GED Science TestLife ScienceHard
A patient is experiencing severe muscle cramps, weakness, and an irregular heartbeat. Blood tests reveal an imbalance in the concentration of certain ions crucial for nerve impulse transmission and muscle contraction. Which regulatory system is primarily responsible for maintaining the balance of these essential ions in the body?
- AEndocrine system
- BIntegumentary system
- CDigestive system
- DRespiratory system
Show answer & explanationAnswer & explanation
Correct answer: A. Endocrine system
The endocrine system, through hormones like parathyroid hormone (calcium), aldosterone (sodium/potassium), and calcitonin (calcium), plays a primary role in regulating the concentration of ions (electrolytes) in the blood and extracellular fluid, which is crucial for nerve and muscle function. Imbalances in these ions (e.g., calcium, potassium, sodium) can lead to the described symptoms.
Why the other options are wrong
- B. The integumentary system (skin) helps with vitamin D synthesis and some excretion, but not primary ion balance regulation.
- C. The digestive system absorbs ions, but the endocrine system primarily regulates their ongoing balance and excretion.
- D. The respiratory system regulates blood pH and gas exchange, not primarily ion balance for muscle/nerve function.
Electrolyte Balance Regulation
The process by which the body maintains the proper concentration of ions (electrolytes) in body fluids, primarily regulated by hormones from the endocrine system.
- Crucial for nerve impulses and muscle contraction
- Key ions include Na+, K+, Ca2+, Mg2+
- Regulated by hormones like aldosterone, ADH, parathyroid hormone
Memory trick: Endocrine's Hormones Handle Homeostasis