You are drafting detailed medical exam answers for a BPT (Physiology) preliminary exam answer key. This is for an authoritative "model answer sheet" - be thorough, accurate, and exam-appropriate (like a topper's answer script). For EACH question below, consult the medical-library skill first (read /skills/readonly/medical-library/SKILL.md if not already familiar) and use query_library_db (paragraphs_fts / headings_fts) to pull accurate textbook content (cite book title + page/section if available). Use at most 5 query_library_db calls total across all questions - be efficient, batch searches. Supplement with your own accurate physiology knowledge where the library doesn't have enough detail. Also use search_image (at most 4 calls total) to find 1-2 real relevant diagram images for the most visual topics (cardiac cycle/Wiggers diagram, oxygen-hemoglobin dissociation curve, dorsal column pathway) and include their image URLs with captions in your output. QUESTIONS TO ANSWER (write a full detailed, well-organized answer for EACH, with clear headings, definitions, mechanisms, and a description of what diagram/flowchart should accompany it — describe diagram content in enough detail that someone could draw or format it, e.g. "Draw a graph with X-axis = time (sec), Y-axis = pressure (mmHg), plot LV pressure, aortic pressure, LA pressure, and ECG below aligned by time, mark phases: isovolumetric contraction, rapid ejection..."): 1. (10 marks) Define cardiac cycle. Draw and explain in detail the left ventricular pressure changes during a cardiac cycle. (Describe all phases: atrial systole, isovolumetric contraction, rapid ejection, reduced ejection, isovolumetric relaxation, rapid filling, diastasis - with pressure values, valve events, heart sounds, and Wiggers diagram description.) 2a. (10 marks) Draw and explain the oxygen dissociation curve. Define Bohr effect. (Sigmoid curve, P50, factors shifting curve right/left - CO2, H+, temperature, 2,3-DPG, describe axes and shape in detail) 2b. (10 marks - alternative to 2a) Describe the dorsal column pathway with a neat-labelled diagram. List the sensations carried by this pathway. (Gracile and cuneate fasciculus, first/second/third order neurons, decussation, medial lemniscus, thalamus, sensory cortex - describe pathway diagram in detail, list sensations: fine touch, vibration, proprioception, two-point discrimination) 3a. (5 marks) Define and classify immunity. What is autoimmunity? 3b. (5 marks - alternative to 3a) Describe excitation-contraction coupling with diagrams. (Describe the diagram of sarcomere/T-tubule/SR/calcium release with steps) 4. (5 marks) Describe the intrinsic pathway of coagulation. (Include a flowchart description: Factor XII -> XI -> IX -> VIII -> X -> prothrombin -> thrombin -> fibrinogen -> fibrin, with cofactors) 5. (5 marks) Describe the phases of regulation of gastric secretion. (Cephalic, gastric, intestinal phases) 6. (5 marks) Define GFR. Give the normal value. List the factors affecting GFR. 7. (5 marks) Describe the functions of insulin hormone. Return your final answer as clean, well-structured Markdown with numbered sections matching question numbers (Q1, Q2a, Q2b, Q3a, Q3b, Q4, Q5, Q6, Q7), each with subheadings (Definition, Mechanism/Description, Diagram Description, Clinical points if relevant). Include any image URLs found via search_image inline as markdown image syntax with a one-line caption, plus the textbook citations you used (book title + page/section). Be comprehensive enough to earn full marks in a physiology exam - this must be genuinely detailed (not superficial), roughly 400-700 words per major long-essay question (Q1, Q2a, Q2b) and 200-350 words per short essay question (Q3-Q7).

You are drafting detailed medical exam answers for a BPT (Physiology) preliminary exam answer key. This is for an authoritative "model answer sheet" - be thorough, accurate, and exam-appropriate (like a topper's answer script). For EACH question below, consult the medical-library skill first (read /skills/readonly/medical-library/SKILL.md if not already familiar) and use query_library_db (paragraphs_fts / headings_fts) to pull accurate textbook content (cite book title + page/section if available). Use at most 5 query_library_db calls total across all questions - be efficient, batch searches. Supplement with your own accurate physiology knowledge where the library doesn't have enough detail. Also use search_image (at most 4 calls total) to find 1-2 real relevant diagram images for the most visual topics (spirogram/lung volumes, CSF circulation, thyroid hormone regulation axis) and include their image URLs with captions in your output. QUESTIONS TO ANSWER — SET 1, Short Essay questions (5 marks each, write ~250-350 words each with clear structure, definitions, mechanisms, and describe any diagram/flowchart that should accompany the answer in enough detail that someone could draw/format it): Q8. Discuss heat loss and heat gain mechanisms in the body. (Include a flowchart description of thermoregulation: hypothalamus as thermostat, afferent input from peripheral/central thermoreceptors, effector mechanisms for heat loss - vasodilation, sweating, and heat gain - vasoconstriction, shivering, non-shivering thermogenesis) Q9. Describe the phases of endometrial changes during the menstrual cycle with hormonal basis. (Menstrual phase, proliferative phase, secretory phase - correlate with ovarian hormones estrogen/progesterone and pituitary FSH/LH, describe as a diagram/flowchart showing hormone levels across the 28-day cycle) Q10. Define and give the normal values of lung volumes and capacities with a neat-labelled diagram of spirogram. (Tidal volume, IRV, ERV, RV, IC, FRC, VC, TLC - with normal values in mL, describe spirogram tracing diagram in detail) Q11. Describe the formation, circulation and absorption of cerebrospinal fluid (CSF). List its functions. (Choroid plexus formation, circulation pathway through ventricles, subarachnoid space, absorption via arachnoid villi into venous sinuses - describe as a flowchart) Q12. Describe the regulation of thyroid hormone secretion. What is the cause of cretinism? (Hypothalamus-pituitary-thyroid axis: TRH -> TSH -> T3/T4, negative feedback - describe as a flowchart diagram) QUESTIONS TO ANSWER — SET 2, Short Answer questions (3 marks each, write ~100-150 words each, concise but complete, definitions/lists/examples as asked): Q13. Define primary active transport. Give example. Q14. What is the beneficial effect in relation to muscle contraction? (this likely refers to "staircase phenomenon/Treppe" or "Bohr effect in muscle" - answer as: Treppe effect/staircase phenomenon - the beneficial effect of repeated stimulation on muscle contraction, explain mechanism via calcium) Q15. List the centers for neural regulation of respiration. (Medullary dorsal/ventral respiratory groups, pontine pneumotaxic and apneustic centers) Q16. List the differences between cortical and medullary nephrons. (Table format: location, loop of Henle length, function - e.g. juxtamedullary role in concentrating urine) Q17. List the functions of bile salts. Q18. List the factors regulating spermatogenesis. Q19. List the types of shock. (Hypovolemic, cardiogenic, septic, anaphylactic, neurogenic, obstructive) Q20. Define Landsteiner's law. (Blood group antigen-antibody law) Q21. What is aphasia? List the types. (Broca's, Wernicke's, global, conduction aphasia) Q22. List the types of errors of refraction. (Myopia, hypermetropia, astigmatism, presbyopia) Return your final answer as clean, well-structured Markdown with numbered sections matching question numbers (Q8-Q22), each question answered fully. Use tables for list/comparison questions where appropriate. Include any image URLs found via search_image inline as markdown image syntax with a one-line caption, plus textbook citations used (book title + page/section).