Only lymphocytes possessing ________ that can bind with the ________ on an invading pathogen are involved in the immune response against it.

The most superior portion of the stomach is the __________.

________, a localized response to infection, attracts leukocytes to the affected tissues to destroy the pathogens.

The folds in the mucosa and submucosa of the stomach which allow it to expand as it fills with food are the __________.

About 23% of the CO2 in the blood is transportedas ______.

The auditory tubes open into the ______.

___________ results from long-term exposure to airborne irritants; is characterized by a rupture of the pulmonary alveoli, forming large spaces in the lungs.

The end products of protein digestion are ________, which are absorbed into ________ of villi.

The part of the respiratory system with the largest internal surface area is the ___________.

The QRS complex of an ECG is produced by the ______.