Chapter 8: Basic Questions About The Digestive System

The three main functions of the digestive system are digestion, absorption, and elimination. Digestion refers to the breakdown of food into smaller molecules that can be absorbed by the body. Absorption is the process by which these molecules are taken up by the bloodstream and transported to cells for energy and other functions. Elimination involves the removal of waste products from the body through the process of defecation. These three functions work together to ensure that nutrients are obtained from food and waste materials are properly eliminated.

The large intestines can be divided into four distinct sections: cecum, colon, rectum, and anal canal. The cecum is the first part of the large intestine, followed by the colon, which is further divided into four sections: ascending colon, transverse colon, descending colon, and sigmoid colon. The rectum is the final straight portion of the large intestine, and it connects to the anal canal, which is responsible for the elimination of waste from the body.

Peristalsis is a wavelike contraction that occurs involuntarily in hollow tubes of the body, especially the alimentary canal. It helps to propel food and other substances through the digestive system by contracting and relaxing the muscles in a coordinated manner. This movement allows for efficient digestion and absorption of nutrients. Pharyngeal refers to the throat, peptic relates to the stomach, and nausea is a feeling of sickness or discomfort in the stomach.

Chyme is the correct answer because it refers to the semi-liquid mixture of partially digested food and stomach acids that is formed in the stomach and then passes into the small intestine for further digestion and absorption of nutrients. Waste, bile, and urine are not appropriate terms to describe semi-liquid food.

The duodenum is the first portion of the small intestine. It is located immediately after the stomach and is responsible for receiving partially digested food from the stomach and further breaking it down with the help of digestive enzymes. It plays a crucial role in the absorption of nutrients from food into the bloodstream. The jejunum and ileum are also parts of the small intestine, but they come after the duodenum. The cecum, on the other hand, is a pouch-like structure at the beginning of the large intestine and is not part of the small intestine.

The correct answer is insulin and glucagon. These two hormones are secreted into the bloodstream by the pancreas. Insulin helps regulate blood sugar levels by promoting the uptake of glucose into cells, while glucagon raises blood sugar levels by stimulating the liver to release stored glucose. These hormones work together to maintain balance and control in the body's blood sugar levels.

The pancreas is the organ that produces digestive enzymes and has specialized cells that secrete the hormones insulin and glucagon directly into the bloodstream.

The gallbladder is the organ that stores and concentrates bile produced by the liver. Bile is a substance that helps in the digestion and absorption of fats. The liver produces bile and releases it into the gallbladder, where it is stored until it is needed for digestion. When food containing fats enters the small intestine, the gallbladder contracts and releases the concentrated bile into the intestine to aid in the breakdown and absorption of fats.

The correct answer is liver. The liver is responsible for playing an important role in metabolism, manufacturing bile, and storing iron and vitamins B12, A, D, E, and K. It is a vital organ that performs multiple functions in the body, including detoxification, protein synthesis, and production of biochemicals necessary for digestion.

Digestion and absorption chiefly take place in the small intestine. This is because the small intestine is where most of the chemical breakdown of food occurs, thanks to the presence of digestive enzymes. It is also in the small intestine that the nutrients from the digested food are absorbed into the bloodstream and transported to the rest of the body for use. The large intestine mainly absorbs water and electrolytes from the remaining undigested food, while the stomach primarily serves as a storage and mixing chamber for food. The mouth is responsible for the initial mechanical breakdown and chemical digestion of food through the action of saliva.

A soft mass of chewed food ready to be swallowed is called a bolus. This term is commonly used in the context of digestion, referring to the cohesive mass that forms as food is chewed and mixed with saliva. The bolus is then passed down the esophagus and into the stomach for further digestion and absorption of nutrients.

The correct answer is parotid, sub-lingual, sub-mandibular. The salivary glands located in and around the mouth include the parotid glands, which are the largest salivary glands and are located in front of the ears; the sub-lingual glands, which are located under the tongue; and the sub-mandibular glands, which are located beneath the lower jaw. These glands produce and secrete saliva, which helps in the digestion of food and lubrication of the mouth.

The four accessory organs of digestion are the salivary glands, gallbladder, liver, and pancreas. These organs play important roles in the digestive process. The salivary glands produce saliva, which contains enzymes that begin the breakdown of carbohydrates. The gallbladder stores and releases bile, which helps in the digestion and absorption of fats. The liver produces bile and also detoxifies harmful substances in the body. The pancreas produces digestive enzymes that break down proteins, fats, and carbohydrates, and also releases insulin to regulate blood sugar levels.

The liver is the largest glandular organ in the body. It is responsible for numerous vital functions such as detoxification, metabolism, and production of bile. It plays a crucial role in filtering and processing blood, storing vitamins and minerals, and breaking down toxins. The liver is located in the upper right side of the abdomen and is essential for maintaining overall health and well-being.

Hydrochloric acid and gastric juices are responsible for converting food into a semiliquid state. These substances are secreted by the stomach and aid in the breakdown of food, particularly proteins. Hydrochloric acid helps to create an acidic environment in the stomach, which activates enzymes that break down proteins. Gastric juices, which include enzymes like pepsin, further break down the food into a semiliquid mixture called chyme. This chyme is then passed into the small intestines for further digestion and absorption of nutrients.

The circulatory system, specifically the lymphatic system, transports nutrients to body cells. The lymphatic system is a network of vessels that carry lymph, a fluid containing nutrients and immune cells, throughout the body. It collects excess fluid from tissues and returns it to the bloodstream, ensuring that nutrients are delivered to cells and waste products are removed. The respiratory system is responsible for oxygenating the blood, while the liver is involved in detoxification and metabolism. The small intestines are responsible for absorbing nutrients from food, but they do not directly transport these nutrients to the body cells.