Which blood vessels connect the two sides of the vascular system?.

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. .

Choice A rationale:

Hemoglobin is an iron-containing biomolecule that binds oxygen and is responsible for the red color of the cells and the blood. -

Choice B rationale:

Hematocrit is not an iron-containing component, but rather a measure of the proportion of blood volume that is occupied by red blood cells. -

Choice C rationale:

Cytoplasm is the fluid inside the cell where cellular components are suspended, but it does not contain iron. -

Choice D rationale:

The nucleus is not present in mature red blood cells.