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Bros256-Week 1 Case Study: Gastroesophageal Reflux Disease The stomach acts as a major site of protein digestion, utilizing a mixture of hydrochloric acid and proteases to breakdown complex proteins into peptides that can be further digested in the small Intestine. However, the utilization of such a strong acid within the body can lead to tissue deterioration if steps are not taken by the digestive system. Within the stomach, mucosal cells can secrete an alkaline mucus that will coat the stomach mucosal lining, preventing the acid from coming into direct contact with the lining. Some conditions such as in peptic ulcers will result in patches within the stomach lining that are not protected with mucus, leading to the acid breaking down the lining. To prevent the acid from escaping the confines of the stomach, sphincters are utilized to prevent the flow of acid up through the esophagus (lower esophageal sphincter) and down to the duodenum (pyloric sphincter). Gastroesophageal reflux disease (GERD) occurs when stomach acid is regurgitated into the esophagus and can lead to a burning sensation in the chest, a sour taste in the back of the throat, sore throat, nausea, and bloating. Some of the conditions that can increase the prevalence of GERD include the consumption of excessive amounts of caffeine, alcohol, chocolate, or spicy foods; pregnancy; delayed stomach emptying; and birth defects such as esophageal atresia (narrowing) and hernias. Common treatments include a change in lifestyle and diet, antacids, histamine H2-receptor antagonist medications, and proton pump inhibitors (PPIs). Antacids work by neutralizing the stomach acid and inhibiting the proteases. Histamine H-receptor antagonists work by preventing the inflammatory responses within the stomach, leading to less production of stomach acid. Proton pump inhibitors act on the proton pumps found in stomach acid producing cells and preventing the pushing of hydrogen ions into the lumen of the stomach, preventing stomach acid from being produced. Background: Siobhan Smith, a 45-year-old instructor, has come to the clinic to discuss frequent "heartburn and vomiting" for the past 3 months. She has no issues with swallowing, food getting stuck, or respiratory issues. There is no abdominal pain. She has tried over-the counter antacids with only a little relief. Desired Outcomes: 1. Determine if Siobhan's sensations of "heartburn" are, in fact, gastroesophageal reflux disease (GERD). 2. Educate Siobhan on the potential causes of GERD. 3. Identify appropriate recommendations based on the findings of a GI endoscopy. Findings: Siobhan's upper GI endoscopy found inflammation within the esophageal and pharyngeal mucosa. No abnormal findings were found within the stomach of intestines. A further esophageal pH test determined that excess acid was built up within the esophagus. Questions: 1. What is the anatomical structure that malfunctions in individuals with GERD? 2. Explain how stomach acid can affect mucus membranes that are not adequately protected.
Module OI Homework Question 18 of 18 (1 point) Question Attempt 1 of Unlimited Experiments were done on a certain pure substance X to determine some of its properties. There's a description of each experiment in the table below. In each case, decide whether the property measured was a chemical or physical property of X, if you can. If you don't have enough information to decide, choose can't decide in the third column. property experiment physical or chemical? P A small sample of X is dissolved in water. Drops of another solution, containing dissolved sodium hydroxide, are slowly added, and a pH indicator is used to determine when the sodium hydroxide has completely reacted with X. From the amount of sodium hydroxide needed, the value of P may be calculated. physical chemical (can't decide) D A sample of X is carefully weighed and put inside a vented flask. Water is added to the flask until it just covers the sample, and the volume of sample and water is recorded. Then the sample is removed and the volume of water alone recorded. From the mass of the sample and the difference in volumes, the value of D may be calculated. physical chemical (can't decide) C A sample of X is carefully weighed and put inside a sealed calorimeter. Pure oxygen gas is injected into the calorimeter, and the mixture ignited. After all of X has reacted with the oxygen gas, the temperature rise of the calorimeter is measured. From this change in temperature the value of C may be calculated. physical chemical (can't decide)