Anatomy Practice Exam

What is the primary function of steroid hormones?

1. To trigger an immune response

2. To bind to surface receptors

3. To enter target cells and affect DNA directly

4. To regulate blood sugar levels

The correct answer is: To enter target cells and affect DNA directly

The primary function of steroid hormones is to enter target cells and affect DNA directly. Steroid hormones are lipophilic molecules, which means they can easily pass through the cell membrane due to their lipid-soluble nature. Once inside the cell, they bind to specific intracellular receptors, forming a hormone-receptor complex. This complex then translocates to the nucleus, where it interacts with specific regions of the DNA, influencing the transcription of genes. This process ultimately leads to changes in protein synthesis, allowing steroid hormones to exert their long-term effects on various physiological processes, such as metabolism, immune response, and development. Other options, while relevant to different aspects of hormonal action or physiological functions, do not accurately describe the primary mechanism by which steroid hormones operate. For example, triggering an immune response is more characteristic of steroid hormones like cortisol, but it is not their main function. Similarly, the binding to surface receptors is more applicable to peptide and protein hormones. Regulating blood sugar levels is a function primarily associated with hormones such as insulin and glucagon, not specifically steroid hormones.