This is Ryan, he strained his calf while performing in the Annual Interschool Soccer Semi-finals. Lucky for him, his immune system has already prepared to swiftly recover the muscle damage in time for the finals!
Step 1 : Making Things Worse (Deconstructing Homeostasis)Positive feedback systemStimulus : Injury to MuscleSensor: Nerve cells in skin and brainOrgan systems involved : Lymphatic, Musculoskeletal, Nervous systemControl: White Blood Cells (Neutrophils & Monocytes)Effector: Muscle eating enzymes and M1 macrophages
Neutrophils release enzymes that eat damaged muscle fibres.
nom nom
M1 macrophages create muscle inflammation and enhance muscle damage.
nom nom
Step 2 : Making Things Better (slightly)Negative feedback systemStimulus : Nitric oxide released by M1 macrophages (Damages muscle cells)Sensor: Nerve cells in skin and brainOrgan systems involved : Lymphatic, Musculoskeletal, Nervous systemControl: Satellite cellsEffector: Satellite cells
Nitric oxide from M1 macrophages causes muscle stem cells aka satellite cells to multiply at the site of injury.