1.
__________ are sometimes referred to as the brush border. They increase the surface area of the intestine for absorption and carry transport proteins which are involved in the uptake of nutrients from the gut lumen to the interior of cells.
Correct Answer
C. Microvilli
Explanation
Microvilli are sometimes referred to as the brush border because they are tiny, finger-like projections on the surface of enterocytes, the cells lining the intestine. They greatly increase the surface area of the intestine, allowing for more efficient absorption of nutrients. Microvilli also carry transport proteins that are responsible for the uptake of nutrients from the gut lumen into the interior of enterocytes, where they can then be transported to the bloodstream.
2.
The blood leaving the gut travels first to the:
Correct Answer
A. Liver
Explanation
After food is digested in the gut, the nutrients and toxins are absorbed into the bloodstream. The blood leaving the gut first travels to the liver through the hepatic portal vein. The liver plays a crucial role in processing and detoxifying these substances. It filters the blood, removes toxins, and metabolizes nutrients before sending the blood to the heart for further circulation throughout the body. Therefore, the liver is the correct answer as it is the first organ to receive blood from the gut.
3.
The movement of sugars across a cell membrane from high concentration (gut lumen) to low concentrations (interior of cells) is an example of:
Correct Answer
B. Diffusion
Explanation
Diffusion is the process by which molecules move from an area of high concentration to an area of low concentration. In this case, the movement of sugars across a cell membrane from the high concentration in the gut lumen to the low concentrations in the interior of cells is an example of diffusion.
4.
The major function of enterocrinin, a proteolytic enzyme produced by the epithilium of the gut, is to:
Correct Answer
E. Activate pancreatic enzymes
Explanation
Enterocrinin is a proteolytic enzyme produced by the gut epithelium. Proteolytic enzymes are responsible for breaking down proteins. Therefore, it can be inferred that the major function of enterocrinin is to activate pancreatic enzymes, which are also involved in the breakdown of proteins.
5.
Damage to the ileum will most likely result in malabsorption of:
Correct Answer
D. Fat
Explanation
Damage to the ileum, which is a part of the small intestine, can lead to malabsorption of fat. The ileum is responsible for the absorption of various nutrients, including fat. If it is damaged, the body may not be able to properly absorb and digest dietary fats, leading to malabsorption. This can result in symptoms such as diarrhea, weight loss, and deficiencies in fat-soluble vitamins. Therefore, damage to the ileum is most likely to affect the absorption of fat.
6.
It is thought that very young infants are more likely to develop milk-protein and other allergic reactions when these substances are absorbed from foods/fluids that have been introduced too early.
Correct Answer
A. Intact proteins
Explanation
Very young infants have an immature digestive system, making them more susceptible to developing allergic reactions to intact proteins found in foods or fluids. Intact proteins are larger molecules that can be difficult for the infant's body to break down and digest properly. When these proteins are introduced too early, the infant's immune system may react to them as foreign substances, leading to allergic reactions. Therefore, it is recommended to delay the introduction of intact proteins until the infant's digestive system is more developed.
7.
Three major organs involved in providing digestive enzymes to the small intestine are:
Correct Answer
D. Pancreas, liver, gall bladder
Explanation
The pancreas, liver, and gall bladder are all involved in providing digestive enzymes to the small intestine. The pancreas produces enzymes such as amylase, lipase, and protease that help break down carbohydrates, fats, and proteins respectively. The liver produces bile, which is stored in the gall bladder, and helps in the digestion and absorption of fats. When food reaches the small intestine, the gall bladder releases bile into the intestine, and the pancreas releases its enzymes, both of which aid in the digestion process. Therefore, the correct answer is pancreas, liver, and gall bladder.
8.
Most nutrients are absorbed in the:
Correct Answer
C. Small intestine
Explanation
The small intestine is responsible for the absorption of most nutrients. It is the longest part of the digestive system and has a large surface area due to its numerous folds and finger-like projections called villi. These villi increase the absorption capacity of the small intestine. As food passes through the small intestine, nutrients such as carbohydrates, proteins, fats, vitamins, and minerals are broken down and absorbed into the bloodstream. The absorbed nutrients are then transported to the cells of the body to provide energy and support various physiological functions.
9.
The regular contractions and movement of contents along the intestine is called:
Correct Answer
E. Peristalsis
Explanation
Peristalsis refers to the regular contractions and movement of contents along the intestine. It is a coordinated muscular movement that helps propel food and waste through the digestive system. This process allows for the efficient absorption of nutrients and elimination of waste. Pinocytosis, active transport, osmosis, and diffusion are all different processes that occur in cells and are not specifically related to the movement of contents along the intestine.
10.
One of the main functions of the colon is thought to be:
Correct Answer
D. Production of short chain fatty acids and flatus from fermentation of dietary fibre by anaerobic bacteria
Explanation
The colon is responsible for the production of short chain fatty acids and flatus through the process of fermentation. Fermentation of dietary fiber by anaerobic bacteria in the colon results in the production of short chain fatty acids, which are important for energy production and the maintenance of a healthy gut environment. Flatus, or gas, is also produced as a byproduct of this fermentation process. This function of the colon is essential for the overall digestive process and the proper functioning of the gastrointestinal system.
11.
Which of the following statements regarding saliva is correct?
Correct Answer
C. Contains non essential salivary amylase
Explanation
Saliva is a fluid produced by the salivary glands in the mouth. It helps in the digestion process by breaking down food particles and lubricating the mouth and throat. Saliva contains various enzymes, including salivary amylase, which is responsible for breaking down starches into simpler sugars. However, salivary amylase is not considered essential for digestion as the majority of starch digestion occurs in the small intestine. Therefore, the statement that "saliva contains non-essential salivary amylase" is correct.
12.
One of the main functions of the stomach is:
Correct Answer
B. The production of an acidic liquid chyme by mixing food and digestive secretions
Explanation
The stomach produces an acidic liquid called chyme by mixing food and digestive secretions. This acidic environment helps to break down the food further and aid in digestion. The stomach's muscular contractions also help to mix the food and digestive secretions together, creating the chyme. This chyme is then passed on to the small intestine for further digestion and absorption of nutrients.