Glossary
Diabetes
A metabolic disease characterized by high blood glucose levels, resulting from either insufficient insulin production (Type I) or the body's cells not responding properly to insulin (Type II).
Example:
Understanding how insulin resistance develops is key to comprehending the progression of Type II diabetes.
Glucagon
A hormone produced by the pancreas that raises blood glucose levels by signaling the liver to break down stored glycogen into glucose and release it into the bloodstream.
Example:
If you skip a meal and your blood sugar drops, your body releases glucagon to signal your liver to release stored glucose, preventing hypoglycemia.
Glycogen
A complex carbohydrate that serves as the primary storage form of glucose in animals, predominantly found in the liver and muscle cells.
Example:
Athletes often 'carb-load' before a big event to maximize their glycogen stores, providing a readily available energy source during prolonged exercise.
Homeostasis
The ability of an organism to maintain a stable internal environment despite changes in external conditions.
Example:
Your body's ability to keep its core temperature at a steady 37°C (98.6°F), regardless of whether you're in a cold or hot room, is a prime example of homeostasis.
Insulin
A hormone produced by the pancreas that lowers blood glucose levels by signaling cells, especially the liver and muscle, to take up glucose from the bloodstream.
Example:
After consuming a sugary drink, your body releases insulin to move the excess glucose from your blood into your cells for energy or storage.
Liver
A large, vital organ that plays a central role in metabolism, including storing glucose as glycogen and converting it back to glucose when needed.
Example:
When your blood sugar is high, your liver acts like a sponge, absorbing glucose and converting it into glycogen for later use.
Negative Feedback Loops
Mechanisms that reduce or reverse a change in a system, bringing it back to a set point to maintain balance.
Example:
When your blood pressure rises, negative feedback loops cause your heart rate to slow down and blood vessels to dilate, bringing your blood pressure back to normal.
Oxytocin
A hormone released by the pituitary gland that plays a role in social bonding, reproduction, and stimulating uterine contractions during childbirth.
Example:
The increasing intensity of uterine contractions during labor is driven by the release of oxytocin, which stimulates stronger and more frequent contractions.
Pancreas
An organ located behind the stomach that produces digestive enzymes and hormones, including insulin and glucagon, which regulate blood sugar.
Example:
If you eat a large meal, your pancreas will detect the rise in blood glucose and release insulin to help your body process the sugar.
Positive Feedback Loops
Mechanisms that amplify an initial change, pushing the system further away from its initial state and often leading to a specific outcome or completion of a process.
Example:
During the ripening of fruit, the production of ethylene gas stimulates more ethylene production, creating a positive feedback loop that accelerates the ripening process.