Carbon dioxide is transported in blood via: 

Most chemical digestion occurs in the: 

The outer layer of the gastrointestinal tract is the: 

Most chemical digestion occurs in the: 

An isotope of an element has the same number of _?_ but a di…

The deepest layer of the epidermis would be the: 

The walls of abdominal organs are composed of:

The intestines are _?_ to the skeletal muscle.

Of the nine abdominopelvic regions which one is the lowest m…

The innemost layer of the heart is said to be the: