Study Notes
Hormones play a crucial role in regulating homeostasis and reproduction in humans, including controlling blood glucose levels and the menstrual cycle.
- Insulin — a hormone secreted by β cells of the pancreas to decrease blood glucose levels.
Example: Stimulates glycogen synthesis in the liver. - Glucagon — a hormone secreted by α cells of the pancreas to increase blood glucose levels.
Example: Stimulates glycogen breakdown in the liver. - Thyroxin — a hormone secreted by the thyroid gland to regulate metabolic rate and body temperature.
Example: Increases heat production through increased respiration. - Leptin — a hormone secreted by adipose cells to inhibit appetite.
Example: Acts on the hypothalamus to reduce food intake. - Melatonin — a hormone secreted by the pineal gland to control circadian rhythms.
Example: Regulates sleep timing. - Testosterone — a hormone secreted by the testes for male development and secondary sexual characteristics.
Example: Responsible for the development of male genitalia. - Estrogen and Progesterone — hormones secreted by the ovaries for female development and secondary sexual characteristics.
Example: Involved in the menstrual cycle.
Exam Tips
Key Definitions to Remember
- Insulin and glucagon roles in blood glucose regulation
- Thyroxin's effect on metabolic rate
- Leptin's role in appetite control
- Melatonin's regulation of circadian rhythms
- Testosterone's role in male development
- Estrogen and progesterone's role in female development
Common Confusions
- Difference between insulin and glucagon functions
- How leptin affects weight loss
- The role of melatonin in jet lag
Typical Exam Questions
- How does insulin affect blood glucose levels? Insulin decreases blood glucose by promoting glycogen synthesis.
- What is the role of thyroxin in the body? Thyroxin increases metabolic rate and heat production.
- How do estrogen and progesterone regulate the menstrual cycle? They control the cycle through feedback mechanisms involving ovarian and pituitary hormones.
What Examiners Usually Test
- Understanding of hormone functions and their effects on the body
- The mechanisms of blood glucose regulation
- The phases and hormonal changes in the menstrual cycle