Which important white blood cells travel throughout the bloodstream seeking out bacteria?.

The correct answer is Choice C.

Choice A rationale:

Nerves are responsible for transmitting signals between different parts of the body, not for connecting muscles to bones.

Choice B rationale:

Ligaments connect bone to bone at a joint, not muscle to bone.

Choice C rationale:

Tendons are the connective tissue that attaches muscle to bone.

Choice D rationale:

Cartilage is a flexible connective tissue found in various parts of the body, but it does not connect muscles to bones.

Choice A rationale:

Sinuses are indeed air-filled cavities. They are hollow spaces in the skull and the face bones around your nose.

Choice B rationale:

Sinuses are located in the skull and around the nose. There are four pairs of sinuses, named for the bones that they’re located in.

Choice C rationale:

One of the functions of the sinuses is to help lighten the head. The air-filled cavities provide a sort of crumple zone that can absorb impact and protect the brain.

Choice D rationale:

Gas exchange does not occur in the sinuses. The primary function of the sinuses is to produce mucus that moistens the inside of the nose. This mucus layer serves to trap dust and other particles that might otherwise reach the lungs.

Choice E rationale:

The sinuses do not directly help with hearing. The structures that are primarily responsible for hearing are the ears, specifically the eardrums and the bones of the middle ear. So, the correct answers are Choices A, B, and C, after analyzing all choices. .