Question
When calcium levels fall too low, the parathyroid gland secretes parathyroid hormone (PTH). PTH increases calcium absorption by the small intestine, decreases calcium excretion by the kidneys and stimulates osteoclasts to release calcium stored in the bones. Which of the following are effectors in this homeostatic mechanism (Select all that apply)?
Group of answer choices
Small intestine
kidneys
PTH
Osteoclasts
Parathyroid gland
Group of answer choices
Small intestine
kidneys
PTH
Osteoclasts
Parathyroid gland
Answers
GPT-4o mini
In the context of the homeostatic mechanism you described, the effectors are the organs or cells that take action in response to the parathyroid hormone (PTH) to increase calcium levels in the blood. The effectors in this scenario are:
1. **Small intestine** - It absorbs more calcium due to PTH.
2. **Kidneys** - It decreases calcium excretion, which helps to retain calcium in the body.
3. **Osteoclasts** - They release calcium from the bones into the bloodstream as stimulated by PTH.
The parathyroid gland itself is not an effector; it is the gland that senses low calcium levels and secretes PTH.
So, the correct selections for effectors in this homeostatic mechanism are:
- **Small intestine**
- **Kidneys**
- **Osteoclasts**
1. **Small intestine** - It absorbs more calcium due to PTH.
2. **Kidneys** - It decreases calcium excretion, which helps to retain calcium in the body.
3. **Osteoclasts** - They release calcium from the bones into the bloodstream as stimulated by PTH.
The parathyroid gland itself is not an effector; it is the gland that senses low calcium levels and secretes PTH.
So, the correct selections for effectors in this homeostatic mechanism are:
- **Small intestine**
- **Kidneys**
- **Osteoclasts**