Homestasis Negative Feedback Loops

High Blood Sugar Regulation – Stimulus

Increase in blood glucose

High Blood Sugar Regulation – Receptor

Pancreatic beta cells

High Blood Sugar Regulation – Control Center

Pancreas

High Blood Sugar Regulation – Effector

Liver stores glucose as glycogen; body cells take up glucose

High Blood Sugar Regulation – Response

Blood glucose decreases

Low Blood Sugar Regulation – Stimulus

Decrease in blood glucose

Low Blood Sugar Regulation – Receptor

Pancreatic alpha cells

Low Blood Sugar Regulation – Control Center

Pancreas

Low Blood Sugar Regulation – Effector

Liver breaks down glycogen to glucose

Low Blood Sugar Regulation – Response

Blood glucose increases

Thermoregulation (High Temp) – Stimulus

Increase in body temperature

Thermoregulation (High Temp) – Receptor

Thermoreceptors in skin and hypothalamus

Thermoregulation (High Temp) – Control Center

Hypothalamus

Thermoregulation (High Temp) – Effector

Sweat glands and vasodilation

Thermoregulation (High Temp) – Response

Body temperature decreases

Thermoregulation (Low Temp) – Stimulus

Decrease in body temperature

Thermoregulation (Low Temp) – Receptor

Thermoreceptors in skin and hypothalamus

Thermoregulation (Low Temp) – Control Center

Hypothalamus

Thermoregulation (Low Temp) – Effector

Shivering and vasoconstriction

Thermoregulation (Low Temp) – Response

Body temperature increases

Osmoregulation (Dehydration) – Stimulus

Increase in blood osmolarity

Osmoregulation (Dehydration) – Receptor

Osmoreceptors in hypothalamus

Osmoregulation (Dehydration) – Control Center

Hypothalamus & posterior pituitary

Osmoregulation (Dehydration) – Effector

Kidneys reabsorb water; thirst triggers drinking

Osmoregulation (Dehydration) – Response

Blood osmolarity decreases

Osmoregulation (Overhydration) – Stimulus

Decrease in blood osmolarity

Osmoregulation (Overhydration) – Receptor

Osmoreceptors

Osmoregulation (Overhydration) – Control Center

Hypothalamus

Osmoregulation (Overhydration) – Effector

Kidneys excrete excess water

Osmoregulation (Overhydration) – Response

Blood osmolarity increases

Calcium Regulation (High) – Stimulus

Increase in blood calcium (Ca²⁺)

Calcium Regulation (High) – Receptor

Thyroid cells detect Ca²⁺

Calcium Regulation (High) – Control Center

Thyroid gland (releases calcitonin)

Calcium Regulation (High) – Effector

Bones store calcium; kidneys excrete calcium

Calcium Regulation (High) – Response

Blood calcium decreases

Calcium Regulation (Low) – Stimulus

Decrease in blood calcium (Ca²⁺)

Calcium Regulation (Low) – Receptor

Parathyroid detects Ca²⁺ levels

Calcium Regulation (Low) – Control Center

Parathyroid gland (releases PTH)

Calcium Regulation (Low) – Effector

Bones release calcium; kidneys retain calcium; intestines absorb calcium

Calcium Regulation (Low) – Response

Blood calcium increases

Blood Pressure Regulation (High) – Stimulus

Increase in blood pressure

Blood Pressure Regulation (High) – Receptor

Baroreceptors in arteries

Blood Pressure Regulation (High) – Control Center

Medulla oblongata

Blood Pressure Regulation (High) – Effector

Heart decreases rate; blood vessels dilate

Blood Pressure Regulation (High) – Response

Blood pressure decreases

Blood Pressure Regulation (Low) – Stimulus

Decrease in blood pressure

Blood Pressure Regulation (Low) – Receptor

Baroreceptors in arteries

Blood Pressure Regulation (Low) – Control Center

Medulla oblongata

Blood Pressure Regulation (Low) – Effector

Heart increases rate; blood vessels constrict

Blood Pressure Regulation (Low) – Response

Blood pressure increases