1. Saturday Study Session 2 Theme of the day: Information Transfer Session 2 – Cell signaling in the Immune and Nervous systems

2. Question 1 Answer C Clue: depolarization = Na+ in

3. Impulse generation Resting potential Threshold Membrane potential (mV) Action potential Time –100 –50 +50 0 Potassium channel Extracellular fluid Plasma membrane Na + Resting state Inactivation gate Activation gates Sodium channel K+K+ Cytosol Na + Depolarization K+K+ Na + Rising phase of the action potential K+K+ Na + Falling phase of the action potential K+K+ Na + Undershoot K+K+ Na +

4. Question 2 Answer D Clue: Sum = add them together

5. Summation = add them together Start with -70 mV IPSPs = -0.5 x 6 = -3.0 EPSPs = 0.5 X 2 = 1.0 Theerfore, -70mV + -3.0mV + 1.0mV = - 72.0mV

6. Question 3 Answer D Clue: large distance in very little time

7. Saltatory Conduction Cell body Schwann cell Depolarized region (node of Ranvier) Myelin sheath Axon

8. Question 4 Answer B Clue: chemical synapse= neurotransmitter

9. Synapse at the axon terminal Postsynaptic cell Presynaptic cell Synaptic vesicles containing neurotransmitter Presynaptic membrane Voltage-gated Ca 2+ channel Ca 2+ Postsynaptic membrane Postsynaptic membrane Neuro- transmitter Ligand- gated ion channel Na + K+K+ Ligand-gated ion channels Synaptic cleft

10. Question 5 Answer A Clue: receptor in step 3

12. MHCs Antigen- presenting cell Antigen fragment Class II MHC molecule T cell receptor Helper T cell Antigen fragment Class I MHC molecule T cell receptor Cytotoxic T cell Infected cell Microbe

15. Question 6 Answer B Clue:

17. Math Grid In Answer The correct answer is: 760 mm 2 2 long sides with widths of 6mm = 6X 20 = 120 mm 2 each 2 long sides with widths of 10mm = 10X 20 = 200 mm 2 each 2 ends at 6 x10 = 60 mm 2 each Total surface area = (120 x 2) +(200 X 2)+ (60 x 2) = 240 + 400 + 120 = 760 mm 2

18. Short Free Response 1 (4 points possible… must have structure and function together) Possible points awarded for: Discussion of the numerous dendrites covering a large area and detecting a stimulus. Discussion of the cell body being the collecting point of stimulus energies and containing the cell organelles. Discussion of the one dendrite being the exit point for the nerve impulse on the way to the CNS or effector. Discussion of there being a gap (synapse) at the end of the axon (axon terminal) where neurotransmitter is released.

19. Neuron structure

20. Short Free Response 2 (4 points possible) Possible points awarded for: Bark – outer protection like skin Tannins – Chemical defenses to make plant taste bitter, like tears or saliva. Thorns – protection from herbivores Needles – cactus protection from animals