Steroid hormones

Options

A. have only cell surface receptors
B. are lipophobic
C. have receptors within the nucleus
D. are produced by only adrenal cortex.

Answer

### Step-by-Step Solution:

1. **Understanding Steroid Hormones**:
- Steroid hormones are a class of hormones that are derived from cholesterol. They include hormones such as cortisol, testosterone, and progesterone.

2. **Characteristics of Steroid Hormones**:
- Steroid hormones are **lipophilic**, meaning they can easily pass through cell membranes due to their lipid-soluble nature.

3. **Receptor Location**:
- Unlike peptide hormones, which have receptors on the cell surface, steroid hormones have **intracellular receptors**. These receptors are typically located in the cytoplasm or the nucleus of the target cells.

4. **Production Sites**:
- While the adrenal cortex produces certain steroid hormones (like cortisol), other steroid hormones such as testosterone and progesterone are produced by the gonads (testes and ovaries, respectively). Therefore, it is incorrect to say that steroid hormones are produced only by the adrenal cortex.

5. **Evaluating the Statements**:
- **"Have only cell surface receptors"**: Incorrect, as steroid hormones have intracellular receptors.
- **"Are lipophobic"**: Incorrect, as steroid hormones are lipophilic.
- **"Have receptors within the nucleus"**: Correct, as steroid hormones do have receptors that can be found in the nucleus.
- **"Produced by only adrenal cortex"**: Incorrect, as steroid hormones are also produced by the gonads.

6. **Conclusion**:
- The only correct statement regarding steroid hormones is that they have receptors within the nucleus. Therefore, the correct option is the one that states this fact.

### Final Answer:
The correct statement about steroid hormones is that they have receptors within the nucleus.

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