3. Use a pressure-volume diagram below to illustrate the effects of increased inotropy. What effects does the
increased inotropy have on end-systolic volume? Assuming that the end-diastolic volume is fixed, what effect will
increased inotropy have on the stroke volume? (5 marks)
6. a) What region of the sarcomere are associated with t-tubule invagination in heart and skeletal muscle? (2
b) Briefly speculate on a possible reason for having the t-tubule invaginations occuring at these locations (2 marks).
10 a) What is the function of gap junction channels (2 marks)?
b) Roughly draw the structure of gap junction channels (2 marks)?
13. List three possible effects of beta-subunit channel proteins on ion channels (3 marks).
1 of 8 pages 18. The membrane potential is +70 mV and the reversal (Nernst) potential for Na ions across the membrane is
a) What direction will Na flow across the membrane (i.e. what is the directioNaof I )? (1 mark).