When you are not breathing, your respiratory system cannot perform its function. Unwanted gases, such as carbon dioxide, cannot be removed from the system and necessary gases, such as oxygen, cannot enter the system. This causes a buildup of carbon dioxide in the body, which leads to acidosis. Carbon dioxide is converted to carbonic acid via carbonic anhydrase. This carbonic acid builds in the blood, lowering its pH.

The majority of chemical (enzymatic) digestion occurs in the duodenum, the first segment of the small intestine. Proteases, amylase, lipases, and other enzymes are secreted into the duodenum from the pancreas. These enzymes are used to digest proteins, carbohydrates, and lipids, respectively.

The liver produces bile, which is stored in the gall bladder. During digestion, bile is released to help emulsify fats for digestion. The spleen is part of the lymphatic system, and is not involved in digestion.

The small intestine is the primary site of digestion and absorption in the body. This chemical digestion is possible thanks to the digestive enymes secreted by the pancreas.

While it is true that the liver creates and secretes bile, storage of bile is accomplished by the gall bladder.

The correct answer is carbohydrates.

Salivary amylase can only digest carbohydrates. Proteases further along in the digestive pathway breakdown proteins, while lipases digest fats. Amino acids are the product of digested proteins.

Pepsinogen is released by chief cells into the stomach lumen. In the presence of hydrochloric acid (secreted by parietal cells), this inactive enzyme will be cleaved, creating pepsin. Pepsin is a protease responsible for breaking down proteins that enter the stomach.

Carbohydrates are digested by amylase enzymes, lipids are digested by lipases, and nucleic acids are digested by nucleases.

Bile is a salt solution used to emulsify fats in the small intestine in order to facilitate absorption. It is created by the liver, but stored in the gall bladder. During digestion, the bile is released from the gall bladder into the duodenum.

The stomach is mainly responsible for mechanical digestion, caused by smooth muscle contractions, and a small amount of protease function. The pancreas secretes a number of digestive enzymes into the duodenum to facilitate digestion of macromolecules. Neither organ is involved in the production of bile.

The islets of Langerhans contain the endocrine pancreatic cells. 3 cell types within are the , , and  cells.  cells secrete glucagon,  cells secrete insulin, and  cells secrete somatostatin.

Answering this question requires you to know which organ assists in neutralizing acidic chyme once it enters the small intestine. This is the responsibility of the pancreas, which secretes bicarbonate ions. This helps raise the pH of the chyme in the small intestine, and prevents damage.

The heart has four valves, used to prevent backflow of blood during contraction of each chamber. The two atrioventricular valves separate the atria from the ventricles, and the two semilunar valves separate the ventricles from the exiting arteries. The right atrium and ventricle are separated by the tricuspid valve, while the left atrium and ventricle are separated by the bicuspid, or mitral, valve. The aortic semilunar valve separates the aorta from the left ventricle and the pulmonary semilunar valve separates the pulmonary arteries from the right ventricle.