Which term refers to the internal organs specifically?

The term that specifically refers to the internal organs is "viscera." In medical terminology, "viscera" encompasses the organs within the chest and abdomen, such as the heart, lungs, liver, and intestines. This term is derived from Latin, where it initially referred to the internal organs of the body.

Understanding the context of this term is essential in various medical fields, as knowledge of internal organs is crucial for diagnosing and treating illnesses. The other options present terms that relate to different concepts: "viscid" refers to a sticky or gelatinous substance, "adenoid" relates to the lymphatic tissue located in the throat, and "zygote" is the fertilized egg before it develops into an embryo. Thus, "viscera" stands out as the precise term dealing with the internal organs.