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What is the role of the small intestine’s MALT?

A. secreting mucus

B. buffering acidic chyme

C. activating pepsin

D. preventing bacteria from entering the bloodstream

Answer Explanation:

b) buffering acidic chyme

- Correct: MALT (Mucosa-Associated Lymphoid Tissue) in the small intestine plays a role in buffering acidic chyme. MALT contains immune cells, such as lymphocytes and plasma cells, that help protect the intestinal mucosa from pathogens and foreign substances. Additionally, MALT helps regulate the pH of the intestinal contents by neutralizing acidic chyme, which is important for optimal enzymatic activity and absorption in the small intestine.

a) secreting mucus

- Incorrect: The secretion of mucus is primarily the role of goblet cells, which are scattered throughout the epithelium of the small intestine. Mucus serves to lubricate and protect the intestinal epithelium from mechanical damage and chemical irritation.

c) activating pepsin

- Incorrect: Pepsin is an enzyme involved in protein digestion, and its activation primarily occurs in the stomach under acidic conditions. It is produced as pepsinogen by chief cells in the gastric glands and is activated by hydrochloric acid (HCl) secreted by parietal cells.

d) preventing bacteria from entering the bloodstream

- Incorrect: While MALT helps protect the intestinal mucosa from pathogens and foreign substances, its primary role is not to prevent bacteria from entering the bloodstream. Instead, MALT functions in the local immune defense of the mucosal surface of the intestine, including the initiation of immune responses against pathogens encountered in the gastrointestinal tract.

Therefore, the Correct Answer is B.

More Questions on TEAS 7 Science

  • Q #1: A disorder of the digestive system that can cause severe dehydration is known as

    A. appendicitis

    B. gallstones

    C. constipation

    D. diarrhea

    Answer Explanation

    D) diarrhea

    - Correct: Diarrhea is a disorder of the digestive system that can cause severe dehydration. Diarrhea is characterized by frequent, loose, or watery bowel movements, often accompanied by abdominal cramps, bloating, and urgency. It occurs when the intestines fail to properly absorb water or when excess fluid is secreted into the intestines. Diarrhea can lead to significant fluid loss and electrolyte imbalance, resulting in dehydration, particularly if not promptly treated by replenishing lost fluids and electrolytes.

    A) appendicitis

    - Incorrect: Appendicitis is inflammation of the appendix, a small pouch located near the junction of the small and large intestines. While appendicitis can cause symptoms such as abdominal pain, fever, and vomiting, it is not directly associated with dehydration.

    B) gallstones

    - Incorrect: Gallstones are hardened deposits that form in the gallbladder and can cause symptoms such as abdominal pain, nausea, and jaundice. While gallstones can lead to complications such as obstruction of the bile duct, they are not directly associated with dehydration.

    C) constipation

    - Incorrect: Constipation refers to infrequent bowel movements or difficulty passing stool, often characterized by hard, dry stools that are difficult to pass. While severe constipation can cause discomfort and complications such as fecal impaction, it is not directly associated with dehydration.

  • Q #2: Your digestive system works on the foods you eat for about:

    A. 5 hours

    B. 10 hours

    C. 15 hours

    D. 20 hours

    Answer Explanation

    The digestive system typically works on the foods you eat for about 10 hours. The entire process of digestion, from the moment food enters the mouth until waste is eliminated from the body, generally takes around 24 to 72 hours. However, the actual time it takes for food to move through the digestive tract and be fully digested varies depending on factors such as the type of food consumed, individual metabolism, and overall gastrointestinal health. On average, food spends approximately 4 to 6 hours in the stomach and small intestine, and another 12 to 36 hours in the large intestine before being eliminated as waste. Therefore, the total time for digestion and elimination is typically around 24 to 72 hours.

  • Q #3: Where does the chemical digestion of starch begin?

    A. mouth

    B. esophagus

    C. stomach

    D. small intestine

    Answer Explanation

    a) mouth

    - Correct: The chemical digestion of starch begins in the mouth. Salivary amylase, an enzyme secreted by the salivary glands, initiates the breakdown of starch molecules into maltose and other smaller carbohydrate molecules. This process begins as soon as food enters the mouth and continues as it is mixed with saliva during chewing and swallowing.

    b) esophagus

    - Incorrect: The esophagus is not directly involved in the chemical digestion of starch. It serves primarily as a conduit for the passage of food from the mouth to the stomach via peristaltic contractions.

    c) stomach

    - Incorrect: While some minor digestion may occur in the stomach due to the presence of salivary amylase from swallowed saliva, the stomach is not the primary site of starch digestion. Its acidic environment inhibits the activity of salivary amylase, so significant starch digestion does not occur there.

    d) small intestine

    - Incorrect: Starch digestion continues in the small intestine, primarily in the duodenum, but it does not begin there. Enzymes such as pancreatic amylase and brush border enzymes further break down starch into simpler sugars in the small intestine.