the tongue has what specific taste receptors from what nerve
    • Sweet, sour, salty
    • Facial nerve (VII)
  25. The posterior 1/3 of the tongue is innervated by what nerve and has what taste receptors
    Glossopharyngeal nerve (IX), sour and bitter
  26. What nerves innervate the epithelium and touch receptors of the tongue
    • Trigeminal (V) - Ant. 2/3
    • Glossopharyngeal (IX) - Post. 1/3
  27. The epiglottis has taste and touch receptors innervated by
    CN X Vagus
  28. At higher concentrations most papillae become
    Less selective for taste
  29. Capsaicin
    • Principle ingredient for peppers
    • Activates on subset of C fibers normally used for heat
  30. What nerve transmits the sense from Capsaicin
    Trigeminal nerve through C fibers
  31. What are the nerves that send taste from the tongue
    • Facial
    • Trigeminal (partially)
    • Glosspharyngeal
    • Vagus
  32. What nerve tract is used for taste
  33. What is the taste pathway
    • Cranial ganglia axons
    • Solitary nucleus
    • VPM
    • Insula
  34. Ageusia
    Loss of taste sensation
  35. Hypogeusia
    Decreased taste sensation
  36. Dysgeusia
    Distorted taste perception
  37. Phantogeusia
    Perception of taste where there is none
  38. What can cause a loss of olfactory ability
    • Radiation
    • Oral neoplasm
    • Stroke
    • Surgery
    • Tumour
    • Trauma
    • "ROSS TT"
Card Set
Chemosensation S2M1