13.7 Inflammation Resets the Set-Points

Three short movements: the case, the anatomyThe study of the structure of the human body. and physiologyThe study of how the body functions., then the tie back to Stina. Each links to the scene where you’ll see it move.

I · The island in the sea, and the pair that never agrees

The pancreasA gland that produces digestive enzymes and hormones like insulin and glucagon. lies retroperitoneal Referring to organs located behind the peritoneum, such as the kidneys and pancreas., headRounded proximal end that fits into the acetabulum of the hip bone. in the C of the duodenumThe first section of the small intestine where most digestion occurs; it receives chyme, bile, and p, tail at the spleen; it is ninety-nine parts exocrineGlands that secrete substances via ducts (e.g., sweat glands). — the dark acini of slide 188 pouring enzymesProteins that speed up chemical reactions in the body. and bicarbonate(HCO₃⁻) – A crucial buffer in blood that helps maintain pH balance; formed when carbon dioxide react down the pancreatic duct, the Digestive module’s business — and one part endocrine: the pancreatic islets, pale islands in that dark sea, secreting into the venule side of their own capillariesThe smallest blood vessels where gas, nutrient, and waste exchange occurs between blood and tissues.. On slide 190B the islet is mostly beta cellsThe basic structural and functional units of life. (about three-quarters, central) making insulin, alpha cells (about a fifth, at the rim) making glucagonIncreases blood sugar by promoting glycogen breakdown., delta cells making somatostatinInhibits GH, insulin, and glucagon secretion., which quiets both, a few PP cells, and amylinHormone secreted with insulin to slow glucose absorption. co-secreted with insulin. Insulin, 51 amino acids, answers a rise in glucose — a humoral trigger, primed by the gut’s incretins — by moving glucose transporters to the membranes of muscle and fat and telling the liver to store glycogenA storage form of glucose found in animals.; brain, red cells, liver and kidney take glucose without it. Glucagon, 29 amino acids, answers a fall by breaking liver glycogen and making new glucose. They are the textbook antagonistic pair, and cortisol, growth hormone(GH): Stimulates growth and metabolism. and epinephrineadrenaline): Fight-or-flight hormone from the adrenal medulla. all play on glucagon’s side — which is why a stress axis run hot raises glucose, and why her fasting 88 is the loop the signal had not yet moved. Too little insulin is type 1 diabetes — the three polys, the ketones; tissues that stop listening is type 2.

See it move: Scene 1 · The Pancreas on a Slide · Scene 2 · Insulin and Glucagon: the Antagonistic Pair

II · The part-time players

The island of misfit hormones, the lecture calls them. The kidney makes erythropoietin(EPO): A hormone produced by the kidneys that stimulates erythropoiesis. when oxygen falls (Module 14 will need it), reninAn enzyme secreted by the juxtaglomerular cells that helps regulate blood pressure by triggering the when pressureThe force exerted by gases in the respiratory system, affecting airflow and gas exchange. falls, calcitriolThe active form of vitamin D, promoting calcium absorption in the intestines. on PTH’s order. The heart’s stretched atria make atrial natriuretic peptide, which drops sodium(Na⁺): Major ECF cation; important for fluid balance, nerve function., stops aldosteroneA hormone that increases sodium and water reabsorption in the kidneys, helping regulate blood pressu and lowers pressure. Fat makes leptinA hormone involved in regulating energy balance and puberty onset., in proportion to its mass, and adiponectin, which keeps tissues listening to insulin. The skin makes cholecalciferol in the sun. The stomach makes ghrelinHunger hormone from the stomach. before a meal and gastrinA hormone that stimulates gastric acid secretion and motility. during one; the intestine makes secretin, cholecystokinin and the incretins that prime the beta cell. The liver makes IGF-1 for growthAn increase in size and number of cells. hormone, angiotensinogen for renin, thrombopoietin for platelets, and hepcidin, which locks iron away during inflammation. The kidney’s EPO is the one Module 14 turns on — it answers oxygen, not cell counts. Bone makes osteocalcin and FGF23; the thymus thymosins; the pineal melatoninRegulates sleep-wake cycles. in the dark. Contribute to homeostasisThe maintenance of a stable internal environment in the body. and you get your name in the endocrine systemThe organ system consisting of glands that secrete hormones to regulate body functions. — and several of these (hepcidin, EPO, calcitriol, leptin) answer inflammatory signals directly.

See it move: Scene 3 · The Part-Time Players

III · Four findings, one fire — reset, not broken

Put the chart on one page and the pattern is almost loud. A calcium that wanders. A PTH that never fits it. A vitamin D that stays low. A cortisol rhythm worn flat. A spine thinner than her age allows. Each was met with the same two words — perimenopause, or stress — and rechecked in six months, and none of the clinicians was wrong about the value in front of them. They were wrong about the borders of the case. Chronic IL-1β and IL-6 do not break endocrine machinery; they move its set-points and lean on its target tissues, so loops that work perfectly defend the wrong numbers: osteoclasts driven, so calcium surges and bone thins; the vitamin D store lowered, so calcium drifts back and PTH chases; CRH and ACTH driven until the rhythm flattens and the tissues go deaf; the hypothalamus itself — the molecule that sets a fever — tilting the axes below it together. The distinction the module built to is the one 13.8 prints as two columns. A gland that fails: its hormone falls, its trophic signal rises, replacement corrects the picture. A set-point that moves: the gland works, the loop obeys, the pair stays consistent at a new number, and replacement alone never settles it. Her 2013 panel is the second column, five times. That is Chart Clue #13: the dials were not broken; something kept moving the set-points — and “calcium and vitamin D, recheck in six months” was a prescription for the readings.

See it move: Scene 4 · Four Findings, One Fire · Scene 5 · Reset, Not Broken

5 scenes. Each one has a short animation or a slide, something to explore, a true/false spot-check of your thinking, and a quick check. Every scene gives you an evidence card for your board.

Every scene gave you an evidence card, and the chart adds more. Sort each card into the column it supports: A set-point moved by one upstream signal, Neither on its own, or A gland that failed, or her age. Some cards can honestly go in more than one place — that’s allowed, and the feedback tells you which cards decide the case.

Time to decide. Look back at your bet, then build your verdict from statements that hold up — no writing needed.