Which one of the following statements is correct?

Options

A. Hormones produced by the ovary affects uterine contractions.
B. Hormones produced by intestine stimulates heartbeat.
C. Hormones produced by kidney regulates general blood pressure.
D. Hormones produced by thyroid regulates general metabolism.

Explanation

To determine which statement is correct, let's analyze each option step by step:

### Step 1: Analyze Option 1
- **Statement**: Hormones produced by the ovaries affect uterine contraction.
- **Explanation**: The ovaries produce hormones such as estrogen and progesterone, which are involved in the menstrual cycle and pregnancy. However, the hormone primarily responsible for uterine contractions is oxytocin, which is produced by the posterior pituitary gland.
- **Conclusion**: This statement is **incorrect**.

### Step 2: Analyze Option 2
- **Statement**: Hormones produced by the intestines stimulate heartbeat.
- **Explanation**: Hormones produced in the intestines, such as gastrin and secretin, primarily regulate digestive processes, not heart rate. The heart rate is mainly influenced by hormones like adrenaline (epinephrine) produced by the adrenal glands.
- **Conclusion**: This statement is **incorrect**.

### Step 3: Analyze Option 3
- **Statement**: Hormones produced by the kidney regulate general blood pressure.
- **Explanation**: The kidneys produce erythropoietin, which stimulates red blood cell production, but they also play a role in regulating blood pressure through the renin-angiotensin system. However, erythropoietin itself is not directly responsible for blood pressure regulation.
- **Conclusion**: This statement is **incorrect**.

### Step 4: Analyze Option 4
- **Statement**: Hormones produced by the thyroid regulate general metabolism.
- **Explanation**: The thyroid gland produces hormones such as thyroxine (T4) and triiodothyronine (T3), which are crucial for regulating metabolism, including the basal metabolic rate (BMR).
- **Conclusion**: This statement is **correct**.

### Final Answer
The correct statement is **Option 4: Hormones produced by the thyroid regulate general metabolism.**

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