Nokea
Where does chemical digestion of carbohydrates begin?
- A. Mouth
- B. Stomach
- C. Small intestine
- D. Large intestine
Correct Answer: A
Rationale: The correct answer is A: Mouth. In the mouth, salivary amylase is secreted, which starts breaking down carbohydrates into simpler sugars like maltose. This initial breakdown of carbohydrates through the enzyme amylase marks the beginning of chemical digestion. The stomach primarily digests proteins, not carbohydrates (eliminating option B). The small intestine is where most of the carbohydrate digestion and absorption occurs, but the process begins in the mouth (eliminating option C). The large intestine is responsible for absorbing water and electrolytes, not carbohydrate digestion (eliminating option D).
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What is the fate of any excess glucose that goes to the liver that is not required for energy and not stored as glycogen?
- A. it is converted into fat
- B. it is converted into protein
- C. it is immediately released back into the bloodstream
- D. it is degraded
Correct Answer: A
Rationale: The correct answer is A: it is converted into fat. Excess glucose not needed for immediate energy or stored as glycogen is converted into fat through a process called de novo lipogenesis in the liver. This occurs when glucose levels are high and glycogen stores are full. The liver converts the excess glucose into fatty acids and then into triglycerides for storage in adipose tissue. This process helps regulate blood glucose levels and prevents hyperglycemia.
Other choices are incorrect:
B: Glucose is not directly converted into protein. Proteins are synthesized from amino acids, not glucose.
C: Releasing excess glucose back into the bloodstream would lead to high blood sugar levels, which is not a typical physiological response.
D: Glucose is not simply degraded; it is either used for energy, stored as glycogen, or converted into fat when in excess.
A two-week-old boy develops persistent projectile vomiting. The most likely diagnosis is:
- A. pyloric stenosis
- B. esophageal atresia
- C. annular pancreas
- D. incomplete rotation of the gut
Correct Answer: A
Rationale: The correct answer is A: pyloric stenosis. In pyloric stenosis, there is hypertrophy of the pyloric sphincter muscle, leading to gastric outlet obstruction and projectile vomiting. This typically presents in infants around 2-6 weeks of age. Other choices (B) esophageal atresia presents with difficulty feeding and choking, (C) annular pancreas with duodenal obstruction, and (D) incomplete rotation of the gut with volvulus or obstruction due to malrotation. Pyloric stenosis is the most likely diagnosis in this scenario based on the age of the infant and the symptom of projectile vomiting.
Histamine stimulates the ______ cells to release ______.
- A. parietal; intrinsic factor
- B. chief; pepsinogen
- C. parietal; HCl
- D. mucous neck; mucus
Correct Answer: C
Rationale: Histamine stimulates the parietal cells in the stomach lining to release hydrochloric acid (HCl). This process plays a crucial role in the digestion of food. Parietal cells are responsible for producing stomach acid, which helps break down food and kill bacteria. Choice A is incorrect because intrinsic factor is not released by parietal cells in response to histamine. Choice B is incorrect because pepsinogen is released by chief cells, not parietal cells. Choice D is incorrect because mucous neck cells secrete mucus to protect the stomach lining, but they are not directly stimulated by histamine to release mucus.
What causes the systemic effects of viral hepatitis?
- A. Cholestasis
- B. Impaired portal circulation
- C. Toxins produced by the infected liver
- D. Activation of the complement system by antigen-antibody complexes
Correct Answer: D
Rationale: Step-by-step rationale for why choice D is correct: Activation of the complement system by antigen-antibody complexes leads to systemic effects in viral hepatitis. This process triggers inflammation, tissue damage, and immune responses that contribute to the systemic effects seen in viral hepatitis. The other choices (A, B, and C) do not directly cause systemic effects in viral hepatitis. Cholestasis and impaired portal circulation are more localized effects, while toxins produced by the infected liver may contribute to liver damage but not necessarily systemic effects.
An individual has the following symptoms: jaundice, pale in color, liver with a buildup of connective tissue. This individual most likely has
- A. gastritis.
- B. pancreatitis.
- C. gall stones.
- D. cirrhosis.
Correct Answer: D
Rationale: The correct answer is D: cirrhosis. Jaundice, pale skin, and liver with connective tissue buildup are classic symptoms of cirrhosis - a condition characterized by scarring of the liver due to long-term damage. Jaundice occurs when the liver is unable to properly process bilirubin, leading to yellowing of the skin and eyes. The pale color can be due to anemia often seen in cirrhosis. The buildup of connective tissue is indicative of fibrosis and scarring in the liver. Gastritis (A) is inflammation of the stomach lining, pancreatitis (B) is inflammation of the pancreas, and gallstones (C) are solid particles that form in the gallbladder. These conditions do not typically present with the combination of symptoms described.