Cu ions released from copper-releasing intra uterine devices (IUDs)

Options

A. make uterus unsuitable for implantation
B. increase phagocytosis of sperms
C. suppress sperm motility
D. prevent ovulation

Answer

### Step-by-Step Solution:

1. **Understanding Copper IUDs**: Copper-releasing intrauterine devices (IUDs), commonly referred to as copper T, are contraceptive devices placed inside the uterus. They release copper ions into the uterine environment.

2. **Mechanism of Action**: The primary mechanism by which copper IUDs prevent pregnancy involves the release of copper ions. These ions have several effects on the reproductive system.

3. **Effect on Sperm Motility**: One of the key functions of copper ions is to suppress sperm motility. This means that the sperm are less able to swim effectively towards the egg, reducing the chances of fertilization.

4. **Cervical Mucosa**: Copper IUDs also increase the viscosity of cervical mucus. Thicker cervical mucus creates a barrier that further prevents sperm from entering the uterus.

5. **Implantation and Ovulation**: While copper IUDs do create an environment that is less favorable for implantation, their primary action is not to prevent ovulation. Instead, they primarily work by affecting sperm motility and creating a hostile environment for sperm.

6. **Conclusion**: The correct answer regarding the function of copper ions released from copper-releasing IUDs is that they suppress sperm motility.

### Final Answer:
The copper ions released from copper-releasing IUDs primarily **suppress sperm motility**.

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